Microbiology Research doi: 10.3390/microbiolres15020030
Authors: Odo J. Bassey Jabulani R. Gumbo Munyaradzi Mujuru Adeeyo Adeyemi Farai Dondofema
Over the decades, the aquaculture sector has witnessed substantial growth, contributing significantly to the nation’s economy. However, the menace of CyanoHABs threatens the sustainability of fish farming. Considering the possible hazards linked to cyanotoxins in food and water, a comparative study design between commercial fish in Nigeria and South Africa was employed to investigate cyanotoxins in the water from fishponds. Six commercial fishponds in Calabar Municipality—Nigeria and Duthuni—South Africa with varying climatic zones were selected. Water samples from the ponds were collected at intervals during different seasons (summer, winter, dry, and wet seasons) to capture climate-induced variation. Liquid chromatography–mass spectrometry (LCMS) in combination with the metabolites database was used for the identification of toxic cyanometabolites in water samples. The molecular networking approach, coupled with the Global Natural Products Social Molecular Networking (GNPS) database and CANOPUS annotation, enabled the putative identification of cyanometabolites. The resulting molecular network unveiled discernible clusters representing related molecule families, aiding in the identification of both known cyanotoxins and unfamiliar analogues. Furthermore, the molecular network revealed that water samples from different fishponds shared specific metabolites, including ethanesulfonic acid, pheophorbide A, cholic acid, phenylalanine, amyl amine, phosphocholine (PC), and sulfonic acid, despite variations in location, local climatic factors, and sampling sites. The fishponds in Nigeria showed the presence of multiple cyanotoxin classes in the dry, wet, and summer seasons in the water. Aflatoxin was identified in all sampling sites in Nigeria (N1, N2, and N3). The Duthuni, South Africa, sampling sites (P1, P2, and P3) exhibited the presence of microginins and microcystins. All the fishponds displayed a widespread occurrence of anabaenopeptins, aplysiatoxins, aflatoxin, microcolins, and marabmids during the selected summer. In conclusion, the untargeted metabolome analysis, guided by GNPS, proved highly effective in identifying both toxic and non-toxic metabolites in fishponds.
]]>Microbiology Research doi: 10.3390/microbiolres15020029
Authors: Patricia-Andrada Reștea Ștefan Tigan Luminita Fritea Laura Grațiela Vicaș Eleonora Marian Mariana Eugenia Mureșan Liana Stefan
The purpose of this research was to analyze the impact of SARS-CoV-2 infection on ionic calcium, total calcium and serum magnesium upon hospital admission, taking into account the association of type 2 diabetes as a metabolic comorbidity. Our study included 57 patients: a group of 28 patients without diabetes, but with SARS-CoV-2 virus infection, and a second group of 29 patients with type 2 diabetes and SARS-CoV-2 virus infection. The serum level of calcium and magnesium of the patients included in the study did not differ statistically significantly in those with type 2 diabetes compared to those without type 2 diabetes who were infected with the SARS-CoV-2 virus at the time of hospitalization. Ionic calcium, total calcium, and serum magnesium did not statistically significantly influence the survival of the patients with COVID-19 infection included in this research, but the type of infection severity (mild or moderate) did influence the survival rate. Concerning the diabetic patients, a statistically significant correlation was found between serum total calcium and total serum proteins, and another one between ionic calcium and uric acid, urea, and total cholesterol. Serum total calcium and D-dimers were statistically significantly correlated with being transferred to the intensive care unit. On the other hand, magnesium significantly correlated with lipids (triglycerides, total lipids) and inflammatory (fibrinogen, ESR) biomarkers.
]]>Microbiology Research doi: 10.3390/microbiolres15010028
Authors: Constant Gillot Julien Favresse Clara David Vincent Maloteau Jean-Michel Dogne Jonathan Douxfils
Background: The detection of neutralizing anti-SARS-CoV-2 antibodies is important since they represent the subset of antibodies able to prevent the virus to invade human cells. The aim of this study is to evaluate the clinical performances of an in-house pseudovirus neutralization test (pVNT) versus a commercial surrogate neutralization test (sVNT). Material and Methods: A total of 114 RT-PCR positives samples from 75 COVID-19 patients were analyzed using a pVNT and an sVNT technique. Fifty-six pre-pandemic samples were also analyzed to assess the specificity of the two techniques. An analysis of the repeatability and the reproducibility of the pVNT was also performed. Results: A coefficient of variation (CV) of 10.27% for the repeatability of the pVNT was computed. For the reproducibility test, CVs ranged from 16.12% for low NAbs titer to 6.40% for high NAbs titer. Regarding the clinical sensitivity, 90 RT-PCR positive samples out of 114 were positive with the pVNT (78.94%), and 97 were positive with the sVNT (84.21%). About the clinical specificity, all 56 pre-pandemic samples were negative in both techniques. When comparing the sVNT to the pVNT, the specificity and sensibility were 66.67% (95%CI: 47.81–85.53%) and 98.88% (95%CI: 96.72–99.99%), respectively. Conclusions: The results obtained with the automated sVNT technique are consistent with those obtained with the pVNT technique developed in-house. The results of the various repeatability and reproducibility tests demonstrate the good robustness of the fully manual pVNT technique.
]]>Microbiology Research doi: 10.3390/microbiolres15010027
Authors: Kritsana Jatuwong Worawoot Aiduang Tanongkiat Kiatsiriroat Wassana Kamopas Saisamorn Lumyong
Biochar and arbuscular mycorrhizal fungi (AMF), a promising environmentally friendly soil enhancer and biostimulant, play a crucial role in sustainable agriculture by influencing soil properties and plant growth. This research investigates the chemical properties of three biochar types [bamboo (BB-char), corn cob (CC-char), and coffee grounds (CG-char)] derived from different biomass sources and their impact on soil quality and Chinese kale growth. The results reveal significant differences in chemical properties among different types of biochar. Particularly, CG-char showed the greatest pH value and phosphorus content, with an average of 10.05 and 0.44%, respectively. On the other hand, CC-char had the highest potassium content, with an average of 2.16%. Incorporating biochar into degraded soil enhances soil structure, promoting porosity and improved texture, as evidenced by scanning electron microscope images revealing distinct porous structures. Soil chemistry analyses in treatment T2–T14 after a 42-day cultivation demonstrate the impact of biochar on pH, electrical conductivity, organic matter, and organic carbon levels in comparison to the control treatment (T1). Furthermore, the research assesses the impact of biochar on Chinese kale growth and photosynthetic pigments. Biochar additions, especially 5% BB-char with AMF, positively influence plant growth, chlorophyll content, and photosynthetic pigment levels. Notably, lower biochar concentrations (5%) exhibit superior effects compared to higher concentrations (10%), emphasizing the importance of optimal biochar application rates. The study also delves into the total phenolic content in Chinese kale leaves, revealing that the synergistic effect of biochar and AMF enhances phenolic compound accumulation. The combination positively influences plant health, soil quality, and nutrient cycling mechanisms. Overall, the research indicates the multifaceted impact of biochar on soil and plant dynamics, emphasizing the need for tailored application strategies to optimize benefits in sustainable agriculture.
]]>Microbiology Research doi: 10.3390/microbiolres15010026
Authors: Bianca A. Amézquita-López Marcela Soto-Beltrán Bertram G. Lee Edgar F. Bon-Haro Ofelia Y. Lugo-Melchor Beatriz Quiñones
Shiga toxin-producing Escherichia coli (STEC) are zoonotic enteric pathogens linked to human gastroenteritis worldwide. To aid the development of pathogen control efforts, the present study characterized the genotypic diversity and pathogenic potential of STEC recovered from sources near agricultural fields in Northwest Mexico. Samples were collected from irrigation river water and domestic animal feces in farms proximal to agricultural fields and were subjected to enrichment followed by immunomagnetic separation and plating on selective media for the recovery of the STEC isolates. Comparative genomic analyses indicated that the recovered STEC with the clinically relevant serotypes O157:H7, O8:H19, and O113:H21 had virulence genes repertoires associated with host cell adherence, iron uptake and effector protein secretion. Subsequent phenotypic characterization revealed multidrug resistance against aminoglycoside, carbapenem, cephalosporin, fluoroquinolone, penicillin, phenicol, and tetracycline, highlighting the need for improved surveillance on the use of antimicrobials. The present study indicated for the first time that river water in the agricultural Culiacan Valley in Mexico is a relevant key route of transmission for STEC O157 and non-O157 with a virulence potential. In addition, feces from domestic farm animals near surface waterways can act as potential point sources of contamination and transport of diverse STEC with clinically relevant genotypes.
]]>Microbiology Research doi: 10.3390/microbiolres15010025
Authors: Guadalupe Gutiérrez-Soto Iosvany López-Sandin Jesús Salvador Hernández Ochoa Carlos Eduardo Hernadez-Luna Juan Francisco Contreras-Cordero Carlos Alberto Hernández-Martínez
Macrolepiota sp. CS185 is a basidiomycete with high potential as a biocontrol agent against various phytopathogenic fungi. Regardless of its pronounced potential as a post-harvest fungi biocontrol agent, its activity in tomato seedlings infected with Alternaria alternata has not been well studied. Thus, the present work aimed to evaluate the cultures and supernatants’ antagonistic activity against fig fruits’ post-harvest fungi and antifungal activity production kinetics. The culture antagonistic characteristics were assessed through multiple confrontations, the supernatant concentration effect, and the kinetics of antagonistic action. The multiple confrontations showed differences (p ≤ 0.05) among phytopathogens and over time, with Colletotrichum sp. 2 being the most susceptible. Based on the 9-day incubation profile, the treatment fractions supplemented with a 50% concentration of Macrolepiota sp. CS185 supernatants showed a higher inhibition percentage (%In). Except for Alternaria alternata 1 and 2, the rest of the isolates showed a similar decrease in antagonistic activity up to a certain extent over time. Among all tested strains, Colletotrichum sp. 2 was found with a higher susceptibility. Regarding the production kinetics of antagonistic activity, a triple interaction was observed between the phytopathogen, the age of the Macrolepiota sp. CS 185 culture, and incubation time. In addition, changes in the mycelium growth rate (p ≤ 0.05) along with the higher activity in the supernatants of 20 and 30 days were observed and suggested the production of multiple bioactive metabolites. These results indicate that Macrolepiota sp. CS185 produces antifungal metabolites at different times and could be a suitable candidate to control fig fruits’ post-harvest fungi issues.
]]>Microbiology Research doi: 10.3390/microbiolres15010024
Authors: Enrico Maria Criscuolo Fabrizio Barbanti Patrizia Spigaglia
C. difficile infection (CDI) has an important impact on both human and animal health. The rapid detection and monitoring of C. difficile PCR-ribotypes (RTs) cause of CDI is critical to control and prevent this infection. This study reports the first application of the Molecular Beacon (MB)-based real-time PCR method in genotyping important C. difficile RTs of the main evolutionary clades. The cdtR gene was used as target and the cdtR sequences were analyzed after extraction from deposited genomes or were obtained after sequencing from strains of different origin. cdtR alleles were identified after sequence comparisons and MB-based real-time PCR assays were developed to discriminate them. In total, 550 cdtR sequences were compared, 38 SNPs were found, and five different cdtR alleles were identified. In total, one or two alleles were associated to the RTs grouped in the same evolutionary clade. A MB-based real-time assay was designed for each allele and for optimized testing of the C. difficile strains. The results obtained demonstrated that the MB-based real-time PCR assays developed in this study represent a powerful, original, and versatile tool to identify C. difficile types/clades and to monitor changes in the population structure of this important pathogen.
]]>Microbiology Research doi: 10.3390/microbiolres15010023
Authors: Jaqueline Oliveira Reis Carine Baggio Cavalcante Nathaly Barros Nunes Adelino Cunha Neto Maxsueli Aparecida Moura Machado Yuri Duarte Porto Vinicius Silva Castro Eduardo Eustáquio de Souza Figueiredo
Salmonella spp. is not part of the fish microbiota, being introduced through contaminated water or improper handling. In slaughterhouses, five parts per million (ppm) of free chlorine is recommended in the washing step to eliminate this pathogen. However, Salmonella spp. is still detected in fish processing plants due to persistent contamination as a result of chlorine–organic matter interactions that reduce chlorine effectiveness. Therefore, this study aimed to test whether organic matter contained in culture media and fish washes interferes with the efficacy of chlorine at 2 and 5 ppm, and what is the time of action required to inactivate ATCC and wild strains of S. typhimurium. For this, the elimination or survival of these strains was investigated when exposed to chlorinated solution for different durations (0, 5, 30, 60, 90 and 120 min) in culture medium, 0.85% saline solution and fish wash (in natura and sterilized). The results showed that the use of 5 ppm of free chlorine is efficient, even when the chlorine remains in contact with the organic matter (washed from the fish), as it reduced the bacterial population by ~5 log log10 CFU/mL of Salmonella spp., showing that this reduction was due to interactions, as long as the chlorine action time was 30 min.
]]>Microbiology Research doi: 10.3390/microbiolres15010022
Authors: Wenxin Guo Xinyu Shi Lu Wang Xin Cong Shuiyuan Cheng Linling Li Hua Cheng
Selenium nanoparticles (SeNPs) have greater bioavailability and safety than inorganic selenium, and was widely used in medical, agricultural, nutritional supplements, and antibacterial fields. The present study screened a strain L11 producing SeNPs from a selenium rich dairy cow breeding base in Hubei Province, China. The strain was identified as Bacillus subtilis through physiological, biochemical, and molecular biology analysis. By adjusting the cultivation conditions, the experiment determined the ideal parameters for L11 to efficiently produce SeNPs. These parameters include a pH value of 6, a cultivation temperature of 37 °C, a concentration of 4 mmol/L Na2SeO3, and a cultivation of 48 h. X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS), and Transmission Electron Microscopy (TEM) were used to verify that the Se particles produced by L11 are SeNPs with diameters ranging from 50 to 200 nm. The combination of the protein analysis of different cell components and TEM analysis showed that L11 mainly produces SeNPs through the transformation of the cell’s periplasmic space, cell membrane, and cell wall. Adding the L11 SeNPs complex to sheep feed can significantly enhance the antioxidant activity and immunity of sheep, and increase the Se content in the neck muscles, liver, and spleen tissues.
]]>Microbiology Research doi: 10.3390/microbiolres15010021
Authors: Rodrigo Reis Moura Douglas Alfradique Monteiro Eduardo da Silva Fonseca Fabiano de Carvalho Balieiro Fernando Cesário Caio Tavora Coelho da Costa Rachid
In soils, pH stands as the main factor modulating bacterial communities’ composition. However, most studies address its effects in bulk soils in natural systems, with few focusing on its effects in the rhizosphere of plants. Predicting pH effects in the rhizosphere is an important step towards successful microbiome manipulation, aiming to increase crop production. Here, we modulated an acidic soil’s pH to four different ranges (4.7, 5.2, 7.5 and 8.2), while correcting for fertility differences among ranges, thus isolating pH effects from other physicochemical characteristics. Then, two crops with distinct metabolisms (maize and bean) were cultivated in a greenhouse experiment and the effects of pH and cover crops on the rhizosphere bacteriome after 90 days explored through 16S rRNA gene sequencing, aiming to characterize pH effects on the rhizosphere of two different plants across this gradient. Alpha diversity indexes (OTU richness and Shannon index) were statistically different with pH but not crop species, with an interaction among factors. For beta diversity, both pH and crop species were significant modulators of community composition, without an interaction, but pH effects were 2.5 times bigger than those of plant species. Additionally, strong and significant positive correlations were observed between pH and Bacteroidetes and Deltaproteobacteria, while Actinobacteria, Planctomycetes and Acidobacteria were negatively correlated with pH. Regarding OTUs, 27 and 46 were correlated with pH in maize and bean’s rhizosphere, respectively, while 11 were shared between them. Altogether, these results provide valuable information on the isolated effect of pH in the rhizosphere of important crop plants, aiding future microbiome manipulation studies.
]]>Microbiology Research doi: 10.3390/microbiolres15010020
Authors: Razique Anwer
Antimicrobial resistance poses a severe threat, particularly in developing countries where the ready availability of drugs and increased consumption lead to improper antibiotic usage, thereby causing a surge in resistance levels compared to developed areas. Despite the past success of antibiotics, their effectiveness diminishes with regular use, posing a significant threat to medical efficacy. Pseudomonas aeruginosa, an opportunistic pathogen, triggers various infection-related issues, occurring on occasions including chronic wounds, burn injuries, respiratory problems in cystic fibrosis, and corneal infections. Targeting the quorum sensing (QS) of P. aeruginosa emerges as a strategic approach to combat infections caused by this bacterium. The objective of this study was to check the effect of antimycobacterial drugs against the potential QS targets in P. aeruginosa and identify lead candidates. The antimycobacterial drugs were first examined for the toxicological and pharmacokinetic profile. By virtual screening through molecular docking, delamanid and pretomanid stood out as major candidates. The binding energies of delamanid and pretomanid with LasR were determined to be −8.3 and −10.9 kcal/mol, respectively. The detailed analysis of the complexes of lead compounds were examined through molecular dynamics simulations. The molecular simulations data validated a sustained interaction of lead drugs with target proteins (PqsR, LasI, and LasA) in a physiological environment. The negligible changes in the secondary structure of proteins in presence of hit antimycobacterial drugs further strengthened the stability of the complexes. These findings highlight the potential repurposing of delamanid and pretomanid, specifically in targeting P. aeruginosa quorum-sensing mechanisms.
]]>Microbiology Research doi: 10.3390/microbiolres15010019
Authors: Wang Wenzhi Muhammad Aleem Ashraf Hira Ghaffar Zainab Ijaz Waqar ul Zaman Huda Mazhar Maryam Zulfqar Shuzhen Zhang
Sugarcane mosaic virus (SCMV) (genus, Potyvirus; family, Potyviridae) is widespread, deleterious, and the most damaging pathogen of sugarcane (Saccharum officinarum L. and Saccharum spp.) that causes a substantial barrier to producing high sugarcane earnings. Sugarcane mosaic disease (SCMD) is caused by a single or compound infection of SCMV disseminated by several aphid vectors in a non-persistent manner. SCMV has flexuous filamentous particle of 700–750 nm long, which encapsidated in a positive-sense, single-stranded RNA molecule of 9575 nucleotides. RNA interference (RNAi)-mediated antiviral innate immunity is an evolutionarily conserved key biological process in eukaryotes and has evolved as an antiviral defense system to interfere with viral genomes for controlling infections in plants. The current study aims to analyze sugarcane (Saccharum officinarum L. and Saccharum spp.) locus-derived microRNAs (sof-miRNAs/ssp-miRNAs) with predicted potential for targeting the SCMV +ssRNA-encoded mRNAs, using a predictive approach that involves five algorithms. The ultimate goal of this research is to mobilize the in silico- predicted endogenous sof-miRNAs/ssp-miRNAs to experimentally trigger the catalytic RNAi pathway and generate sugarcane cultivars to evaluate the potential antiviral resistance surveillance ability and capacity for SCMV. Experimentally validated mature sugarcane (S. officinarum, 2n = 8X = 80) and (S. spp., 2n = 100–120) sof-miRNA/ssp-miRNA sequences (n = 28) were downloaded from the miRBase database and aligned with the SCMV genome (KY548506). Among the 28 targeted mature locus-derived sof-miRNAs/ssp-miRNAs evaluated, one sugarcane miRNA homolog, sof-miR159c, was identified to have a predicted miRNA binding site, at nucleotide position 3847 of the SCMV genome targeting CI ORF. To verify the accuracy of the target prediction accuracy and to determine whether the sugarcane sof-miRNA/ssp-miRNA could bind the predicted SCMV mRNA target(s), we constructed an integrated Circos plot. A genome-wide in silico-predicted miRNA-mediated target gene regulatory network was implicated to validate interactions necessary to warrant in vivo analysis. The current work provides valuable computational evidence for the generation of SCMV-resistant sugarcane cultivars.
]]>Microbiology Research doi: 10.3390/microbiolres15010018
Authors: Rida Chaudhary Ali Nawaz Mireille Fouillaud Laurent Dufossé Ikram ul Haq Hamid Mukhtar
The microbial biosynthesis of proteins, primary metabolites, and chemicals is gaining extraordinary momentum and is presently viewed as an advancing approach in the industrial research sector. Increased threats to the environment and the possibility of declining petroleum assets have switched the spotlight to microbial cell factories (MCFs). Aside from possessing various advantages over chemical synthesis, such as less toxicity, cheaper methodologies, and an environmentally benign nature, microbes can be cultivated in fermenters, resulting in an effective bioprocessing approach in terms of industrial relevance. As the overwhelming majority of biodiversity is microbial, this review first highlights the microbial biodiversity of industrially vital microorganisms. Then, the paper delineates the production pathways for generating valuable bioproducts via microbial workhorses. Many host cells synthesize bio-compounds as a part of their natural mechanism; however, several techniques have also been developed to attain the desired end product from non-native microbes with selected properties. The microbial biosynthetic pathways can be categorized as native-existing pathways, heterologous pathways, and artificial de novo pathways. Systems metabolic engineering, which integrates metabolic engineering with evolutionary engineering, synthetic biology, and systems biology, has further revolutionized the field of engineering robust phenotypes. The employment of these strategies improves the performance of the strain, eventually achieving high titer and productivity rates of bio-chemicals. Modern trends and tools for exploiting native pathways and designing non-native-created pathways are also briefly discussed in this paper. Finally, the review discusses the use of microbial workhorses for producing a myriad of materials and chemicals, including carboxylic acids, amino acids, plant natural products (PNPs), carotenoids, flavors, and fragrances, unveiling the efficacy of utilizing microbial species to generate sustainable bio-based products.
]]>Microbiology Research doi: 10.3390/microbiolres15010017
Authors: Radosław Wróbel Monika Andrych-Zalewska Jędrzej Matla Justyna Molska Gustaw Sierzputowski Agnieszka Szulak Radosław Włostowski Adriana Włóka Małgorzata Rutkowska-Gorczyca
During the COVID-19 pandemic, microbiological controls neglected the spread of viruses through the air. Techniques to identify this threat required additional research to enable control measures to be introduced to protect against the spread of disease through this route. Due to the very high level of risk occurring during research on the COVID-19 and SARS-CoV-2 viruses, it seems necessary to use analogous microorganisms that will allow, through an experiment, to validate or challenge a method that stops the spread of infectious microorganisms, without unnecessary risk to research staff. The presented work was carried out to assess the possibility of using airborne microorganisms that are safe for humans for this type of research. The work presents the selection process of bacteria and viruses (bacteriophages) that have the greatest potential for use in experimental studies on airborne-droplet transmission indoors, especially in hospital facilities. In the study, it was assumed that determining the survival rates of groups of organisms would allow them to be used as a proxy for studying more dangerous bacteria and viruses. Survival studies of selected microorganisms were carried out, and the paper selected microorganisms with the highest survival rate in a given environment.
]]>Microbiology Research doi: 10.3390/microbiolres15010016
Authors: Nqobile Truelove Ndhlovu Farida Minibayeva Richard Peter Beckett
In lichens, secondary metabolites have been shown to protect against biotic stresses such as pathogen attacks and grazing, and abiotic stresses such as ultraviolet (UV) and high photosynthetically active radiation (PAR). Lichen secondary metabolites are known to have strong antioxidant activity, and while theoretically they may have roles in tolerance to other abiotic stresses, these roles remain largely unclear. Here, we used the acetone rinsing method to harmlessly remove most of the secondary metabolites from the thalli of six lichen species. This enabled us to compare the effects of desiccation on thalli with and without the presence of secondary metabolites. Results showed that in general, the presence of lichen substances reduces the effects of desiccation stress. For all species, substances significantly improved the photosystem two (PSII) activity of the photobiont during either desiccation or rehydration. In the mycobiont, in four of the six species, the presence of substances reduced membrane damage, which was assessed by measuring ion leakage during rehydration following desiccation. However, in one species, secondary metabolites had no effect, while in another the presence of substances increased membrane damage. Nevertheless, it seems clear that in addition to their more established roles in protecting lichens against pathogen attacks and grazing, lichen substances can also play a role in aiding desiccation tolerance.
]]>Microbiology Research doi: 10.3390/microbiolres15010015
Authors: Vasiliy Akimkin Tatiana A. Semenenko Svetlana V. Ugleva Dmitry V. Dubodelov Kamil Khafizov
The COVID-19 pandemic, etiologically related to a new coronavirus, has had a catastrophic impact on the demographic situation on a global scale. The aim of this study was to analyze the manifestations of the COVID-19 epidemic process, the dynamics of circulation, and the rate of the spread of new variants of the SARS-CoV-2 virus in the Russian Federation. Retrospective epidemiological analysis of COVID-19 incidence from March 2020 to fall 2023 and molecular genetic monitoring of virus variability using next-generation sequencing technologies and bioinformatics methods were performed. Two phases of the pandemic, differing in the effectiveness of anti-epidemic measures and the evolution of the biological properties of the pathogen, were identified. Regularities of SARS-CoV-2 spread were determined, and risk territories (megacities), risk groups, and factors influencing the development of the epidemic process were identified. It was found that with each subsequent cycle of disease incidence rise, the pathogenicity of SARS-CoV-2 decreased against the background of the increasing infectiousness of SARS-CoV-2. Data on the mutational variability of the new coronavirus were obtained using the Russian platform of viral genomic information aggregation (VGARus) deployed at the Central Research Institute of Epidemiology. Monitoring the circulation of SARS-CoV-2 variants in Russia revealed the dominance of Delta and Omicron variants at different stages of the pandemic. Data from molecular genetic studies are an essential component of epidemiologic surveillance for making management decisions to prevent the further spread of SARS-CoV-2 and allow for prompt adaptation to pandemic control tactics.
]]>Microbiology Research doi: 10.3390/microbiolres15010014
Authors: Nashwa A. H. Fetyan Tarek A. Essa Tamer M. Salem Ahmed Aboueloyoun Taha Samah Fawzy Elgobashy Nagwa A. Tharwat Tamer Elsakhawy
Developing innovative, eco-friendly fungicide alternatives is crucial to mitigate the substantial threat fungal pathogens pose to crop yields. In this study, we assessed the in vitro effectiveness of SiO2, CuO, and γFe2O3 nanoparticles against Rhizoctonia solani. Furthermore, greenhouse experiments were conducted in artificially infested soil to evaluate the in vivo impact of nanoparticles under study. Two application methods were employed: soil drenching with 10 mL per pot at concentrations of 50, 100, and 200 mg L−1, and seedling dipping in nanoparticle suspensions at each concentration combined with soil drench. The combined treatment of 200 mg L−1 γFe2O3 or CuO nanoparticles showed the highest in vitro antifungal activity. Conversely, SiO2 nanoparticles demonstrated the lowest in vitro activity. Notably, the application of 200 mg/L SiO2 via the dipping and soil drenching methods decreased counts of silicate-solubilizing bacteria and Azospirillum spp. Whereas, application of 100 mg L−1 γFe2O3 nanoparticles via soil drenching increased soil bacterial counts, and CuO nanoparticles at 50 mg L−1 through dipping and soil drenching had the highest dehydrogenase value. γFe2O3 nanoparticles improved plant photosynthetic pigments, reduced malondialdehyde levels, and minimized membrane leakage in lettuce plants. A root anatomical study showed that 200 mg L−1 CuO nanoparticles induced toxicity, whereas 200 mg L−1 γFe2O3 or SiO2 nanoparticles positively affected root diameter, tissue structure, and various anatomical measurements in lettuce roots. γFe2O3 nanoparticles hold promise as a sustainable alternative for managing crop diseases.
]]>Microbiology Research doi: 10.3390/microbiolres15010013
Authors: Alejandro Alarcón-Zayas Luis Guillermo Hernández-Montiel Diana Medina-Hernández Edgar Omar Rueda-Puente Wilson Geobel Ceiro-Catasú Ramón Jaime Holguín-Peña
Arbuscular mycorrhizal fungi, plant-growth-promoting bacteria (PGPB) and vermicompost constitute important environmental and economic resources for improving the production and quality of tomato fruits. The present research aims to determine the single and combined effect of Glomus fasciculatum (Gf) fungus, Azotobacter chroococcum (Azot), PGPB and vermicompost leachate (VL) organic fertilizer on the yield and quality of tomato fruit. Thus, an open-field experiment was established with seven treatments, a control and three replicates. Total soluble solids, vitamin C, acidity, fruit mass and fruit diameter were evaluated as fruit quality variables; the yield was recorded and estimated in tons per hectare−1. The results showed that Gf, Azot and VL were effective in promoting tomato yield and fruit quality. As a trend, the triple combination (Gf + Azot + VL) evidently obtained the highest values of total soluble solids, vitamin C and fruit acidity. The range of improvement concerning the fruit size was 66.6% (single treatment) compared to 78.5% (triple combination). The maximum yield of 54.5 t/ha−1 was recorded for the Gf + Azot + VL combination. Therefore, G. fasciculatum, A. chroococcum and VL are considered useful as organic alternatives for open-field tomato biofertilization programs in tropical countries.
]]>Microbiology Research doi: 10.3390/microbiolres15010012
Authors: Fayyaz Ali Shah Roderick I. Mackie Qaisar Mahmood
The current investigation delved into the utilization of cattle and municipal sanitary inocula for anaerobic digestion of poultry wastes, addressing a crucial and pragmatic challenge in waste management. The emphasis on poultry waste is pertinent due to its well-documented impediments in anaerobic digestion, attributed to heightened levels of ammonia and volatile fatty acids (VFAs). The strategic selection of cattle and municipal sanitary inocula suggests an approach aimed at bolstering the anaerobic digestion process. In this study, we evaluated the use of cattle and municipal sanitary inocula for the anaerobic digestion of various poultry wastes, which is often challenged by high levels of ammonia and volatile fatty acids (VFAs). The substrates tested included belt waste (Poultry A), poultry litter plus feed residues (Poultry B), tray hatchery ©, and stillage. These substrates were processed in two continuous stirred tank reactors (CSTRs), R-1 (with antibiotic monensin) and R-2 (without monensin). Initially, both reactors operated with the same hydraulic retention time (HRT), using a substrate ratio of stillage: belt: tray hatchery (S:B:T) of 70:15:15. On the 41st day, the HRT was adjusted to 20 days, and the substrate ratio was changed to S:A:T 70:40:40. The specific methane yield for R-1 started at 10.768 L g−1 COD, but decreased to 2.65 L g−1 COD by the end of the experiment. For R-2, the specific methane yield varied between 0.45 L g−1 COD and 0.243 L g−1 COD. Microbial composition in the reactors changed over time. In R-1, bacteroides were consistently dominant, while firmicutes were less abundant compared to R-2. Proteobacteria were initially low in abundance, but spirochetes were found in both reactors throughout the experiment. The study concluded that Poultry B substrates, due to their rich nutrient and trace element composition, are suitable for biogas plants. Municipal sanitary inocula also showed promise due to their resilience in high ammonia concentrations. Further research into biofilm interactions is recommended to better understand microbial responses to high ammonia concentrations, which can lead to propionate production in anaerobic digestion (AD).
]]>Microbiology Research doi: 10.3390/microbiolres15010011
Authors: Khalid Alhudaib Ahmed Mahmoud Ismail
Coffee leaf rust (CLR) is a major disease of Arabica coffee caused by the biotrophic fungus Hemileia vastatrix. Jazan region in Saudi Arabia has long been one of the last coffee-producing regions in the world free of this disease. In August 2023, CLR was initially observed in coffee plantations located in Fyfa district one of the main coffee-producing mountains of Jazan region. The source of the infection is unknown, however CLR could have entered Jazan from the nearest coffee-producing locations that haven the pathogen. During a scheduled survey in August 2023, symptoms were observed including yellowish-orange lesions that frequently combined to form chlorotic lesions and exhibited the powdery appearance of yellow uredospores on the abaxial surface of leaves. The uredospores and teliospores were microscopically examined and their morphology matched the previously published description for H. vastatrix. The identity of H. vastatrix specimens was further confirmed based on PCR amplification and sequencing of ITS, sharing a 99–100% identity with previously published sequences, as belonging to H. vastatrix. The pathogenicity of H. vastatrix specimens was investigated on Coffee arabica plants under growth chamber conditions, and all were pathogenic relative to control, with 100% of disease incidence, therefore fulfilling Koch’s postulates. Based on our findings, this is the first documentation of H. vastatrix causing CLR in Saudi Arabia.
]]>Microbiology Research doi: 10.3390/microbiolres15010010
Authors: Liliya Biktasheva Alexander Gordeev Anastasia Kirichenko Polina Kuryntseva Svetlana Selivanovskaya
The production of biosurfactants from organic wastes has received significant attention due to its potential cost savings. This study involved the isolation of biosurfactant-producing microorganisms from waste sources. The surfactant properties of the 37 studied isolates were assessed by reducing surface tension and their emulsifying properties, determined by the emulsification index E24. We assessed the ability of these isolated strains to produce biosurfactants using various waste substrates, namely potato peelings, waste cooking oil and sunflower cake. Our results showed that sunflower cake exhibited better growth and biosurfactant production for most of the strains studied. This highlights that sunflower cake is a potentially effective and economical substrate for the production of biosurfactants. The most effective strains allowing to achieve an emulsification index above 50% and reduce surface tension below 40 mN m−1 were Enterobacter sp. 2pp, strain 2wfo, Peribacillus sp. 1mo, Sphingomonas sp. 2mo, Ochrobactrum sp. 5mo, Shouchella sp. 6mo, Bacillus sp. 1os, Bacillus sp. 2os. Among these strains, both previously known strains as biosurfactant producers and previously unknown strains were found. Thus, we found that among representatives of the genus Sphingomonas there are effective producers of biosurfactants. The highest yield of biosurfactant on a medium with glycerol and glucose was shown by the Bacillus sp. 2os strain of 0.501 and 0.636 g L−1, respectively.
]]>Microbiology Research doi: 10.3390/microbiolres15010009
Authors: Alexandru Scafa-Udriste Mircea-Ioan Popa Gabriela-Loredana Popa
Staphylococcus aureus, a prevalent human pathogen and a leading cause of hospital-acquired infections, is increasingly evolving antibiotic-resistant strains, increasing mortality and morbidity rates. Anti-staphylococcal vaccine research for prevention and treatment has become a priority. Antibodies against specific S. aureus components, toxins, and polysaccharides have demonstrated encouraging results in animal studies regarding protection against colonization or infection. However, human immunization trials have yielded less optimistic outcomes, with no anti-staphylococcal having passed clinical trials up to now. Although multiple formulation attempts triggered strong antibody responses, the vaccines could not effectively prevent S. aureus infections. This article delves into the results of immunotherapeutic strategies against S. aureus in both animal and human studies, discussing the feasibility of adequate immunization approaches against S. aureus in humans.
]]>Microbiology Research doi: 10.3390/microbiolres15010008
Authors: Federica Valeriani Lory Marika Margarucci Francesca Ubaldi Gianluca Gianfranceschi Vincenzo Romano Spica
During the COVID-19 pandemic, extensive efforts focused on developing a better understanding of indirect transmission routes, environmental monitoring of fomites, and suitable surveillance strategies, providing new perspectives to also face other communicable diseases. Rapid methods for monitoring environmental contamination are strongly needed to support risk assessment, epidemiological surveillance and prevent infections from spreading. We optimized and automatized a protocol based on fomite detection by qPCR, using a microbial-signature approach based on marker genes belonging to the microbiota of droplets or different biological fluids. The procedure was implemented by exploiting the available tools developed for SARS-CoV-2 tracing, such as flocked swab sampling, real-time PCR equipment and automatic extraction of nucleic acids. This approach allowed scaling up, simplifying, and speeding up the extraction step of environmental swabs, processing at least 48 samples within 45 min vs. 90 min for about 24 samples by manual protocols. A comparison of microflora data by Next-Generation Sequencing (NGS) strongly supports the effectiveness of this semiautomated extraction procedure, providing good quality DNA with comparable representation of species as shown by biodiversity indexes. Today, equipment for qPCR is widely available and relatively inexpensive; therefore this approach may represent a promising tool for hospital hygiene in surveilling fomites associated with SARS-CoV-2 or other pathogen’s transmission.
]]>Microbiology Research doi: 10.3390/microbiolres15010007
Authors: Min Kee Son Yuri Song Jin Chung Hee Sam Na
Healthy individuals often have different gut microbiota, and these differences can be influenced by their country of origin or their race. This study aimed to compare the gut microbiota compositions of healthy Germans and Koreans using 16S rRNA sequencing data extracted from public sources. Two cohorts, comprising 1592 samples (804 Germans and 788 Koreans), were analyzed for alpha and beta diversity, core microbiome, and abundances of specific taxa. The Prevotella enterotype was more prevalent in Koreans, and significant diversity differences were observed depending on cohorts and enterotypes. The core microbiomes across all enterotypes and cohorts included Bacteroides, Faecalibacterium, Parabacteroides, and Lachnospira. Several common core microbiomes were also found depending on enterotype. Koreans exhibited higher abundances of Faecalibacterium, Prevotella, and Bacteroides, while Germans had higher abundances of Blautia, Subdoligranulum, and Agathobacter. Distinctive microbiomes were identified by enterotype. The study enhances comprehension of gut microbiome variations linked to enterotype and geographical factors, and emphasizes the need for additional research to establish correlations between specific microbial properties and individual health status.
]]>Microbiology Research doi: 10.3390/microbiolres15010006
Authors: Venkateswari Ramachandra Usharani Brammacharry Aaina Muralidhar Anbazhagi Muthukumar Revathi Mani Muthuraj Muthaiah Govindarajan Soundappan Asha Frederick
GeneXpert MTB/RIF is a rapid molecular diagnostic tool capable of simultaneously detecting Mycobacterium tuberculosis and rifampicin resistance. This study aimed to assess the diagnostic precision of GeneXpert MTB/RIF assay to detect pulmonary and extrapulmonary tuberculosis and evaluate the performance for detecting of rifampicin resistance. Of 37,695 samples, 7156 (18.98%) were tuberculosis-positive, and 509 (7.11%) were rifampicin-resistant. The sensitivity, specificity, positive predictive value, negative predictive value, disease prevalence, and accuracy of the GeneXpert MTB/RIF assay for pulmonary tuberculosis were 99.87% (95%CI: 99.75–99.94), 99.92% (95%CI: 99.88–99.95), 99.71% (95%CI: 99.54–99.82), 99.97% (95%CI: 99.93–99.98), 21.38% (95%CI: 20.92–21.86), and 99.91% (95%CI: 99.87–99.94), respectively. For extrapulmonary tuberculosis, the sensitivity, specificity, PPV, NPV, disease prevalence, and accuracy of GeneXpert MTB/RIF assay accounted for 99.45% (95%CI: 98.73–99.82), 99.84% (95%CI: 99.73–99.92), 98.70% (95%CI: 97.73–99.25), 99.93% (95%CI: 99.84–99.97), 10.64% (95%CI: 9.99–11.31), and 99.80% (95%CI: 99.68–99.88), respectively. Despite its high sensitivity for detecting tuberculosis and rifampicin resistance, GeneXpert MTB/RIF had contradictory results for 20.5% of cases among patients with smear-negative results and 54.9% of cases among patients with a high risk of multidrug-resistant tuberculosis. Of 46% fluoroquinolone-resistant cases, 16.56% (26/157) were multidrug-resistant tuberculosis isolates, and 4.02% (20/498) were isoniazid-resistant, a characteristic distribution leading to about 17.2% of fluoroquinolone-resistance events and relevant marker gyr-A mutations in MDR tuberculosis isolates. Further, our study indicated that increased fluoroquinolone resistance among rifampicin-resistant and isoniazid-resistant tuberculosis endangers the success of newly endorsed MDR-TB regimens.
]]>Microbiology Research doi: 10.3390/microbiolres15010005
Authors: Valery M. Dembitsky
This article explores the diverse array of biologically active compounds derived from microbial symbionts, particularly focusing on the isolation and characterization of diepoxides, highly oxygenated triterpenoids, secosteroids, ergostane-type steroids, and meroterpenoids from various marine and plant-derived fungi. We highlight significant discoveries such as vitamin D variants from fungal species, unique sesterterpenoids from mangrove endophytic fungi, and secosteroids with potential medicinal applications. The study delves into the structural uniqueness and bioactivities of these compounds, including their anti-inflammatory, antibacterial, antifungal, antiviral, and cytotoxic effects. Notable findings include the isolation of compounds with significant activity against cancer cell lines, the inhibition of acetylcholinesterase, and promising antifouling properties. This work underscores the potential of microbial symbionts as a rich source of novel bioactive compounds with diverse therapeutic applications, highlighting the importance of marine and fungal biodiversity in drug discovery and development.
]]>Microbiology Research doi: 10.3390/microbiolres15010004
Authors: Mehabo Penistacia Maela Mahloro Hope Serepa-Dlamini
Peribacillus sp. AS_2, a leaf endophytic bacterium isolated from the medicinal plant Alectra sessiliflora, was previously identified using the 16S rRNA gene sequence. The draft genome of AS_2 had a 5,482,853 bp draft circular chromosome, 43 contigs, N50 of 360,633 bp and an average G + C% content of 40.5%. Whole genome sequencing and phenotypic analysis showed that AS_2 was Gram-positive, endospore-forming, motile, and rod-shaped and it showed a high sequence similarity with P. frigoritolerans DSM 8801T. Genomic digital DNA–DNA hybridisation (dDDH) between strain AS_2 and Peribacillus frigoritolerans DSM 8801T and P. castrilensis N3T was 84.8% and 79.2%, respectively, and the average nucleotide identity (ANI) of strain AS_2 with P. frigoritolerans DSM 8801T and P. castrilensis N3T was 97.0% and 96.7%, respectively. The antiSMASH software predicted a total of eight secondary metabolite gene clusters comprising non-ribosomal peptide synthetase (NRPS) type koranimine, terpenes, and siderophore clusters. Strain AS_2 also displayed genes involved in endophytic lifestyle and antibiotic resistance gene clusters such as small multidrug resistance antibiotic efflux pumps (qacJs). Using the multilocus sequence analysis (MLSA), together with the phenotypic data and genomic analysis, we demonstrated that strain AS_2 is a subspecies of P. frigoritolerans DSM 8801T. Genome sequencing of Peribacillus sp. AS_2 from medicinal plants provides valuable genomic information and allows us to further explore its biotechnological applications.
]]>Microbiology Research doi: 10.3390/microbiolres15010003
Authors: Daniel Uribe-Ramírez Eliseo Cristiani-Urbina Liliana Morales-Barrera
Microbial treatment of free-cyanide-polluted wastewater is a cost-effective, efficient, and eco-friendly method. Free-cyanide-degrading microbial cultures were isolated from different sources using batch-enrichment culture techniques, with acetate as the carbon source. Five microbial cultures were able to tolerate and grow at 1500 mg/L free cyanide, which was used as the only nitrogen source under strongly alkaline conditions (pH = 11). Among them, one bacterial strain (B11) was selected for further study because of its high free-cyanide-biodegradation efficiency. Bacterial strain B11 was molecularly identified as Bacillus licheniformis CDBB B11. Free cyanide inhibited the growth rate of B. licheniformis CDBB B11 at initial cyanide concentrations >75 mg/L. Despite this, the bacterial strain demonstrated 100% cyanide-biodegradation efficiency at initial cyanide concentrations ranging from 25 to 75 mg/L, which decreased to 32% as the initial cyanide concentration increased from 75 to 1500 mg/L. Free-cyanide biodegradation corresponds to bacterial growth and ammonia accumulation in the culture medium. The alkaliphilic B. licheniformis CDBB B11 strain is a robust candidate for the detoxification of free-cyanide-laden wastewater because it tolerates and efficiently degrades free cyanide at concentrations of up to 1500 mg/L.
]]>Microbiology Research doi: 10.3390/microbiolres15010002
Authors: Elena Voronina Ekaterina Sokolova Irina Tromenschleger Olga Mishukova Inna Hlistun Matvei Miroshnik Oleg Savenkov Maria Buyanova Ilya Ivanov Maria Galyamova Natalya Smirnova
Plant-growth-promoting bacteria are an important economic and environmental resource as biofertilizers that can stimulate plant growth and improve agricultural yields. In this study, potential plant growth-promoting bacteria were isolated from soil samples collected in Russia. Strains that manifested active growth on a nitrogen-free medium, the Pikovskaya medium (with insoluble phosphates) and CAS (Chrome Azurol S) agar, were selected for the study. All bacterial isolates were identified by 16S rRNA gene sequencing analysis. Seventeen bacterial isolates of different species were purified and quantified for their ability to grow on nitrogen-free media; dissolve phosphate; and produce ammonium, indole-3-acetic acid, siderophores, and antifungal activity. Principal component analysis identified three groups of strains: one with the maximum signs of providing “plant nutrition”; one with signs of “antimicrobial activity”; and a group “without outstanding signs”. All 17 strains were involved in experiments involving growing inoculated wheat seeds (Triticum aestivum) in pots under natural environmental conditions, and were assessed by their effect on the wheat growth and yield as well as on the chemical composition of the soil. For the “plant nutrition” group, regression analysis revealed a connection between indicators of plant growth, ear length, and ammonium accumulation in the soil. However, in other groups, there were also strains showing a positive effect on plant growth, which suggests the necessity of involving additional factors to predict the ability of strains to affect plants when screened in the laboratory.
]]>Microbiology Research doi: 10.3390/microbiolres15010001
Authors: Muhammad Aleem Ashraf Judith K. Brown Muhammad Shahzad Iqbal Naitong Yu
Cotton leaf curl Kokhran virus (CLCuKoV) (genus, Begomovirus; family, Geminiviridae) is one of several plant virus pathogens of cotton (Gossypium hirsutum L.) that cause cotton leaf curl disease in Pakistan. Begomoviruses are transmitted by the whitefly Bemisia tabaci cryptic species group and cause economic losses in cotton and other crops worldwide. The CLCuKoV strain, referred to as CLCuKoV-Bur, emerged in the vicinity of Burewala, Pakistan, and was the primary causal virus associated with the second CLCuD epidemic in Pakistan. The monopartite ssDNA genome of (2.7 Kb) contains six open reading frames that encode four predicted proteins. RNA interference (RNAi)-mediated antiviral immunity is a sequence-specific biological process in plants and animals that has evolved to combat virus infection. The objective of this study was to design cotton locus-derived microRNA (ghr-miRNA) molecules to target strains of CLCuKoV, with CLCuKoV-Lu, as a typical CLCuD-begomovirus genome, predicted by four algorithms, miRanda, RNA22, psRNATarget, and RNA hybrid. Mature ghr-miRNA sequences (n = 80) from upland cotton (2n = 4x = 52) were selected from miRBase and aligned with available CLCuKoV-Lu genome sequences. Among the 80 cotton locus-derived ghr-miRNAs analyzed, ghr-miR2950 was identified as the most optimal, effective ghr-miRNA for targeting the CLCuKoV-Lu genome (nucleotide 82 onward), respectively, based on stringent criteria. The miRNA targeting relies on the base pairing of miRNA–mRNA targets. Conservation and potential base pairing of binding sites with the ghr-miR2950 were validated by multiple sequence alignment with all available CLCuKoV sequences. A regulatory interaction network was constructed to evaluate potential miRNA–mRNA interactions with the predicted targets. The efficacy of miRNA targeting of CLCuKoV was evaluated in silico by RNAi-mediated mRNA cleavage. This predicted targets for the development of CLCuD-resistant cotton plants.
]]>Microbiology Research doi: 10.3390/microbiolres14040145
Authors: Papa Fall Ibrahima Diouf Abdoulaye Deme Semou Diouf Doudou Sene Benjamin Sultan Serge Janicot
In sub-Saharan Africa, temperatures are generally conducive to malaria transmission, and rainfall provides mosquitoes with optimal breeding conditions. The objective of this study is to assess the impact of future climate change on malaria transmission in West Africa using community-based vector-borne disease models, TRIeste (VECTRI). This VECTRI model, based on bias-corrected data from the Phase 6 Coupled Model Intercomparison Project (CMIP6), was used to simulate malaria parameters, such as the entomological inoculation rate (EIR). Due to the lack of data on confirmed malaria cases throughout West Africa, we first validated the forced VECTRI model with CMIP6 data in Senegal. This comparative study between observed malaria data from the National Malaria Control Program in Senegal (Programme National de Lutte contre le Paludisme, PNLP, PNLP) and malaria simulation data with the VECTRI (EIR) model has shown the ability of the biological model to simulate malaria transmission in Senegal. We then used the VECTRI model to reproduce the historical characteristics of malaria in West Africa and quantify the projected changes with two Shared Socio-economic Pathways (SSPs). The method adopted consists of first studying the climate in West Africa for a historical period (1950–2014), then evaluating the performance of VECTRI to simulate malaria over the same period (1950–2014), and finally studying the impact of projected climate change on malaria in a future period (2015–2100) according to the ssp245 ssp585 scenario. The results showed that low-latitude (southern) regions with abundant rainfall are the areas most affected by malaria transmission. Two transmission peaks are observed in June and October, with a period of high transmission extending from May to November. In contrast to regions with high latitudes in the north, semi-arid zones experience a relatively brief transmission period that occurs between August, September, and October, with the peak observed in September. Regarding projections based on the ssp585 scenario, the results indicate that, in general, malaria prevalence will gradually decrease in West Africa in the distant future. But the period of high transmission will tend to expand in the future. In addition, the shift of malaria prevalence from already affected areas to more suitable areas due to climate change is observed. Similar results were also observed with the ssp245 scenario regarding the projection of malaria prevalence. In contrast, the ssp245 scenario predicts an increase in malaria prevalence in the distant future, while the ssp585 scenario predicts a decrease. These findings are valuable for decision makers in developing public health initiatives in West Africa to mitigate the impact of this disease in the region in the context of climate change.
]]>Microbiology Research doi: 10.3390/microbiolres14040144
Authors: Nouf M. Al-Enazi Khawla Alsamhary Fuad Ameen Marcos Augusto Lima Nobre
This study aimed to enhance the anticancer and antibacterial properties of Pistacia atlantica through a new parenteral formulation. The innovative approach involved loading P. atlantica fruit extract onto a novel Pluronic vesicular nano platform (Nio), analyzed using various techniques like GC-Mass, SEM, DLS, and UV-vis. The results revealed a stable, spherical Nio/Extract formulation of 103 ± 4.1 nm, possessing a high zeta potential of −30 ± 2.3 mV, with an impressive encapsulation efficiency of nearly 90 ± 3.5%. This formulation exhibited heightened cytotoxicity against BT-20 and MCF-10 cell lines compared to the extract alone, indicating its potential as a drug carrier with prolonged release characteristics. Additionally, the Nio/Extract demonstrated superior antibacterial effects against Pseudomonas aeruginosa, Staphylococcus epidermidis, and Candida albicans compared to the free extract, showcasing MIC values of 211, 147, and 187 ug/mL, respectively, versus 880, 920, and 960 ug/mL for the pathogens. These findings highlight the potential of niosomal nano-carriers housing P. atlantica extract as a viable therapeutic strategy for combating both malignancies and microbial infections.
]]>Microbiology Research doi: 10.3390/microbiolres14040143
Authors: Bonface M. Nthuku Esther W. Kahariri Johnson K. Kinyua Evans N. Nyaboga
Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense (Foc), significantly affects the productivity of the banana crop in the field. Currently, there are no effective control measures available, and therefore, there is an urgent need to develop novel strategies to control the spread of the disease. Biological control is a promising strategy for the management and control of the disease. The aim of this study was to identify fungal endophytes associated with Moringa (Moringa oleifera), Neem tree (Azadirachta indica) and Lavender (Lavandula angustifolia) and their antifungal activities against Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4). We isolated 69 fungal endophytes from different tissues of M. oleifera, A. indica and L. angustifolia and screened for antifungal activity against Foc TR4. Six fungal endophytes exhibited highest antagonistic activity against Foc TR4 based on dual-culture assays. Based on morphology and ITS gene sequence analysis, the selected six endophytes were identified to be related to Alternaria alternata (MB7 and NR3), Neofusicoccum parvum (LB1), Fusarium oxysporum (LR1), Talaromyces amestolkiae (MB14) and Alternaria tenuissima (NB6). The culture filtrates of the six fungal endophytes (LB1, LR1, MB7, MB14, NB6 and NR3) exhibited more than 50% inhibition of mycelial growth of Foc TR4 in vitro and were producers of β-1,3-glucanase. The six fungal endophytes showed biocontrol efficacy against Fusarium wilt in pot experiments. The findings from this study demonstrate that fungal endophytes LB1, LR1, MB7, MB14, NB6 and NR3 should be explored as biocontrol agents and biofertilizers in banana production.
]]>Microbiology Research doi: 10.3390/microbiolres14040142
Authors: Aleksandra Kalinina Vladimir Naumov Alena Verakhina Svetlana Ovchinnikova Diana Yakovleva Aleksandr Dobrov Tatyana Sokolova Julia Lukyanova Polina Afanasieva
The use of algae for carbon dioxide fixation is based on their natural ability to photosynthesize. Dynamic experiments make it possible to calculate the short-term photosynthetic activity of microalgae strains in photobioreactors. In this study, the effect of temperature and culture time on the intensity of reproduction and on CO2 absorption by some microalgae was evaluated. It was found that the maximum increase in biomass occurred during algae cultivation at 29–32 °C and pH = 8.4. A ratio of ~2.0 was observed between CO2 absorption and the increase in biomass for different microalgae. When using the Chlorella genus, the increase in biomass under comparable conditions was greater than when cultivating microalgae of the Scenedesmus genus.
]]>Microbiology Research doi: 10.3390/microbiolres14040141
Authors: Nadia El Allaoui Hiba Yahyaoui Allal Douira Abdellatif Benbouazza Moha Ferrahi El Hassan Achbani Khaoula Habbadi
Environmental concerns are gradually reducing the global yield capacity of agricultural systems, with climate change representing the most significant challenge. Globally, Potatoes are the most essential non-cereal crop. Therefore, understanding the potential impacts of climate change on potato production is crucial for maintaining future global food security. This study aims to explore the roles played by PGPMs in two distinct regions, which are characterized by different climatic conditions, to assess their influence on two potato varieties, namely Siena and Bellini. Inoculation with these strains, particularly the Aureobasidium pullulans strains Ach1-1 and Ach1-2, resulted in significant improvements in growth and yield. In 2018, impressive yields of 194.1 kg/0.05 ha and 186.6 kg/0.05 ha were recorded for the two strains, with the Ain Taoujdate site achieving yields of 157.1 kg/0.05 ha and 151.1 kg/0.05 ha for each of the two strains. Additionally, further observations revealed that the Siena variety is more susceptible to rot than the Bellini variety. However, Ach1-1 and Ach1-2 strains had a significant effect on this rot, showcasing their potential to mitigate this negative issue in the Bellini variety. These promising results underscore the potential of PGPMs to enhance potato production in the Fez–Meknes region of Morocco, contributing to global food security amid climate change.
]]>Microbiology Research doi: 10.3390/microbiolres14040140
Authors: Esra Aksoy Nilgün Güler İbrahim Sözdutmaz Serkan Kökkaya Engin Berber Ayşe Gençay Göksu
Bovine rotaviruses (BRVs) are significant causative agents of severe diarrhea in newborn calves, resulting in substantial economic losses in the livestock industry. Inhibition of bovine rotavirus using extracts prepared from a Cucurbitaceae plant, which contains trypsin protease inhibitors, might offer a potential anti-rotaviral effect in vitro. Ecballium elaterium (E. elaterium) belongs to the Cucurbitaceae family, indigenous to the Mediterranean, contains E. elaterium trypsin isoinhibitors (EETIso), and has been used in traditional medicine. This study aimed to evaluate the in vitro efficacy of E. elaterium extract against bovine rotavirus infections. Ethanol extracts were prepared from E. elaterium seeds and fruit juice, and their non-toxic concentrations were determined using MA-104 cells. The cells were infected with bovine rotavirus in the presence of E. elaterium extract. The results demonstrated a significant decrease in the rotavirus titer in vitro upon treatment with the E. elaterium extract, suggesting its potential as a therapeutic agent against bovine rotavirus-induced diarrhea in calves. The utilization of E. elaterium extract may contribute to reduced calf mortality, lower medication costs, and improved economic value in cattle farming.
]]>Microbiology Research doi: 10.3390/microbiolres14040139
Authors: Luis G. Hernández-Montiel Juan P. Ciscomani-Larios Esteban Sánchez-Chávez Irasema Vargas-Arispuro Abeer Hashem Elsayed F. Abd_Allah Graciela D. Avila-Quezada
Enhancing crop nutrition though biofortification with essential minerals can, in some circumstances, increase the resistance of plants to the attack by pathogens. As a result, plants activate their defense mechanisms and produce bioactive compounds (BCs) in response. To date, there has been no investigation into the response of green bean plants fortified with magnesium (Mg) salts to the presence of Colletotrichum lindemuthianum. This research involved two Mg sources applied by the edaphic route. The pathogen was inoculated on green bean pods, and subsequent analysis was conducted on the accumulation of BCs, including total anthocyanins, total phenols, and total flavonoids, within both symptomatic and healthy tissues. Remarkably, the plant’s defense system was activated, as evidenced by the significantly higher concentration of anthocyanins (p ≤ 0.05) observed in the symptomatic tissues following treatments with both MgCl2 and MgSO4. Further, green bean plants treated with MgSO4 displayed notably elevated concentrations of phenols (p ≤ 0.05) in the inoculated tissues of the pods, suggesting a plausible plant defense mechanism. The levels of BCs were considerably higher in green bean pods of the biofortified plants compared to those which were nonbiofortified. However, perhaps one of the most noteworthy findings is that there were no discernible differences between biofortified and nonbiofortified treatments in stopping anthracnose in green bean pods. These results provide valuable insights contributing to a deeper understanding of this interaction.
]]>Microbiology Research doi: 10.3390/microbiolres14040138
Authors: Alaa El-Dein Omara Fatma M. El-maghraby
Because agricultural wastes are abundant in biologically active substances, they can be used as a substitute source to produce highly valuable products while lowering pollution levels in the environment. Therefore, we aimed at determining the best agricultural wastes to increase the biomass production rate and the effectiveness of the biocontrol strain Trichoderma lixii SARS 111 in a solid-state fermentation system. The potential for its use in enhancing growth dynamics and controlling the Fusarium oxysporum NCAIM-F-00779-caused damping-off disease of cowpea plants grown in greenhouse conditions was also studied. Using a one-factor-at-a-time experiment, five cheap agricultural waste substrates (faba bean, cowpea, sweet potato, pumpkin, and cassava) were studied using the Plackett–Burman design (PBD) and the central composite design (CCD) to optimize the nutritional and growth conditions to maximize the production of Trichoderma conidia. The findings demonstrated that increasing Candida production quantitatively required the use of 3 g of sweet potato, 3 g of cassava, pH 6, 25 °C, and pre-treatment with dH2O. The shelf life and viability of T. lixii strain were measured as log10 CFU g−1 per substrate at room temperature (RT, 25 °C) at the beginning of month 0 and subsequently at 2-month intervals for 12 months. Data showed that the fungal counts increased with the use of 4 g of sweet potato + 2 g of cassava up to 7 months and then sharply decreased, lasting up to 12 months. Additionally, this bioformulation was applied to cowpea plants in a greenhouse experiment, where a significantly higher level of plant growth traits, photosynthetic pigments, antioxidant enzymes, and chemical content in the leaves, as well as lower incidence of the damping-off disease, were noted. Accordingly, it is possible to suggest 4 g of sweet potato and 2 g of cassava as a suitable bioformulation for the industrial-scale production of the T. lixii strain, which may be a potential biocontrol agent for preventing the cowpea damping-off disease caused by F. oxysporum and improving the growth dynamics.
]]>Microbiology Research doi: 10.3390/microbiolres14040137
Authors: Valentina Dimartino Fernanda Scopelliti Caterina Cattani Gianluca Nicolella Andrea Cavani
The rising migration and travel from and towards endemic areas has brought renewed concerns about many parasitic infections, including neglected tropical diseases, such as schistosomiasis. Although serology is the most widely used method for the screening of schistosomiasis in non-endemic countries, this technique lacks sensitivity, especially to distinguish between past and ongoing infections. More recently, a molecular test based on the detection of Schistosoma cell-free DNA in the serum has been proposed as a diagnostic procedure for parasitosis. To test the performance of a blood PCR assay, this work investigated 102 serum samples collected from migrants coming from endemic areas by using primers specific to genomic regions of S. mansoni and S. haematobium patients. The results were then compared with the detection of specific IgG Abs with serological tests. Molecular analysis detected Schistosoma DNA in 32 patients. Among them, we characterized nine S. haematobium, 20 S. mansoni, and three coinfections. Compared with molecular assay, serological analysis detected specific antibodies against Schistosoma antigens in 52 out of 102 patients. Concordance between the two tests was found in 76 out of 102 patients (74.51%): in particular, both diagnostic tests were positive in 29 patients (28.43%) and negative in 47 (46.08%). The specificity of the molecular test was 94%. Overall, our data suggest that serological diagnosis could be combined with the molecular approach, providing the clinician with the serotyping of the parasite and useful information about the infection as well as the required further diagnostic procedures.
]]>Microbiology Research doi: 10.3390/microbiolres14040136
Authors: Ilva Liekniņa Anna Kozlova Marina Šaško Ināra Akopjana Kalvis Brangulis Kaspars Tārs
Lyme disease affects several hundred thousand people worldwide annually, yet there is no registered vaccine for the disease available for human use. The disease is caused by Borrelia burgdorferi sensu lato complex bacteria, which harbor numerous outer surface proteins, and many of which have been targeted for vaccine development. However, to effectively combat various Borrelia species, the target protein should ideally be conserved and located in the chromosome. In this study, we evaluated the potential of seven conservative, chromosome-encoded outer surface proteins as vaccine candidates. Unfortunately, four of the initial candidates could not be produced in E. coli. The remaining BB0028, BB0158, and BB0689 proteins were administered to mice in both the free form and as conjugates with virus-like particles (VLPs). In most cases, high antibody titers were obtained, confirming the good immunogenicity of the selected proteins. However, for BB0158 and BB0689 proteins, adverse effects were observed following the injection of free proteins, which were not observed when they were coupled to VLPs. Bactericidity tests of the obtained antibodies suggested that none of the vaccine candidates could induce the production of bactericidal antibodies.
]]>Microbiology Research doi: 10.3390/microbiolres14040135
Authors: Esteban Charria-Girón Aída M. Vasco-Palacios Bibiana Moncada Yasmina Marin-Felix
The current list of fungi from Colombia updated in the present review contains a total of 7619 species. The Ascomycota appears as the most diverse group, with 4818 species, followed by the Basidiomycota, with 2555 species. Despite this, we presume that the actual fungal diversity in Colombia could amount to between 105,600 and 300,000 species. Fungi represent an underestimated resource, indispensable for human well-being. Even though the current knowledge on potential applications of Colombian fungi is still limited, the number of studies on areas such as natural products discovery, biological control, and food and beverages, among other biotechnological applications, are increasing. With the current review, we aim to present a comprehensive update on the fungal diversity in Colombia and its potential applications. Colombia’s native fungal biodiversity holds much potential within the country’s current social-economical context, and the future must ensure efforts to preserve both the biodiversity and the untapped resources of the fungi in Colombia, which in alignment with the Sustainable Development Goals (SDGs) might result in new bioeconomy avenues for the country.
]]>Microbiology Research doi: 10.3390/microbiolres14040134
Authors: Woon-Jong Yu Dawoon Chung Seung Seob Bae Yong Min Kwon Eun-Seo Cho Grace Choi
Marine yeasts have versatile applications in the industrial, medical, and environmental fields. However, they have received little attention compared to terrestrial yeasts and filamentous fungi. In this study, a phylogenetic analysis of 11 marine-derived yeasts was conducted using internal transcribed spacers and nuclear large subunit rDNA, and their bioactivities, such as antioxidant, antibacterial, and tyrosinase inhibition activities, were investigated. The 11 marine-derived yeasts were identified to belong to seven species including Geotrichum candidum, Metschnikowia bicuspidata, Papiliotrema fonsecae, Rhodotorula mucilaginosa, Vishniacozyma carnescens, Yamadazyma olivae, and Yarrowia lipolytica, and three strains of these were candidates for new species of the genera Aureobasidium, Rhodotorula, and Vishniacozyma. Most extracts showed antioxidant activity, whereas seven strains exhibited antibacterial activities against Bacillus subtilis. Only Aureobasidium sp. US-Sd3 among the 11 isolates showed tyrosinase inhibition. Metschnikowia bicuspidata BP-Up1 and Yamadazyma olivae K2-6 showed notable radical-scavenging activity, which has not been previously reported. Moreover, Aureobasidium sp. US-Sd3 exhibited the highest antibacterial and tyrosinase inhibitory activities. These results demonstrate the potential of marine-derived yeasts as a source of bioactive compounds for improving industrial applications.
]]>Microbiology Research doi: 10.3390/microbiolres14040133
Authors: Kridsada Unban Natchanon Muangkajang Pratthana Kodchasee Apinun Kanpiengjai Kalidas Shetty Chartchai Khanongnuch
This study evaluated the ability of a yeast strain isolated from traditional fermented tea leaves (Camellia sinensis var. assamica), Miang from northern Thailand, to grow and produce ethanol in the presence of tannin. Among 43 Miang samples, 25 yeast isolates displayed gas-forming character in the presence of 1% (w/v) tannin, but only ML1-1 and ML1-2 isolates were confirmed as ethanol-producing yeast capable of tannin tolerance. These isolates were further identified to be Pichia occidentalis and Saccharomyces cerevisiae, respectively, based on D1/D2 domain sequence analysis. S. cerevisiae ML1-2 was selected for further studies and exhibited growth at 20–35 °C, pH 4–7, and tolerance to high sugar concentrations of up to 350 g/L. Supplementation of 1% (w/v) tannin had no effect on sugar utilization and ethanol production, while delayed sugar consumption and ethanol production were observed in the reference strain S. cerevisiae TISTR 5088. However, 5 and 10% (w/v) tannin showed inhibitory effects on the growth and ethanol production of the selected yeast isolates. During the fermentation under high tannin conditions derived by mixing Java plum fruit with ground seed, S. cerevisiae ML1-2 showed significant advantages in growth and enhanced the content of ethanol, polyphenols, tannin, and flavonoids compared to S. cerevisiae TISTR 5088. This indicated its potential for high-tannin substrate-based bioconversion for the production of either fuel ethanol or functional alcoholic beverages.
]]>Microbiology Research doi: 10.3390/microbiolres14040132
Authors: Shulin Fu Xinyue Tian Jingyang Li Yuzhen Yuan Jing He Chun Peng Ling Guo Chun Ye Yu Liu Bingbing Zong Yinsheng Qiu
The gut microbiota is engaged in multiple interactions affecting host health, and gut dysbiosis can lead to many diseases. However, the effects of acetylcysteine (NAC) on the gut microbiome composition in pigs using metagenomic sequencing have not been reported. In this study, we used metagenome sequencing to study the effects of NAC on the pig gut microbiome. Sequencing results showed that microbial diversity was changed after NAC treatment. Antibiotic Resistance Genes Database (ARDB) analysis demonstrated that the main genes modified were macb, tsnr, norm, bl2be-per, vansb and pbp1b in the NAC group. Our data showed that NAC could affect microbial distribution at the phylum, gene and species levels. At the species level, NAC significantly increased the abundances of Megasphaera, Lactobacillus reuteri and Megasphaeraelsdenii and reduced the abundances of Phascolarctobacterium succinatutens, Prevotellacopri and Selenomonasbovis compared with the control group. In addition, Gene Ontology (GO) analysis revealed that in the NAC group, cellular process, metabolic process and single-organism process were the dominant terms. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis demonstrated that RNA transport, MAPK signaling pathway, cell cycle, glycosylphosphatidylinositol (GPI)-anchor biosynthesis and VEGF signaling pathway were the dominant signaling pathways in the NAC group. In conclusion, our results suggest that NAC may modify the piglet gut microbiome composition and these findings might provide a new strategy for maintaining animal and human health in the future.
]]>Microbiology Research doi: 10.3390/microbiolres14040131
Authors: Vladimir I. Muronetz Lidia P. Kurochkina Evgeniia V. Leisi Sofia S. Kudryavtseva
This review discusses a few examples of specific mechanisms mediating the contribution of the GIT microbiota to the development of amyloid neurodegenerative diseases caused by the pathologic transformation of prion protein, or alpha-synuclein. The effect of the bacterial GroE chaperonin system and phage chaperonins (single-ring OBP and double-ring EL) on prion protein transformation has been described. A number of studies have shown that chaperonins stimulate the formation of cytotoxic amyloid forms of prion protein in an ATP-dependent manner. Moreover, it was found that E. coli cell lysates have a similar effect on prion protein, and the efficiency of amyloid transformation correlates with the content of GroE in cells. Data on the influence of some metabolites synthesized by gut microorganisms on the onset of synucleinopathies, such as Parkinson’s disease, is provided. In particular, the induction of amyloid transformation of alpha-synuclein from intestinal epithelial cells with subsequent prion-like formation of its pathologic forms in nervous tissues featuring microbiota metabolites is described. Possible mechanisms of microbiota influence on the occurrence and development of amyloid neurodegenerative diseases are considered.
]]>Microbiology Research doi: 10.3390/microbiolres14040130
Authors: Omkar Pokharkar Grigory V. Zyryanov Mikhail V. Tsurkan
Among the oldest marine species on the planet, the genus Salinispora is often encountered inhabiting sediments and other marine creatures in tropical and subtropical marine settings. This bacterial genus produces a plethora of natural products. The purpose of this study was to examine the potential for salinispora-based natural products (NPs) to combat the SARS-CoV-2 virus. The RCSB PDB was used to obtain the crystal structures of proteins 3CLpro and PLpro. All 125 NPs were obtained from online databases. Using Autodock Vina software v1.2.0 the molecular docking process was carried out after the proteins and ligands were prepared. Assessments of binding affinities and interacting amino acids were rigorously examined prior to MD simulations. The docking experiments revealed 35 NPs in total for both 3CLpro and PLpro, with high docking scores ranging from −8.0 kcal/mol to −9.0 kcal/mol. However, a thorough binding residue analyses of all docked complexes filtered nine NPs showing strong interactions with HIS: 41 and CYS: 145 of 3CLpro. Whereas, for PLpro, merely six NPs presented good interactions with residues CYS: 111, HIS: 272, and ASP: 286. Further research was conducted on residue–residue and ligand–residue interactions in both the filtered docked complexes and the Apo-protein structures using the Protein Contacts Atlas website. All complexes were found to be stable in CABS-flex 2.0 MD simulations conducted at various time frames (50, 125, 500, and 1000 cycles). In conclusion, salinaphthoquinone B appears to be the most promising metabolite, based on favorable amino acid interactions forming stable confirmations towards 3CLpro and PLpro enzymes, acting as a dual inhibitor.
]]>Microbiology Research doi: 10.3390/microbiolres14040129
Authors: Ramamoorthi M. Sivashankari Yuki Miyahara Takeharu Tsuge
The use of stable isotope-labeled polymers in in situ biodegradation tests provides detailed information on the degradation process. As isotope-labeled raw chemicals are generally expensive, it is desirable to prepare polymer samples with high production yields and high isotope-labeling ratios. The biodegradable plastic poly[(R)-3-hydroxybutyrate)] (P(3HB)) is produced by microorganisms. In this study, to produce carbon 13 (13C)-labeled P(3HB) from [U-13C6]D-glucose (13C-glucose), the culture conditions needed for high production yields and high 13C-labeling ratios were investigated using Ralstonia eutropha NCIMB 11599 and recombinant Escherichia coli JM109. We found that over 10 g/L of P(3HB) could be obtained when these microorganisms were cultured in Luria-Bertani (LB3) medium containing 3 g/L NaCl and 40 g/L 13C-glucose, while 1.4–4.7 g/L of P(3HB) was obtained when a mineral salt (MS) medium containing 20 g/L 13C-glucose was used. The 13C-labeling ratio of P(3HB) was determined by 1H nuclear magnetic resonance and gas chromatography-mass spectrometry (GC-MS), and both analytical methods yielded nearly identical results. High 13C-labeling ratios (97.6 atom% by GC-MS) were observed in the MS medium, whereas low 13C-labeling ratios (88.8–94.4 atom% by GC-MS) were observed in the LB3 medium. Isotope effects were observed for the P(3HB) content in cells cultured in the LB3 medium and the polydispersity of P(3HB).
]]>Microbiology Research doi: 10.3390/microbiolres14040128
Authors: Hanan Balto Musarat Amina Ramesa Shafi Bhat Hanan M. Al-Yousef Sayed H. Auda Afaf Elansary
The current study evaluated the biogenic synthesis of nickel oxide nanoparticles (SP-NiONPs) from the root extract of (Salvadora persica) S. persica and their biological properties. The nanoparticles were characterized using spectroscopic and microscopic techniques and then evaluated for their antimicrobial properties against 10 oral pathogens. The ultraviolet-visible (UV–Vis) spectra exhibited a distinctive resonance spectrum at 334 nm for the SP-NiONPs produced from S. persica. The fourier transform infrared (FTIR) analysis revealed the presence of functional groups of biomolecules of S. persica that served as reducing and capping agents of the SP-NiONPs. The scanning electron microscope (SEM) and transmission electron microscopy (TEM) analyses showed that the nanoparticles were spherical-shaped, tightly packed, and ranged in size from 18.20 nm to 45.12 nm. The energy dispersive x-ray (EDX) analysis confirmed 69.9% of the nickel (Ni) content by weight, and the X-ray diffraction (XRD) results showed the face-centered cubic (FCC) crystalline structure of the formed SP-NiONPs. The antioxidant activity of the SP-NiONPs exhibited a dose-dependent profile with an IC50 value of 51.45 ± 0.65 and a 54.13 ± 0.98 DPPH• and ABTS•+ radical scavenging activity, respectively. The SP-NiONPs showed an antibacterial activity against all the test strains; however, E. cloacae was found to be the most sensitive strain, with an inhibition zone of 31 ± 0.50 mm. The SEM image of the E. cloacae cells treated with SP-NiONPs showed irregular shapes and ruptured, destroyed cell membranes. Our findings revealed that SP-NiONPs could be used as excellent antibacterial agents against oral pathogens.
]]>Microbiology Research doi: 10.3390/microbiolres14040127
Authors: Massimo Pisano Francesco Giordano Giuseppe Sangiovanni Nicoletta Capuano Alfonso Acerra Francesco D’Ambrosio
Background: The human being is defined as a ‘superorganism’ since it is made up of its own cells and microorganisms that reside inside and outside the human body. Commensal microorganisms, which are even ten times more numerous than the cells present in the body, perform very important functions for the host, as they contribute to the health of the host, resist pathogens, maintain homeostasis, and modulate the immune system. In the mouth, there are different types of microorganisms, such as viruses, mycoplasmas, bacteria, archaea, fungi, and protozoa, often organized in communities. The aim of this umbrella review is to evaluate if there is a connection between the oral microbiome and systematic diseases. Methodology: A literature search was conducted through PubMed/MEDLINE, the COCHRANE library, Scopus, and Web of Science databases without any restrictions. Because of the large number of articles included and the wide range of methods and results among the studies found, it was not possible to report the results in the form of a systematic review or meta-analysis. Therefore, a narrative review was conducted. We obtained 73.931 results, of which 3593 passed the English language filter. After the screening of the titles and abstracts, non-topic entries were excluded, but most articles obtained concerned interactions between the oral microbiome and systemic diseases. Discussion: A description of the normal microbial flora was present in the oral cavity both in physiological conditions and in local pathological conditions and in the most widespread systemic pathologies. Furthermore, the therapeutic precautions that the clinician can follow in order to intervene on the change in the microbiome have been described. Conclusions: This review highlights what are the intercorrelations of the oral microbiota in healthy subjects and in subjects in pathological conditions. According to several recent studies, there is a clear correlation between dysbiosis of the oral microbiota and diseases such as diabetes, cardiovascular diseases, chronic inflammatory diseases, and neurodegenerative diseases.
]]>Microbiology Research doi: 10.3390/microbiolres14040126
Authors: Gabriele Sass David A. Stevens
Co-infection with Pseudomonas (Pa) and Aspergillus (Af) commonly occurs in the airways of immune-compromised patients or in cystic fibrosis and frequently results in more severe outcomes than mono-infection. We affixed both pathogens to agar beads, separately (Af beads, Pa beads) or on the same bead (AfPa beads) and infected immunocompetent mice, an in vivo Af-Pa interaction model. Endotracheal administration was superior to intranasal, allowing larger beads to be administered resulting in longer lung residence. The CFU of the Af beads, diameter 150–250 µm, were detectable for ≤21 days. Af-bead-infected mice cleared the Af infection more than mice infected with AfPa beads, but Af clearance was the same with a combination of beads (Af beads + Pa beads). Pa-infected mice had more Pa clearance in the presence of Af than with Pa beads alone. In vitro studies supported our conclusion that the close proximity of Af and Pa (on AfPa beads) was disadvantageous for Af, whereas a larger distance (Af + Pa beads) was not. We demonstrated that the interaction between Pseudomonas and Aspergillus during co-infection can be studied in immunocompetent mice. The mutual inhibition of Af and Pa in vivo appears to be dependent on their proximity. We review the literature relating to animal models of infection with Af, Pa, or both.
]]>Microbiology Research doi: 10.3390/microbiolres14040125
Authors: Monserrat Alonso-Vargas Lizbeth Anahí Portillo-Torres Yuridia Mercado-Flores María del Rocío Ramírez-Vargas Arturo Cadena-Ramírez
This study elucidates the effects of Carbon/Nitrogen (C/N) ratios on the respiratory behavior of Paracoccus denitrificans PD1222, a microorganism noted for its metabolic adaptability. We explored its ability to undergo dissimilative denitrification, a less understood process where energy is harnessed from nutrient consumption without resultant growth. By manipulating the C/N ratios and available nitrogen sources in our experimental design, we were able to demonstrate significant shifts in P. denitrificans metabolic behavior. At a C/N ratio of 1.34, with nitrate as the sole nitrogen source, dissimilative denitrification occurred with no observable increase in biomass. Succinate, the provided carbon source, was quickly metabolized without contributing to cell growth. Our results contribute to the understanding of environmental microbiology, specifically denitrification processes, and indicate P. denitrificans’s potential for wastewater treatment scenarios, where pollutant consumption without biomass proliferation is desired.
]]>Microbiology Research doi: 10.3390/microbiolres14040124
Authors: Ramón Ignacio Arteaga-Garibay Raúl Jacobo Delgado-Macuil Lorena Jacqueline Gómez-Godínez Carlos Iván Cruz-Cárdenas Zuamí Villagrán Silvia Giono-Cerezo Lily Xochitl Zelaya-Molina Luis Miguel Anaya-Esparza José Martín Ruvalcaba-Gómez
Lactic acid bacteria (LAB) comprise a group of microorganisms responsible for developing the sensory and chemical characteristics of several foods and fermented products, particularly cheese. For this reason, after isolation and identification of LAB, validated protocols and procedures for their long-term preservation without compromising its integrity and technological properties, as well as methodologies aiming to assess their viability and integrity are paramount. This study aimed to isolate and identify autochthonous LAB from artisanal Adobera cheese and determine the effect of LAB cryopreservation with thioglycolate broth and glycerol on their viability, membrane integrity, and kinetics. Sixteen LAB were isolated and genetically identified from artisanal cheese samples; eleven of those strains were selected (genus Lactobacillus, Leuconostoc, Streptococcus, and Lactococcus) and included in the cryo-preservation assay. The initial average concentration of the bacterial suspensions was 6.89 log10 CFU mL−1; increasing to 8.9 log10 CFU mL−1 21 days later and slightly reduced at day 42 post-preservation (losses below one logarithm). About 77% of the cells maintained their membrane potential 180 days after their preservation and showed normal Kinetic parameters, maintaining normal adaptation times (Lag phase) and Log phases (9 h average), before reaching the stationary phase. The proposed protocol constitutes a viable alternative to the long-term preservation of different LAB genera because it keeps their viability and integrity. Using flow cytometry allowed the enumeration of viable LAB and provide evidence of the integrity of their membrane.
]]>Microbiology Research doi: 10.3390/microbiolres14040123
Authors: Yana Ilieva Maya Margaritova Zaharieva Lyudmila Dimitrova Mila D. Kaleva Joanna Jordanova Maya Dimitrova Michaela Beltcheva Iliana Aleksieva Yordan Georgiev Yordan Manasiev Hristo Najdenski
Small mammals are bioindicator organisms, and, through their gut microbiota (GM), could be carriers of pathogens and resistant bacteria. Also, wild GM composition has been suggested to have large implications for conservation efforts. Seventeen bacterial species were obtained from intestinal samples of Bulgarian yellow-necked mice (Apodemus flavicollis) and bank voles (Myodes glareolus) via classic microbiological cultivation and biochemical identification. Twelve Gram-negative—Escherichia coli, Yersinia enterocolitica, Yersinia kristensenii, Hafnia alvei, Serratia liquefaciens, Serratia marcescens, Serratia proteamaculans, Pseudescherichia vulneris, Klebsiella pneumoniae ssp. ozaenae, Enterobacter cloacea, Pantoea agglomerans, Pseudomonas fluorescens group—and five Gram-positive bacteria, Enterococcus faecium, Enterococcus faecalis, Enterococcus hirae, Bacillus thuringiensis, and Lysinibacillus sphaericus, were discovered. Enterobacteriaceae was the most abundant family. The isolates belonged to one of the major reported taxa in rodents, Firmicutes (the Gram-positive species) and to the less abundant, but still among the first, phyla, Proteobacteria (the Gram-negative strains). We did not find any members of the other major phylum, Bacteroidetes, likely due to lack of metagenomic techniques. E. coli and Y. enterocolitica were confirmed with polymerase chain reaction. Almost all strains had pathogenic potential, but the good condition of the test animals suggests their commensal role. The Y. enterocolitica strains did not have the ail pathogenicity gene. There was high prevalence of multi-drug resistance (MDR), but for the expected species with high level of intrinsic resistance, such as the enterococci and S. marcescens. E. coli and some other species had very low antimicrobial resistance (AMR), in line with other studies of wild rodents. Many of the strains had biotechnological potential; e.g., B. thuringiensis is the most used biological insecticide, with its proteins incorporated into the Bt genetically modified maize. The GM of the tested wild mice and voles from Bulgaria proved to be a source of bacterial diversity; many of the strains were promising in terms of biotechnology, and, in addition, the samples did not contain the African swine fever virus.
]]>Microbiology Research doi: 10.3390/microbiolres14040122
Authors: Panbo Deng Lulu Wang Xia Li Jinshan Zhang Haiming Jiang
Geobacter grbiciae can grow via coupling oxidation of ethanol to the reduction of various forms of soluble Fe(III) and poorly crystalline Fe(III) oxide, suggesting that G. grbiciae can act as an electron-donor microbe for forming co-cultures through direct interspecies electron transfer (DIET). In this report, potential co-cultures through DIET of G. grbiciae and Methanosarcina barkeri 800, G. sulfurreducens Δhyb, or Methanospirillum hungatei, as electron-acceptor microbes, were examined. Co-cultures of G. grbiciae and G. sulfurreducens Δhyb were performed with ethanol as the sole electron-donor substance and fumarate as the electron-acceptor substance in the presence of granular activated carbon (GAC), magnetite, or polyester felt. The conditions for co-culturing G. grbiciae and M. barkeri 800 (or M. hungatei) were the same as those for G. grbiciae and G. sulfurreducens Δhyb, except fumarate was absent and different cultivation temperatures were used. All co-cultures were anaerobically cultivated. Samples were regularly withdrawn from the co-cultures to monitor methane, fumarate, and succinate via gas or high-performance liquid chromatography. G. grbiciae formed functional co-cultures with M. barkeri 800 in the presence of GAC or magnetite. No co-culture of G. grbiciae with the H2/formate-utilizing methanogen M. hungatei was observed. Additionally, G. grbiciae formed functional co-cultures with H2/formate-un-utilizing G. sulfurreducens Δhyb without the GAC or magnetite supplement. These findings indicate electron transfer between G. grbiciae and M. barkeri 800/G. sulfurreducens Δhyb is via DIET rather than H2/formate, confirming that G. grbiciae acts as an electron-donor microbe. Although the co-cultures of G. grbiciae and M. barkeri 800 syntrophically converted ethanol to methane through DIET, the conversion of propionate or butyrate to methane was not observed. These findings expand the range of microbes that can act as electron donors for interaction with other microbes through DIET. However, propionate and butyrate metabolism through DIET in mixed microbial communities with methane as a product requires further analysis. This study provides a framework for finding new electron-donor microbes.
]]>Microbiology Research doi: 10.3390/microbiolres14040121
Authors: Matías Jofré Bartholin Boris Barrera Vega Liliana Berrocal Silva
Antimicrobial resistance (AMR) is a critical global issue affecting public and animal health. The overuse of antibiotics in human health, animal production, agriculture, and aquaculture has led to the selection of antibiotic-resistant strains, particularly in Gram-negative bacteria. Mutations and horizontal gene transfer play a significant role in the development of antimicrobial resistance, leading to the reduced efficacy of current antibiotics. Today, AMR in bacteria and antibiotic-resistance genes (ARGs) are increasingly recognized in multiple environmental sources, including recreational and irrigation waters. This study aims to identify Gram-negative bacteria from surface aquatic reservoirs in southern Chile and assess their susceptibility to clinically relevant antibiotics. Water samples were collected from four lakes, five rivers, one waterfall, and one watershed in southern Chile to isolate environmental Gram-negative bacilli (GNB). API-20E and MALDI–TOF were employed for bacterial identification. Kirby–Bauer disc diffusion tests and multiplex PCR were performed to determine their susceptibility profile. A total of 26 GNB strains were isolated from environmental water samples, predominantly belonging to the Pseudomonas (n = 9) and Acinetobacter (n = 7) genera. Among these strains, 96.2% were resistant to ampicillin and cefazoline, while 26.9% and 34.6% showed resistance to ceftazidime and cefepime, respectively. Additionally, 38.5% exhibited resistance to colistin. Two Enterobacter cloacae strains obtained from Cachapoal River (sixth region) and Villarrica Lake (ninth region), respectively, presented a multidrug-resistant (MDR) phenotype and carried at least two extended-spectrum β-lactamase (ESBL) genes. Thus, antibiotic-resistant GNB and ARGs were found in natural water reservoirs, raising concerns about the dissemination of resistance determinants among potentially pathogenic bacteria in environmental microbial communities.
]]>Microbiology Research doi: 10.3390/microbiolres14040120
Authors: Carlos D. Sánchez-Cárdenas Mariel Isa-Pimentel Roberto Arenas
Phaeohyphomycosis, a worldwide fungal infection, refers to uncommon superficial, subcutaneous, or systemic infections caused by melanized fungi. Currently, about 70 genera and 150 species have been described. It can be confirmed by mycological, histopathological, or molecular methods. Treatment can be performed by surgery or systemic antifungals.
]]>Microbiology Research doi: 10.3390/microbiolres14040119
Authors: Ashlesha Pal Noorulain Altaf Anum Mahmood Shazia Akbar Nazrah Maher Naresh Kumar Muhammad Sohail Zafar Laura Murcia Ricardo E. Oñate-Sánchez
Caries is a common dental problem brought on by factors like excessive sugar consumption, poor oral hygiene, and the presence of microorganisms in the mouth. This dental pathology is treated with a variety of filling materials, including tooth-colored direct resin dental composite (RDC), glass ionomer cement (GIC), and dental amalgam (also known as silver filling). RDC is the most preferred filling material in dental clinics due to its excellent esthetics and minimal tooth preparation, making it the need of the modern era. However, antimicrobial agents were added to this material in order to enhance its ability to prevent secondary caries. The antibacterial activity of RDC has been tested using a variety of methods, but testing protocols have been found to vary. Thusly, the point of this article is to examine the disparity in the strategy involved by specialists for testing the antibacterial properties of RDCs.
]]>Microbiology Research doi: 10.3390/microbiolres14040118
Authors: Eman M. Elsayed Ahmed A. Farghali Mohamed I. Zanaty Medhat Abdel-Fattah Dalal Hussien M. Alkhalifah Wael N. Hozzein Ahmed M. Mahmoud
Natural polymers have good biological, biocompatible properties and a low degradation rate, so they can be used in medical applications. This study demonstrates an optimized biosynthesis for poly-gamma-glutamic acid nano-polymer (ɣ-PGA NP) using three bacterial isolates encoded as B4, B5, and B6. The 16S rRNA gene sequence of the isolates showed 98.5, 99, and 99.8% similarity with Bacillus sp., with accession numbers MZ976778, MZ976779, and MZ956153, respectively. The optimal conditions of the biosynthesis were 35 °C, followed by incubation for 30 h, 7 pH, 0.7 O.D600 of bacterial broth, carbon sources of glutamic acid and glucose, and ammonium sulfate as the nitrogen source. Biosynthesized ɣ-PGA NPs were characterized using X-ray diffraction (XRD), Zeta sizer, Fourier transform infrared (FT-IR), transmission electron microscopy (TEM), and nuclear magnetic resonance (1HNMR). The TEM study showed the formation of oval-shaped ɣ-PGA NPs with sizes 31.75–32.69 nm, 18.63–21.66 nm, and 37.57–39.22 nm for B4, B5, and B6, respectively. XRD, FT-IR, and 1HNMR confirmed the purity of the polymer. The hemolysis rates of the biosynthesized ɣ-PGA NPs were below the acceptable value. Moreover, the cytotoxicity test conducted using an MTT assay on peripheral blood mononuclear cells (PBMCs) revealed no significant effect on the cell viability within a dose range of up to 512 μg/mL.
]]>Microbiology Research doi: 10.3390/microbiolres14040117
Authors: Kanto Razanamalala Tantely Razafimbelo Pierre-Alain Maron Lionel Ranjard Nicolas Chemidlin Prévost-Bouré Samuel Dequiedt Thierry Becquer Jean Trap Eric Blanchart Laetitia Bernard
Carbon sequestration in agricultural soils, through the accumulation of high-quality organic matter, represents great potential to mitigate climate change and simultaneously improve soil fertility. Such a challenge is particularly important and relevant in developing tropical countries like Madagascar, where soil carbon storage is vulnerable to climatic variations and where fertilization is generally applied through amendments in organic matter of various origins. The priming effect (PE) is considered here as the stimulation of the mineralization of soil organic matter (SOM) by a supply of fresh organic matter (FOM). PE results from different microbial processes driven by specific biotic and abiotic parameters. Depending on the processes involved, it has been suggested that PE could either counteract SOM accumulation or promote it. The objective of the present study was to explore the relationships between certain agricultural practices (type of crop, quality of fertilization, association with trees), the potential intensity of PE, as well as several abiotic (texture, quantity and quality SOM, nutrient enrichment) a1nd biotic (biomass and phylogenetic composition of microbial communities) factors which have been proposed in the literature as specific determinants of the different PE generation mechanisms. The soils for this study come from a network of farms in a commune in the Highlands of Madagascar. The PE, generated by a supply of 13C-enriched wheat straw, could not directly correlate with agricultural treatments. However, several indirect correlations could be found via several specific abiotic and microbial determinants that are discussed in terms of soil fertility restoration.
]]>Microbiology Research doi: 10.3390/microbiolres14040116
Authors: Amany Y. El-Sayed Mahmoud Shehata Sara H. Mahmoud Mahmoud ElHefnawi Dina M. Seoudi Mohamed A. Ali
The Middle East respiratory syndrome coronavirus (MERS-CoV) was first isolated from a patient with acute pneumonia and renal failure in Saudi Arabia in 2012. By July 2023, MERS-CoV had resulted in 2605 human cases worldwide, causing a fatality rate of 36%, with 90.2% of cases being located in the Arabian Peninsula. The dromedary camel (Camelus dromedarius) is presumed to be an intermediate host for viral transmission to humans. So far, no prophylactic vaccines or effective antiviral treatments have been approved for MERS-CoV. RNA silencing is a novel approach for treating several diseases. A web-based bioinformatics tool (i-Score Designer) with integrative computational methods was used to predict and evaluate the designed siRNAs. This approach enabled the targeting of a highly conserved region of the MERS-CoV membrane (M) gene to inhibit virus replication. siRNA-M1, -M2, and -M3 were selected as the best of 559 designed siRNA candidates for an in vitro validation based on 2nd generation algorithm scoring, thermodynamic properties, off-target filtration, position-specific nucleotide preferences, and a free immune-stimulatory motifs. siRNAs were evaluated in Vero cells for their cytotoxicity and antiviral efficacy in vitro. Our results showed that the predicted siRNAs had no apparent cytotoxicity observed in Vero cells. The obtained results from the plaque reduction assay and RT-qPCR indicated that siRNA-M3 was the best candidate to inhibit MERS-CoV replication with a defined concentration of 400 picoMolar (pM). The computational methods used, and the in vitro evaluation, may provide an insight for a new antiviral strategy against MERS-CoV, a further in vivo study will nevertheless be required.
]]>Microbiology Research doi: 10.3390/microbiolres14040115
Authors: Patricia-Andrada Reștea Ștefan Țigan Laura Grațiela Vicaș Luminița Fritea Eleonora Marian Tunde Jurca Annamaria Pallag Iulius Liviu Mureșan Corina Moisa Otilia Micle Mariana Eugenia Mureșan
The aim of this study was to analyze other possible new markers of severity, at hospital admission, that can be assessed in patients with type 2 diabetes and a SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection. Our study included 90 subjects: 45 patients with type 2 diabetes mellitus infected with the SARS-CoV-2 virus, and 45 healthy persons as controls. The serum level of ceruloplasmin at hospital admission was statistically significant and directly correlated with the severity of COVID-19 (coronavirus disease) (p = 0.037) and with the serum level of IL-6 (interleukin 6) (p = 0.0001). Ceruloplasmin was statistically significant and inversely correlated with the serum iron level (p = 0.0001). However, we observed that ACE (angiotensin-converting enzyme) decreased in severe forms of SARS-CoV-2 infections in patients with type 2 diabetes (p = 0.001). Moreover, the decrease in ACE levels was correlated with an increase in IL-6 levels in these patients (p = 0.001). IL-6 increases were statistically significant and inversely correlated with serum iron, transferrin, and ACE levels. There was a noticed decreasing tendency of the transferrin depending on the severity of the COVID-19 infection (p = 0.0001). In addition to the known severity factors in the context of infection with the new coronavirus, increased concentrations of ceruloplasmin and decreased concentrations of ACE and transferrin may represent new markers of COVID-19 severity in patients with type 2 diabetes. These parameters, if analyzed upon admission to the hospital, could better inform health professionals about the evolution towards more severe forms of SARS-CoV-2 infections.
]]>Microbiology Research doi: 10.3390/microbiolres14040114
Authors: Mohammad Altaf Nagma Parveen Faizan Abul Qais K. M. Abdullah Iqbal Ahmad
Antimicrobial resistance (AMR) has become a critical global health challenge. Infections, particularly those caused by multidrug-resistant (MDR) pathogens, rank among the top causes of human mortality worldwide. Pseudomonas aeruginosa occupies a prominent position among pathogens responsible for opportunistic infections in humans. P. aeruginosa stands as a primary cause of chronic respiratory infections, significantly contributing to the burden of these chronic diseases. In the medical domain, nanotechnologies offer significant potential, spanning various applications, including advanced imaging, diagnostic devices, drug delivery systems, implants, tissue-engineered structures, and pharmaceutical treatments. Given the challenges associated with AMR and the limited discovery of new drugs to combat MDR microbes, there is a critical need for alternative strategies to address the problem of AMR. In this study, we synthesized titanium–cerium nanocomposites (Ti–Ce–NCs) using an eco-friendly green synthesis approach. X-ray diffraction (XRD) analysis confirmed the crystalline nature of the Ti–Ce–NCs and determined the particle size to be 17.07 nm. Electron microscopy revealed the size range of the particles to be 13 to 54 nm, where the majority of the particles were in the 20 to 25 nm range. Upon examining the composition, the Ti–Ce–NCs were determined to be composed of cerium, oxygen, and titanium, whose relative abundance were 36.86, 36.6, and 24.77% by weight, respectively. These nanocomposites were then evaluated for their effectiveness against various virulent traits and biofilms in P. aeruginosa. Out of six tested virulence factors, more than 50% inhibition of five virulence factors of P. aeruginosa was found. Roughly 60% inhibition of biofilm was also found in the presence of 400 µg/mL Ti–Ce–NCs. The nanocomposites also altered the biofilm architecture of the test bacterium. The success of this research opens doors for the potential use of such nanomaterials in the discovery of new antibacterial agents to combat drug-resistant bacteria.
]]>Microbiology Research doi: 10.3390/microbiolres14040113
Authors: Elena S. Bogdanova Maria A. Danilova Maria S. Smirnova Elena V. Trubnikova Hoa T. Nguyen Svetlana N. Petrova Sergey V. Apanasenok Alexei B. Shevelev
Probiotics can act as an alternative to antibiotics in animal feeding, but their use is minimal due to their expensive production. Dry grass is rich with bacteria beneficial for animal feeding and can be used as a probiotic. However, data about the quantitative dependence of the grass microbiome on environmental factors and seasons remain insufficient for preparing “grass-meal-based probiotics”. Four grass samples were collected in two geographically remote regions of Russia; their microbiome was characterized by metagenomic sequencing of 16S rDNA libraries and microbiological seeding, and biological testing of the grass meal was carried out on 6 groups of birds containing 20 Ross 308 cross broilers each for a period of 42 days. The positive control group (PC) obtained 16–25 mg/mL toltrazuril (coccidiostatic agent) and 0.5 mL/L liquid antibiotic enrostin (100 mg/mL ciprofloxacin and 106 MU/mL colistin sulfate in the commercial preparation) within the drinking water, while the negative control group (NC) obtained no medicines. Four experimental groups were fed the diet supplemented with 1% grass meal over the period of 7–42 days of life; no commercial medicines were used here. A spontaneous infection with Eimeria was registered in the NC control groups, which caused the loss of 7 chickens. No losses were registered in the PC group or the two experimental groups. In two other experimental groups, losses of coccidiosis amounted to 10% and 15%, respectively. All specimens of the grass meal demonstrated a significant effect on the average body weight gain compared to NC. Taken together, these observations support the hypothesis that the grass meal may substitute toltrazuril for protecting the chickens from parasitic invasion and increase average daily weight gain (ADG) as effectively as the antibiotic enrostin.
]]>Microbiology Research doi: 10.3390/microbiolres14040112
Authors: Jagath C. Kasturiarachchi
This study investigated the development of aptamer-based molecular probes to detect Methicillin-Resistant Staphylococcus aureus (MRSA) and evaluated the antibacterial activity. Early detection of MRSA infection will improve patients’ recovery and reduce the cost for treating patients. S. aureus can become resistant to methicillin and other β-lactam antibiotics through the expression of PBP2A protein, which is resistant to the action of methicillin. We have developed two aptamer molecular probes against PBP2A protein and whole bacterial cell (MRSA) under optimized in vitro conditions using SELEX approach. Target aptamer sequences were identified, and chemically synthesized aptamer probes were evaluated using fluorescently-labelled aptamer probes using flow cytometry and confocal imaging. Antibacterial activities of those aptamers were also evaluated using a bacterial killing assay. The results showed that high specific aptamers were developed against purified PBP2A protein. However, these aptamers showed less specificity to detect MRSA under in vitro condition. These aptamers showed no cytotoxic effect on 3T3 cells and no antibacterial activity against MRSA. The results suggested that the specific aptamer development and the in vitro selection methodology require further refinement to improve the diagnostic and therapeutic utility of these aptamers.
]]>Microbiology Research doi: 10.3390/microbiolres14040111
Authors: María Fernanda Celaya Corella Jorge Omer Rodeles Nieblas Donato Antonio Rechy Iruretagoyena Gerson Ney Hernández Acevedo
The goal of this study was to determine the most common microorganisms present in COVID-19 patients with co-infections at the General Hospital of Mexicali. Bacterial co-infections have been reported in two previous global pandemics caused by viruses. In a retrospective observational study, we obtained information from 1979 patients. All had symptoms of respiratory disease, and we performed real-time Polymerase Chain Reaction tests on nasopharyngeal swab samples. Of the 1979 patients, 316 were negative; so, they were excluded. One thousand and sixty-three patients had positive results for COVID-19; one hundred and seventy-two (10.34%) had respiratory co-infections. These data were corroborated by positive growth results in culture media and identified using the MALDI-TOF MS System. Vitek 2® Compact, an automated identification system, determined the antimicrobial susceptibility testing results. We analyzed and determined the microorganisms in co-infected patients. Different microorganisms were found, including bacteria and fungi. The most prevalent of all the organisms was Acinetobacter baumannii, which was present in 64 patients (37.2%). We recommend improving the diagnostic and surveillance protocols for possible cases of co-infections in patients with COVID-19. Unlike co-infections in pandemic influenza, the spectrum of microorganisms that cause COVID-19 is too broad and varied to recommend empiric antibiotic therapy.
]]>Microbiology Research doi: 10.3390/microbiolres14040110
Authors: Rihaf Alfaraj Esra K. Eltayb Bashayer M. AlFayez Amjad Abohamad Eram Eltahir Naifa A. Alenazi Sandra Hababah Hamad Alkahtani Thamer A. Almangour Fulwah Y. Alqahtani Fadilah S. Aleanizy
Quorum-sensing inhibitors have recently garnered great interest, as they reduce bacterial virulence, lower the probability of resistance, and inhibit infections. In this work, meta-bromo-thiolactone (mBTL), a potent quorum and virulence inhibitor of Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA), was formulated in chitosan nanoparticles (ChNPs) using the ionic gelation method. The mBTL-loaded-ChNPs were characterized by their particle size, polydispersity index, zeta potential, morphology, and drug release profile. The results show that the mBTL-loaded-CNPs comprised homogenized, spherical nanoparticles ranging from 158 ± 1.3 to 284 ± 5.6 nm with a sustainable release profile over 48 h at 37 °C. These findings confirm the successful preparation of mBTL-loaded-ChNPs. Confocal laser scanning microscopy showed a significant reduction in the number of viable cells, indicating the antibacterial efficacy of mBTL. Biofilms were observed by scanning electron microscopy, which showed that the bacterial cells in the control experiment were enclosed in thick biofilms. In the presence of mBTL, the bacterial cells remained disordered and did not form a biofilm. mBTL-loaded-ChNPs represent a potential approach to overcoming antimicrobial resistance in the treatment of MRSA infection.
]]>Microbiology Research doi: 10.3390/microbiolres14040109
Authors: H. Ghaoui N. Achour A. Saad-Djaballah S. I. Belacel I. Bitam P. E. Fournier
Our study aimed at assessing the role of Coxiella burnetii in nonspecific febrile illness at the National Center of Infectious Diseases in Algeria, EL-HADI FLICI Hospital. Seventy patients were included and compared to seventy controls without any ongoing infection. Coxiella burnetii infection was investigated using IFA serology and qPCR. Serology was positive in 3 of 70 patients (4.30%), including 1 in whom PCR was also positive (1.42%). All three patients reported frequent contact with ruminants. These results suggest that C. burnetii is an agent of nonspecific febrile illness in Algeria.
]]>Microbiology Research doi: 10.3390/microbiolres14040108
Authors: Talita Loureiro Maria Manuel Mesquita Maria de Lurdes Enes Dapkevicius Luís Serra Ângela Martins Isabel Cortez Patrícia Poeta
Xylella fastidiosa (Xf) is classified as a quarantine pest due to its consequences on economically significant crops. Its main form of transmission in Europe is through the insect Philaenus spumarius. Due to climate change, the populations of insect vectors have become more extensive, resulting in the dissemination of the bacteria over longer periods, but the destruction of these insects raises issues due to their role in nature. Upon infection, Xf causes the occlusion of xylem vessels via bacterial aggregates and tylosis production by the plant as a response to infection. Although symptomatic manifestations of Xf are often linked to water stress, a variety of plant species have been found to carry the pathogen without symptoms, making it all too easy to evade detection when relying on visual inspections. Beyond water stress, other conditions (individual plant resistance/tolerance, bacterial concentrations, transpiration rates, and interactions between subspecies) may be implicated in symptom development. A thorough understanding of how this disease develops, especially its capacity to spread from the initial focus and establish a systemic infection, is imperative. This review focuses on the Xf infection process, the development of symptoms, its spread within Portugal, and the actions that have been taken to counter it.
]]>Microbiology Research doi: 10.3390/microbiolres14040107
Authors: Jamal Wadi Al-Ramahi Rola Ali Ghanem Omar Helmy Sayyouh Dima Al-Jammal Mayar M. Said Salwa Nasrat Mona El-Shokry Mahmoud Gazo Tamer Saied Osman
Candida auris (C. auris) is an opportunistic budding yeast that has been identified across 41 countries, including several countries in the Middle East. The increasing global concern stems from the pathogen’s acquired resistance to antifungal drugs and its ability to form biofilms, which allows it to survive on hospital surfaces and medical devices for up to 14 days, compromising infection prevention measures in hospitals. In this report, we present the first (reported) case of C. auris isolated from a urine sample from a 48-year-old female living in Jordan. The patient succumbed to illness five days following admission to hospital. The isolate was identified retrospectively through the national surveillance system in Jordan and was confirmed by real-time PCR. Antifungal susceptibility was carried out using the microbroth dilution technique and the isolate was found to be susceptible to all tested antifungal drugs. Overall, the report emphasizes the need for active surveillance for the rapid identification of high-risk patients colonized with C. auris. It also stresses the importance of understanding the inter-clade difference in the susceptibility pattern of C. auris to facilitate the development of preventive and therapeutic strategies.
]]>Microbiology Research doi: 10.3390/microbiolres14040106
Authors: Benedikte N. Pedersen Andrew Jenkins Katrine M. Paulsen Coraline Basset Åshild K. Andreassen
The tick-borne encephalitis virus (TBEV) is transmitted to humans through tick bites. In recent years, the appearance of the Siberian subtype of TBEV in Ixodes ricinus in Finland, together with deaths from the normally mild European subtype in the same country, have raised concerns about a possible spread of virulent variants of TBEV in Western Europe. Thus, there is a need to monitor the spread of strains, particularly of the European and Siberian subtypes. In this study, we develop a new real-time PCR method targeting Siberian and European subtypes of TBEV. The primers amplify a 176 bp fragment of the E gene, which is suitable for subsequent strain identification by Sanger sequencing. This study pioneers a new approach to primer design where the melting temperature (Tm) of primers annealed to representative mismatched target sequences is empirically determined and used to guide improvements in primer sequence. This allowed the range of TBEV strains detected to be extended to cover most European and Siberian strains tested, in addition to a strain of the Far-Eastern subtype. The limit of detection was 10–100 DNA copies per reaction and amplification efficiency varied between 83% and 94%, depending on the TBEV strain. Experimental determination of primer Tm proved to be a fruitful approach and will be a useful tool for future primer design and diagnostics.
]]>Microbiology Research doi: 10.3390/microbiolres14040105
Authors: Damian López-Peña Heriberto Torres-Moreno Max Vidal-Gutiérrez Ramón Enrique Robles-Zepeda Aldo Gutiérrez Martín Esqueda
The genus Ganoderma has been little studied in arid areas worldwide. Ganoderma subincrustatum and Ganoderma weberianum strains were obtained from the Sonoran Desert, Sonora, Mexico. Ganoderma spp. synthesize triterpenoids such as ganoderic acids with antiproliferative activity because they inhibit specific targets, induce apoptosis, and increase the activity of killer cells. Mycelium and fruiting body chloroform extracts from G. subincrustatum and G. weberianum were tested on HeLa, A549, L-929, and RAW 264.7 cell lines. Extracts from the fruiting body present higher antiproliferative activity than mycelium. All extracts induced vesicle and cellular debris formation in all cell lines, being non-selective for cancerous cells. Chloroform extract from G. subincrustatum fruiting bodies presented higher activity against all cell lines. Fractions F7 and F15 from this extract exhibited an IC50 of 37.9 and 41.9 µg/mL on the A549 cell line, respectively; however, chloroform crude extract showed higher activity (IC50 of <25 µg/mL) in all cell lines. Flow cytometry assays of F7 revealed cell death by apoptosis in A549 cells. NMR suggested the presence of ganoderic acids in F7. In future research, it will be interesting to characterize these fractions (metabolites, their bioactivities, and mechanism of action).
]]>Microbiology Research doi: 10.3390/microbiolres14040104
Authors: Ondrej Zahornacky Štefan Porubčin Alena Rovňáková Ján Fedačko Pavol Jarčuška
Leptospirosis is a zoonotic disease caused by bacteria from the genus Leptospira. The infection occurs mainly in developing countries in the tropical zone and countries with lower hygiene standards. The highest incidence is observed especially in environments associated with the presence of rodents, mainly rats, which are a potential source of infection. The clinical manifestations and severity of leptospirosis are highly variable. This case report describes the a 53-year-old patient (male) without comorbidities, who was admitted to an infectious disease department in the east of Slovakia for jaundice, general fatigue, weakness, and fever (health difficulties for approximately 7 days at home). The clinical laboratory picture of the patient was dominated by significant hyperbilirubinemia, acute renal failure, hepatopathy, severe thrombocytopenia, and involvement of the lung parenchyma in the sense of bilateral interstitial pneumonia on chest X-ray. A double combination of antibiotics (ceftriaxone and clarithromycin) were added to the treatment. During hospitalization, a diagnosis of leptospirosis was suspected based on medical history and the results of laboratory tests and was subsequently confirmed serologically. The antibiotic regimen was de-escalated to cephalosporin (ceftriaxone) monotherapy with adequate laboratory and clinical effects (on the 4th day). The patient was discharged after a total of 18 days in good clinical condition.
]]>Microbiology Research doi: 10.3390/microbiolres14040103
Authors: Luzmaria R. Morales-Cedeño Ignacio A. Barajas-Barrera Fannie I. Parra-Cota Valeria Valenzuela-Ruiz Sergio de los Santos-Villalobos Pedro D. Loeza-Lara Alejandra Herrera-Pérez Ma. del Carmen Orozco-Mosqueda Gustavo Santoyo
Fungal pathogens are the main causal agents of postharvest diseases of fruits and vegetables. To prevent this problem and avoid the use of harmful chemical fungicides, safer and greener alternatives have been sought. One of these alternatives is the use of plant-growth-promoting bacteria (PGPB). In this study, we evaluated in vitro four well-known PGPB strains (Pseudomonas fluorescens UM270, Bacillus toyonensis COPE52, Bacillus sp. E25, and Bacillus thuringiensis CR71) for their biocontrol potential against nineteen postharvest fungal pathogens. In vivo assays were also performed, and bacterial cells were inoculated on harvested strawberries and grapes with the pathogens Botrytis cinerea, Alternaria alternata, and Fusarium brachygibbosum to evaluate loss of firmness and disease incidence. Our results show that the four strains antagonized fungi in direct and indirect confrontation assays. Stronger antagonism was observed by the action of diffusible metabolites (DMs) compared to volatile organic compound (VOC) activity. All PGPB significantly improved the fruit firmness and reduced disease incidence caused by the fungal pathogens tested. However, strain UM270 showed excellent biocontrol activity, reducing the disease incidence of Fusarium brachygibbosum, Botrytis cinerea, and Alternaria alternata on strawberry fruits by 60%, 55%, and 65%, respectively. Diffusible antifungals and VOCs such as 2,4-diacetyl phloroglucinol, siderophores, auxins, fengycins, and N, N-dimethyl-hexadecyl amine, among others, might be responsible for the beneficial activities observed. These results suggest excellent biocontrol activities to inhibit postharvest pathogenic fungi and improve harvested fruit quality.
]]>Microbiology Research doi: 10.3390/microbiolres14040102
Authors: Mohamed Sharaf Eman Jassim Mohammed Eman M. Farahat Amani A. Alrehaili Abdulsalam Alkhudhayri Ahmed Mohamed Ali Abdullah A. Zahra Shadi A. Zakai Amr Elkelish Maha AlHarbi Mai Farag Saad
This study targeted developing a novel Zinc oxide with alpha hematite nanoflowers (NFs)-loaded bee venom (Bv) (Bv-ZnO@αFe2O3 NFs) as a bio-natural product from bees to combine both the advantages of combination magnetic properties and the antimicrobial and anti-biofilm properties on isolated coliform bacteria from the effluent of wastewater treatment plants. About 24 isolates of treated wastewater isolates were multidrug resistant (MDR). The phylogenetic grouping of Escherichia coli (E. coli) and Klebsiella pneumonia (K. pneumonia) showed that the largest group was Group A, followed by Group B2 and Group B1. Fourier transform infrared (FTIR), The X-ray diffraction (XRD), and scanning electron microscopy-energy dispersive X-ray analysis (SEM− EDX) validated the coating operation’s contact with Bv onto ZnO@αFe2O3 NFs. According to high-resolution transmission electron microscopy (TEM) and selected area electron diffraction (SAED), pattern analyses for prepared nanoformulations exhibited a spherical shape of αFe2O3 (~9–15 nm), and floral needle shapes with uniform distribution of size with aggregation of ZnOαFe2O3 and Bv-ZnO@αFe2O3 NFs around (~100–200 nm). The toxicity of Bv-ZnO@αFe2O3 NFs was comparable up to 125 µg mL−1, when it reached 64.79% (IC50, 107.18 µg mL−1). The antibacterial activity showed different zones of inhibition against different isolates. The biofilm inhibitory activity of NPs and NFs showed a highly significant reduction (p < 0.001) in treated biofilms with ZnO@αFe2O3 and Bv-ZnO@αFe2O3. In essence, ZnO@αFe2O3 and Bv-ZnO@αFe2O3 NFs are promising antimicrobials for inhibiting the growth and biofilm of MDR E. coli and K. pneumonia isolates, thereby, biocontrol of wastewater.
]]>Microbiology Research doi: 10.3390/microbiolres14040101
Authors: Midori Kurahashi Angelica Naka Kazuhiko Enokida Yasuhiko Morita
The microalga Dunaliella salina can produce antioxidants such as glutathione, which is an essential and powerful regulator of major cell functions. Changes in the glutathione concentration occur due to a microalga’s response to oxidative stress, which usually occurs when cells are exposed to environmental stressors or reach senescence. This study represents one of the few examples where changes in the glutathione concentration were tracked over the entire growth cycle of an alga. We found significant differences in the glutathione concentration depending on the growth stage. During the early lag growth phase, D. salina had relatively low levels of glutathione (190–280 µmol/1012 cell), which gradually increased as it entered the log phase (280–500 µmol/1012 cell) but then decreased as it entered the stationary phase (320–370 µmol/1012 cell). We also observed that the ratio between the reduced form of glutathione (GSH) and the oxidized form (GSSG) decreased with time, probably as a result of senescence or a lack of nutrients.
]]>Microbiology Research doi: 10.3390/microbiolres14030100
Authors: Ganesh Khadka Thirunavukkarasu Annamalai Kateel G. Shetty Yuk-Ching Tse-Dinh Krish Jayachandran
Microorganisms associated with medicinal plants are of great interest as they are the producers of important bioactive compounds effective against common and drug-resistant pathogens. The characterization and biodiversity of fungal endophytes of the Petiveria alliacea plant and their antimicrobial production potential are of great interest as they are known for their antimicrobial and anticancer properties. In this study, we investigated the endophytic fungal microbiome associated with P. alliacea, and the endophytic fungal isolates were classified into 30 morphotypes based on their cultural and morphological characteristics. Ethyl acetate extract of fungal endophytes was obtained by liquid–liquid partitioning of culture broth followed by evaporation. The crude extract dissolved in dimethyl sulfoxide was screened for antimicrobial activity against three bacterial strains (Escherichia coli ATTC 25902, Staphylococcus aureus ATTC 14775, Bacillus subtilis NRRL 5109) and two fungal strains (Candida albicans ATTC 10231 and Aspergillus fumigatus NRRL 5109). Among the crude extracts from endophytes isolated from leaves, 65% of them showed antimicrobial activity against the bacteria tested. Similarly, 71 and 88% of the fungal crude extracts from endophytes isolated from root and stem, respectively, showed inhibitory activities against at least one of the bacterial strains tested. Crude extracts (at a concentration of 10 mg/mL) from ten of the fungal isolates have shown a zone of inhibition of more than 12 mm against both Gram-positive and negative bacteria tested. Sequenced data from isolates showing strong inhibitory activity revealed that Fusarium solani, F. proliferatum, and Fusarium oxysporium are the major endophytes responsible for bioactive potential. These results indicate that Petiveria alliacea harbors fungal endophytes capable of producing antimicrobial metabolites. Future studies need to focus on testing against drug-resistant bacteria (ESKAPE group) and other pathogenic bacteria and fungi.
]]>Microbiology Research doi: 10.3390/microbiolres14030099
Authors: Yehya Mohsen Nathalie Tarchichi Rana Barakat Inas Kawtharani Rayane Ghandour Zeinab Ezzeddine Ghassan Ghssein
Salmonella enterica (S. enterica) serovars Enteritidis and Typhimurium are the main causes of bacterial gastroenteritis worldwide. This Gram-negative rods bacterium possesses several virulence factors that enable it to survive the host’s nutritional immunity. Toxins and metallophores are among these factors. Heavy metals, in particular, are essential for the survival of all living organisms including bacteria. During infection, S. enterica competes with the host for the available heavy metals by secreting metallophores, which are secondary metabolites. Once produced in the extracellular medium, metallophores complex heavy metals thus allowing Salmonella to acquire metal ions through importing them via channels embedded in their membranes. This review highlights the biosynthesis, export, import, and genetic regulation of different metallophores synthesized by this germ.
]]>Microbiology Research doi: 10.3390/microbiolres14030098
Authors: Basar Karaca Mervi Gursoy Fadime Kiran Vuokko Loimaranta Eva Söderling Ulvi Kahraman Gursoy
Postbiotics offer better properties than probiotics. This study investigated the antimicrobial activity of Lactiplantibacillus plantarum EIR/IF-1 postbiotics against pH-adaptive bacteria, namely Prevotella denticola, Fusobacterium nucleatum, and Streptococcus sanguinis. Cell-free culture media of L. plantarum EIR/IF-1 were used as postbiotics in either crude (acidic) or neutralized form to also understand non-pH-dependent antimicrobial potential. Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and viable cell counts were determined for crude and neutralized postbiotics. Culture media adjusted to different pH values were also compared to adjusted media with postbiotics to understand the strength of organic acids in postbiotics. Antibiofilm activity of postbiotics was determined against polymicrobial biofilm formation. Finally, the toxicity of crude postbiotics was tested on human periodontal ligament fibroblast cells (hPDLFCs). MIC values of crude postbiotics were 12.5 mg/mL for all strains. F. nucleatum and P. denticola strains were sensitive to neutralized postbiotics after 48 h of incubation. Moreover, 12.5 and 25 mg/mL postbiotics inhibited biofilm formation and 2.5 mg/mL and lower concentrations of crude postbiotics showed no cytotoxicity in hPDLFCs. This study showed that postbiotics have antimicrobial activity against pH-adaptive oral bacteria and no cytotoxic effect on hPDLFCs depending on the dose. The non-acidic antimicrobial components of postbiotics could also enable their safe use in the oral cavity.
]]>Microbiology Research doi: 10.3390/microbiolres14030097
Authors: Peiyan Sun Yaqiong Yang Hongxing Cheng Shulin Fu Yulan Liu Yinsheng Qiu Hongbo Chen Jing Zhang Huanhuan Zhou Liangyu Shi Hongyan Ren Zhe Chao Ling Guo
Glaesserella parasuis (G. parasuis) can elicit meningitis in pigs; however, the pathogenic mechanisms of meningitis induced by G. parasuis remain unclear. Long non-coding RNAs (lncRNAs) have been proven to play key roles in a variety of physiological and pathological processes. However, whether lncRNAs are involved in meningitis triggered by G. parasuis has not been investigated. In this study, we performed an integrative analysis of lncRNAs expression profiles in the porcine brain infected with G. parasuis using RNA-seq. The results showed that lncRNA expressions in G. parasuis-induced meningitis were modified, and a total of 306 lncRNAs exhibited significant differential expression, in which 176 lncRNAs were up-regulated and 130 lncRNAs were down-regulated. KEGG enrichment analysis demonstrated that the differentially expressed target mRNAs of affected lncRNAs in G. parasuis-infected porcine brain were mainly involved in the cell adhesion molecules (CAMs), Jak-STAT signaling pathway, PI3k-Akt signaling pathway, and TNF signaling pathway. The expression relationship between the most affected differential lncRNAs and their differential target mRNAs was visualized by a co-expression network. A protein-protein interaction network consisting of 12 differential targets was constructed using STRING analysis. In addition, differential expressions of important lncRNAs were validated by qRT-PCR. lncRNA ALDBSSCT0000007362, ALDBSSCT0000001959, ALDBSSCT0000005529, MSTRG.2939.1, and MSTRG.32374.1 showed the same expression pattern with the lncRNA sequencing data. Our results demonstrated that G. parasuis could modify the lncRNA expression profiles in the porcine brain. To the best of our knowledge, this is the first report revealing the integrative analysis of lncRNA expression profiles in G. parasuis-induced meningitis, which could enhance important information to understand the inflammatory functions of lncRNAs involved in swine meningitis, and also provide a foundation for finding out novel strategies to prevent and treat meningitis in piglets triggered by G. parasuis.
]]>Microbiology Research doi: 10.3390/microbiolres14030096
Authors: Joseph Antony Sundarsingh Tensingh Vijayalakshmi Shankar
The overconsumption of energy results in the depletion of fossil fuels. Generally, biodiesels are produced from wastes of animal fats and vegetable oils. In this study, we have tried to produce biodiesel from both the wild strain and ion beam mutated strain and compared the concentration of lipids produced from both the strains and their properties. Lipids were extracted from microbes using the Bligh and Dyer method and analyzed using gas chromatography and mass spectrophotometry (GCMS) and Fourier-transform infrared (FTIR) spectroscopy. Extracted lipids (free fatty acids) were converted into biodiesel (fatty acid methyl esters) using a base catalyst. The end product biodiesel was characterized and analyzed based on ASTM standards.
]]>Microbiology Research doi: 10.3390/microbiolres14030095
Authors: Eman A. Alhomaidi Aisha Umar Salam S. Alsharari Sami Alyahya
In the present study, we investigated the effects of different carbon sources (glucose, sucrose, and maltose) on laccase production from mycelium of Ganoderma multistipitatum grown on malt extract agar plates. The preliminary screening test was performed on the guaiacol plate, where a maroon brown zone formed after laccase oxidation. A few pure mycelial discs of Ganoderma species were transferred into submerged fermentation nutrient broth. The nutrient medium of submerged fermentation at 20 g of glucose revealed the highest laccase activities (2300 U/L) than other carbon sources. The interesting results also shown by inorganic NaNO3 in the production of maximum laccase (7800 ± 1.1 U/L). The organic nitrogen inducer, namely yeast extract, exhibited 5834 U/L laccase activity and a potential source of laccase secretion. The results concluded that C and N inducers enhanced the laccase production. This production process is eco-friendly and effective in the removal of dye from water. Laccase from the cultural broth was partially purified by SDS-PAGE for molecular weight determination, while Native-PAGE confirmed the laccase band after staining with guaiacol. The Km and Vmax values of Lacc134 were 1.658 mm and 2.452 mM min−1, respectively. The Lacc134 of this study effectively removed the Remazol Brilliant Blue R (RBBR) dye (extensively used in textile industries and wastewater). For dye removal capacity, 2.0 mg, 4.0 mg, 5.0 mg, and 6.0 mg were used, from which 6.0 mg was most effective in removal (85% and 88%) dye concentration in 1st and 2nd h interval treatment, respectively. Total organic carbon (TOC) quantity after dye removal percentage in the first- and second-hour time interval was 62% and 89%, respectively, at 30 g glucose. According to the experimental finding of this study, the breakdown products catalyzed by Lacc134 are less hazardous due to lower molecular weight than the dye itself.
]]>Microbiology Research doi: 10.3390/microbiolres14030094
Authors: Pietro Crispino
Clostridioides difficile is a bacterium responsible for a healthcare-associated gastrointestinal infection, primarily affecting people who have undergone prolonged antibiotic treatment or who have compromised immune systems. The CD is of particular concern due to its high recurrence rates and the potential for serious outcomes, including life-threatening conditions such as pseudomembranous colitis, septic shock, and all associated conditions. Since this infection is a disease associated with other health conditions, a general vision of the problems is necessary which aims to obtain a general overview of the manifestations that generally correlate with care. Clinical reasoning following the disease-clustering method is able to produce a categorization process by grouping the possible correlations of the various conditions or factors underlying diseases on the basis of certain similarities or common models. The clustering process is performed using data analysis techniques which, by statically correlating each other, give an exact dimension of all the information related to a particular disease. In the case of CD, reasoning based on disease clustering has better clarified the practices, appropriateness in infection control, judicious use of antibiotics, and research into therapeutic and preventive strategies. This review, taking advantage of the clustering strategy, aimed to analyze the contingent conditions of the infection under examination, to reduce the incidence and impact of CD, having as its mission the improvement of the results deriving from the contrast of all those correlated pathological conditions to healthcare for the improvement of public health.
]]>Microbiology Research doi: 10.3390/microbiolres14030093
Authors: Erick De La Torre Tarazona Daniel Jiménez Daniel Marcos-Mencía Alejandro Mendieta-Baro Alejandro Rivera-Delgado Beatriz Romero-Hernández Alfonso Muriel Mario Rodríguez-Domínguez Sergio Serrano-Villar Santiago Moreno
The susceptibility to SARS-CoV-2 infection and the severity of COVID-19 manifestations vary significantly among individuals, prompting the need for a deeper understanding of the disease. Our objective in this study was to investigate whether previous infections with human common cold coronaviruses (hCCCoV) might impact susceptibility to and the progression of SARS-CoV-2 infections. We assessed the serum antibody levels against SARS-CoV-2 and four hCCCoV (H-CoV-OC43, -NL63, -HKU1, and -229E) in three distinct populations: 95 uninfected individuals (COVID-19-negative), 83 individuals with mild or asymptomatic COVID-19 (COVID-19-mild), and 45 patients who died due to COVID-19 (COVID-19-severe). The first two groups were matched in terms of their exposure to SARS-CoV-2. We did not observe any differences in the mean antibody levels between the COVID-19-mild and the COVID-19-negative participants. However, individuals in the COVID-19-mild group exhibited a higher frequency of antibody levels (sample/control) > 0.5 against H-CoV-HKU1, and >1 against H-CoV-229E and -OC43 (p < 0.05). In terms of severity, we noted significantly elevated H-CoV-NL63 IgG levels in the COVID-19-severe group compared to the other groups (p < 0.01). Our findings suggest a potential mild influence of hCCCoV antibody levels on the susceptibility to SARS-CoV-2 infection and the severity of COVID-19. These observations could aid in the development of strategies for predicting and mitigating the severity of COVID-19.
]]>Microbiology Research doi: 10.3390/microbiolres14030092
Authors: Deng-Hai Chen Jian-Yuan Wang Mon-Tarng Chen Yen-Chun Liu Kuang-Dee Chen
(1) Background: Ganoderic acids (GAs) are specific triterpenes of Ganoderma lucidum. The HPLC fingerprint profile of GAs of the fruiting body is well known, but their mycelial fingerprinting remains unclear. (2) Methods: An ethanol extract of the mycelium of G. lucidum (YK-01) was further purified via preparative HPLC. The triterpenoid compositions for four strains of G. lucidum and one strain of G. formosanum (purple lingzhi) were analyzed using HPLC. (3) Results: Nineteen lanostane triterpenes, including five new triterpenes, GA-TP (1), ganodermic acid Jc (GmA-Jc) (2), GmA-Jd (3), GA-TQ1 (4), and ganoderal B1 (5), and fourteen known triterpenes 6–19 were isolated from the ethanol extract. Their structures were identified by mass and extensive NMR spectroscopy. A green chemical HPLC analytical method was developed using ethanol and acetic acid as a mobile phase, and all isolated compounds can be well separated. These triterpenes comprise a unique HPLC chromatograph of the G. lucidum mycelium. All four G. lucidum strains showed the same HPLC chromatographic pattern, whereas G. formosanum displayed a different pattern. Quantitation methods for ganoderic acid T (10) and S (12) were also validated. (4) Conclusions: The triterpenoid HPLC analytical method can be used to identify the G. lucidum species and to determine the contents of GA-T and GA-S.
]]>Microbiology Research doi: 10.3390/microbiolres14030091
Authors: Monika Beinhauerova Monika Moravkova Ruzena Seydlova Magdalena Crhanova
The achlorophyllous unicellular microalga of the genus Prototheca, a causative agent of bovine mammary gland infection, is receiving increasing attention in the field of veterinary medicine. Mastitis caused by these algae leads to significant economic losses for farmers worldwide and represents a source of threat to raw milk quality and dairy food-chain safety. This case report describes an outbreak of bovine mastitis in dairy cattle caused by Prototheca bovis and the on-farm practices that resulted in the recovery of the affected herd and elimination of the presence of Prototheca spp. in the farm environment. Effective management strategies that played a crucial role in protothecosis eradication included regular screening, timely identification, strict separation of Prototheca-positive cows, a change of housing regime associated with the utilisation of straw mattresses and removal of deep bedding and, finally, the introduction of intermediate disinfection of teat cups with peracetic acid to prevent the spread of infection to other healthy individuals. The eradication process lasted approximately three years and required the removal of 139 cows from the farm. The corrective and preventive measures described in this case report provide guidance to farmers on how to successfully deal with protothecal mastitis on farms.
]]>Microbiology Research doi: 10.3390/microbiolres14030090
Authors: Pin Chen Geng Wang Jiping Chen Weichao Zhang Yin He Ping Qian
Both porcine circovirus (PCV) and porcine parvovirus (PPV) cause various diseases and bring huge economic losses to the global swine industry. PCV2 is associated with several diseases and syndromes, including postweaning multisystemic wasting syndrome (PMWS), porcine dermatitis and nephropathy syndrome (PDNS) and porcine respiratory disease complex (PRDC). The classical PPV is one of the most common causes of reproductive failure in pigs. In this study, tissue samples (tonsil, lung, mesenteric lymph node, hilar lymph node and superficial inguinal lymph node) were collected from pigs with suspected PCV2-associated disease (PCVAD), and viral DNA was extracted. The coinfection of PCV2 and PPV1–5 was detected using the polymerase chain reaction (PCR) method. Phylogenetic analysis based on capsid genes of PCV2, PPV2, PPV3 and PPV5 was conducted. The prevalence rates of PCV2, PPV1, PPV2, PPV3, PPV4 and PPV5 were 51.2%, 15.9%, 36.6%, 19.5%, 14.6% and 10.9% on the individual pig level, respectively. The coinfection rates of PCV2 with PPV1, PPV2, PPV3, PPV4 and PPV5 were 8.5%, 25.6%, 17.1%, 13.4% and 3.7%, respectively. The prevalence of PPV2, PPV3 and PPV4 in PCV2-positive pigs was significantly higher than those in PCV2-negative pigs. Phylogenetic analyses were performed using the neighbor-joining (NJ) method with 1000 bootstraps. The results indicated the existence of PCV2d and two major clusters of PPV2, PPV3 and PPV5 in the Guangxi Autonomous Region. PCV2d was the dominant strain, and the novel PPVs were circulating in domestic pigs in the Guangxi Autonomous Region. The results of this study underline the importance of active surveillance of PCV2d and PPVs from the swine population in this area.
]]>Microbiology Research doi: 10.3390/microbiolres14030089
Authors: Davide Buzzanca Elisabetta Chiarini Ilaria Mania Francesco Chiesa Valentina Alessandria
The presence of foodborne pathogens in meat is linked to several contamination sources, and the slaughterhouse environment represents a relevant reservoir of contamination. Aureimonas altamirensis is a Gram-negative bacteria associated with different isolation sources, including human clinical cases. This study aims to identify and characterize an A. altamirensis isolate from chicken guts collected in an Italian slaughterhouse. The study approach includes whole-genome analysis jointly with phenotypical tests. Whole-genome sequencing (WGS) confirms the initial MALDI-TOF MS identification, finding putative virulence and biofilm-related genes. Moreover, the gene class evaluation reveals that the numerically largest gene category in the A. altamirensis genome is related to amino acid metabolism and transport. The analyses performed on a human gut mucus-producing cell line (HT29-MTX-E12) demonstrated the ability of A. altamirensis to colonize the host cell layer. Moreover, the antibiotic resistance test showed a high resistance of A. altamirensis to gentamicin (MIC 0.5 mg/L). The detection of a potential pathogenic and antibiotic-resistant A. altamirensis strain isolated from a slaughterhouse underlines the necessity of active surveillance studies focused on this species and the need for further studies about A. altamirensis in foods.
]]>Microbiology Research doi: 10.3390/microbiolres14030088
Authors: Nadia Lombardi Angela Pironti Gelsomina Manganiello Roberta Marra Francesco Vinale Stefania Vitale Matteo Lorito Sheridan Lois Woo
Nine isolates of Trichoderma were obtained from the diverse phases of compost preparation and the production of different commercial varieties of oyster mushrooms Pleurotus spp. with the apparent presence of green mould disease. The isolates were morphologically and genetically characterized. Molecular fingerprinting indicated that the isolates belonged to the species T. pleuroticola and T. harzianum. In order to identify control measures, changes in temperature, pH, and application of fungicides were tested on the present isolates, using known Trichoderma biocontrol strains as a reference. Fungicide effects on the growth of Pleurotus isolates were also assessed. The optimal growth temperatures were 25 °C for Trichoderma isolates and 28 °C for Pleurotus isolates, and Trichoderma always grew faster than Pleurotus. In particular, a reduction of about 30% was recorded for some of the Trichoderma isolates when comparing the colony growth at 25 and 28 °C. Trichoderma isolates developed well within a wide pH range, with the best growth occurring between pH 5 and 7, whereas Pleurotus preferred more alkaline conditions (pH 8 to 9). Prochloraz and metrafenone were found to inhibit Trichoderma growth with different dose responses that did not affect the growth of Pleurotus spp. In particular, metrafenone was the most effective active ingredient that inhibited the majority of the Trichoderma isolates (1–25% growth reduction).
]]>Microbiology Research doi: 10.3390/microbiolres14030087
Authors: Vijaya Samoondeeswari Selvarajan Ramganesh Selvarajan Jeevan Pandiyan Akebe Luther King Abia
The rising concerns regarding antibiotic resistance and the harmful effects of synthetic preservatives have led to an increasing interest in exploring natural alternatives. Plant oils have been traditionally used for their antimicrobial properties, but systematic investigations into their efficacy against foodborne pathogens are necessary for potential applications in food preservation. This study aimed to evaluate the antibacterial potential of various plant oils (neem, coconut, castor, and olive oil) against common foodborne pathogens and analyze their chemical composition using gas chromatography–mass spectrometry (GC-MS). The oils were tested against foodborne pathogens using the disk diffusion method. Minimum inhibitory concentrations (MICs) were determined to assess the potency of the oils. GC-MS was employed to identify the compounds present in each oil. Neem oil exhibited significant antibacterial activity against all tested pathogens, with pronounced effects against Staphylococcus aureus and Bacillus cereus. Coconut oil showed notable activity against Listeria monocytogenes. Castor oil displayed moderate activity, while olive oil exhibited minimal antibacterial effects. The GC-MS analysis revealed a diverse array of compounds in neem oil, which is likely to contribute to its potent antibacterial properties. Neem and coconut oils, owing to their rich bioactive components, emerged as promising candidates for the development of natural antimicrobial agents. These brief findings support the potential application of plant oils in food preservation and emphasize the need for further research into understanding the underlying mechanisms and optimizing their use.
]]>Microbiology Research doi: 10.3390/microbiolres14030086
Authors: Rima Biswas Nick Pinkham Seth T. Walk Qian Wang Shrikant Ambalkar Ashish R. Satav Mark H. Wilcox Rahul Reghunath Kiran Chawla Padmaja A. Shenoy Amit R. Nayak Aliabbas A. Husain Dhananjay V. Raje Rajpal Singh Kashyap Tanya M. Monaghan
This prospective observational cohort study aimed to establish and compare baseline rates of Clostridioides difficile infection (CDI) in community and hospitalized patients in Nagpur and rural Melghat Maharashtra, including adults aged ≥18 years with a diagnosis of diarrhoea as defined as 3 or more loose stools in a 24 h period. All diarrhoeal samples were tested for CDI using the C. diff Quik Chek Complete enzyme immunoassay. C. difficile-positive stool samples were characterised by toxigenic culture, antimicrobial susceptibility testing and PCR ribotyping. C. difficile testing was performed on 1683 patients with acute diarrhoea. A total of 54 patients (3.21%; 95% CI: 2.42–4.17) tested positive for both the GDH antigen and free toxin. The risk factors for CDI included the presence of co-morbidities, antibiotic usage, and immunosuppression. The detected PCR ribotypes included 053-16, 017, 313, 001, 107, and 216. Our findings show that toxigenic C. difficile is an important but neglected aetiologic agent of infective diarrhoea in Central India. These results underscore the need to enhance the awareness and testing of patients with diarrhoea in India regarding the presence of toxigenic C. difficile, particularly in high-risk individuals with multiple co-morbidities, immunosuppression, and recent or ongoing antibiotic exposure or hospitalization.
]]>Microbiology Research doi: 10.3390/microbiolres14030085
Authors: Mohamed Husain Syed Abuthakir V. Hemamalini Reham M. Alahmadi Anis Ahamed Ashraf Atef Hatamleh Razack Abdullah Jeyam Muthusamy
Microsporum gypseum is a dermatophyte with a geophilic nature that is found all over the globe. It mainly causes tinea in the scalp, arms, and legs in humans. Squalene epoxidase (SE) is a crucial enzyme in M. gypseum for the biosynthesis of ergosterol. The medicinal plant Balanites aegyptiaca is an abundant supply of secondary constituents with great therapeutic values. In this research, the fruit epicarp portion was used to inhibit M. gypseum using experimental and computational techniques. The anti-dermatophytic activity of epicarp extracts on M. gypseum was evaluated using the poison plate method at five different concentrations. At 3 mg/mL, the M. gypseum was completely controlled by the fractioned chloroform extract of epicarp. The compounds from previous research were utilized for docking studies (Abuthakir et al., 2022). The ideal compounds and the drug terbinafine were then docked using Schrödinger’s Glide module. It demonstrates that (3E)-7-Hydroxy-3,7-dimethyl-3-octen-1-yl-6-O-(6-deoxy-alpha-L-mannopyranosyl)-beta-D-glucopyranoside outperforms other substances and the drug terbinafine in docking analysis. Desmond, Schrödinger Molecular Dynamics simulations were also performed for (3E)-7-Hydroxy-3,7-dimethyl-3-octen-1-yl-6-O-(6-deoxy-alpha-L-mannopyranosyl)-beta-D-glucopyranoside-squalene epoxidase complexes. The complex appears to be more stable, according to the MD simulation research. This study indicates that (3E)-7-Hydroxy-3,7-dimethyl-3-octen-1-yl-6-O-(6-deoxy-alpha-L-mannopyranosyl)-beta-D-glucopyranoside could be used as a potential inhibitor of M. gypseum growth, and it could be studied further.
]]>Microbiology Research doi: 10.3390/microbiolres14030084
Authors: Veronika Řezáčová Ema Némethová Iva Stehlíková Alena Czakó Milan Gryndler
Arbuscular mycorrhizal fungi (AMF) improve plant growth and may be useful in maintaining and even restoring soil. However, data on the latter function are sparse and only indirect, which is especially true for conventional management conditions with adequate nutrient availability. Our study focused on utilizing the prevalent AMF species, Funneliformis mosseae, to enhance Glycine max production, while also exploring its partly explored impact on soil aggregation. Working in greenhouse conditions, we examined whether, in a nutrient-sufficient environment, AMF would improve crop biomass accumulation and nutrition, as well as the stability of soil aggregates (SAS). We also looked for a synergistic effect of dual inoculation using AMF and symbiotic rhizobium. Plants were or were not inoculated with AMF or Bradyrhizobium japonicum in a two-factorial design. AMF inoculation increased soybean biomass, but AMF inoculation had no impact on P and N input to the shoots. Mycorrhiza did not affect either glomalin abundance or SAS. All the impacts were, however, independent from rhizobial inoculation, which was ineffective in this nutrient-available environment. Our assay suggests that arbuscular mycorrhiza may have a positive effect on soybean growth even under conventional management with adequate nutrition. The positive effects of AMF on soybean growth, together with the fact that AMF generally do not thrive in good nutrient availability, should be taken into account when planning mineral fertilization levels.
]]>Microbiology Research doi: 10.3390/microbiolres14030083
Authors: Shaimaa S. Sobieh Shereen A. H. Mohamed Manal A. El-Sayed Soad A. Abdallah
Background Antimicrobial resistance has become one of the most widespread threats to humans. Acinetobacter baumannii is one of the pathogens responsible for healthcare-associated infections (nosocomial). Colistin is considered the last resort antibiotic against infections with pandrug-resistant (PDR) pathogens. Results: Eleven isolates were detected phenotypically as PDR A. baumannii and were confirmed molecularly using 16S rDNA. The MCR-1 gene was not detected within the chromosomal DNA of the selected isolates. Plasmid bearing the MCR-1 gene was identified in 10 selected isolates of A. baumannii that had not been previously observed to carry the MCR-1 gene. Moreover, the use of colistin in combination with anionic antibiotics or natural compound pterostilbene poses a viable therapeutic alternative for PDR and revives colistin’s bactericidal effects on MCR-1-positive A. baumannii. Finally, the transmission electron microscopy studies proved the synergistic effect of these combinations and revealed the disruption of resistant A. baumannii’s outer membrane and alteration of the permeability properties that allowed overcoming the resistance of the isolates to colistin. Conclusions: Antimicrobial resistance of A. baumannii is related to the presence of the transferable plasmid-bearing MCR-1 gene. This study proved the ability of the combinations of colistin with anionic antibiotics and/or natural compound pterostilbene to restore the bactericidal effect of colistin. Overall, these combinations could be novel promising clinical alternatives against the increasing threat of the widespread multidrug-resistant A. baumannii.
]]>Microbiology Research doi: 10.3390/microbiolres14030082
Authors: Mariem Chamtouri Abderrahmen Merghni Naoufel Gaddour Maha Mastouri Silvia Arboleya Clara G. de los Reyes-Gavilán
Alterations in faecal lactobacilli in autistic children have been reported, but little is known related to age and disorder severity. We used a culture-based method and partial 16S rRNA gene sequencing to isolate and identify lactobacilli strains from faeces of Tunisian autistic children (ASD group) and compared them with strains isolated from siblings (SIB) and children from the general population (GP). The ASD group displayed an increased number of different species compared to SIB and GP. Differences in species abundance with age accounted for a significant decrease in the abundance of Lactiplantibacillus plantarum/Lactiplantibacillus pentosus isolates in the GP at the age of 8–10 years compared to the age of 4–7 years, and to a significantly lower abundance of Lacticaseibacillus rhamnosus in the ASD group with respect to SIB and the GP at the age of 8–10 years. Simpson’s and Shannon–Wiener indices showed a more pronounced species diversity increase with age in the GP group compared to the ASD and SIB groups. Minor differences were found in lactobacilli prevalence and in species diversity between children with severe and mild-to-moderate ASD. Overall, we found substantial differences in the profile of faecal lactobacilli species in the ASD and GP groups at the age of 8–10 years.
]]>Microbiology Research doi: 10.3390/microbiolres14030081
Authors: Sang-Mo Kang Arjun Adhikari Yu-Na Kim In-Jung Lee
Drought has severely impacted worldwide agricultural land, resulting in substantial yield loss and abiotic pressures in crops such as Chinese cabbage. Paclobutrazol (PBZ) and plant growth-stimulating bacteria have been extensively recommended to reduce a variety of stresses in crops. Considering these facts, we used PBZ and rhizobacterium Variovorax sp. YNA59, a microbe with potential plant growth-stimulating qualities, in Chinese cabbage under drought stress and non-stressed conditions, and we observed their impacts on morphological and physiological attributes. Our findings revealed a considerable improvement in total plant biomass growth after treatment with YNA59 (28%) and PBZ (8%) under drought conditions. In contrast, negative results of PBZ were observed under normal conditions, suppressing plant growth and reducing plant biomass. The increase in physiological parameters, such as chlorophyll content, relative water content, and photochemical efficiencies of PS II, were observed in YNA59-treated plants, followed by PBZ, especially under drought. Furthermore, drought stress significantly increased the endogenous phytohormone abscisic acid level, whereas PBZ and YNA59 inoculations significantly decreased it. Antioxidant analysis revealed that PBZ and YNA increased glutathione and catalase and decreased polyphenol oxidase and peroxidase levels. These findings suggested that rhizobacterium YNA59 could be more significant for conferring water stress in the Chinese cabbage plant than PBZ.
]]>Microbiology Research doi: 10.3390/microbiolres14030080
Authors: Hideyuki Suzuki Kazuki Nishida Tatsuya Nakamura
The goal of this study was to produce a sufficient amount of glutathione in the fermentation medium without the addition of cysteine. This would simplify and reduce the cost of its purification. In addition to reducing the cost of cysteine, it also avoids the inhibition of bacterial growth by cysteine. The gshA, gshB, and cysE genes of Escherichia coli were cloned under the control of the strong T5 promoter of the pQE-80L plasmid and introduced into an E. coli strain knocked out for the genes encoding γ-glutamyltranspeptidase and the GsiABCD glutathione transporter, which are responsible for the recycling of excreted glutathione. The overexpression of the gshA and gshB genes, genes for γ-glutamylcysteine synthetase and glutathione synthetase, and the cysEV95R D96P gene, a gene for serine acetyltransferase with the V95R D96P mutation that makes it insensitive to cysteine, were effective on glutathione production. Na2S2O3 was a good sulfur source for glutathione production, while the addition of Na2SO4 did not affect the glutathione production. With the addition of 50 mM glutamic acid and 75 mM glycine, but without the addition of cysteine, to the simplified SM1 medium, 4.6 mM and 0.56 mM of the reduced and oxidized glutathione, respectively, were accumulated in the extracellular space after 36 h of batch culture. This can eliminate the need to extract glutathione from the bacterial cells for purification.
]]>Microbiology Research doi: 10.3390/microbiolres14030079
Authors: Pengfei Gu Shuo Zhao Chengwei Li Shuixing Jiang Hao Zhou Qiang Li
L-phenylalanine is an important aromatic amino acid that is widely used in the area of feed, food additives, and pharmaceuticals. Among the different strategies of L-phenylalanine synthesis, direct microbial fermentation from raw substrates has attracted more and more attention due to its environment friendly process and low-cost raw materials. In this study, a rational designed recombinant Escherichia coli was constructed for L-phenylalanine production. Based on wild type E. coli MG1655, multilevel engineering strategies were carried out, such as directing more carbon flux into the L-phenylalanine synthetic pathway, increasing intracellular level of precursors, blocking by-product synthesis pathways and facilitating the secretion of L-phenylalanine. During 5 L fed batch fermentation, recombinant E. coli MPH-3 could produce 19.24 g/L of L-phenylalanine with a yield of 0.279 g/g glucose. To the best of our knowledge, this is one of the highest yields of L-phenylalanine producing E. coli using glucose as the sole carbon source in fed-batch fermentation.
]]>Microbiology Research doi: 10.3390/microbiolres14030078
Authors: Gerardo Ávila-Torres Gabriela Rosiles-González Victor Hugo Carrillo-Jovel Gilberto Acosta-González Eduardo Cejudo-Espinosa Daniela Ortega-Camacho Cecilia Hernández-Zepeda Oscar Alberto Moreno Valenzuela
The eutrophication of freshwater ecosystems allows the proliferation of cyanobacteria that can produce secondary metabolites such as microcystins. The main aim of this study was to explore the occurrence and concentration of microcystin and the mcyA gene in water bodies located in agricultural, urban, and recreational areas in the karst aquifer of the Yucatan peninsula of Mexico (YPM) and to analyze the water quality variables and chlorophyll-a (Chl-a) associated with their presence. Water samples were collected from 14 sites, and microcystin concentrations were quantified using antibody-based ELISA test. Total DNA was isolated from filters and used for PCR amplification of a fragment of the mcyA gene. Amplicons were cloned and sequenced to identify toxin-producing cyanobacteria present in water. Results showed that water bodies had different trophic status based on Carlson’s trophic state index. Dissolved inorganic nitrogen (DIN: NH4+ + NO3− + NO2−) and P-PO43− concentrations were within a range of 0.077–18.305 mg DIN/L and 0.025–2.5 mg P-PO43−/L, respectively, per sampled site. All sampled sites presented microcystin concentrations within a range of ≥0.14 µg/L to ≥5.0 µg/L, from which 21.4% (3/14) exceeded the limit established in water quality standards for water consumption (1 µg/L). The mcyA gene fragment was detected in 28.5% (4/14) of the sites. A total of 23 sequences were obtained from which 87% (20/23) shared >95% nucleotide identity (nt) with the genus Microcystis and 13% (3/23) shared >87% nt identity with uncultured cyanobacteria. No correlation with the presence of the mcyA gene and microcystins was found; however, a positive correlation was detected between microcystin concentrations with pH and Chl-a.
]]>Microbiology Research doi: 10.3390/microbiolres14030077
Authors: Laura Morante-Carriel Fernando Abasolo Carlos Bastidas-Caldes Erwin A. Paz Rodrigo Huaquipán Rommy Díaz Marco Valdes David Cancino Néstor Sepúlveda John Quiñones
The aim of this study was to characterize lactic acid bacteria (LAB) isolated from cocoa mucilage and beef and evaluate their inhibitory effect in vitro against pathogenic bacteria, as well as determine their effect on beef quality. For the antagonist assay, 11 strains of LAB were selected and tested against pathogenic strains of Escherichia coli and Salmonella sp. The pathogenic bacteria were cultured in a medium, and a previously reactivated LAB bacterial pellet was added. After incubation, halos were observed around the bacterial colonies of the pathogenic strains, indicating inhibition by the LAB. It was identified that the LAB strains used belonged to the genus Lactobacillus, and the CCN-5 strain showed high percentages of inhibition against Salmonella sp. (58.33%) and E. coli (59%). The effectiveness of LAB application methods (immersion, injection, and spraying) did not present statistical differences. Furthermore, no significant changes in the physicochemical characteristics of beef were observed after the application of LAB. The results obtained demonstrate the potential of cocoa mucilage, as a biological control agent through LAB application, for beef biopreservation due to its ability to inhibit the growth of pathogenic bacteria.
]]>Microbiology Research doi: 10.3390/microbiolres14030076
Authors: Warin Intana Prisana Wonglom Kim Sreang Dy Anurag Sunpapao
Stem canker on dragon fruit caused by Neoscytalidium dimidiatum causes severe losses in production of this fruit worldwide. Biological control by Trichoderma species is widely used to control several plant diseases. However, environmental conditions affect the use of biocontrol agents in the field. The development of a new formulation may offer an alternative way to address the problem of stem canker on dragon fruit caused by N. dimidiatum. In this study, we sought to develop a Trichoderma asperelloides PSU-P1 formulation that would be effective against N. dimidiatum. Three vegetable oils, two emulsifier-dispersing agents (Tween 20 and Tween 80), and one source of carbon (dextrose) were tested for carrier additives. We assessed the viability and antifungal ability of formulations incubated at ambient temperature and at 10 °C during a storage period of 1–6 months. The formulation composed of coconut oil, DW, and tween 20 in a ratio of 30:60:10 required a mixing time of 1.14 min; this was significantly faster than the mixing times of other formulations. Application of this formulation suppressed canker development; a canker area of 0.53 cm2 was recorded, compared with a control (pathogen only) area of 1.65 cm2. In terms of viability, this formulation stored at ambient temperature showed a surface area percentage of T. asperelloides PSU-P1 ranging from 64.43 to 75.7%; the corresponding range for the formulation stored at cool temperature was 70.59–75.6%. For both formulations, percentage inhibition gradually decreased from 1 to 6 months, with ranges of 59.21–77% and 60.65–76.19% for formulations incubated at ambient and cool temperatures, respectively. Our findings suggest that the formulation developed in this study prolongs the viability of T. asperelloides PSU-P1 conidia by up to 6 months, effectively inhibits N. dimidiatum in vitro, and reduces stem canker in vivo.
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