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Microorganisms, Volume 12, Issue 5 (May 2024) – 191 articles

Cover Story (view full-size image): Plasmids are mobile DNA elements actively exchanged among microorganisms. As mobile elements, they can carry genes associated with the production of secondary metabolites that enhance fitness and survival of the microbes acquiring them. The presence of plasmid-borne biosynthetic gene clusters of secondary metabolites was investigated in prokaryotic metagenome-assembled genomes (MAGs) from the geochemically stratified water column of the Cariaco Basin off Venezuela’s coast. Acquired and integrated terpene-biosynthetic genes and genes for the production of ribosomal and non-ribosomal peptides were found in archaeal and bacterial MAGs. While this mode of horizontal gene transfer may promote the cosmopolitan distribution of the taxa acquiring them, their ecological and evolutionary significance in oxygen-depleted water columns remains largely unexplored. View this paper
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12 pages, 712 KiB  
Article
Identifying Mortality Predictors in Hospitalized COVID-19 Patients: Insights from a Single-Center Retrospective Study at a University Hospital
by Ondrej Zahornacky, Alena Rovnakova, Maria Surimova, Stefan Porubcin and Pavol Jarcuska
Microorganisms 2024, 12(5), 1032; https://doi.org/10.3390/microorganisms12051032 - 20 May 2024
Viewed by 301
Abstract
Introduction: The pandemic instigated by the SARS-CoV-2 virus has led to over 7 million deaths globally, primarily attributable to viral pneumonia. Identifying fundamental markers associated with an elevated risk of mortality can aid in the early identification of patients prone to disease progression [...] Read more.
Introduction: The pandemic instigated by the SARS-CoV-2 virus has led to over 7 million deaths globally, primarily attributable to viral pneumonia. Identifying fundamental markers associated with an elevated risk of mortality can aid in the early identification of patients prone to disease progression to a severe state, enabling prompt intervention. Methods: This was a single-center, retrospective study. Results: In this study, we examined 299 patients admitted to the Department of Infectology and Travel Medicine in Košice, Slovakia, with PCR-confirmed COVID-19 pneumonia. Patients were monitored from 1 January 2021 to 31 March 2021, with the endpoint being discharge from the hospital or death. All patient-related data were retrospectively collected from medical records. This study identified several risk factors significantly associated with an increased risk of mortality, including the requirement of HFNO (p < 0.001), age over 60 years (p < 0.001), Ne/Ly values of >6 (p < 0.001), as well as certain lymphocyte subtypes—CD4+ < 0.2 × 109/L (p = 0.035), CD8+ < 0.2 × 109/L (p < 0.001), and CD19+ < 0.1 × 109/L (p < 0.001)—alongside selected biochemical inflammatory markers—IL-6 > 50 ng/L (p < 0.001) and lactate > 3 mmol/L (p < 0.001). Conclusions: We confirmed that the mentioned risk factors were significantly associated with the death of patients from viral pneumonia in the hospital. Full article
(This article belongs to the Special Issue Advances in SARS-CoV-2 Infection—Third Edition)
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40 pages, 2035 KiB  
Review
Expanding the Spectrum of Diseases and Disease Associations Caused by Edwardsiella tarda and Related Species
by J. Michael Janda and Muhammed Duman
Microorganisms 2024, 12(5), 1031; https://doi.org/10.3390/microorganisms12051031 - 20 May 2024
Viewed by 251
Abstract
The genus Edwardsiella, previously residing in the family Enterobacteriaceae and now a member of the family Hafniaceae, is currently composed of five species, although the taxonomy of this genus is still unsettled. The genus can primarily be divided into two pathogenic [...] Read more.
The genus Edwardsiella, previously residing in the family Enterobacteriaceae and now a member of the family Hafniaceae, is currently composed of five species, although the taxonomy of this genus is still unsettled. The genus can primarily be divided into two pathogenic groups: E. tarda strains are responsible for almost all human infections, and two other species (E. ictaluri, E. piscicida) cause diseases in fish. Human infections predominate in subtropical habitats of the world and in specific geospatial regions with gastrointestinal disease, bloodborne infections, and wound infections, the most common clinical presentations in decreasing order. Gastroenteritis can present in many different forms and mimic other intestinal disturbances. Chronic gastroenteritis is not uncommon. Septicemia is primarily found in persons with comorbid conditions including malignancies and liver disease. Mortality rates range from 9% to 28%. Most human infections are linked to one of several risk factors associated with freshwater or marine environments such as seafood consumption. In contrast, edwardsiellosis in fish is caused by two other species, in particular E. ictaluri. Both E. ictaluri and E. piscicida can cause massive outbreaks of disease in aquaculture systems worldwide, including enteric septicemia in channel catfish and tilapia. Collectively, these species are increasingly being recognized as important pathogens in clinical and veterinary medicine. This article highlights and provides a current perspective on the taxonomy, microbiology, epidemiology, and pathogenicity of this increasingly important group. Full article
(This article belongs to the Special Issue Microorganisms and Diseases Associated with Aquatic Animals 2.0)
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14 pages, 1633 KiB  
Article
Characteristics of Vaginal Microbiota of Women of Reproductive Age with Infections
by Wanting Dong, Siyi Wang, Xi Wang, Guojin Xu, Qiuying Liu, Zheng Li, Na Lv, Yuanlong Pan, Qian Xiong, Donglai Liu and Baoli Zhu
Microorganisms 2024, 12(5), 1030; https://doi.org/10.3390/microorganisms12051030 - 20 May 2024
Viewed by 243
Abstract
The vaginal microbiota can be classified into five major community state types (CSTs) based on the bacterial content. However, the link between different CST subtypes and vaginal infection remains unclear. Here, we analyzed 2017 vaginal microbiota samples from women of a reproductive age [...] Read more.
The vaginal microbiota can be classified into five major community state types (CSTs) based on the bacterial content. However, the link between different CST subtypes and vaginal infection remains unclear. Here, we analyzed 2017 vaginal microbiota samples from women of a reproductive age with vaginal infections that were published in the last decade. We found that L. iners was the most dominant in 34.8% of the vaginal samples, followed by L. crispatus (21.2%). CST I was common in healthy individuals, whereas CST III and IV were associated with dysbiosis and infection. CST III-B, IV-A, IV-B, and IV-C0 were prevalent in patients with bacterial vaginosis (BV). Based on the relative abundance of bacteria at the (sub)genus level, a random forest classifier was developed to predict vaginal infections with an area under the curve of 0.83. We further identified four modules of co-occurring bacterial taxa: L. crispatus, Gardnerella, Prevotella, and Bacteroides. The functional prediction revealed that nucleotide biosynthesis pathways were upregulated in patients with human papilloma virus, and carbohydrate degradation pathways were downregulated in patients with BV. Overall, our study identified the bacterial signatures of healthy and infected vaginal microbiota, providing unique insights into the clinical diagnosis and health status prediction of women of a reproductive age. Full article
(This article belongs to the Special Issue Vaginal Microbiome in Women's Health)
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23 pages, 5076 KiB  
Article
Selective Isolation and Identification of Microorganisms with Dual Capabilities: Leather Biodegradation and Heavy Metal Resistance for Industrial Applications
by Manuela Bonilla-Espadas, Basilio Zafrilla, Irene Lifante-Martínez, Mónica Camacho, Elena Orgilés-Calpena, Francisca Arán-Aís, Marcelo Bertazzo and María-José Bonete
Microorganisms 2024, 12(5), 1029; https://doi.org/10.3390/microorganisms12051029 - 20 May 2024
Viewed by 325
Abstract
Tanning, crucial for leather production, relies heavily on chromium yet poses risks due to chromium’s oxidative conversion, leading to significant wastewater and solid waste generation. Physico-chemical methods are typically used for heavy metal removal, but they have drawbacks, prompting interest in eco-friendly biological [...] Read more.
Tanning, crucial for leather production, relies heavily on chromium yet poses risks due to chromium’s oxidative conversion, leading to significant wastewater and solid waste generation. Physico-chemical methods are typically used for heavy metal removal, but they have drawbacks, prompting interest in eco-friendly biological remediation techniques like biosorption, bioaccumulation, and biotransformation. The EU Directive (2018/850) mandates alternatives to landfilling or incineration for industrial textile waste management, highlighting the importance of environmentally conscious practices for leather products’ end-of-life management, with composting being the most researched and viable option. This study aimed to isolate microorganisms from tannery wastewater and identify those responsible for different types of tanned leather biodegradation. Bacterial shifts during leather biodegradation were observed using a leather biodegradation assay (ISO 20136) with tannery and municipal wastewater as the inoculum. Over 10,000 bacterial species were identified in all analysed samples, with 7 bacterial strains isolated from tannery wastewaters. Identification of bacterial genera like Acinetobacter, Brevundimonas, and Mycolicibacterium provides insights into potential microbial candidates for enhancing leather biodegradability, wastewater treatment, and heavy metal bioremediation in industrial applications. Full article
(This article belongs to the Special Issue New Insights into the Diversity and Characterization of Extremophiles)
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12 pages, 2173 KiB  
Article
Exploring the Frozen Armory: Antiphage Defense Systems in Cold-Adapted Bacteria with a Focus on CRISPR-Cas Systems
by Greta Daae Sandsdalen, Animesh Kumar and Erik Hjerde
Microorganisms 2024, 12(5), 1028; https://doi.org/10.3390/microorganisms12051028 - 20 May 2024
Viewed by 256
Abstract
Our understanding of the antiphage defense system arsenal in bacteria is rapidly expanding, but little is known about its occurrence in cold-adapted bacteria. In this study, we aim to shed light on the prevalence and distribution of antiphage defense systems in cold-adapted bacteria, [...] Read more.
Our understanding of the antiphage defense system arsenal in bacteria is rapidly expanding, but little is known about its occurrence in cold-adapted bacteria. In this study, we aim to shed light on the prevalence and distribution of antiphage defense systems in cold-adapted bacteria, with a focus on CRISPR-Cas systems. Using bioinformatics tools, Prokaryotic Antiviral Defense LOCator (PADLOC) and CRISPRCasTyper, we mapped the presence and diversity of antiphage defense systems in 938 available genomes of cold-adapted bacteria from diverse habitats. We confirmed that CRISPR-Cas systems are less frequent in cold-adapted bacteria, compared to mesophilic and thermophilic species. In contrast, several antiphage defense systems, such as dXTPases and DRTs, appear to be more frequently compared to temperate bacteria. Additionally, our study provides Cas endonuclease candidates with a potential for further development into cold-active CRISPR-Cas genome editing tools. These candidates could have broad applications in research on cold-adapted organisms. Our study provides a first-time map of antiphage defense systems in cold-adapted bacteria and a detailed overview of CRISPR-Cas diversity. Full article
(This article belongs to the Special Issue Cold-Adapted Bacteria and Marine Bacteria)
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15 pages, 3785 KiB  
Article
Transcriptome Analysis Reveals Candidate Genes for Light Regulation of Elsinochrome Biosynthesis in Elsinoë arachidis
by Dan Liu, Jingzi Piao, Yang Li, Haiwen Guan, Jingwen Hao and Rujun Zhou
Microorganisms 2024, 12(5), 1027; https://doi.org/10.3390/microorganisms12051027 - 19 May 2024
Viewed by 239
Abstract
Light regulation is critical in fungal growth, development, morphogenesis, secondary metabolism, and the biological clock. The fungus Elsinoë arachidis is known to produce the mycotoxin Elsinochrome (ESC), a key factor contributing to its pathogenicity, under light conditions. Although previous studies have predominantly focused [...] Read more.
Light regulation is critical in fungal growth, development, morphogenesis, secondary metabolism, and the biological clock. The fungus Elsinoë arachidis is known to produce the mycotoxin Elsinochrome (ESC), a key factor contributing to its pathogenicity, under light conditions. Although previous studies have predominantly focused on the light-induced production of ESC and its biosynthetic pathways, the detailed mechanisms underlying this process remain largely unexplored. This study explores the influence of light on ESC production and gene expression in E. arachidis. Under white light exposure for 28 days, the ESC yield was observed to reach 33.22 nmol/plug. Through transcriptome analysis, 5925 genes were identified as differentially expressed between dark and white light conditions, highlighting the significant impact of light on gene expression. Bioinformatics identified specific light-regulated genes, including eight photoreceptor genes, five global regulatory factors, and a cluster of 12 genes directly involved in the ESC biosynthesis, with expression trends confirmed by RT-qPCR. In conclusion, the study reveals the substantial alteration in gene expression associated with ESC biosynthesis under white light and identifies potential candidates for in-depth functional analysis. These findings advance understanding of ESC biosynthesis regulation and suggest new strategies for fungal pathogenicity control. Full article
(This article belongs to the Section Microbiomes)
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20 pages, 1106 KiB  
Review
A Review of the Mechanisms of Bacterial Colonization of the Mammal Gut
by Qingjie Lin, Shiying Lin, Zitao Fan, Jing Liu, Dingcheng Ye and Pingting Guo
Microorganisms 2024, 12(5), 1026; https://doi.org/10.3390/microorganisms12051026 - 19 May 2024
Viewed by 299
Abstract
A healthy animal intestine hosts a diverse population of bacteria in a symbiotic relationship. These bacteria utilize nutrients in the host’s intestinal environment for growth and reproduction. In return, they assist the host in digesting and metabolizing nutrients, fortifying the intestinal barrier, defending [...] Read more.
A healthy animal intestine hosts a diverse population of bacteria in a symbiotic relationship. These bacteria utilize nutrients in the host’s intestinal environment for growth and reproduction. In return, they assist the host in digesting and metabolizing nutrients, fortifying the intestinal barrier, defending against potential pathogens, and maintaining gut health. Bacterial colonization is a crucial aspect of this interaction between bacteria and the intestine and involves the attachment of bacteria to intestinal mucus or epithelial cells through nonspecific or specific interactions. This process primarily relies on adhesins. The binding of bacterial adhesins to host receptors is a prerequisite for the long-term colonization of bacteria and serves as the foundation for the pathogenicity of pathogenic bacteria. Intervening in the adhesion and colonization of bacteria in animal intestines may offer an effective approach to treating gastrointestinal diseases and preventing pathogenic infections. Therefore, this paper reviews the situation and mechanisms of bacterial colonization, the colonization characteristics of various bacteria, and the factors influencing bacterial colonization. The aim of this study was to serve as a reference for further research on bacteria–gut interactions and improving animal gut health. Full article
(This article belongs to the Section Veterinary Microbiology)
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24 pages, 2858 KiB  
Review
Insights into the Impact of Physicochemical and Microbiological Parameters on the Safety Performance of Deep Geological Repositories
by Mar Morales-Hidalgo, Cristina Povedano-Priego, Marcos F. Martinez-Moreno, Miguel A. Ruiz-Fresneda, Margarita Lopez-Fernandez, Fadwa Jroundi and Mohamed L. Merroun
Microorganisms 2024, 12(5), 1025; https://doi.org/10.3390/microorganisms12051025 - 19 May 2024
Viewed by 274
Abstract
Currently, the production of radioactive waste from nuclear industries is increasing, leading to the development of reliable containment strategies. The deep geological repository (DGR) concept has emerged as a suitable storage solution, involving the underground emplacement of nuclear waste within stable geological formations. [...] Read more.
Currently, the production of radioactive waste from nuclear industries is increasing, leading to the development of reliable containment strategies. The deep geological repository (DGR) concept has emerged as a suitable storage solution, involving the underground emplacement of nuclear waste within stable geological formations. Bentonite clay, known for its exceptional properties, serves as a critical artificial barrier in the DGR system. Recent studies have suggested the stability of bentonite within DGR relevant conditions, indicating its potential to enhance the long-term safety performance of the repository. On the other hand, due to its high resistance to corrosion, copper is one of the most studied reference materials for canisters. This review provides a comprehensive perspective on the influence of nuclear waste conditions on the characteristics and properties of DGR engineered barriers. This paper outlines how evolving physico-chemical parameters (e.g., temperature, radiation) in a nuclear repository may impact these barriers over the lifespan of a repository and emphasizes the significance of understanding the impact of microbial processes, especially in the event of radionuclide leakage (e.g., U, Se) or canister corrosion. Therefore, this review aims to address the long-term safety of future DGRs, which is critical given the complexity of such future systems. Full article
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16 pages, 3374 KiB  
Article
Reference Genes for Expression Analyses by qRT-PCR in Enterobacter cancerogenus
by Yang Pan, Yue Zhao, Hua-Rui Zeng, Jia-Qi Wu, Ying-Ying Song, Ya-Hao Rao, Guo-Qing Li and Lin Jin
Microorganisms 2024, 12(5), 1024; https://doi.org/10.3390/microorganisms12051024 - 19 May 2024
Viewed by 252
Abstract
The Enterobacter cancerogenus strain EcHa1 was isolated from the dead larvae of Helicoverpa armigera, and has the potential for biocontrol of some Lepidoptera insects. In order to screen insecticidal-related genes by qRT-PCR, stable endogenous reference genes used for normalizing qRT-PCR data were [...] Read more.
The Enterobacter cancerogenus strain EcHa1 was isolated from the dead larvae of Helicoverpa armigera, and has the potential for biocontrol of some Lepidoptera insects. In order to screen insecticidal-related genes by qRT-PCR, stable endogenous reference genes used for normalizing qRT-PCR data were selected and evaluated from 13 housekeeping genes (HKGs). The expression levels of the HKGs were determined using qRT-PCR under different experimental conditions, including two culture temperatures and three bacterial OD values. Five stability analysis methods (Ct, BestKeeper, NormFinder, geNorm, and RefFinder) were used to comprehensively rank the candidate genes. The results showed that the optimal reference genes varied under different experimental conditions. The combination of gyrA and gyrB was recommended as the best reference gene combination at 28 °C, while gyrA and rpoB was the best combination at 37 °C. When the OD values were 0.5, 1.0 and 2.0, the recommended reference gene combinations were ftsZ and gyrA, rpoB and gyrB, and gyrA and pyk, respectively. The most suitable reference genes were gyrA and gyrB under all experimental conditions. Using gyrA and gyrB as the reference genes for qRT-PCR, EcHa1 was found to invade all tissues of the H. armigera larvae, and expressed a candidate pathogenic factor Hcp at high levels in gut, Malpighian tubules, and epidermis tissues. This study not only establishes an accurate and reliable normalization for qRT-PCR in entomopathogenic bacteria but also lays a solid foundation for further study of functional genes in E. cancerogenus. Full article
(This article belongs to the Section Microbiomes)
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8 pages, 1486 KiB  
Communication
Customized 16S-23S rDNA ITS Amplicon Metagenomics for Acetic Acid Bacteria Species Identification in Vinegars and Kombuchas
by Alja Ribič and Janja Trček
Microorganisms 2024, 12(5), 1023; https://doi.org/10.3390/microorganisms12051023 - 18 May 2024
Viewed by 242
Abstract
Acetic acid bacteria (AAB) are involved in food and beverage production bioprocesses, like those in vinegar and kombucha. They oxidize sugars and alcohols into various metabolites, resulting in the final products’ pleasant taste and aroma. The 16S rDNA amplicon metagenomics using Illumina technology [...] Read more.
Acetic acid bacteria (AAB) are involved in food and beverage production bioprocesses, like those in vinegar and kombucha. They oxidize sugars and alcohols into various metabolites, resulting in the final products’ pleasant taste and aroma. The 16S rDNA amplicon metagenomics using Illumina technology is usually used to follow the microbiological development of these processes. However, the 16S rRNA gene sequences among different species of AAB are very similar, thus not enabling a reliable identification down to the species level but only to the genus. In this study, we have constructed primers for amplifying half of the 16S-23S rRNA gene internal transcribed spacer (ITS) for library construction and further sequencing using Illumina technology. This approach was successfully used to estimate the relative abundance of AAB species in defined consortia. Further application of this method for the analysis of different vinegar and kombucha samples proves it suitable for assessing the relative abundance of AAB species when these bacteria represent a predominant part of a microbial community. Full article
(This article belongs to the Section Microbiomes)
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15 pages, 1323 KiB  
Article
Interplay of Demographic Influences, Clinical Manifestations, and Longitudinal Profile of Laboratory Parameters in the Progression of SARS-CoV-2 Infection: Insights from the Saudi Population
by Sarah Al-Hassinah, Sooad Al-Daihan, Mashael Alahmadi, Sara Alghamdi, Rawabi Almulhim, Dalia Obeid, Yaseen Arabi, Abdulrahman Alswaji, Marwh Aldriwesh and Majed Alghoribi
Microorganisms 2024, 12(5), 1022; https://doi.org/10.3390/microorganisms12051022 - 18 May 2024
Viewed by 229
Abstract
Understanding the factors driving SARS-CoV-2 infection progression and severity is complex due to the dynamic nature of human physiology. Therefore, we aimed to explore the severity risk indicators of SARS-CoV-2 through demographic data, clinical manifestations, and the profile of laboratory parameters. The study [...] Read more.
Understanding the factors driving SARS-CoV-2 infection progression and severity is complex due to the dynamic nature of human physiology. Therefore, we aimed to explore the severity risk indicators of SARS-CoV-2 through demographic data, clinical manifestations, and the profile of laboratory parameters. The study included 175 patients either hospitalized at King Abdulaziz Medical City–Riyadh or placed in quarantine at designated hotels in Riyadh, Saudi Arabia, from June 2020 to April 2021. Hospitalized patients were followed up through the first week of admission. Demographic data, clinical presentations, and laboratory results were retrieved from electronic patient records. Our results revealed that older age (OR: 1.1, CI: [1.1–1.12]; p < 0.0001), male gender (OR: 2.26, CI: [1.0–5.1]; p = 0.047), and blood urea nitrogen level (OR: 2.56, CI: [1.07–6.12]; p = 0.034) were potential predictors of severity level. In conclusion, the study showed that apart from laboratory parameters, age and gender could potentially predict the severity of SARS-CoV-2 infection in the early stages. To our knowledge, this study is the first in Saudi Arabia to explore the longitudinal profile of laboratory parameters among risk factors, shedding light on SARS-CoV-2 infection progression parameters. Full article
(This article belongs to the Special Issue Advances in SARS-CoV-2 Infection—Third Edition)
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18 pages, 4546 KiB  
Article
Facial Skin Microbiome Composition and Functional Shift with Aging
by Allison Garlet, Valerie Andre-Frei, Nicolas Del Bene, Hunter James Cameron, Anita Samuga, Vimal Rawat, Philipp Ternes and Sabrina Leoty-Okombi
Microorganisms 2024, 12(5), 1021; https://doi.org/10.3390/microorganisms12051021 - 18 May 2024
Viewed by 475
Abstract
The change in the skin microbiome as individuals age is only partially known. To provide a better understanding of the impact of aging, whole-genome sequencing analysis was performed on facial skin swabs of 100 healthy female Caucasian volunteers grouped by age and wrinkle [...] Read more.
The change in the skin microbiome as individuals age is only partially known. To provide a better understanding of the impact of aging, whole-genome sequencing analysis was performed on facial skin swabs of 100 healthy female Caucasian volunteers grouped by age and wrinkle grade. Volunteers’ metadata were collected through questionnaires and non-invasive biophysical measurements. A simple model and a biological statistical model were used to show the difference in skin microbiota composition between the two age groups. Taxonomic and non-metric multidimensional scaling analysis showed that the skin microbiome was more diverse in the older group (≥55 yo). There was also a significant decrease in Actinobacteria, namely in Cutibacterium acnes, and an increase in Corynebacterium kroppenstedtii. Some Streptococcus and Staphylococcus species belonging to the Firmicutes phylum and species belonging to the Proteobacteria phylum increased. In the 18–35 yo younger group, the microbiome was characterized by a significantly higher proportion of Cutibacterium acnes and Lactobacillus, most strikingly, Lactobacillus crispatus. The functional analysis using GO terms revealed that the young group has a higher significant expression of genes involved in biological and metabolic processes and in innate skin microbiome protection. The better comprehension of age-related impacts observed will later support the investigation of skin microbiome implications in antiaging protection. Full article
(This article belongs to the Special Issue Microbiota in Human Health and Disease)
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19 pages, 34859 KiB  
Article
Role of Probiotics in Gut Microbiome and Metabolome in Non-Alcoholic Fatty Liver Disease Mouse Model: A Comparative Study
by Tian Wu, Zheng Zeng and Yanyan Yu
Microorganisms 2024, 12(5), 1020; https://doi.org/10.3390/microorganisms12051020 - 17 May 2024
Viewed by 255
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver condition worldwide. Numerous studies conducted recently have demonstrated a connection between the dysbiosis of the development of NAFLD and gut microbiota. Rebuilding a healthy gut ecology has been proposed as a strategy [...] Read more.
Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver condition worldwide. Numerous studies conducted recently have demonstrated a connection between the dysbiosis of the development of NAFLD and gut microbiota. Rebuilding a healthy gut ecology has been proposed as a strategy involving the use of probiotics. The purpose of this work is to investigate and compare the function of probiotics Akkermansia muciniphila (A. muciniphila) and VSL#3 in NAFLD mice. Rodent NAFLD was modeled using a methionine choline-deficient diet (MCD) with/without oral probiotic delivery. Subsequently, qPCR, histological staining, and liver function tests were conducted. Mass spectrometry-based analysis and 16S rDNA gene sequencing were used to investigate the liver metabolome and gut microbiota. We found that while both A. muciniphila and VSL#3 reduced hepatic fat content, A. muciniphila outperformed VSL#3. Furthermore, probiotic treatment restored the β diversity of the gut flora and A. muciniphila decreased the abundance of pathogenic bacteria such as Ileibacterium valens. These probiotics altered the metabolism in MCD mice, especially the glycerophospholipid metabolism. In conclusion, our findings distinguished the role of A. muciniphila and VSL#3 in NAFLD and indicated that oral-gavage probiotics remodel gut microbiota and improve metabolism, raising the possibility of using probiotics in the cure of NAFLD. Full article
(This article belongs to the Special Issue Probiotics, Prebiotics, and Gut Microbes)
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14 pages, 1000 KiB  
Article
Efficiency of Virucidal Disinfectants on Wood Surfaces in Animal Husbandry
by Martin J. Oettler, Franz J. Conraths, Uwe Roesler, Sven Reiche, Timo Homeier-Bachmann and Nicolai Denzin
Microorganisms 2024, 12(5), 1019; https://doi.org/10.3390/microorganisms12051019 - 17 May 2024
Viewed by 183
Abstract
The aim of this study was to test the inactivation of viruses on germ carriers of different types of wood using a disinfectant in order to assess the biosafety of wood as a building material in animal husbandry. The laboratory disinfectant efficacy tests [...] Read more.
The aim of this study was to test the inactivation of viruses on germ carriers of different types of wood using a disinfectant in order to assess the biosafety of wood as a building material in animal husbandry. The laboratory disinfectant efficacy tests were based on German testing guidelines and current European standards. Five different types of wood germ carriers, i.e., spruce (Picea abies), pine (Pinus sylvestris), poplar (Populus sp.), beech (Fagus sylvatica) and Douglas fir (Pseudotsuga menziesii), were inoculated with enveloped or non-enveloped viruses and then treated with one of three different disinfectants. The results revealed that intact, fine-sawn timber with a low roughness depth can be effectively inactivated. Peracetic acid proved to be the most effective disinfectant across all tests. Regardless of the pathogen and the type of wood, a concentration of 0.1% of the pure substance at a temperature of 10 °C and an exposure time of one hour can be recommended. At a temperature of −10 °C, a concentration of 0.75% is recommended. The basic chemicals formic acid and glutaraldehyde demonstrated only limited effectiveness overall. The synergistic effects of various wood components on the inactivation of viruses offer potential for further investigation. Disinfectant tests should also be conclusively verified in field trials to ensure that the results from standardised laboratory tests can be transferred to real stable conditions. Full article
(This article belongs to the Special Issue Disinfection and Sterilization of Microorganisms)
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17 pages, 5358 KiB  
Article
Rapid Identification of Brucella Genus and Species In Silico and On-Site Using Novel Probes with CRISPR/Cas12a
by Yan Zhang, Yufei Lyu, Dongshu Wang, Meijie Feng, Sicheng Shen, Li Zhu, Chao Pan, Xiaodong Zai, Shuyi Wang, Yan Guo, Shujuan Yu, Xiaowei Gong, Qiwei Chen, Hengliang Wang, Yuanzhi Wang and Xiankai Liu
Microorganisms 2024, 12(5), 1018; https://doi.org/10.3390/microorganisms12051018 - 17 May 2024
Viewed by 204
Abstract
Human brucellosis caused by Brucella is a widespread zoonosis that is prevalent in many countries globally. The high homology between members of the Brucella genus and Ochrobactrum spp. often complicates the determination of disease etiology in patients. The efficient and reliable identification and [...] Read more.
Human brucellosis caused by Brucella is a widespread zoonosis that is prevalent in many countries globally. The high homology between members of the Brucella genus and Ochrobactrum spp. often complicates the determination of disease etiology in patients. The efficient and reliable identification and distinction of Brucella are of primary interest for both medical surveillance and outbreak purposes. A large amount of genomic data for the Brucella genus was analyzed to uncover novel probes containing single-nucleotide polymorphisms (SNPs). GAMOSCE v1.0 software was developed based on the above novel eProbes. In conjunction with clinical requirements, an RPA-Cas12a detection method was developed for the on-site determination of B. abortus and B. melitensis by fluorescence and lateral flow dipsticks (LFDs). We demonstrated the potential of these probes for rapid and accurate detection of the Brucella genus and five significant Brucella species in silico using GAMOSCE. GAMOSCE was validated on different Brucella datasets and correctly identified all Brucella strains, demonstrating a strong discrimination ability. The RPA-Cas12a detection method showed good performance in detection in clinical blood samples and veterinary isolates. We provide both in silico and on-site methods that are convenient and reliable for use in local hospitals and public health programs for the detection of brucellosis. Full article
(This article belongs to the Section Microbial Biotechnology)
18 pages, 12881 KiB  
Article
Sodium Polyoxotungstate Inhibits the Replication of Influenza Virus by Blocking the Nuclear Import of vRNP
by Zhuogang Li, Yuanyuan Duan, Yang Yu, Yue Su, Mingxin Zhang, Yarou Gao, Lefang Jiang, Haonan Zhang, Xiaoqin Lian, Xingjian Zhu, Jiaxin Ke, Qun Peng and Xulin Chen
Microorganisms 2024, 12(5), 1017; https://doi.org/10.3390/microorganisms12051017 - 17 May 2024
Viewed by 263
Abstract
Both pandemic and seasonal influenza are major health concerns, causing significant mortality and morbidity. Current influenza drugs primarily target viral neuraminidase and RNA polymerase, which are prone to drug resistance. Polyoxometalates (POMs) are metal cation clusters bridged by oxide anions. They have exhibited [...] Read more.
Both pandemic and seasonal influenza are major health concerns, causing significant mortality and morbidity. Current influenza drugs primarily target viral neuraminidase and RNA polymerase, which are prone to drug resistance. Polyoxometalates (POMs) are metal cation clusters bridged by oxide anions. They have exhibited potent anti-tumor, antiviral, and antibacterial effects. They have remarkable activity against various DNA and RNA viruses, including human immunodeficiency virus, herpes simplex virus, hepatitis B and C viruses, dengue virus, and influenza virus. In this study, we have identified sodium polyoxotungstate (POM-1) from an ion channel inhibitor library. In vitro, POM-1 has been demonstrated to have potent antiviral activity against H1N1, H3N2, and oseltamivir-resistant H1N1 strains. POM-1 can cause virion aggregation during adsorption, as well as endocytosis. However, the aggregation is reversible; it does not interfere with virus adsorption and endocytosis. Our results suggest that POM-1 exerts its antiviral activity by inhibiting the nuclear import of viral ribonucleoprotein (vRNP). This distinct mechanism of action, combined with its wide range of efficacy, positions POM-1 as a promising therapeutic candidate for influenza treatment and warrants further investigation. Full article
(This article belongs to the Section Antimicrobial Agents and Resistance)
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19 pages, 8889 KiB  
Article
Divergence within the Taxon ‘Candidatus Phytoplasma asteris’ Confirmed by Comparative Genome Analysis of Carrot Strains
by Rafael Toth, Anna-Marie Ilic, Bruno Huettel, Bojan Duduk and Michael Kube
Microorganisms 2024, 12(5), 1016; https://doi.org/10.3390/microorganisms12051016 - 17 May 2024
Viewed by 200
Abstract
Phytoplasmas are linked to diseases in hundreds of economically important crops, including carrots. In carrots, phytoplasmosis is associated with leaf chlorosis and necrosis, coupled with inhibited root system development, ultimately leading to significant economic losses. During a field study conducted in Baden-Württemberg (Germany), [...] Read more.
Phytoplasmas are linked to diseases in hundreds of economically important crops, including carrots. In carrots, phytoplasmosis is associated with leaf chlorosis and necrosis, coupled with inhibited root system development, ultimately leading to significant economic losses. During a field study conducted in Baden-Württemberg (Germany), two strains of the provisional taxon ‘Candidatus Phytoplasma asteris’ were identified within a carrot plot. For further analysis, strains M8 and M33 underwent shotgun sequencing, utilising single-molecule-real-time (SMRT) long-read sequencing and sequencing-by-synthesis (SBS) paired-end short-read sequencing techniques. Hybrid assemblies resulted in complete de novo assemblies of two genomes harboring circular chromosomes and two plasmids. Analyses, including average nucleotide identity and sequence comparisons of established marker genes, confirmed the phylogenetic divergence of ‘Ca. P. asteris’ and a different assignment of strains to the 16S rRNA subgroup I-A for M33 and I-B for M8. These groups exhibited unique features, encompassing virulence factors and genes, associated with the mobilome. In contrast, pan-genome analysis revealed a highly conserved gene set related to metabolism across these strains. This analysis of the Aster Yellows (AY) group reaffirms the perception of phytoplasmas as bacteria that have undergone extensive genome reduction during their co-evolution with the host and an increase of genome size by mobilome. Full article
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22 pages, 7000 KiB  
Article
Exploring Gut Microbiota Alterations with Trimethoprim-Sulfamethoxazole and Dexamethasone in a Humanized Microbiome Mouse Model
by George B. H. Green, Alexis N. Cox-Holmes, Olivia Backan, Olivia Valbak, Anna Claire E. Potier, Dongquan Chen, Casey D. Morrow, Christopher D. Willey and Braden C. McFarland
Microorganisms 2024, 12(5), 1015; https://doi.org/10.3390/microorganisms12051015 - 17 May 2024
Viewed by 614
Abstract
Along with the standard therapies for glioblastoma, patients are commonly prescribed trimethoprim-sulfamethoxazole (TMP-SMX) and dexamethasone for preventing infections and reducing cerebral edema, respectively. Because the gut microbiota impacts the efficacy of cancer therapies, it is important to understand how these medications impact the [...] Read more.
Along with the standard therapies for glioblastoma, patients are commonly prescribed trimethoprim-sulfamethoxazole (TMP-SMX) and dexamethasone for preventing infections and reducing cerebral edema, respectively. Because the gut microbiota impacts the efficacy of cancer therapies, it is important to understand how these medications impact the gut microbiota of patients. Using mice that have been colonized with human microbiota, this study sought to examine how TMP-SMX and dexamethasone affect the gut microbiome. Two lines of humanized microbiota (HuM) Rag1−/− mice, HuM1Rag and HuM2Rag, were treated with either TMP-SMX or dexamethasone via oral gavage once a day for a week. Fecal samples were collected pre-treatment (pre-txt), one week after treatment initiation (1 wk post txt), and three weeks post-treatment (3 wk post txt), and bacterial DNA was analyzed using 16S rRNA-sequencing. The HuM1Rag mice treated with TMP-SMX had significant shifts in alpha diversity, beta diversity, and functional pathways at all time points, whereas in the HuM2Rag mice, it resulted in minimal changes in the microbiome. Likewise, dexamethasone treatment resulted in significant changes in the microbiome of the HuM1Rag mice, whereas the microbiome of the HuM2Rag mice was mostly unaffected. The results of our study show that routine medications used during glioblastoma treatment can perturb gut microbiota, with some microbiome compositions being more sensitive than others, and these treatments could potentially affect the overall efficacy of standard-of-care therapy. Full article
(This article belongs to the Special Issue Gut Microbiota and Precise Modulation)
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30 pages, 1875 KiB  
Review
Probiotics in the New Era of Human Milk Oligosaccharides (HMOs): HMO Utilization and Beneficial Effects of Bifidobacterium longum subsp. infantis M-63 on Infant Health
by Chyn Boon Wong, Huidong Huang, Yibing Ning and Jinzhong Xiao
Microorganisms 2024, 12(5), 1014; https://doi.org/10.3390/microorganisms12051014 - 17 May 2024
Viewed by 596
Abstract
A healthy gut microbiome is crucial for the immune system and overall development of infants. Bifidobacterium has been known to be a predominant species in the infant gut; however, an emerging concern is the apparent loss of this genus, in particular, Bifidobacterium longum [...] Read more.
A healthy gut microbiome is crucial for the immune system and overall development of infants. Bifidobacterium has been known to be a predominant species in the infant gut; however, an emerging concern is the apparent loss of this genus, in particular, Bifidobacterium longum subsp. infantis (B. infantis) in the gut microbiome of infants in industrialized nations, underscoring the importance of restoring this beneficial bacterium. With the growing understanding of the gut microbiome, probiotics, especially infant-type human-residential bifidobacteria (HRB) strains like B. infantis, are gaining prominence for their unique ability to utilize HMOs and positively influence infant health. This article delves into the physiology of a probiotic strain, B. infantis M-63, its symbiotic relationship with HMOs, and its potential in improving gastrointestinal and allergic conditions in infants and children. Moreover, this article critically assesses the role of HMOs and the emerging trend of supplementing infant formulas with the prebiotic HMOs, which serve as fuel for beneficial gut bacteria, thereby emulating the protective effects of breastfeeding. The review highlights the potential of combining B. infantis M-63 with HMOs as a feasible strategy to improve health outcomes in infants and children, acknowledging the complexities and requirements for further research in this area. Full article
(This article belongs to the Special Issue Probiotics, Prebiotics, and Gut Microbes)
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20 pages, 355 KiB  
Review
A Review: Microbes and Their Effect on Growth Performance of Litopenaeus vannamei (White Leg Shrimps) during Culture in Biofloc Technology System
by Bilal Raza, Zhongming Zheng, Jinyong Zhu and Wen Yang
Microorganisms 2024, 12(5), 1013; https://doi.org/10.3390/microorganisms12051013 - 17 May 2024
Viewed by 264
Abstract
In the modern era of Aquaculture, biofloc technology (BFT) systems have attained crucial attention. This technology is used to reduce water renewal with the removal of nitrogen and to provide additional feed. In BFT, microorganisms play a crucial role due to their complex [...] Read more.
In the modern era of Aquaculture, biofloc technology (BFT) systems have attained crucial attention. This technology is used to reduce water renewal with the removal of nitrogen and to provide additional feed. In BFT, microorganisms play a crucial role due to their complex metabolic properties. Pathogens can be controlled through multiple mechanisms using probiotics, which can promote host development and enhance the quality of the culture environment. During culturing in a biofloc technology system, the supplementation of microalgae and its accompanying bacteria plays a beneficial role in reducing nitrogenous compounds. This enhances water quality and creates favorable environmental conditions for specific bacterial groups, while simultaneously reducing the dependency on carbon sources with higher content. The fluctuations in the bacterial communities of the intestine are closely associated with the severity of diseases related to shrimp and are used to evaluate the health status of shrimp. Overall, we will review the microbes associated with shrimp culture in BFT and their effects on shrimp growth. We will also examine the microbial impacts on the growth performance of L. vannamei in BFT, as well as the close relationship between probiotics and the intestinal microbes of L. vannamei. Full article
(This article belongs to the Special Issue Microbial Ecology and Sustainable Aquaculture)
15 pages, 5567 KiB  
Article
Bacillus siamensis Improves the Immune Status and Intestinal Health of Weaned Piglets by Improving Their Intestinal Microbiota
by Huawei Liu, Xinyu Liu, Haiyang Liu, Jiaqi Tang, Wei He, Tianqi Xu, Baojing Cheng, Baoming Shi and Jianchun Han
Microorganisms 2024, 12(5), 1012; https://doi.org/10.3390/microorganisms12051012 - 17 May 2024
Viewed by 245
Abstract
Previous studies on the early interference of gut microbiota by Bacillus siamensis (B. siamensis) in weaned piglets are rarely reported, and the present trial is a preliminary study. This experiment was conducted to investigate the effects of B. siamensis supplementation on [...] Read more.
Previous studies on the early interference of gut microbiota by Bacillus siamensis (B. siamensis) in weaned piglets are rarely reported, and the present trial is a preliminary study. This experiment was conducted to investigate the effects of B. siamensis supplementation on the growth performance, serum biochemistry, immune response, fecal short-chain fatty acids and microbiota of weaned piglets. Sixty weaned piglets were randomly divided into a control group (CON) and a B. siamensis group (BS), which were fed a basal diet and the basal diet supplemented with 5 × 1010 CFU B. siamensis per kg, respectively. Each group had 3 replicates and 10 piglets per replicate. The trial lasted for 28 days. The results showed that B. siamensis significantly increased the serum growth hormone (GH) and insulin-like growth factor (IGF) in piglets. Compared with the CON group, the levels of serum immunoglobulin and inflammatory factors in the BS group were significantly improved. In addition, the serum concentrations of zonulin and endotoxin (ET) in the BS group were lower. The dietary addition of B. siamensis significantly increased fecal short-chain fatty acid (SCFA) levels in piglets. Notably, B. siamensis improved the microbial composition by increasing beneficial genera, including Weissella, Lachnospiraceae_NK4A136_group and Bifidobacterium, and decreasing pathogenic genera, including Pantoea, Fusobacterium and Gemella, in piglet feces. Correlation analysis showed that the benefits of dietary B. siamensis supplementation were closely related to its improved microbial composition. In summary, the addition of B. siamensis can improve the immunity function, inflammatory response, gut permeability and SCFA levels of weaned piglets, which may be achieved through the improvement of their microbiota. Full article
(This article belongs to the Section Gut Microbiota)
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14 pages, 1224 KiB  
Article
In-Host Flat-like Quasispecies: Characterization Methods and Clinical Implications
by Josep Gregori, Sergi Colomer-Castell, Marta Ibañez-Lligoña, Damir Garcia-Cehic, Carolina Campos, Maria Buti, Mar Riveiro-Barciela, Cristina Andrés, Maria Piñana, Alejandra González-Sánchez, Francisco Rodriguez-Frias, Maria Francesca Cortese, David Tabernero, Ariadna Rando-Segura, Tomás Pumarola, Juan Ignacio Esteban, Andrés Antón and Josep Quer
Microorganisms 2024, 12(5), 1011; https://doi.org/10.3390/microorganisms12051011 - 17 May 2024
Viewed by 306
Abstract
The repeated failure to treat patients chronically infected with hepatitis E (HEV) and C (HCV) viruses, despite the absence of resistance-associated substitutions (RAS), particularly in response to prolonged treatments with the mutagenic agents of HEV, suggests that quasispecies structure may play a crucial [...] Read more.
The repeated failure to treat patients chronically infected with hepatitis E (HEV) and C (HCV) viruses, despite the absence of resistance-associated substitutions (RAS), particularly in response to prolonged treatments with the mutagenic agents of HEV, suggests that quasispecies structure may play a crucial role beyond single point mutations. Quasispecies structured in a flat-like manner (referred to as flat-like) are considered to possess high average fitness, occupy a significant fraction of the functional genetic space of the virus, and exhibit a high capacity to evade specific or mutagenic treatments. In this paper, we studied HEV and HCV samples using high-depth next-generation sequencing (NGS), with indices scoring the different properties describing flat-like quasispecies. The significance of these indices was demonstrated by comparing the values obtained from these samples with those from acute infections caused by respiratory viruses (betacoronaviruses, enterovirus, respiratory syncytial viruses, and metapneumovirus). Our results revealed that flat-like quasispecies in HEV and HCV chronic infections without RAS are characterized by numerous low-frequency haplotypes with no dominant one. Surprisingly, these low-frequency haplotypes (at the nucleotide level) exhibited a high level of synonymity, resulting in much lower diversity at the phenotypic level. Currently, clinical approaches for managing flat-like quasispecies are lacking. Here, we propose methods to identifying flat-like quasispecies, which represents an essential initial step towards exploring alternative treatment protocols for viruses resistant to conventional therapies. Full article
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12 pages, 1623 KiB  
Article
Use of Lactoperoxidase Inhibitory Effects to Extend the Shelf Life of Meat and Meat Products
by Filip Beňo, Adéla Velková, Filip Hruška and Rudolf Ševčík
Microorganisms 2024, 12(5), 1010; https://doi.org/10.3390/microorganisms12051010 - 17 May 2024
Viewed by 266
Abstract
Lactoperoxidase (LP) is an important enzyme of the salivary and mammary glands. It has been proven to increase the shelf life of raw milk by inhibiting the growth of bacteria, especially Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Pseudomonas spp. [...] Read more.
Lactoperoxidase (LP) is an important enzyme of the salivary and mammary glands. It has been proven to increase the shelf life of raw milk by inhibiting the growth of bacteria, especially Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Pseudomonas spp. The aim of this work was to verify the use of LP to extend the shelf life of meat products. In vitro experiments showed inhibitory effects on the selected bacteria (Listeria innocua (ATCC 33090), Staphylococcus saprophyticus (CP054440.1), and Pseudomonas fluorescens (ATCC 13525) due to a prolongation of the lag phase of growth curves. A lower increase in viable counts (p < 0.05) was also found by testing pork cubes’ surface treated with LP solution (5%) + L. innocua and stored for 7 days at 15 °C. LP has also been studied at concentrations of 0.25 and 0.50% in meat products (pork ham and pâté) during refrigerated storage (4 °C for 28 days). Lower viable counts were observed throughout the storage experiment, especially for 0.50% LP (p < 0.05). Meat products containing LP also showed lower levels of oxidation (MAD) (p < 0.05). According to these results, LP could extend the shelf life of a wider range of products. Full article
(This article belongs to the Section Food Microbiology)
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16 pages, 720 KiB  
Review
Residents or Tourists: Is the Lactating Mammary Gland Colonized by Residential Microbiota?
by Ruomei Xu, Grace McLoughlin, Mark Nicol, Donna Geddes and Lisa Stinson
Microorganisms 2024, 12(5), 1009; https://doi.org/10.3390/microorganisms12051009 - 17 May 2024
Viewed by 230
Abstract
The existence of the human milk microbiome has been widely recognized for almost two decades, with many studies examining its composition and relationship to maternal and infant health. However, the richness and viability of the human milk microbiota is surprisingly low. Given that [...] Read more.
The existence of the human milk microbiome has been widely recognized for almost two decades, with many studies examining its composition and relationship to maternal and infant health. However, the richness and viability of the human milk microbiota is surprisingly low. Given that the lactating mammary gland houses a warm and nutrient-rich environment and is in contact with the external environment, it may be expected that the lactating mammary gland would contain a high biomass microbiome. This discrepancy raises the question of whether the bacteria in milk come from true microbial colonization in the mammary gland (“residents”) or are merely the result of constant influx from other bacterial sources (“tourists”). By drawing together data from animal, in vitro, and human studies, this review will examine the question of whether the lactating mammary gland is colonized by a residential microbiome. Full article
(This article belongs to the Section Microbiomes)
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11 pages, 420 KiB  
Article
Epidemiological Study of Pathogens in Spontaneous Bacterial Peritonitis in 2017–2024—A Preliminary Report of the University Hospital in South-Eastern Poland
by Jolanta Gruszecka and Rafał Filip
Microorganisms 2024, 12(5), 1008; https://doi.org/10.3390/microorganisms12051008 - 17 May 2024
Viewed by 230
Abstract
Spontaneous Bacterial Peritonitis (SBP) is a serious complication and a common cause of death in patients with liver cirrhosis. Between January 2017 and March 2024, a retrospective study was conducted involving 302 patients (>18 years old) with ascites treated at a tertiary referral [...] Read more.
Spontaneous Bacterial Peritonitis (SBP) is a serious complication and a common cause of death in patients with liver cirrhosis. Between January 2017 and March 2024, a retrospective study was conducted involving 302 patients (>18 years old) with ascites treated at a tertiary referral center in south-eastern Poland. Microbiological analysis of the ascitic fluids was performed in all patients. The presence of microorganisms was found in samples from 17 patients, and 21 pathogens were isolated, including 15 Gram-positive bacteria and 6 Gram-negative bacteria. Staphylococcus epidermidis, MRCNS (methicillin-resistant coagulase-negative staphylococci, resistant to all beta-lactam antibiotics: penicillins, penicillins with beta-lactamase inhibitor, cephalosporins and carbapenems) was the main pathogen detected (19.05%, 4/21), followed by Enterococcus faecalis (9.52%, 2/21), Enterococcus faecium (9.52%, 2/21), Staphylococcus haemolyticus, MRCNS (4.76%, 1/21), Streptococcus mitis (9.52%, 2/21), Streptococcus parasanguinis (9.52%, 2/21), Micrococcus luteus (4.76%, 1/21) and Bacillus spp. (4.76%, 1/21). The following Gram-negative bacteria were also found in the specimens examined: Escherichia coli, ESBL (extended-spectrum β-lactamase producing E. coli) (4.76%, 1/21), Escherichia coli (4.76%, 1/21), Pseudomonas aeruginosa (4.76%, 1/21), Klebsiella oxytoca (9.52%, 2/21) and Sphingomonas paucimobilis (4.76%, 1/21). Gram-positive bacteria caused nosocomial infections in nine patients with SBP, Gram-negative bacteria caused nosocomial infections in two patients. In six patients with SBP, community-acquired infections caused by Gram-negative bacteria were found in three cases, Gram-positive bacteria in two cases, and in one case, community-acquired infection was caused by mixed Gram-positive and Gram-negative. Bacteria isolated from patients with hospital-acquired SBP showed higher drug resistance than those found in patients with non-hospital SBP. Bacterial infections in cirrhotic patients with complications may be responsible for their deteriorating health. Prompt intervention is critical to reducing mortality. Full article
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17 pages, 2333 KiB  
Article
Abundance, Characterization and Diversity of Culturable Anoxygenic Phototrophic Bacteria in Manitoban Marshlands
by Katia Messner and Vladimir Yurkov
Microorganisms 2024, 12(5), 1007; https://doi.org/10.3390/microorganisms12051007 - 17 May 2024
Viewed by 352
Abstract
Marshes are an important ecosystem, acting as a biodiversity hotspot, a carbon sink and a bioremediation site, breaking down anthropogenic waste such as antibiotics, metals and fertilizers. Due to their participation in these metabolic activities and their capability to contribute to primary productivity, [...] Read more.
Marshes are an important ecosystem, acting as a biodiversity hotspot, a carbon sink and a bioremediation site, breaking down anthropogenic waste such as antibiotics, metals and fertilizers. Due to their participation in these metabolic activities and their capability to contribute to primary productivity, the microorganisms in such habitats have become of interest to investigate. Since Proteobacteria were previously found to be abundant and the waters are well aerated and organic-rich, this study on the presence of anoxygenic phototrophic bacteria, purple non-sulfur bacteria and aerobic anoxygenic phototrophs in marshes was initiated. One sample was collected at each of the seven Manitoban sites, and anoxygenic phototrophs were cultivated and enumerated. A group of 14 strains, which represented the phylogenetic diversity of the isolates, was physiologically investigated further. Aerobic anoxygenic phototrophs and purple non-sulfur bacteria were present at each location, and they belonged to the α- and β-Proteobacteria subphyla. Some were closely related to known heavy metal reducers (Brevundimonas) and xenobiotic decomposers (Novosphingobium and Sphingomonas). All were able to synthesize the photosynthetic complexes aerobically. This research highlights the diversity of and the potential contributions that anoxygenic phototrophs make to the essential functions taking place in wetlands. Full article
(This article belongs to the Section Environmental Microbiology)
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15 pages, 1553 KiB  
Article
Ticks and Tick-Borne Pathogens Circulating in Peri-Domestic Areas in Mainland Portugal
by Leonardo Moerbeck, Ricardo Parreira, Magdalena Szczotko, Gonçalo Seixas, Rita Velez, Małgorzata Dmitryjuk, Ana Sofia Santos, Ana Domingos and Sandra Antunes
Microorganisms 2024, 12(5), 1006; https://doi.org/10.3390/microorganisms12051006 - 16 May 2024
Viewed by 424
Abstract
Over the years, tick-borne pathogens (TBPs) have garnered significant interest due to their medical, veterinary and economic importance. Additionally, TBPs have drawn attention to how these microorganisms interact with their own vectors, increasing the risk to human and animal infection of emerging and [...] Read more.
Over the years, tick-borne pathogens (TBPs) have garnered significant interest due to their medical, veterinary and economic importance. Additionally, TBPs have drawn attention to how these microorganisms interact with their own vectors, increasing the risk to human and animal infection of emerging and reemerging zoonoses. In this sense, ticks, which are obligate hematophagous ectoparasites, have a key role in maintaining and transmitting TBPs among humans and animals. The aim of this study was to assess the prevalence of neglected TBPs in mainland Portugal, namely Anaplasma spp., Babesia spp., Ehrlichia spp. and Neoehrlichia mikurensis. DNA fragments were detected in questing ticks collected from five different ecological areas under investigation. To the best of the authors’ knowledge, this study reports new worldwide findings, including B. bigemina infecting Ixodes frontalis, Ixodes ricinus and Rhipicephalus sanguineus sensu lato. Additionally, it presents new findings in Portugal of N. mikurensis infecting I. ricinus and of presumably Wolbachia endosymbionts being detected in I. ricinus. Overall, there were 208 tick samples that were negative for all screened TBPs. The results herein obtained raise concerns about the circulation of neglected TBPs in mainland Portugal, especially in anthropophilic ticks, highlighting the importance of adopting a One Health perspective. Full article
(This article belongs to the Special Issue The One Health Challenge: Zoonotic Parasites)
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16 pages, 2836 KiB  
Article
Pre-Bleaching Coral Microbiome Is Enriched in Beneficial Taxa and Functions
by Laís F. O. Lima, Amanda T. Alker, Megan M. Morris, Robert A. Edwards, Samantha J. de Putron and Elizabeth A. Dinsdale
Microorganisms 2024, 12(5), 1005; https://doi.org/10.3390/microorganisms12051005 - 16 May 2024
Viewed by 323
Abstract
Coral reef health is tightly connected to the coral holobiont, which is the association between the coral animal and a diverse microbiome functioning as a unit. The coral holobiont depends on key services such as nitrogen and sulfur cycling mediated by the associated [...] Read more.
Coral reef health is tightly connected to the coral holobiont, which is the association between the coral animal and a diverse microbiome functioning as a unit. The coral holobiont depends on key services such as nitrogen and sulfur cycling mediated by the associated bacteria. However, these microbial services may be impaired in response to environmental changes, such as thermal stress. A perturbed microbiome may lead to coral bleaching and disease outbreaks, which have caused an unprecedented loss in coral cover worldwide, particularly correlated to a warming ocean. The response mechanisms of the coral holobiont under high temperatures are not completely understood, but the associated microbial community is a potential source of acquired heat-tolerance. Here we investigate the effects of increased temperature on the taxonomic and functional profiles of coral surface mucous layer (SML) microbiomes in relationship to coral–algal physiology. We used shotgun metagenomics in an experimental setting to understand the dynamics of microbial taxa and genes in the SML microbiome of the coral Pseudodiploria strigosa under heat treatment. The metagenomes of corals exposed to heat showed high similarity at the level of bacterial genera and functional genes related to nitrogen and sulfur metabolism and stress response. The coral SML microbiome responded to heat with an increase in the relative abundance of taxa with probiotic potential, and functional genes for nitrogen and sulfur acquisition. Coral–algal physiology significantly explained the variation in the microbiome at taxonomic and functional levels. These consistent and specific microbial taxa and gene functions that significantly increased in proportional abundance in corals exposed to heat are potentially beneficial to coral health and thermal resistance. Full article
(This article belongs to the Special Issue Marine Microbial Diversity: Focus on Corals)
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29 pages, 2902 KiB  
Review
Exploring the Toxin-Mediated Mechanisms in Clostridioides difficile Infection
by Evdokia Pourliotopoulou, Theodoros Karampatakis and Melania Kachrimanidou
Microorganisms 2024, 12(5), 1004; https://doi.org/10.3390/microorganisms12051004 - 16 May 2024
Viewed by 376
Abstract
Clostridioides difficile infection (CDI) is the leading cause of nosocomial antibiotic-associated diarrhea, and colitis, with increasing incidence and healthcare costs. Its pathogenesis is primarily driven by toxins produced by the bacterium C. difficile, Toxin A (TcdA) and Toxin B (TcdB). Certain strains [...] Read more.
Clostridioides difficile infection (CDI) is the leading cause of nosocomial antibiotic-associated diarrhea, and colitis, with increasing incidence and healthcare costs. Its pathogenesis is primarily driven by toxins produced by the bacterium C. difficile, Toxin A (TcdA) and Toxin B (TcdB). Certain strains produce an additional toxin, the C. difficile transferase (CDT), which further enhances the virulence and pathogenicity of C. difficile. These toxins disrupt colonic epithelial barrier integrity, and induce inflammation and cellular damage, leading to CDI symptoms. Significant progress has been made in the past decade in elucidating the molecular mechanisms of TcdA, TcdB, and CDT, which provide insights into the management of CDI and the future development of novel treatment strategies based on anti-toxin therapies. While antibiotics are common treatments, high recurrence rates necessitate alternative therapies. Bezlotoxumab, targeting TcdB, is the only available anti-toxin, yet limitations persist, prompting ongoing research. This review highlights the current knowledge of the structure and mechanism of action of C. difficile toxins and their role in disease. By comprehensively describing the toxin-mediated mechanisms, this review provides insights for the future development of novel treatment strategies and the management of CDI. Full article
(This article belongs to the Special Issue Recent Advances in Clostridioides difficile Infection)
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21 pages, 2232 KiB  
Article
Whole Genome Sequence Analysis of Listeria monocytogenes Isolates Obtained from the Beef Production Chain in Gauteng Province, South Africa
by James Gana, Nomakorinte Gcebe, Rian Edward Pierneef, Yi Chen, Rebone Moerane and Abiodun Adewale Adesiyun
Microorganisms 2024, 12(5), 1003; https://doi.org/10.3390/microorganisms12051003 - 16 May 2024
Viewed by 279
Abstract
The study used whole-genome sequencing (WGS) and bioinformatics analysis for the genomic characterization of 60 isolates of Listeria monocytogenes obtained from the beef production chain (cattle farms, abattoirs, and retail outlets) in Gauteng province, South Africa. The sequence types (STs), clonal complexes (CCs), [...] Read more.
The study used whole-genome sequencing (WGS) and bioinformatics analysis for the genomic characterization of 60 isolates of Listeria monocytogenes obtained from the beef production chain (cattle farms, abattoirs, and retail outlets) in Gauteng province, South Africa. The sequence types (STs), clonal complexes (CCs), and the lineages of the isolates were determined using in silico multilocus sequence typing (MLST). We used BLAST-based analyses to identify virulence and antimicrobial genes, plasmids, proviruses/prophages, and the CRISPR-Cas system. The study investigated any association of the detected genes to the origin in the beef production chain of the L. monocytogenes isolates. Overall, in 60 isolates of Listeria monocytogenes, there were seven STs, six CCs, forty-four putative virulence factors, two resistance genes, one plasmid with AMR genes, and three with conjugative genes, one CRISPR gene, and all 60 isolates were positive for proviruses/prophages. Among the seven STs detected, ST204 (46.7%) and ST2 (21.7%) were the most prominent, with ST frequency varying significantly (p < 0.001). The predominant CC detected were CC2 (21.7%) and CC204 (46.7%) in lineages I and II, respectively. Of the 44 virulence factors detected, 26 (across Listeria Pathogenicity Islands, LIPIs) were present in all the isolates. The difference in the detection frequency varied significantly (p < 0.001). The two AMR genes (fosX and vga(G)) detected were present in all 60 (100%) isolates of L. monocytogenes. The only plasmid, NF033156, was present in three (5%) isolates. A CRISPR-Cas system was detected in six (10%), and all the isolates carried proviruses/prophages. The source and sample type significantly affected the frequencies of STs and virulence factors in the isolates of L. monocytogenes. The presence of fosX and vga(G) genes in all L. monocytogenes isolates obtained from the three industries of the beef production chain can potentially cause therapeutic implications. Our study, which characterized L. monocytogenes recovered from the three levels in the beef production chain, is the first time genomics was performed on this type of data set in the country, and this provides insights into the health implications of Listeria. Full article
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