Frontiers in antibiotics最新文献

{"title":"Antimicrobial susceptibility testing and tentative epidemiological cut-off values for <i>Lactobacillaceae</i> family species intended for ingestion.","authors":"Katrine Nøhr-Meldgaard, Carsten Struve, Hanne Ingmer, Anna Koza, Kosai Al-Nakeeb, Yvonne Agersø","doi":"10.3389/frabi.2023.1162636","DOIUrl":"10.3389/frabi.2023.1162636","url":null,"abstract":"<p><strong>Introduction: </strong>In this work, 170 strains covering 13 species from the <i>Lactobacillaceae</i> family were analyzed to determine minimal inhibitory concentration (MIC) distributions to nine antimicrobial agents, and genes potentially conferring resistance. This allows a proposal of tentative Epidemiological Cut-Offs (ECOFFs) that follows the phylogeny for interpretation of resistance in the 13 species.</p><p><strong>Methods: </strong>The 170 strains originated from different sources, geographical areas, and time periods. MICs for nine antibiotics were determined according to the ISO 10932 standard for lactobacillia and by a modified CLSI-method for <i>Leuconostoc</i> and <i>Pediococcus</i> which ensured sufficient growth. The strains were whole genome sequenced, subtyped by core genome analysis, and assessed for the presence of antibiotic resistance genes using the ResFinder and NCBI AMRFinder databases.</p><p><strong>Results and discussion: </strong>The data provide evidence that antimicrobial susceptibility follows phylogeny instead of fermentation pattern and accordingly, tentative ECOFFs were defined. For some species the tentative ECOFFs for specific antibiotics are above the cut-off values set by the European Food Safety Authority (EFSA) which are primarily defined according to fermentation pattern or at genus level. The increased tolerance for specific antibiotics observed for some species was evaluated to be innate, as only for one strain phenotypic resistance was found to be related to an acquired resistance gene. In general, more data are needed to define ECOFFs and since the number of isolates available for industrial relevant bacterial species are often limited compared to clinically relevant species, it is important; 1) that strains are unambiguously defined at species level and subtyped through core genome analysis, 2) MIC determination are performed by use of a standardized method to define species-specific MIC distributions and 3) that known antimicrobial resistance genes are determined in whole genome sequences to support the MIC determinations.</p>","PeriodicalId":73065,"journal":{"name":"Frontiers in antibiotics","volume":" ","pages":"1162636"},"PeriodicalIF":0.0,"publicationDate":"2023-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11732008/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46572607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Allele distribution and phenotypic resistance to ciprofloxacin and gentamicin among extended-spectrum β-lactamase-producing <i>Escherichia coli</i> isolated from the urine, stool, animals, and environments of patients with presumptive urinary tract infection in Tanzania.","authors":"Adam A Mwakyoma, Benson R Kidenya, Caroline A Minja, Martha F Mushi, Alison Sandeman, Wilber Sabiti, Mathew T G Holden, Stephen E Mshana","doi":"10.3389/frabi.2023.1164016","DOIUrl":"10.3389/frabi.2023.1164016","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Additional antimicrobial resistance to extended-spectrum β-lactamase (ESBL)-producing &lt;i&gt;E. coli&lt;/i&gt; exhausts treatment options. We investigated allele distribution and resistance to ciprofloxacin and gentamicin among ESBL-producing &lt;i&gt;E. coli&lt;/i&gt; isolates from the urine, stool, animals, and environments of presumptive urinary tract infection (UTI) patients, in order to gain a crucial insight toward devising prevention and control measures and treatment guidelines.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;Archived ESBL-producing &lt;i&gt;E. coli&lt;/i&gt; isolates from the urine, stool, animals, and surrounding environments of presumptive UTI patients were retrieved. Antimicrobial susceptibility profiles for ciprofloxacin and gentamicin were done followed by multiplex Polymerase chain reaction (PCR) for &lt;i&gt;bla&lt;sub&gt;CTX-M&lt;/sub&gt;&lt;/i&gt; , &lt;i&gt;bla&lt;sub&gt;TEM&lt;/sub&gt;&lt;/i&gt; , and &lt;i&gt;bla&lt;sub&gt;SHV&lt;/sub&gt;&lt;/i&gt; , to determine ESBL allele distribution. Data were analyzed using STATA version 17.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;A total of 472 confirmed ESBL-producing &lt;i&gt;E. coli&lt;/i&gt; isolates from Mwanza 243 (51.5%), Kilimanjaro 143 (30.3%), and Mbeya 86 (18.2%) were analyzed. Of these, 75 (15.9%) were from urine, 199 (42.2%) from stool, 58 (12.3%) from rectal/cloaca swabs of animals, and 140 (29.7%) from surrounding environments. Out of the 472 ESBL-producing &lt;i&gt;E. coli&lt;/i&gt;, 98.9% (467) had at least one ESBL allele. The most frequent allele was &lt;i&gt;bla&lt;sub&gt;CTX-M&lt;/sub&gt;&lt;/i&gt; , which was detected in 88.1% (416/472) of isolates, followed by the &lt;i&gt;bla&lt;sub&gt;TEM&lt;/sub&gt;&lt;/i&gt; allele, which was detected in 51.5% (243/472) of isolates. A total of 40.7% (192/472) of isolates harbored dual &lt;i&gt;bla&lt;sub&gt;CTX-M&lt;/sub&gt;&lt;/i&gt;  + &lt;i&gt;bla&lt;sub&gt;TEM&lt;/sub&gt;&lt;/i&gt; alleles and only 0.2% (1/472) of isolates had dual &lt;i&gt;bla&lt;sub&gt;CTX-M&lt;/sub&gt;&lt;/i&gt;  + &lt;i&gt;bla&lt;sub&gt;SHV&lt;/sub&gt;&lt;/i&gt; alleles, whereas 2.3% (11/472) of isolates had a combination of all three alleles (&lt;i&gt;bla&lt;sub&gt;CTX-M&lt;/sub&gt;&lt;/i&gt;  + &lt;i&gt;bla&lt;sub&gt;TEM&lt;/sub&gt;&lt;/i&gt;  + &lt;i&gt;bla&lt;sub&gt;SHV&lt;/sub&gt;&lt;/i&gt; ). None of the isolates harbored a combination of &lt;i&gt;bla&lt;sub&gt;TEM&lt;/sub&gt;&lt;/i&gt;  + &lt;i&gt;bla&lt;sub&gt;SHV&lt;/sub&gt;&lt;/i&gt; only. Resistance to ciprofloxacin and gentamicin was observed in 70.8% (334/472) and 46.0% (217/472) of isolates, respectively. There was a significant difference in the distribution of resistance to ciprofloxacin as well as gentamicin among ESBL-producing &lt;i&gt;E. coli&lt;/i&gt; isolated from various sources (&lt;i&gt;p&lt;/i&gt;-value &lt; 0.001 and 0.002, respectively).&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;Almost all ESBL-producing &lt;i&gt;E. coli&lt;/i&gt; isolates carry &lt;i&gt;bla&lt;sub&gt;CTX-M&lt;/sub&gt;&lt;/i&gt; , &lt;i&gt;bla&lt;sub&gt;TEM&lt;/sub&gt;&lt;/i&gt; , and &lt;i&gt;bla&lt;sub&gt;SHV&lt;/sub&gt;&lt;/i&gt; either alone or in combination, with the most common allele being &lt;i&gt;bla&lt;sub&gt;CTX-M.&lt;/sub&gt;&lt;/i&gt; The resistance to ciprofloxacin and gentamicin, which are frontline antibiotics for UTIs among ESBL-producing &lt;i&gt;E. coli&lt;/i&gt;, is high. This implies the need to continually revise the local guidelines used for optimal empirical therapy for UTIs, and for continual r","PeriodicalId":73065,"journal":{"name":"Frontiers in antibiotics","volume":" ","pages":"1164016"},"PeriodicalIF":0.0,"publicationDate":"2023-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11732152/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44201076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence and antimicrobial resistance profile of bacterial foodborne pathogens in Nile tilapia fish (<i>Oreochromis niloticus</i>) at points of retail sale in Nairobi, Kenya.","authors":"Millicent T Mumbo, Evans N Nyaboga, Johnson Kinyua, Edward K Muge, Scholastica G K Mathenge, Geoffrey Muriira, Henry Rotich, Bernard Njiraini, Joshua M Njiru","doi":"10.3389/frabi.2023.1156258","DOIUrl":"10.3389/frabi.2023.1156258","url":null,"abstract":"&lt;p&gt;&lt;p&gt;&lt;i&gt;Proteus spp&lt;/i&gt;., &lt;i&gt;Staphylococcus spp&lt;/i&gt;., &lt;i&gt;Pseudeomonas spp&lt;/i&gt;., and pathogenic Vibrios are among the major foodborne pathogens associated with the consumption of contaminated fish. The increasing occurrence of antimicrobial resistance in these pathogens is a serious public health concern globally and therefore continuous monitoring of antimicrobial resistance of these bacteria along the food chain is crucial for for control of foodborne illnesses. The aim of this study was to assess the prevalence, antimicrobial resistance patterns, antibiotic resistance genes, and genetic diversity of bacterial foodborne pathogens recovered from fresh Nile tilapia (&lt;i&gt;Oreochromis niloticus&lt;/i&gt;) obtained from retail markets in Nairobi, Kenya. A total of 68 &lt;i&gt;O. niloticus&lt;/i&gt; fish with an average weight of 300.12 ± 25.66 g and body length of 23.00 ± 0.82 cm were randomly sampled from retail markets and tested for the presence of &lt;i&gt;Proteus, Staphylococcus aureus, Pseudomonas aeruginosa, Vibrio cholerae&lt;/i&gt;, and &lt;i&gt;Vibrio parahaemolyticus&lt;/i&gt;. Standard culture-based microbiological and Kirby-Bauer agar disk diffusion methods were used to isolate and determine the antimicrobial resistance patterns of the isolates to 11 selected antibiotics. Statistical analysis was performed using Minitab v17.1, with &lt;i&gt;p&lt;/i&gt; &lt; 0.05 considered significant. The genetic diversity of the multidrug-resistant (MDR) and extensively drug-resistant (XDR) bacteria was determined using 16S rRNA sequencing and phylogenetic analysis, and polymerase chain reaction (PCR) was used for detection of antibiotic resistance genes in MDR bacterial isolates. High levels of bacterial contamination were detected in fresh &lt;i&gt;O. niloticus&lt;/i&gt; fish (44/68, 64.71%). The most prevalent bacteria were &lt;i&gt;Proteus&lt;/i&gt; spp. (44.12%), with the rest of the bacterial species registering a prevalence of 10.29%, 4.41%, 2.94%, and 2.94% (for &lt;i&gt;S. aureus&lt;/i&gt;, &lt;i&gt;P. aeruginosa&lt;/i&gt;, &lt;i&gt;V. cholerae&lt;/i&gt;, and &lt;i&gt;V. parahaemolyticus&lt;/i&gt;, respectively). Antimicrobial resistance was detected in all the bacteria species and all the isolates were resistant to at least one antibiotic except cefepime (30 µg). Additionally, 86.36% of the isolates exhibited multidrug resistance, with higher multiple antibiotic resistance indices (MAR index &gt;0.3) indicating that fresh &lt;i&gt;O. niloticus&lt;/i&gt; fish were highly contaminated with MDR bacteria. Results of 16S rRNA sequences, BLASTn analysis, and phylogenetic trees confirmed the identified MDR bacterial isolates as &lt;i&gt;Proteus mirabilis&lt;/i&gt; and other &lt;i&gt;Proteus&lt;/i&gt; spp.&lt;i&gt;, S. aureus&lt;/i&gt;, &lt;i&gt;P. aeruginosa&lt;/i&gt;, &lt;i&gt;V. cholerae&lt;/i&gt;, and &lt;i&gt;V. parahaemolyticus&lt;/i&gt;. PCR analysis confirmed the presence of multiple antibiotic resistance genes &lt;i&gt;bla&lt;/i&gt;TEM-1, &lt;i&gt;bla&lt;/i&gt;CMY-2, &lt;i&gt;tet&lt;/i&gt;A, &lt;i&gt;tet&lt;/i&gt;C, &lt;i&gt;Sul&lt;/i&gt;2, &lt;i&gt;dfr&lt;/i&gt;A7, &lt;i&gt;str&lt;/i&gt;A, and &lt;i&gt;aad&lt;/i&gt;A belonging to β-lactamases, tetracycline, sulfonamide, trimethoprim, and aminoglycosides in all the MDR bacterial isolates. There was","PeriodicalId":73065,"journal":{"name":"Frontiers in antibiotics","volume":" ","pages":"1156258"},"PeriodicalIF":0.0,"publicationDate":"2023-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11731917/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46063868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"C-1 Substituted isoquinolines potentiate the antimycobacterial activity of rifampicin and ethambutol.","authors":"Liam T Martin, Eleanor D Lamming, Arundhati Maitra, Parisa N Mortazavi, Rebecca Roddan, John M Ward, Sanjib Bhakta, Helen C Hailes","doi":"10.3389/frabi.2023.1095013","DOIUrl":"10.3389/frabi.2023.1095013","url":null,"abstract":"<p><strong>Introduction: </strong>The emergence of extensively drug-resistant strains of <i>Mycobacterium tuberculosis</i> threatens decades of progress in the treatment of a disease which remains one of the leading infectious causes of death worldwide. The development of novel antimycobacterial compounds is therefore essential to reinforce the existing antitubercular drug discovery pipeline. There is also interest in new compounds which can synergize with existing antitubercular drugs and can be deployed as part of a combination therapy. This strategy could serve to delay the emergence of resistance to first-line anti-tuberculosis drugs and increase their efficacy against resistant strains of tuberculosis. Previous research has established that several C-1 substituted tetrahydroisoquinolines have antimycobacterial activity. Here we sought to expand our understanding of their antimycobacterial structure activity relationships and their potential to act as adjunct therapies alongside existing antitubercular drugs.</p><p><strong>Methods: </strong>Three chemical series were synthesised and assayed for their antimycobacterial potency, mammalian cell toxicity, inhibition of whole-cell efflux and synergism with isoniazid, rifampicin, and ethambutol.</p><p><strong>Results: </strong>Several compounds were found to inhibit the growth of mycobacteria. Potent inhibitors of whole-cell efflux were also identified, as well as compounds which exhibited synergism with rifampicin and ethambutol.</p><p><strong>Conclusions: </strong>Structure-activity relationships were identified for antimycobacterial potency, improved selectivity, whole cell efflux inhibition and synergism. Potent whole-cell efflux inhibitors and synergistic compounds were identified, suggesting potential development as adjuncts to existing anti-tuberculosis chemotherapy.</p>","PeriodicalId":73065,"journal":{"name":"Frontiers in antibiotics","volume":" ","pages":"1095013"},"PeriodicalIF":0.0,"publicationDate":"2023-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11731654/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44117459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extended-spectrum beta-lactamases in poultry in Africa: a systematic review.","authors":"Akeemat O Ayinla, Ana L P Mateus","doi":"10.3389/frabi.2023.1140750","DOIUrl":"10.3389/frabi.2023.1140750","url":null,"abstract":"<p><p>Extended-spectrum beta-lactamase (ESBL)-producing bacteria present a unique problem because of their ability to cause infections that are difficult to treat in animals and humans. The presence of ESBL-<i>Escherichia coli</i> (<i>E. coli</i>) in poultry raises a major public health concern due to the risk of zoonotic transfer <i>via</i> the food chain and direct contact with birds and the environment. This review aimed to determine the frequency of ESBL-producing <i>E. coli</i> and associated ESBL genes in poultry in Africa. Three databases (PubMed, ScienceDirect, and Web of Science) and predetermined websites were searched to identify scientific and grey literature. Studies (1582) were screened at title, abstract, and full-text levels. This review was registered with PROSPERO (CRD42021259872). Thirty-three studies were deemed eligible for this review. Phenotypic ESBL expression was confirmed in 22 studies (66.7%) with a wide range of colonization noted in sampled poultry (1 - 100%). The <i>bla</i> <b>_CTX-M</b> gene was the most commonly isolated with the variants <i>bla</i> <b>_CTX-M-1</b> and <i>bla</i> <b>_CTX-M-15</b> being the most predominant in North and West Africa respectively. ESBL-producing <i>E. coli</i> isolates are frequently detected in poultry in farms and slaughterhouses across Africa thereby posing a potential health risk to humans. The paucity of data however does not allow for inferences to be made about the true extent of ESBLs in poultry in Africa.</p>","PeriodicalId":73065,"journal":{"name":"Frontiers in antibiotics","volume":" ","pages":"1140750"},"PeriodicalIF":0.0,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11732038/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45297025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A spectrum of non-spore-forming fermentative and non-fermentative Gram-negative bacteria: multi-drug resistance, extended-spectrum beta-lactamase, and carbapenemase production.","authors":"Yasin Desalegn, Adane Bitew, Amanuel Adane","doi":"10.3389/frabi.2023.1155005","DOIUrl":"10.3389/frabi.2023.1155005","url":null,"abstract":"<p><strong>Background: </strong>In developing countries, the co-existence of a high burden of infectious diseases caused by Gram-negative bacteria and the rapid increase and spread of multidrug-resistant bacteria have become a serious health threat.</p><p><strong>Objective: </strong>Profiling of Gram-negative bacteria and determining the magnitude of their antimicrobial resistance among patients.</p><p><strong>Results: </strong>A total of 175 non-spore-forming Gram-negative bacteria were isolated from 873 different clinical samples. Of a total of 175 bacteria, 154 (88%) were fermentative Gram-negative bacteria, while 21 (12%) were non-fermentative Gram-negative bacteria<i>. E. coli</i> with a frequency of 58.3% and <i>K. pneumoniae</i> with a frequency of 18.3% were the predominant fermentative Gram-negative bacteria, while <i>P. aeruginosa</i> 9 (5.1%) and <i>A. baumannii</i> 6 (3.4%) were the predominant non-fermentative Gram-negative bacteria. The highest percentage level of antibiotic resistance was seen against ampicillin (86%), and the lowest against meropenem (9.8). About 49 (28%) Gram-negative bacilli were positive for ESBLase. The overall prevalence rate of MDR bacteria was 80.5%, of which 100% of A. <i>baumannii</i>, 90.6% <i>of K. pneumonia.</i> Sixteen isolates were resistant to meropenem, out of which 11 tested for carbapenemase production. Five of the nine were metallo-lactamase producers, with the remaining four being serine carbapenemase producers.</p><p><strong>Conclusion: </strong>The prevalence of Gram-negative bacterial infection was found to be 20%, with a significant proportion (80.0%) due to fermentative Gram-negative bacteria and the remaining 20% due to non-fermentative Gram-negative bacteria. The study has also demonstrated a high prevalence rate of MDR, ESBLase, and carbapenemase-producing Gram-negative bacteria. Antimicrobial resistance of Gram-negative bacteria should be monitored on a regular basis, and an effective infection control program should be implemented.</p>","PeriodicalId":73065,"journal":{"name":"Frontiers in antibiotics","volume":"2 1","pages":"1155005"},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11732051/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42864997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comparison of various feature extraction and machine learning methods for antimicrobial resistance prediction in <i>streptococcus pneumoniae</i>.","authors":"Deniz Ece Kaya, Ege Ülgen, Ayşe Sesin Kocagöz, Osman Uğur Sezerman","doi":"10.3389/frabi.2023.1126468","DOIUrl":"10.3389/frabi.2023.1126468","url":null,"abstract":"<p><p>Streptococcus pneumoniae is one of the major concerns of clinicians and one of the global public health problems. This pathogen is associated with high morbidity and mortality rates and antimicrobial resistance (AMR). In the last few years, reduced genome sequencing costs have made it possible to explore more of the drug resistance of S. pneumoniae, and machine learning (ML) has become a popular tool for understanding, diagnosing, treating, and predicting these phenotypes. Nucleotide k-mers, amino acid k-mers, single nucleotide polymorphisms (SNPs), and combinations of these features have rich genetic information in whole-genome sequencing. This study compares different ML models for predicting AMR phenotype for S. pneumoniae. We compared nucleotide k-mers, amino acid k-mers, SNPs, and their combinations to predict AMR in S. pneumoniae for three antibiotics: Penicillin, Erythromycin, and Tetracycline. 980 pneumococcal strains were downloaded from the European Nucleotide Archive (ENA). Furthermore, we used and compared several machine learning methods to train the models, including random forests, support vector machines, stochastic gradient boosting, and extreme gradient boosting. In this study, we found that key features of the AMR prediction model setup and the choice of machine learning method affected the results. The approach can be applied here to further studies to improve AMR prediction accuracy and efficiency.</p>","PeriodicalId":73065,"journal":{"name":"Frontiers in antibiotics","volume":" ","pages":"1126468"},"PeriodicalIF":0.0,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11731958/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43671745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of antibiotic resistance genes in swine manure storage pits of Iowa, USA.","authors":"Timothy P Neher, Michelle L Soupir, Daniel S Andersen, Maggie L O'Neill, Adina Howe","doi":"10.3389/frabi.2023.1116785","DOIUrl":"10.3389/frabi.2023.1116785","url":null,"abstract":"<p><p>Antimicrobial resistance (AMR) can develop in deep-pit swine manure storage when bacteria are selectively pressured by unmetabolized antibiotics. Subsequent manure application on row crops is then a source of AMR into soil and downstream runoff water. Therefore, understanding the patterns of diverse antibiotic resistance genes (ARGs) in manure among different farms is important for both interpreting the results of the detection of these genes from previous studies and for the use of these genes as bioindicators of manure borne antibiotic resistance in the environment. Previous studies of manure-associated ARGs are based on limited samples of manures. To better understand the distribution of ARGs between manures, we characterized manures from 48 geographically independent swine farms across Iowa. The objectives of this study were to characterize the distribution of ARGs among these manures and to evaluate what factors in manure management may influence the presence of ARGs in manures. Our analysis included quantification of two commonly found ARGs in swine manure, <i>ermB</i> and <i>tetM</i>. Additionally, we characterized a broader suite of 31 ARGs which allowed for simultaneous assays of the presence or absence of multiple genes. We found the company integrator had a significant effect on both <i>ermB</i> (<i>P=0.0007</i>) and <i>tetM</i> gene concentrations (<i>P=0.0425</i>). Our broad analysis on ARG profiles found that the <i>tet(36)</i> gene was broadly present in swine manures, followed by the detection of <i>tetT</i>, <i>tetM</i>, <i>erm(35)</i>, <i>ermF</i>, <i>ermB</i>, <i>str</i>, <i>aadD</i>, and <i>intl3</i> in samples from 14 farms. Finally, we provide a comparison of methods to detect ARGs in manures, specifically comparing conventional and high-throughput qPCR and discuss their role in ARG environmental monitoring efforts. Results of this study provide insight into commonalities of ARG presence in manure holding pits and provide supporting evidence that company integrator decisions may impact ARG concentrations.</p>","PeriodicalId":73065,"journal":{"name":"Frontiers in antibiotics","volume":" ","pages":"1116785"},"PeriodicalIF":0.0,"publicationDate":"2023-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11732143/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47695798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antimicrobial activity of a new class of synthetic retinoid antibiotics and comparator agents against ocular staphylococci.","authors":"Camille André, Cassandra L Schrank, Ana Victoria Cheng Jaramillo, Eleftherios Mylonakis, William M Wuest, Michael S Gilmore, Wooseong Kim, Paulo J M Bispo","doi":"10.3389/frabi.2023.1101450","DOIUrl":"10.3389/frabi.2023.1101450","url":null,"abstract":"<p><strong>Objectives: </strong>Antimicrobial resistance is global pandemic that poses a major threat to vision health as ocular pathogens, especially staphylococcal species, are becoming increasingly resistant to first-line therapies. Here we evaluated the antimicrobial activity of a new class of synthetic retinoids in comparison to currently used antibiotics against clinically relevant ocular staphylococcal isolates.</p><p><strong>Methods: </strong>Antimicrobial susceptibility testing was performed by broth microdilution for 3 novel synthetic retinoids (CD1530, CD437, and a CD437 analogue) and 7 comparator antibiotics, against a collection of 216 clinical isolates.</p><p><strong>Results: </strong>CD437 MIC₅₀ and MIC₉₀ were 2 µg/mL for <i>Staphylococcus aureus</i>, and 1 µg/mL and 2 µg/mL respectively, for coagulase-negative staphylococci (CoNS). CD1530 (MIC₅₀ = 2 µg/mL for all species) also displayed good activity with an <i>in vitro</i> potency slightly lower (2-fold) for <i>S. aureus</i> (MIC₉₀ = 4 µg/mL) when compared to CD437. A CD437 analogue also demonstrated good <i>in vitro</i> activity (MIC₅₀ = 2 µg/mL for all species) and potency (MIC₉₀ = 2 µg/mL for MRSA and 4 µg/mL for MSSA and CoNS). <i>In vitro</i> potencies were similar or higher than that of comparator agents, and were not impacted by multidrug resistance phenotypes.</p><p><strong>Conclusion: </strong>Our results demonstrate that synthetic retinoids display potent <i>in vitro</i> activity against ocular staphylococcal species, including multidrug-resistant isolates.</p>","PeriodicalId":73065,"journal":{"name":"Frontiers in antibiotics","volume":" ","pages":"1101450"},"PeriodicalIF":0.0,"publicationDate":"2023-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11732056/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44899273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gaps in data collection for sex and gender must be addressed in point prevalence surveys on antibiotic use.","authors":"Lynn Lieberman Lawry, Niranjan Konduri, Nkatha Gitonga, Reuben Kiggundu, Mame Mbaye, Andy Stergachis","doi":"10.3389/frabi.2023.1154506","DOIUrl":"10.3389/frabi.2023.1154506","url":null,"abstract":"","PeriodicalId":73065,"journal":{"name":"Frontiers in antibiotics","volume":" ","pages":"1154506"},"PeriodicalIF":0.0,"publicationDate":"2023-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11731600/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47033487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}