Antibiotics

Open AccessArticle

Antimicrobial Usage and Detection of Multidrug-Resistant Staphylococcus aureus: Methicillin- and Tetracycline-Resistant Strains in Raw Milk of Lactating Dairy Cattle

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Antibiotics 2023, 12(4), 673; https://doi.org/10.3390/antibiotics12040673 (registering DOI) - 29 Mar 2023

Abstract

Staphylococcus aureus is a prominent cause of food-borne diseases worldwide. Enterotoxigenic strains of this bacteria are frequently found in raw milk, and some of these strains are resistant to antimicrobials, posing a risk to consumers. The main objectives of this study were to [...] Read more.

Staphylococcus aureus is a prominent cause of food-borne diseases worldwide. Enterotoxigenic strains of this bacteria are frequently found in raw milk, and some of these strains are resistant to antimicrobials, posing a risk to consumers. The main objectives of this study were to determine the antimicrobial resistance pattern of S. aureus in raw milk and to detect the presence of mecA and tetK genes in it. A total of 150 milk samples were obtained aseptically from lactating cattle, including Holstein Friesian, Achai, and Jersey breeds, maintained at different dairy farms. The milk samples were checked for the presence of S. aureus, and it was detected in 55 (37%) of them. The presence of S. aureus was verified by culturing on selective media, gram staining, and performing coagulase and catalase tests. Further confirmation was performed through PCR with a species-specific thermonuclease (nuc) gene. Antimicrobial susceptibility testing of the confirmed S. aureus was then determined by using the Kirby–Bauer disc diffusion technique. Out of the 55 confirmed S. aureus isolates, 11 were determined to be multidrug-resistant (MDR). The highest resistance was found to penicillin (100%) and oxacillin (100%), followed by tetracycline (72.72%), amikacin (27.27%), sulfamethoxazole/trimethoprim (18.18%), tobramycin (18.18%), and gentamycin (9.09%). Amoxicillin and ciprofloxacin were found to be susceptible (100%). Out of 11 MDR S. aureus isolates, the methicillin resistance gene (mecA) was detected in 9 isolates, while the tetracycline resistance gene (tetK) was found in 7 isolates. The presence of these methicillin- and tetracycline-resistant strains in raw milk poses a major risk to public health, as they can cause food poisoning outbreaks that can spread rapidly through populations. Our study concludes that out of nine empirically used antibiotics, amoxicillin, ciprofloxacin, and gentamicin were highly effective against S. aureus compared to penicillin, oxacillin, and tetracycline. Full article

(This article belongs to the Special Issue Molecular Epidemiology, Antimicrobial Resistance, and Virulence Genes in Drug-Resistant Bacteria)

Open AccessArticle

General Perceptions and Knowledge of Antibiotic Resistance and Antibiotic Use Behavior: A Cross-Sectional Survey of US Adults

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Antibiotics 2023, 12(4), 672; https://doi.org/10.3390/antibiotics12040672 (registering DOI) - 29 Mar 2023

Abstract

This study aimed to assess understanding of antibiotic resistance and evaluate antibiotic use themes among the general public. In March 2018, respondents that were ≥21 years old and residing in the United States were recruited from ResearchMatch.org and surveyed to collect data on [...] Read more.

This study aimed to assess understanding of antibiotic resistance and evaluate antibiotic use themes among the general public. In March 2018, respondents that were ≥21 years old and residing in the United States were recruited from ResearchMatch.org and surveyed to collect data on respondent expectations, knowledge, and opinions regarding prescribing antibiotics and antibiotic resistance. Content analysis was used to code open-ended definitions of antibiotic resistance into central themes. Chi-square tests were used to assess differences between the definitions of antibiotic resistance and antibiotic use. Among the 657 respondents, nearly all (99%) had taken an antibiotic previously. When asked to define antibiotic resistance, the definitions provided were inductively coded into six central themes: 35% bacteria adaptation, 22% misuse/overuse, 22% resistant bacteria, 10% antibiotic ineffectiveness, 7% body immunity, and 3% provided an incorrect definition with no consistent theme. Themes that were identified in respondent definitions of resistance significantly differed between those who reported having shared an antibiotic versus those who had not (p = 0.03). Public health campaigns remain a central component in the fight to combat antibiotic resistance. Future campaigns should address the public’s understanding of antibiotic resistance and modifiable behaviors that may contribute to resistance. Full article

(This article belongs to the Special Issue Feature Papers in Antibiotic Use in the Communities)

Open AccessArticle

Staphylococcus spp. Causatives of Infections and Carrier of blaZ, femA, and mecA Genes Associated with Resistance

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Laryssa Ketelyn Lima Pimenta

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Carolina Andrade Rodrigues

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Arlindo Rodrigues Galvão Filho

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Melissa Ameloti Gomes Avelino

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José Daniel Gonçalves Vieira

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Lilian Carneiro

Antibiotics 2023, 12(4), 671; https://doi.org/10.3390/antibiotics12040671 (registering DOI) - 29 Mar 2023

Abstract

Staphylococcus spp. have been associated with cases of healthcare associated infections due to their high incidence in isolates from the hospital environment and their ability to cause infections in immunocompromised patients; synthesize biofilms on medical instruments, in the case of negative coagulase species; [...] Read more.

Staphylococcus spp. have been associated with cases of healthcare associated infections due to their high incidence in isolates from the hospital environment and their ability to cause infections in immunocompromised patients; synthesize biofilms on medical instruments, in the case of negative coagulase species; and change in genetic material, thus making it possible to disseminate genes that code for the acquisition of resistance mechanisms against the action of antibiotics. This study evaluated the presence of blaZ, femA, and mecA chromosomal and plasmid genes of Staphylococcus spp. using the qPCR technique. The results were associated with the phenotypic expression of resistance to oxacillin and penicillin G. We found that the chromosomal femA gene was present in a greater proportion in S. intermedius when compared with the other species analyzed, while the plasmid-borne mecA gene was prevalent in the S. aureus samples. The binary logistic regression performed to verify the association among the expression of the genes analyzed and the acquisition of resistance to oxacillin and penicillin G were not significant in any of the analyses, p > 0.05. Full article

(This article belongs to the Special Issue Antimicrobial Resistance and Healthcare Associated Infections)

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Open AccessArticle

Pseudomonas Bacteremia in a Tertiary Hospital and Factors Associated with Mortality

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Petros Ioannou

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Konstantinos Alexakis

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Sofia Maraki

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Diamantis P. Kofteridis

Antibiotics 2023, 12(4), 670; https://doi.org/10.3390/antibiotics12040670 (registering DOI) - 29 Mar 2023

Abstract

Pseudomonas aeruginosa is the third most commonly identified cause among gram-negative microorganisms causing bloodstream infection (BSI) and carries a very high mortality, higher than that by other gram-negative pathogens. The aim of the present study was to assess the epidemiological and microbiological characteristics [...] Read more.

Pseudomonas aeruginosa is the third most commonly identified cause among gram-negative microorganisms causing bloodstream infection (BSI) and carries a very high mortality, higher than that by other gram-negative pathogens. The aim of the present study was to assess the epidemiological and microbiological characteristics of patients with BSI by Pseudomonas spp. in a tertiary hospital, characterize the resistance rates of different Pseudomonas strains to the most clinically relevant anti-microbials, estimate the mortality rate, and identify factors independently associated with mortality. In total, 540 cultures from 419 patients sent to the microbiology department of the hospital during the 8-year period of the study were positive. Patients had a median age of 66 years, and 262 (62.5%) were male. The blood culture was drawn in the ICU in 201 of the patients (48%). The infection was hospital-acquired in 329 patients (78.5%) and the median hospital day when the blood culture was drawn was 15, with a range of 0 to 267 days. Median duration of stay in the hospital was 36 days, hospital mortality was 44.2% (185 patients), and 30-day mortality was 29.6% (124 patients). The most commonly isolated Pseudomonas species were P. aeruginosa followed by P. putida and P. oryzihabitans. There was a statistically significant reduction of P. aeruginosa isolation relative to non-aeruginosa Pseudomonas species in the post-COVID-19 era. Antimicrobial resistance of P. aeruginosa in clinically relevant antimicrobials with anti-pseudomonal activity was similar before and after the onset of the COVID-19 pandemic with the exception of gentamicin and tobramycin, with P. aeruginosa being more susceptible to these two antimicrobials in the post-COVID-19 era. Rates of multi-drug resistant (MDR), extensively-drug resistant (XDR), and difficult-to-treat (DTR) P. aeruginosa isolation were lower after the onset of the COVID-19 pandemic, even though a carbapenem-focused antimicrobial stewardship program had been implemented in the meantime. Increased age, ICU-acquisition of BSI, and more days in the hospital when positive blood culture was drawn were positively associated with 30-day mortality of patients with Pseudomonas BSI. The fact that rates of MDR, XDR, and DTR P. aeruginosa isolation were lower late in the study period, with a carbapenem-focused antimicrobial stewardship intervention being implemented in the meantime, further increases the understanding that implementation of antimicrobial stewardship interventions may halt the increase in antimicrobial resistance noted previously. Full article

Open AccessReview

Staphylococcus capitis: Review of Its Role in Infections and Outbreaks

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Victoria Heath

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Elaine Cloutman-Green

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Samuel Watkin

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Magdalena Karlikowska

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Antibiotics 2023, 12(4), 669; https://doi.org/10.3390/antibiotics12040669 (registering DOI) - 29 Mar 2023

Abstract

In June 2021, a national incident team was formed due to an increased detection of Staphylococcus capitis in samples from hospitalised infants. Staphylococcus capitis has been known to cause outbreaks in neonatal units across the globe, but the extent of the UK spread [...] Read more.

In June 2021, a national incident team was formed due to an increased detection of Staphylococcus capitis in samples from hospitalised infants. Staphylococcus capitis has been known to cause outbreaks in neonatal units across the globe, but the extent of the UK spread was unclear. A literature review was undertaken to support case identification, clinical management and environmental infection control. A literature search was undertaken on multiple databases from inception to 24 May 2021, using keywords such as “Staphylococcus capitis”, “NRCS-A”, “S. capitis”, “neonate”, “newborn” and “neonatal intensive care unit” (NICU). After screening, 223 articles of relevance were included. Results show incidences of S. capitis outbreaks have frequently been associated with the outbreak clone (NRCS-A) and environmental sources. The NRCS-A harbours a multidrug resistance profile that includes resistance to beta-lactam antibiotics and aminoglycosides, with several papers noting resistance or heteroresistance to vancomycin. The NRCS-A clone also harbours a novel SCCmec-SCCcad/ars/cop composite island and increased vancomycin resistance. The S. capitis NRCS-A clone has been detected for decades, but the reasons for the potentially increased frequency are unclear, as are the most effective interventions to manage outbreaks associated with this clone. This supports the need for improvements in environmental control and decontamination strategies to prevent transmission. Full article

(This article belongs to the Special Issue Epidemiology and Characterization of Bacteria Isolated from Hospital)

Open AccessArticle

Antifungal and Antibiofilm Activity of Colombian Essential Oils against Different Candida Strains

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Antibiotics 2023, 12(4), 668; https://doi.org/10.3390/antibiotics12040668 (registering DOI) - 29 Mar 2023

Abstract

Most Candida species are opportunistic pathogens with the ability to form biofilms, which increases their resistance to antifungal drug therapies and the host immune response. Essential oils (EOs) are an alternative for developing new antimicrobial drugs, due to their broad effect on cellular [...] Read more.

Most Candida species are opportunistic pathogens with the ability to form biofilms, which increases their resistance to antifungal drug therapies and the host immune response. Essential oils (EOs) are an alternative for developing new antimicrobial drugs, due to their broad effect on cellular viability, cell communication, and metabolism. In this work, we evaluated the antifungal and antibiofilm potential of fifty EOs on C. albicans ATCC 10231, C. parapsilosis ATCC 22019, and Candida auris CDC B11903. The EOs’ antifungal activity was measured by means of a broth microdilution technique to determine the minimum inhibitory and fungicidal concentrations (MICs/MFCs) against the different Candida spp. strains. The effects on biofilm formation were determined by a crystal violet assay using 96-well round-bottom microplates incubated for 48 h at 35 °C. The EOs from Lippia alba (Verbenaceae family) carvone-limonene chemotype and L. origanoides exhibited the highest antifungal activity against C. auris. The L. origanoides EOs also presented antifungal and antibiofilm activity against all three Candida spp., thus representing a promising alternative for developing new antifungal products focused on yeast infections, especially those related to biofilm formation, virulence factors, and antimicrobial resistance. Full article

(This article belongs to the Special Issue Antimicrobial and Anti-inflammatory Activity of Bioactive Compounds Extracted from Plants)

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Open AccessArticle

Rapid Screening and Comparison of Chimeric Lysins for Antibacterial Activity against Staphylococcus aureus Strains

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Antibiotics 2023, 12(4), 667; https://doi.org/10.3390/antibiotics12040667 (registering DOI) - 29 Mar 2023

Abstract

Chimeric lysins composed of various combinations of cell wall-lysing (enzymatic) and cell-wall-binding (CWB) domains of endolysins, autolysins, and bacteriocins have been developed as alternatives to or adjuvants of conventional antibiotics. The screening of multiple chimeric lysin candidates for activity via E. coli expression [...] Read more.

Chimeric lysins composed of various combinations of cell wall-lysing (enzymatic) and cell-wall-binding (CWB) domains of endolysins, autolysins, and bacteriocins have been developed as alternatives to or adjuvants of conventional antibiotics. The screening of multiple chimeric lysin candidates for activity via E. coli expression is not cost effective, and we previously reported on a simple cell-free expression system as an alternative. In this study, we sufficiently improved upon this cell-free expression system for use in screening activity via a turbidity reduction test, which is more appropriate than a colony reduction test when applied in multiple screening. Using the improved protocol, we screened and compared the antibacterial activity of chimeric lysin candidates and verified the relatively strong activity associated with the CHAP (cysteine, histidine-dependent amidohydrolase/peptidase) domain of secretory antigen SsaA-like protein (ALS2). ALS2 expressed in E. coli showed two major bands, and the smaller one (subprotein) was shown to be expressed by an innate downstream promoter and start codon (ATG). The introduction of synonymous mutations in the promoter resulted in clearly reduced expression of the subprotein, whereas missense mutations in the start codon abolished antibacterial activity as well as subprotein production. Interestingly, most of the S. aureus strains responsible for bovine mastitis were susceptible to ALS2, but those from human and chicken were less susceptible. Thus, the simple and rapid screening method can be applied to select functional chimeric lysins and define mutations affecting antibacterial activity, and ALS2 may be useful in itself and as a lead molecule to control bovine mastitis. Full article

(This article belongs to the Section Biochemical and Genetics Studies of Infectious Disease Progression and Intervention)

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Open AccessArticle

Comparison of Five Different Selective Agar for the Detection of Vancomycin-Resistant Enterococcus faecium

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Antibiotics 2023, 12(4), 666; https://doi.org/10.3390/antibiotics12040666 - 29 Mar 2023

Abstract

Five commercially available selective agar were evaluated regarding sensitivity and specificity to detect vancomycin-resistant Enterococcus (E.) faecium. Altogether 187 E. faecium strains were included, comprising 119 van-carrying strains (phenotypically vancomycin-resistant n = 105; phenotypically vancomycin-susceptible VVE-B n = 14) [...] Read more.

Five commercially available selective agar were evaluated regarding sensitivity and specificity to detect vancomycin-resistant Enterococcus (E.) faecium. Altogether 187 E. faecium strains were included, comprising 119 van-carrying strains (phenotypically vancomycin-resistant n = 105; phenotypically vancomycin-susceptible VVE-B n = 14) and 68 vancomycin-susceptible isolates. Limit of detection was calculated for each selective agar for pure cultures, stool suspensions and artificial rectal swabs. After 24-h incubation sensitivity ranged between 91.6% and 95.0%. It increased in 2 out of 5 agar after 48-h incubation. Specificity ranged between 94.1% and 100% and was highest after 24 h in 4 out of the 5 agar. Sensitivity of van-carrying phenotypically vancomycin-resistant strains was higher after 24 h (97.1–100%) and 48 h (99.1–100%) when compared to van-carrying strains that tested vancomycin-susceptible (50.0–57.1% after both incubation periods). Overall, chromID VRE, CHROMagar VRE and Brilliance VRE demonstrated the highest detection rates after 24 h. Detection rates of Chromatic VRE and VRESelect improved after 48 h. Adjustment of incubation time depending on the applied media may be advised. As detection of VVE-B was impeded with all selective agar, screening for vancomycin-resistant enterococci relying solely on selective media would not be recommended for critical clinical samples, but rather in combination with molecular methods to improve detection of these strains. Furthermore, stool samples were demonstrated to be superior to rectal swabs and should be favoured, if possible, in screening strategies. Full article

(This article belongs to the Special Issue Antibiotic Treatment and Antibiotic Resistance of Enterococcus Infections)

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Open AccessReview

Anti-COVID-19 Credentials of Chitosan Composites and Derivatives: Future Scope?

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Judy Gopal

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Manikandan Muthu

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Suraj Shiv Charan Pushparaj

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Iyyakkannu Sivanesan

Antibiotics 2023, 12(4), 665; https://doi.org/10.3390/antibiotics12040665 - 28 Mar 2023

Abstract

Chitosan derivatives and composites are the next generation polymers for biomedical applications. With their humble origins from the second most abundant naturally available polymer chitin, chitosan is currently one of the most promising polymer systems, with wide biological applications. This current review gives [...] Read more.

Chitosan derivatives and composites are the next generation polymers for biomedical applications. With their humble origins from the second most abundant naturally available polymer chitin, chitosan is currently one of the most promising polymer systems, with wide biological applications. This current review gives a bird’s eye view of the antimicrobial applications of chitosan composites and derivatives. The antiviral activity and the mechanisms behind the inhibitory activity of these components have been reviewed. Specifically, the anti-COVID-19 aspects of chitosan composites and their derivatives have been compiled from the existing scattered reports and presented. Defeating COVID-19 is the battle of this century, and the chitosan derivative-based combat strategies naturally become very attractive. The challenges ahead and future recommendations have been addressed. Full article

(This article belongs to the Special Issue Life Defense in the New Century: Natural Products in the Development of New Antimicrobial Drugs)

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Open AccessReview

Clinical Aspects of Bacterial Distribution and Antibiotic Resistance in the Reproductive System of Equids

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Panagiota Tyrnenopoulou

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George C. Fthenakis

Antibiotics 2023, 12(4), 664; https://doi.org/10.3390/antibiotics12040664 - 28 Mar 2023

Abstract

Antibiotic administration is a standard therapeutic practice for the treatment of reproductive disorders of equids. This might lead to undesirable microbial imbalance and could favour the acquisition of antibiotic resistance. Therefore, it is imperative for clinicians to understand patterns of antibiotic resistance when [...] Read more.

Antibiotic administration is a standard therapeutic practice for the treatment of reproductive disorders of equids. This might lead to undesirable microbial imbalance and could favour the acquisition of antibiotic resistance. Therefore, it is imperative for clinicians to understand patterns of antibiotic resistance when considering and developing treatment regimes. Continued engagement of clinicians with novel alternative approaches to treat reproductive infections would be essential in order to address this rising threat within the One Health perspective. The objectives of the present review were to present the bacterial infections in the reproductive system of equids (horses, donkeys), to upraise the literature related to the issue of antibiotic resistance of bacteria causing these infections and to discuss the topic from a clinical perspective. Initially, the review summarised the various infections of the reproductive system of equids (genital system of females, genital system of males, mammary glands) and the causal bacteria, providing relevant information about horses and donkeys. Subsequently, the clinical therapeutics of these infections were presented, taking into account the significance of antibiotic resistance of bacteria as a limiting factor in treating the infections. Finally, approaches to circumvent antibiotic resistance in clinical settings were summarized. It was concluded that awareness regarding antibiotic resistance in equine reproductive medicine would increase, as we would recognise the multifaceted problem of resistance. Actions and initiatives within the One Health approach, minimizing the potential dissemination of resistant strains to humans and to the environment, with specific applications in medicine of equids should be appropriately instituted internationally. Full article

(This article belongs to the Special Issue Antimicrobial Resistance and Zoonoses)

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Open AccessArticle

Kaurane-Type Diterpenoids as Potential Inhibitors of Dihydrofolate Reductase-Thymidylate Synthase in New World Leishmania Species

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Chonny Herrera-Acevedo

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Renata Priscila Barros de Menezes

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Natália Ferreira de Sousa

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Luciana Scotti

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Marcus Tullius Scotti

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Ericsson Coy-Barrera

Antibiotics 2023, 12(4), 663; https://doi.org/10.3390/antibiotics12040663 - 28 Mar 2023

Abstract

The bifunctional enzyme Dihydrofolate reductase-thymidylate synthase (DHFR-TS) plays a crucial role in the survival of the Leishmania parasite, as folates are essential cofactors for purine and pyrimidine nucleotide biosynthesis. However, DHFR inhibitors are largely ineffective in controlling trypanosomatid infections, largely due to the [...] Read more.

The bifunctional enzyme Dihydrofolate reductase-thymidylate synthase (DHFR-TS) plays a crucial role in the survival of the Leishmania parasite, as folates are essential cofactors for purine and pyrimidine nucleotide biosynthesis. However, DHFR inhibitors are largely ineffective in controlling trypanosomatid infections, largely due to the presence of Pteridine reductase 1 (PTR1). Therefore, the search for structures with dual inhibitory activity against PTR1/DHFR-TS is crucial in the development of new anti-Leishmania chemotherapies. In this research, using the Leishmania major DHFR-TS recombinant protein, enzymatic inhibitory assays were performed on four kauranes and two derivatives that had been previously tested against LmPTR1. The structure 302 (6.3 µM) and its derivative 302a (4.5 µM) showed the lowest IC₅₀ values among the evaluated molecules. To evaluate the mechanism of action of these structures, molecular docking calculations and molecular dynamics simulations were performed using a DHFR-TS hybrid model. Results showed that hydrogen bond interactions are critical for the inhibitory activity against LmDHFR-TS, as well as the presence of the p-hydroxyl group of the phenylpropanoid moiety of 302a. Finally, additional computational studies were performed on DHFR-TS structures from Leishmania species that cause cutaneous and mucocutaneous leishmaniasis in the New World (L. braziliensis, L. panamensis, and L. amazonensis) to explore the targeting potential of these kauranes in these species. It was demonstrated that structures 302 and 302a are multi-Leishmania species compounds with dual DHFR-TS/PTR1 inhibitory activity. Full article

(This article belongs to the Special Issue Antiprotozoal Activity of Natural Products)

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Open AccessArticle

Assessment of Heavy Metals Contamination and Antimicrobial Drugs Residue in Broiler Edible Tissues in Bangladesh

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Shaikh Mohammad Bakhtiar

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Mohammad Rafiqul Islam

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Md. Jisan Ahmed

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Abdur Rahman

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Kazi Rafiq

Antibiotics 2023, 12(4), 662; https://doi.org/10.3390/antibiotics12040662 - 28 Mar 2023

Abstract

There are substantial public health consequences when hazardous heavy metal contaminants and antimicrobial drug residues are present in broiler edible tissues. This study aimed to assess the concentration of antimicrobial drugs and heavy metals residues in broiler meat, bones and edible composites (combinations [...] Read more.

There are substantial public health consequences when hazardous heavy metal contaminants and antimicrobial drug residues are present in broiler edible tissues. This study aimed to assess the concentration of antimicrobial drugs and heavy metals residues in broiler meat, bones and edible composites (combinations of liver, kidney and gizzard). Samples were collected from different types of broiler farms, broiler wet meat markets and supermarkets, covering all five divisions of Bangladesh. The antimicrobial drug and heavy metal residues were analyzed by uHPLC and ICP-MS, respectively. In addition, a cross-sectional survey was conducted among broiler meat consumers in the study areas to evaluate their attitude towards the consumption of broiler meat. The survey clearly stated that broiler meat consumers in Bangladesh have a negative attitude toward the consumption of broiler meat, although all respondents reported to eat broiler meat regularly. The antibiotic with the highest prevalence of residues in broiler edible tissues was oxytetracycline, followed by doxycycline, sulphadiazine and chloramphenicol. On the other hand, all collected broiler edible tissues contained chromium and lead, followed by arsenic. The fact of the matter is that the antimicrobial drugs and heavy metals residues were found to be below the maximum residue limit (MRL), except for the lead content. In addition, the broiler meat samples from supermarkets had lower levels of antimicrobial drugs and heavy metals residue compared to the broiler meat collected from various types of farms and broiler wet meat markets. Irrespective of the source, broiler meat was found to contain antimicrobial drugs and heavy metals residues below the MRL, except for lead, suggesting that broiler meat is safe for human consumption. Therefore, raising public awareness regarding misconceptions about broiler meat consumption among consumers would be warranted. Full article

(This article belongs to the Special Issue Research of Antimicrobial Resistance in the Food Chain)

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Open AccessReview

Extended-Spectrum β-Lactamases (ESBL) Producing Bacteria in Animals

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Chien-Hao Tseng

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Chia-Wei Liu

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Po-Yu Liu

Antibiotics 2023, 12(4), 661; https://doi.org/10.3390/antibiotics12040661 - 28 Mar 2023

Abstract

Animals have been identified as potential reservoirs and vectors of resistance genes, with studies showing that Gram-negative bacteria can acquire resistance through the horizontal transmission of resistance genes on plasmids. It is important to understand the distribution of antimicrobial-resistant bacteria and their drug-resistant [...] Read more.

Animals have been identified as potential reservoirs and vectors of resistance genes, with studies showing that Gram-negative bacteria can acquire resistance through the horizontal transmission of resistance genes on plasmids. It is important to understand the distribution of antimicrobial-resistant bacteria and their drug-resistant genes in animals. Previous review articles mostly focused on a single bacterium or a single animal. Our objective is to compile all ESBL-producing bacteria isolated from various animals in recent years and provide a comprehensive viewpoint. Using a thorough PubMed literature search spanning from 1 January 2020 to 30 June 2022, studies exploring extended-spectrum beta-lactamase (ESBL) producing bacteria in animals were included. ESBL-producing bacteria are present in animals from various countries around the world. The most common sources of these bacteria were farm animals, and the most frequently isolated bacteria were Escherichia coli and Klebsiella pneumoniae. The most detected ESBL genes were bla_TEM, bla_SHV, and bla_CTX-M. The presence of ESBL-producing bacteria in animals highlights the importance of the One Health approach to address the issue of antibiotic resistance. Further research is needed to better understand the epidemiology and mechanisms of the spread of ESBL-producing bacteria in animal populations and their potential impact on human and animal health. Full article

(This article belongs to the Special Issue Epidemiology of ESBL-Producing Enterobacteriaceae)

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Open AccessReview

Regulation of Host Defense Peptide Synthesis by Polyphenols

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Isabel Tobin

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Guolong Zhang

Antibiotics 2023, 12(4), 660; https://doi.org/10.3390/antibiotics12040660 - 28 Mar 2023

Abstract

The rise of antimicrobial resistance has created an urgent need for antibiotic-alternative strategies for disease control and prevention. Host defense peptides (HDPs), which have both antimicrobial and immunomodulatory properties, are an important component of the innate immune system. A host-directed approach to stimulate [...] Read more.

The rise of antimicrobial resistance has created an urgent need for antibiotic-alternative strategies for disease control and prevention. Host defense peptides (HDPs), which have both antimicrobial and immunomodulatory properties, are an important component of the innate immune system. A host-directed approach to stimulate the synthesis of endogenous HDPs has emerged as a promising solution to treat infections with a minimum risk for developing antimicrobial resistance. Among a diverse group of compounds that have been identified as inducers of HDP synthesis are polyphenols, which are naturally occurring secondary metabolites of plants characterized by the presence of multiple phenol units. In addition to their well-known antioxidant and anti-inflammatory activities, a variety of polyphenols have been shown to stimulate HDP synthesis across animal species. This review summarizes both the in vitro and in vivo evidence of polyphenols regulating HDP synthesis. The mechanisms by which polyphenols induce HDP gene expression are also discussed. Natural polyphenols warrant further investigation as potential antibiotic alternatives for the control and prevention of infectious diseases. Full article

(This article belongs to the Special Issue Reviews on Antimicrobial Peptides)

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Open AccessArticle

Impact of COVID-19 Pandemic on Antibiotic Utilisation in Malaysian Primary Care Clinics: An Interrupted Time Series Analysis

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Tineshwaran Velvanathan

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Mary Chiew Fong Chok

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Sheamini Sivasampu

Antibiotics 2023, 12(4), 659; https://doi.org/10.3390/antibiotics12040659 - 28 Mar 2023

Abstract

The COVID-19 pandemic has resulted in a dramatic change in the delivery of primary healthcare across the world, presumably changing trends in consultations for infectious diseases and antibiotic use. This study aimed at describing and evaluating the impact of COVID-19 on antibiotic use [...] Read more.

The COVID-19 pandemic has resulted in a dramatic change in the delivery of primary healthcare across the world, presumably changing trends in consultations for infectious diseases and antibiotic use. This study aimed at describing and evaluating the impact of COVID-19 on antibiotic use in public primary care clinics in Malaysia between 2018 and 2021. Data from the nationwide procurement database of systemic antibiotics from public primary care clinics in Malaysia between January 2018 and December 2021 were analysed using interrupted time series analysis. The monthly number of defined daily doses per 1000 inhabitants per day (DID) was calculated and grouped by antibiotic class. The trend of antibiotic utilisation rates had been decreasing by 0.007 DID monthly before March 2020 (p = 0.659). With the introduction of national lockdown due to COVID-19 beginning March 2020, there was a significant reduction in the level of antibiotic utilisation rates of 0.707 (p = 0.022). Subsequently, the monthly trend showed a slight upward change until the end of the study period (p = 0.583). Our findings indicate that there was a significant decrease in antibiotic utilisation for systemic use in primary care following the COVID-19 pandemic compared with the preceding years (January 2018–March 2020). Full article

(This article belongs to the Special Issue Antimicrobials in Primary Care: Advances, Failures and Prospects)

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Open AccessSystematic Review

Worldwide Dissemination of bla_KPC Gene by Novel Mobilization Platforms in Pseudomonas aeruginosa: A Systematic Review

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Daniela Forero-Hurtado

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Zayda Lorena Corredor-Rozo

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Julián Santiago Ruiz-Castellanos

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Ricaurte Alejandro Márquez-Ortiz

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Antibiotics 2023, 12(4), 658; https://doi.org/10.3390/antibiotics12040658 - 28 Mar 2023

Abstract

The dissemination of bla_KPC-harboring Pseudomonas aeruginosa (KPC-Pa) is considered a serious public health problem. This study provides an overview of the epidemiology of these isolates to try to elucidate novel mobilization platforms that could contribute to their worldwide spread. [...] Read more.

The dissemination of bla_KPC-harboring Pseudomonas aeruginosa (KPC-Pa) is considered a serious public health problem. This study provides an overview of the epidemiology of these isolates to try to elucidate novel mobilization platforms that could contribute to their worldwide spread. A systematic review in PubMed and EMBASE was performed to find articles published up to June 2022. In addition, a search algorithm using NCBI databases was developed to identify sequences that contain possible mobilization platforms. After that, the sequences were filtered and pair-aligned to describe the bla_KPC genetic environment. We found 691 KPC-Pa isolates belonging to 41 different sequence types and recovered from 14 countries. Although the bla_KPC gene is still mobilized by the transposon Tn4401, the non-Tn4401 elements (NTE_KPC) were the most frequent. Our analysis allowed us to identify 25 different NTE_KPC, mainly belonging to the NTE_KPC-I, and a new type (proposed as IVa) was also observed. This is the first systematic review that consolidates information about the behavior of the bla_KPC acquisition in P. aeruginosa and the genetic platforms implied in its successful worldwide spread. Our results show high NTE_KPC prevalence in P. aeruginosa and an accelerated dynamic of unrelated clones. All information collected in this review was used to build an interactive online map. Full article

(This article belongs to the Special Issue Drugs for Superbugs: Antibiotic Discovery, Modes of Action and Mechanisms of Resistance)

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Open AccessArticle

Determination of the Prevalence and Antimicrobial Resistance of Enterococcus faecalis and Enterococcus faecium Associated with Poultry in Four Districts in Zambia

by

Grace Mwikuma

,

Henson Kainga

,

Simegnew Adugna Kallu

,

Chie Nakajima

,

Yasuhiko Suzuki

and

Bernard Mudenda Hang’ombe

Antibiotics 2023, 12(4), 657; https://doi.org/10.3390/antibiotics12040657 - 28 Mar 2023

Abstract

The presence of antimicrobial-resistant Enterococci in poultry is a growing public health concern worldwide due to its potential for transmission to humans. The aim of this study was to determine the prevalence and patterns of antimicrobial resistance and to detect drug-resistant genes in [...] Read more.

The presence of antimicrobial-resistant Enterococci in poultry is a growing public health concern worldwide due to its potential for transmission to humans. The aim of this study was to determine the prevalence and patterns of antimicrobial resistance and to detect drug-resistant genes in Enterococcus faecalis and E. faecium in poultry from four districts in Zambia. Identification of Enterococci was conducted using phenotypic methods. Antimicrobial resistance was determined using the disc diffusion method and antimicrobial resistance genes were detected using polymerase chain reaction and gene-specific primers. The overall prevalence of Enterococci was 31.1% (153/492, 95% CI: 27.1–35.4). Enterococcus faecalis had a significantly higher prevalence at 37.9% (58/153, 95% CI: 30.3–46.1) compared with E. faecium, which had a prevalence of 10.5% (16/153, 95% CI: 6.3–16.7). Most of the E. faecalis and E. faecium isolates were resistant to tetracycline (66/74, 89.2%) and ampicillin and erythromycin (51/74, 68.9%). The majority of isolates were susceptible to vancomycin (72/74, 97.3%). The results show that poultry are a potential source of multidrug-resistant E. faecalis and E. faecium strains, which can be transmitted to humans. Resistance genes in the Enterococcus species can also be transmitted to pathogenic bacteria if they colonize the same poultry, thus threatening the safety of poultry production, leading to significant public health concerns. Full article

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Open AccessArticle

Molecular Epidemiology and Antibiotic Resistance Analysis of Non-Typeable Haemophilus influenzae (NTHi) in Guangzhou: A Representative City of Southern China

by

,

,

,

,

,

and

Antibiotics 2023, 12(4), 656; https://doi.org/10.3390/antibiotics12040656 - 28 Mar 2023

Abstract

This study aimed to investigate the molecular epidemiology and antibiotic resistance of Haemophilus influenzae in Guangzhou, China. A total of 80 H. influenzae isolates were collected from the First Affiliated Hospital of Guangzhou Medical University from January 2020 to April 2021. Species identification, [...] Read more.

This study aimed to investigate the molecular epidemiology and antibiotic resistance of Haemophilus influenzae in Guangzhou, China. A total of 80 H. influenzae isolates were collected from the First Affiliated Hospital of Guangzhou Medical University from January 2020 to April 2021. Species identification, antimicrobial susceptibility, molecular capsular typing, multilocus sequence typing and the clinical characteristics analysis of patients were performed. For all recruited isolates, the majority of H. influenzae strains from patients with respiratory symptoms were found to be non-typeable H. influenzae (NTHi). The isolates were relative susceptible to third- and fourth-generation cephalosporins, quinolones and chloramphenicol, despite having a high ampicillin resistance rate (>70%). The genotyping results reveal a total of 36 sequence types (STs), with ST12 being the most prevalent ST. Remarkably, the 36 STs identified from 80 NTHi isolates within a short period of 15 months and in a single medical setting have revealed a high genetic diversity in NTHi isolates. In comparison, it is noteworthy that the most prevalent STs found in the present study have rarely been found to overlap with those from previous studies. This is the first study on the molecular epidemiology of NTHi isolates in Guangzhou, a city that is representative of southern China. Full article

(This article belongs to the Collection Antimicrobial Resistance and Anti-Biofilms)

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Open AccessArticle

Assessment of the Antioxidant and Antimicrobial Potential of Ptychotis verticillata Duby Essential Oil from Eastern Morocco: An In Vitro and In Silico Analysis

by

,

,

,

,

,

,

,

,

,

,

,

and

Antibiotics 2023, 12(4), 655; https://doi.org/10.3390/antibiotics12040655 - 27 Mar 2023

Abstract

Ptychotis verticillata Duby, referred to as Nûnkha in the local language, is a medicinal plant that is native to Morocco. This particular plant is a member of the Apiaceae family and has a longstanding history in traditional medicine and has been utilized for [...] Read more.

Ptychotis verticillata Duby, referred to as Nûnkha in the local language, is a medicinal plant that is native to Morocco. This particular plant is a member of the Apiaceae family and has a longstanding history in traditional medicine and has been utilized for therapeutic purposes by practitioners for generations. The goal of this research is to uncover the phytochemical makeup of the essential oil extracted from P. verticillata, which is indigenous to the Touissite region in Eastern Morocco. The extraction of the essential oil of P. verticillata (PVEO) was accomplished through the use of hydro-distillation via a Clevenger apparatus. The chemical profile of the essential oil was then determined through analysis utilizing gas chromatography–mass spectrometry (GC/MS). The study findings indicated that the essential oil of P. verticillata is composed primarily of Carvacrol (37.05%), D-Limonene (22.97%), γ-Terpinene (15.97%), m-Cymene (12.14%) and Thymol (8.49%). The in vitro antioxidant potential of PVEO was evaluated using two methods: the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical trapping assay and the ferric reducing antioxidant power (FRAP) method. The data demonstrated considerable radical scavenging and relative antioxidative power. Escherichia coli, Staphylococcus aureus, Listeria innocua, and Pseudomonas aeruginosa were the most susceptible bacterial strains tested, while Geotrichum candidum, Candida albicans, and Rhodotorula glutinis were the most resilient fungi strains. PVEO had broad-spectrum antifungal and antibacterial properties. To elucidate the antioxidative and antibacterial characteristics of the identified molecules, we applied the methodology of molecular docking, a computational approach that forecasts the binding of a small molecule to a protein. Additionally, we utilized the Prediction of Activity Spectra for Substances (PASS) algorithm; Absorption, Distribution, Metabolism, and Excretion (ADME); and Pro-Tox II (to predict the toxicity in silico) tests to demonstrate PVEO’s identified compounds’ drug-likeness, pharmacokinetic properties, the anticipated safety features after ingestion, and the potential pharmacological activity. Finally, our findings scientifically confirm the ethnomedicinal usage and usefulness of this plant, which may be a promising source for future pharmaceutical development. Full article

(This article belongs to the Special Issue Antimicrobial Activity of Essential Oils, 2nd Volume)

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