# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 4547 | 0 | 1.0000 | Convergence of resistance and evolutionary responses in Escherichia coli and Salmonella enterica co-inhabiting chicken farms in China. Sharing of genetic elements among different pathogens and commensals inhabiting same hosts and environments has significant implications for antimicrobial resistance (AMR), especially in settings with high antimicrobial exposure. We analysed 661 Escherichia coli and Salmonella enterica isolates collected within and across hosts and environments, in 10 Chinese chicken farms over 2.5 years using data-mining methods. Most isolates within same hosts possessed the same clinically relevant AMR-carrying mobile genetic elements (plasmids: 70.6%, transposons: 78%), which also showed recent common evolution. Supervised machine learning classifiers revealed known and novel AMR-associated mutations and genes underlying resistance to 28 antimicrobials, primarily associated with resistance in E. coli and susceptibility in S. enterica. Many were essential and affected same metabolic processes in both species, albeit with varying degrees of phylogenetic penetration. Multi-modal strategies are crucial to investigate the interplay of mobilome, resistance and metabolism in cohabiting bacteria, especially in ecological settings where community-driven resistance selection occurs. | 2024 | 38182559 |
| 3449 | 1 | 0.9998 | Investigation of mobile genetic elements and their association with antibiotic resistance genes in clinical pathogens worldwide. OBJECTIVES: Antimicrobial-resistant bacteria are a major global health threat. Mobile genetic elements (MGEs) have been crucial for spreading resistance to new bacterial species, including human pathogens. Understanding how MGEs promote resistance could be essential for prevention. Here we present an investigation of MGEs and their association with resistance genes in pathogenic bacteria collected from 59 diagnostic units during 2020, representing a snapshot of clinical infections from 35 counties worldwide. METHODS: We analysed 3,095 whole-genome sequenced clinical bacterial isolates from over 100 species to study the relationship between resistance genes and MGEs. The mobiliome of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Klebsiella pneumoniae were further examined for geographic differences, as these species were prevalent in all countries. Genes potentially mobilized by MGEs were identified by finding DNA segments containing MGEs and ARGs preserved in multiple species. Network analysis was used to investigate potential MGE interactions, host range, and transmission pathways. RESULTS: The prevalence and diversity of MGEs and resistance genes varied among species, with E. coli and S. aureus carrying more diverse elements. MGE composition differed between bacterial lineages, indicating strong vertical inheritance. 102 MGEs associated with resistance were found in multiple species, and four of these elements seemed to be highly transmissible as they were found in different phyla. We identified 21 genomic regions containing resistance genes potentially mobilized by MGEs, highlighting their importance in transmitting genes to clinically significant bacteria. CONCLUSION: Resistance genes are spread through various MGEs, including plasmids and transposons. Our findings suggest that multiple factors influence MGE prevalence and their transposability, thereby shaping the MGE population and transmission pathways. Some MGEs have a wider host range, which could make them more important for mobilizing genes. We also identified 103 resistance genes potentially mobilised by MGEs, which could increase their transmissibility to unrelated bacteria. | 2025 | 40824964 |
| 4551 | 2 | 0.9998 | Genomic insights into virulence, antimicrobial resistance, and adaptation acumen of Escherichia coli isolated from an urban environment. Populations of common commensal bacteria such as Escherichia coli undergo genetic changes by the acquisition of certain virulence and antimicrobial resistance (AMR) encoding genetic elements leading to the emergence of pathogenic strains capable of surviving in the previously uninhabited or protected niches. These bacteria are also reported to be prevalent in the environment where they survive by adopting various recombination strategies to counter microflora of the soil and water, under constant selection pressure(s). In this study, we performed molecular characterization, phenotypic AMR analysis, and whole genome sequencing (WGS) of E. coli (n = 37) isolated from soil and surface water representing the urban and peri-urban areas. The primary aim of this study was to understand the genetic architecture and pathogenic acumen exhibited by environmental E. coli. WGS-based analysis entailing resistome and virulome profiling indicated the presence of various virulence (adherence, iron uptake, and toxins) and AMR encoding genes, including bla(NDM-5) in the environmental isolates. A majority of our isolates belonged to phylogroup B1 (73%). A few isolates in our collection were of sequence type(s) (ST) 58 and 224 that could have emerged recently as clonal lineages and might pose risk of infection/transmission. Mobile genetic elements (MGEs) such as plasmids (predominantly) of the IncF family, prophages, pipolins, and insertion elements such as IS1 and IS5 were also observed to exist, which may presumably aid in the propagation of genes encoding resistance against antimicrobial drugs. The observed high prevalence of MGEs associated with multidrug resistance in pathogenic E. coli isolates belonging to the phylogroup B1 underscores the need for extended surveillance to keep track of and prevent the transmission of the bacterium to certain vulnerable human and animal populations. IMPORTANCE: Evolutionary patterns of E. coli bacteria convey that they evolve into highly pathogenic forms by acquiring fitness advantages, such as AMR, and various virulence factors through the horizontal gene transfer (HGT)-mediated acquisition of MGEs. However, limited research on the genetic profiles of environmental E. coli, particularly from India, hinders our understanding of their transition to pathogenic forms and impedes the adoption of a comprehensive approach to address the connection between environmentally dwelling E. coli populations and human and veterinary public health. This study focuses on high-resolution genomic analysis of the environmental E. coli isolates aiming to understand the genetic similarities and differences among isolates from different environmental niches and uncover the survival strategies employed by these bacteria to thrive in their surroundings. Our approach involved molecular characterization of environmental samples using PCR-based DNA fingerprinting and subsequent WGS analysis. This multidisciplinary approach is likely to provide valuable insights into the understanding of any potential spill-over to human and animal populations and locales. Investigating these environmental isolates has significant potential for developing epidemiological strategies against transmission and understanding niche-specific evolutionary patterns. | 2024 | 38376265 |
| 4550 | 3 | 0.9998 | Whole-genome sequencing and gene sharing network analysis powered by machine learning identifies antibiotic resistance sharing between animals, humans and environment in livestock farming. Anthropogenic environments such as those created by intensive farming of livestock, have been proposed to provide ideal selection pressure for the emergence of antimicrobial-resistant Escherichia coli bacteria and antimicrobial resistance genes (ARGs) and spread to humans. Here, we performed a longitudinal study in a large-scale commercial poultry farm in China, collecting E. coli isolates from both farm and slaughterhouse; targeting animals, carcasses, workers and their households and environment. By using whole-genome phylogenetic analysis and network analysis based on single nucleotide polymorphisms (SNPs), we found highly interrelated non-pathogenic and pathogenic E. coli strains with phylogenetic intermixing, and a high prevalence of shared multidrug resistance profiles amongst livestock, human and environment. Through an original data processing pipeline which combines omics, machine learning, gene sharing network and mobile genetic elements analysis, we investigated the resistance to 26 different antimicrobials and identified 361 genes associated to antimicrobial resistance (AMR) phenotypes; 58 of these were known AMR-associated genes and 35 were associated to multidrug resistance. We uncovered an extensive network of genes, correlated to AMR phenotypes, shared among livestock, humans, farm and slaughterhouse environments. We also found several human, livestock and environmental isolates sharing closely related mobile genetic elements carrying ARGs across host species and environments. In a scenario where no consensus exists on how antibiotic use in the livestock may affect antibiotic resistance in the human population, our findings provide novel insights into the broader epidemiology of antimicrobial resistance in livestock farming. Moreover, our original data analysis method has the potential to uncover AMR transmission pathways when applied to the study of other pathogens active in other anthropogenic environments characterised by complex interconnections between host species. | 2022 | 35333870 |
| 4563 | 4 | 0.9998 | Prophages as a source of antimicrobial resistance genes in the human microbiome. Prophages-viruses that integrate into bacterial genomes-are ubiquitous in the microbial realm. Prophages contribute significantly to horizontal gene transfer, including the potential spread of antimicrobial resistance (AMR) genes, because they can collect host genes. Understanding their role in the human microbiome is essential for fully understanding AMR dynamics and possible clinical implications. We analysed almost 15,000 bacterial genomes for prophages and AMR genes. The bacteria were isolated from diverse human body sites and geographical regions, and their genomes were retrieved from GenBank. AMR genes were detected in 6.6% of bacterial genomes, with a higher prevalence in people with symptomatic diseases. We found a wide variety of AMR genes combating multiple drug classes. We discovered AMR genes previously associated with plasmids, such as blaOXA-23 in Acinetobacter baumannii prophages or genes found in prophages in species they had not been previously described in, such as mefA-msrD in Gardnerella prophages, suggesting prophage-mediated gene transfer of AMR genes. Prophages encoding AMR genes were found at varying frequencies across body sites and geographical regions, with Asia showing the highest diversity of AMR genes. | 2025 | 40166311 |
| 5006 | 5 | 0.9998 | Genomic insights of mcr-1 harboring Escherichia coli by geographical region and a One-Health perspective. The importance of the One Health concept in attempting to deal with the increasing levels of multidrug-resistant bacteria in both human and animal health is a challenge for the scientific community, policymakers, and the industry. The discovery of the plasmid-borne mobile colistin resistance (mcr) in 2015 poses a significant threat because of the ability of these plasmids to move between different bacterial species through horizontal gene transfer. In light of these findings, the World Health Organization (WHO) recommends that countries implement surveillance strategies to detect the presence of plasmid-mediated colistin-resistant microorganisms and take suitable measures to control and prevent their dissemination. Seven years later, ten different variants of the mcr gene (mcr-1 to mcr-10) have been detected worldwide in bacteria isolated from humans, animals, foods, the environment, and farms. However, the possible transmission mechanisms of the mcr gene among isolates from different geographical origins and sources are largely unknown. This article presents an analysis of whole-genome sequences of Escherichia coli that harbor mcr-1 gene from different origins (human, animal, food, or environment) and geographical location, to identify specific patterns related to virulence genes, plasmid content and antibiotic resistance genes, as well as their phylogeny and their distribution with their origin. In general, E. coli isolates that harbor mcr-1 showed a wide plethora of ARGs. Regarding the plasmid content, the highest concentration of plasmids was found in animal samples. In turn, Asia was the continent that led with the largest diversity and occurrence of these plasmids. Finally, about virulence genes, terC, gad, and traT represent the most frequent virulence genes detected. These findings highlight the relevance of analyzing the environmental settings as an integrative part of the surveillance programs to understand the origins and dissemination of antimicrobial resistance. | 2022 | 36726572 |
| 3475 | 6 | 0.9998 | Phylogenomics of novel clones of Aeromonas veronii recovered from a freshwater lake reveals unique biosynthetic gene clusters. Aquatic ecosystems serve as crucial reservoirs for pathogens and antimicrobial resistance genes, thus presenting a significant global health risk. Here, we investigated the phylogenomics of Aeromonas veronii from Lake Wilcox in Ontario. Among the 11 bacterial isolates, nine were identified as A. veronii. Notably, 67% of A. veronii isolates were potential human pathogens. Considerable genetic diversity was noted among the A. veronii isolates, suggesting the lake as a reservoir for multiple human pathogenic strains. Comparison of the A. veronii sequenced with global A. veronii genomes highlighted significant genetic diversity and suggests widespread dissemination of strains. All the isolates carried chromosomal genes encoding resistance to β-lactams. Although virulence gene content differed between human and non-human pathogenic strains, type III secretion systems was associated with human pathogenic isolates. The assessment of AMR genes in global isolates showed that β-lactam and tetracycline resistance genes were predominant. Although the machine learning-based pangenome-wide association approach performed did not yield any source-based genes, some genes were enriched in a few isolates from different sources. The mrkABCDF operon that mediates biofilm formation and genes encoding resistance to colistin, chloramphenicol, trimethoprim, and tetracycline were enriched in animal products, whereas macrolide resistance genes and Inc plasmid-types were linked to the aquatic environment. Novel biosynthetic gene clusters were identified, suggesting that A. veronii with varying pathogenic potential could produce unique secondary metabolites. There is a need for continuous tracking of pathogens in aquatic ecosystems to contribute to our understanding of their evolutionary dynamics and the ecological roles of their genetic elements. IMPORTANCE: Lakes and other aquatic ecosystems can harbor harmful bacteria that can make people sick and resist antibiotics, posing a significant global health risk. In this study, we investigated Aeromonas veronii, a Gram-negative bacteria found in Lake Wilcox in Ontario. We used various techniques, including whole-genome sequencing (WGS), to analyze the bacteria and found that many of the isolates had the potential to cause human disease. We also discovered significant genetic diversity among the isolates, indicating that the lake may be a reservoir for multiple human pathogenic strains. All isolates carried genes that confer resistance to antibiotics, and some virulence genes were associated with human pathogenic isolates. This study highlights the importance of monitoring aquatic ecosystems for harmful bacteria to better understand their evolution, potential for human pathogenicity, and the ecological roles of their genetic elements. This knowledge can inform strategies for preventing the spread of antibiotic-resistant bacteria and protecting public health. | 2024 | 39513706 |
| 3478 | 7 | 0.9998 | Bacterial plasmid-mediated quinolone resistance genes in aquatic environments in China. Emerging antimicrobial resistance is a major threat to human's health in the 21(st) century. Understanding and combating this issue requires a full and unbiased assessment of the current status on the prevalence of antimicrobial resistance genes and their correlation with each other and bacterial groups. In aquatic environments that are known reservoirs for antimicrobial resistance genes, we were able to reach this goal on plasmid-mediated quinolone resistance (PMQR) genes that lead to resistance to quinolones and possibly also to the co-emergence of resistance to β-lactams. Novel findings were made that qepA and aac-(6')-Ib genes that were previously regarded as similarly abundant with qnr genes are now dominant among PMQR genes in aquatic environments. Further statistical analysis suggested that the correlation between PMQR and β-lactam resistance genes in the environment is still weak, that the correlations between antimicrobial resistance genes could be weakened by sufficient wastewater treatment, and that the prevalence of PMQR has been implicated in environmental, pathogenic, predatory, anaerobic, and more importantly, human symbiotic bacteria. This work provides a comprehensive analysis of PMQR genes in aquatic environments in Jinan, China, and provides information with which combat with the antimicrobial resistance problem may be fought. | 2017 | 28094345 |
| 4549 | 8 | 0.9998 | Genomic analysis of Salmonella Heidelberg isolated from the Brazilian poultry farms. The rapid expansion of broiler chicken production in Brazil has presented significant sanitation challenges within the poultry industry. Among these challenges, Salmonella enterica subsp. enterica serotype Heidelberg stands as a contributor to global salmonellosis outbreaks. This study analyzed 13 draft genomes of Salmonella Heidelberg isolated from the pre-slaughter broiler chickens farms in Brazil. By conducting in silico analysis of these genomes, the study investigated genome similarity based on single nucleotide polymorphisms (SNPs) and identified genes encoding resistance to antimicrobials, sanitizers, and virulence factors. Furthermore, mobile genetic elements (MGE) were identified to assess their potential role in propagating genes through horizontal gene transfer. A risk classification was also applied based on the resistomes. The genomes revealed a high prevalence of genes conferring resistance to aminoglycosides, fosfomycin, sulfonamides, tetracycline, and genes linked to quaternary ammonium resistance. The study also uncovered six Salmonella pathogenicity islands (SPI) and over 100 genes encoding virulence factors. The association of MGE with antibiotic-resistant genes sul2 and blaCMY-2 raised concerns about the potential transfer to other bacteria, posing a substantial risk for spreading resistance mechanisms according to established risk protocols. Additionally, SNP analysis indicated close phylogenetic relationships among some isolates, suggesting a common origin. This study enhances our understanding of Salmonella Heidelberg strains by identifying key risk factors for transmission and revealing the association between resistance genes and MGEs. This insight provides a foundation for developing and implementing effective control, monitoring, and treatment strategies in the poultry industry. | 2024 | 39441515 |
| 4991 | 9 | 0.9998 | Genomic and metagenomic analysis reveals shared resistance genes and mobile genetic elements in E. coli and Klebsiella spp. isolated from hospital patients and hospital wastewater at intra- and inter-genus level. Antimicrobial resistance (AMR) is a global problem that gives serious cause for concern. Hospital wastewater (HWW) is an important link between the clinical setting and the natural environment, and an escape route for pathogens that cause hospital infections, including urinary tract infections (UTI). Bacteria of the genera Escherichia and Klebsiella are common etiological factors of UTI, especially in children, and they can cause short-term infections, as well as chronic conditions. ESBL-producing Escherichia and Klebsiella have also emerged as potential indicators for estimating the burden of antimicrobial resistance under environmental conditions and the spread of AMR between clinical settings and the natural environment. In this study, whole-genome sequencing and the nanopore technology were used to analyze the complete genomes of ESBL-producing E.coli and Klebsiella spp. and the HWW metagenome, and to characterize the mechanisms of AMR. The similarities and differences in the encoded mechanisms of AMR in clinical isolates (causing UTI) and environmental strains (isolated from HWW and the HWW metagenome) were analyzed. Special attention was paid to the genetic context and the mobility of antibiotic resistance genes (ARGs) to determine the common sources and potential transmission of these genes. The results of this study suggest that the spread of drug resistance from healthcare facilities via HWW is not limited to the direct transmission of resistant clonal lines that are typically found in the clinical setting, but it also involves the indirect transfer of mobile elements carrying ARGs between bacteria colonizing various environments. Hospital wastewater could offer a supportive environment for plasmid evolution through the insertion of new ARGs, including typical chromosomal regions. These results indicate that interlined environments (hospital patients - HWW) should be closely monitored to evaluate the potential transmission routes of drug resistance in bacteria. | 2024 | 39038407 |
| 4964 | 10 | 0.9998 | Distribution of Antimicrobial Resistance and Virulence Genes within the Prophage-Associated Regions in Nosocomial Pathogens. Prophages are often involved in host survival strategies and contribute toward increasing the genetic diversity of the host genome. Prophages also drive horizontal propagation of various genes as vehicles. However, there are few retrospective studies contributing to the propagation of antimicrobial resistance (AMR) and virulence factor (VF) genes by prophage. We extracted the complete genome sequences of seven pathogens, including ESKAPE bacteria and Escherichia coli from a public database, and examined the distribution of both the AMR and VF genes in prophage-like regions. We found that the ratios of AMR and VF genes greatly varied among the seven species. More than 70% of Enterobacter cloacae strains had VF genes, but only 1.2% of Klebsiella pneumoniae strains had VF genes from prophages. AMR and VF genes are unlikely to exist together in the same prophage region except in E. coli and Staphylococcus aureus, and the distribution patterns of prophage types containing AMR genes are distinct from those of VF gene-carrying prophage types. AMR genes in the prophage were located near transposase and/or integrase. The prophage containing class 1 integrase possessed a significantly greater number of AMR genes than did prophages with no class 1 integrase. The results of this study present a comprehensive picture of AMR and VF genes present within, or close to, prophage-like elements and different prophage patterns between AMR- or VF-encoding prophage-like elements. IMPORTANCE Although we believe phages play an important role in horizontal gene transfer in exchanging genetic material, we do not know the distribution of the antimicrobial resistance (AMR) and/or virulence factor (VF) genes in prophages. We collected different prophage elements from the complete genome sequences of seven species-Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter cloacae, and Escherichia coli-and characterized the distribution of antimicrobial resistance and virulence genes located in the prophage region. While virulence genes in prophage were species specific, antimicrobial resistance genes in prophages were highly conserved in various species. An integron structure was detected within specific prophage regions such as P1-like prophage element. Maximum of 10 antimicrobial resistance genes were found in a single prophage region, suggesting that prophages act as a reservoir for antimicrobial resistance genes. The results of this study show the different characteristic structures between AMR- or VF-encoding prophages. | 2021 | 34232073 |
| 9919 | 11 | 0.9998 | An In Vitro Chicken Gut Model Demonstrates Transfer of a Multidrug Resistance Plasmid from Salmonella to Commensal Escherichia coli. The chicken gastrointestinal tract is richly populated by commensal bacteria that fulfill various beneficial roles for the host, including helping to resist colonization by pathogens. It can also facilitate the conjugative transfer of multidrug resistance (MDR) plasmids between commensal and pathogenic bacteria which is a significant public and animal health concern as it may affect our ability to treat bacterial infections. We used an in vitro chemostat system to approximate the chicken cecal microbiota, simulate colonization by an MDR Salmonella pathogen, and examine the dynamics of transfer of its MDR plasmid harboring several genes, including the extended-spectrum beta-lactamase bla(CTX-M1) We also evaluated the impact of cefotaxime administration on plasmid transfer and microbial diversity. Bacterial community profiles obtained by culture-independent methods showed that Salmonella inoculation resulted in no significant changes to bacterial community alpha diversity and beta diversity, whereas administration of cefotaxime caused significant alterations to both measures of diversity, which largely recovered. MDR plasmid transfer from Salmonella to commensal Escherichia coli was demonstrated by PCR and whole-genome sequencing of isolates purified from agar plates containing cefotaxime. Transfer occurred to seven E. coli sequence types at high rates, even in the absence of cefotaxime, with resistant strains isolated within 3 days. Our chemostat system provides a good representation of bacterial interactions, including antibiotic resistance transfer in vivo It can be used as an ethical and relatively inexpensive approach to model dissemination of antibiotic resistance within the gut of any animal or human and refine interventions that mitigate its spread before employing in vivo studies.IMPORTANCE The spread of antimicrobial resistance presents a grave threat to public health and animal health and is affecting our ability to respond to bacterial infections. Transfer of antimicrobial resistance via plasmid exchange is of particular concern as it enables unrelated bacteria to acquire resistance. The gastrointestinal tract is replete with bacteria and provides an environment for plasmid transfer between commensals and pathogens. Here we use the chicken gut microbiota as an exemplar to model the effects of bacterial infection, antibiotic administration, and plasmid transfer. We show that transfer of a multidrug-resistant plasmid from the zoonotic pathogen Salmonella to commensal Escherichia coli occurs at a high rate, even in the absence of antibiotic administration. Our work demonstrates that the in vitro gut model provides a powerful screening tool that can be used to assess and refine interventions that mitigate the spread of antibiotic resistance in the gut before undertaking animal studies. | 2017 | 28720731 |
| 4562 | 12 | 0.9998 | The Dynamics of the Antimicrobial Resistance Mobilome of Salmonella enterica and Related Enteric Bacteria. The foodborne pathogen Salmonella enterica is considered a global public health risk. Salmonella enterica isolates can develop resistance to several antimicrobial drugs due to the rapid spread of antimicrobial resistance (AMR) genes, thus increasing the impact on hospitalization and treatment costs, as well as the healthcare system. Mobile genetic elements (MGEs) play key roles in the dissemination of AMR genes in S. enterica isolates. Multiple phenotypic and molecular techniques have been utilized to better understand the biology and epidemiology of plasmids including DNA sequence analyses, whole genome sequencing (WGS), incompatibility typing, and conjugation studies of plasmids from S. enterica and related species. Focusing on the dynamics of AMR genes is critical for identification and verification of emerging multidrug resistance. The aim of this review is to highlight the updated knowledge of AMR genes in the mobilome of Salmonella and related enteric bacteria. The mobilome is a term defined as all MGEs, including plasmids, transposons, insertion sequences (ISs), gene cassettes, integrons, and resistance islands, that contribute to the potential spread of genes in an organism, including S. enterica isolates and related species, which are the focus of this review. | 2022 | 35432284 |
| 9912 | 13 | 0.9998 | Comprehensive Genomic Investigation of Coevolution of mcr genes in Escherichia coli Strains via Nanopore Sequencing. Horizontal gene transfer facilitates the spread of antibiotic resistance genes, which constitutes a global challenge. However, the evolutionary trajectory of the mobile colistin resistome in bacteria is largely unknown. To investigate the coevolution and fitness cost of the colistin resistance genes in wild strains, different assays to uncover the genomic dynamics of mcr-1 and mcr-3 in bacterial populations are utilized. Escherichia coli strains harboring both mcr-1 and mcr-3.1/3.5 are isolated and mcr genes are associated with diverse mobile elements. Under exposure to colistin, the mcr-1-bearing resistome is stably inherited during bacterial replication, but mcr-3 is prone to be eliminated in populations of certain strains. In the absence of colistin, the persistence rates of the mcr-1 and mcr-3-bearing subclones varies depending on the genomic background. The decay of the mcr-bearing bacterial populations can be mediated by the elimination of mcr-containing segments, large genomic deletions, and plasmid loss. Mobile elements, including plasmids and transposons, are double-edged swords in the evolution of the resistome. The findings support the idea that antibiotic overuse accounts for global spread of multidrug-resistant (MDR) bacteria. Therefore, stringent regulation of antibiotic prescription for humans and animals should be performed systematically to alleviate the threat of MDR bacteria. | 2021 | 33728052 |
| 4545 | 14 | 0.9998 | Beta-lactamases in lactic acid bacteria: Dual role in antimicrobial resistance spread and environmental detoxification of antibiotic residues. Lactic acid bacteria (LAB) are widely used in food production and as probiotics. However, their potential role in the spreading of antimicrobial resistance (AMR) remains underexplored. A major AMR mechanism is the production of beta-lactamases, which is well-documented in most pathogenic bacteria; the diversity and functionality of these enzymes in LAB are less understood. Here, we explored the genomic diversity of beta-lactamase genes in LAB in a broad range of publicly available LAB genomes. Our findings revealed the presence of two distinct types of beta-lactamase genes in LAB: ampC-type beta-lactamases (class C), likely developed within LAB lineages, and bla(TEM)-type (class A), potentially acquired via HGT. Phylogenetic and structural analysis revealed similarities between LAB-derived ampC genes and clinically relevant class C beta-lactamases, while bla(TEM)-type genes were identified to be often flanked by mobility-related genetic elements, indicating a potential for horizontal gene transfer (HGT). Molecular docking studies further showed that LAB beta-lactamases may hydrolyze a broad spectrum of beta-lactam antibiotics, particularly aminopenicillins and cephalosporins. These findings will contribute to the broader field of AMR research, highlighting the importance of monitoring beta-lactamase production by LAB and its implications for food safety, bioremediation of beta-lactam antibiotic residues in wastewater and agro-industrial effluents. | 2025 | 40651383 |
| 4966 | 15 | 0.9998 | Whole Genome Analysis of 335 New Bacterial Species from Human Microbiota Reveals a Huge Reservoir of Transferable Antibiotic Resistance Determinants. BACKGROUND: The emergence and diffusion of strains of pathogenic bacteria resistant to antibiotics constitutes a real public health challenge. Antibiotic resistance genes (ARGs) can be carried by both pathogenic and non-pathogenic bacteria, including commensal bacteria from the human microbiota, which require special monitoring in the fight against antimicrobial resistance. METHODS: We analyzed the proteomes of 335 new bacterial species from human microbiota to estimate its whole range of ARGs using the BLAST program against ARGs reference databases. RESULTS: We found 278 bacteria that harbor a total of 883 potential ARGs with the following distribution: 264 macrolides-lincosamides-streptogramin, 195 aminoglycosides, 156 tetracyclines, 58 β-lactamases, 58 fosfomycin, 51 glycopeptides, 36 nitroimidazoles, 33 phenicols and 32 rifamycin. Furthermore, evolutionary analyses revealed the potential horizontal transfer with pathogenic bacteria involving mobile genetic elements such as transposase and plasmid. We identified many ARGs that may represent new variants in fosfomycin and β-lactams resistance. CONCLUSION: These findings show that new bacterial species from human microbiota should be considered as an important reservoir of ARGs that can be transferred to pathogenic bacteria. In vitro analyses of their phenotypic potential are required to improve our understanding of the functional role of this bacterial community in the development of antibiotic resistance. | 2022 | 35216256 |
| 3915 | 16 | 0.9998 | Phylogenetic signature of lateral exchange of genes for antibiotic production and resistance among bacteria highlights a pattern of global transmission of pathogens between humans and livestock. The exchange of bacterial virulence factors driven by lateral gene transfer (LGT) can help indicate possible bacterial transmission among different hosts. Specifically, overlaying the phylogenetic signal of LGT among bacteria onto the distribution of respective isolation sources (hosts) can indicate patterns of transmission among these hosts. Here, we apply this approach towards a better understanding of patterns of bacterial transmission between humans and livestock. We utilize comparative genomics to trace patterns of LGT for an 11-gene operon responsible for the production of the antibiotic nisin and infer transmission of bacteria among respective host species. A total of 147 bacterial genomes obtained from NCBI were determined to contain the complete operon. Isolated from human, porcine and bovine hosts, these genomes represented six Streptococcus and one Staphylococcus species. Phylogenetic analyses of the operon sequences revealed a signature of frequent and recent lateral gene transfer that indicated extensive bacterial transmission between humans and pigs. For 11 isolates, we detected a Tn916-like transposon inserted into the operon. The transposon contained the tetM gene (tetracycline resistance) and additional phylogenetic analyses indicated transmission among human and animal hosts. The bacteria possessing the nisin operon and transposon were isolated from hosts distributed globally. These findings possibly reflect both the globalization of the food industry and an increasingly mobile and expanding human population. In addition to concerns regarding zoonosis, these findings also highlight the potential threat to livestock worldwide due to reverse zoonosis. | 2018 | 29631053 |
| 3914 | 17 | 0.9998 | Genomic Insights into Drug Resistance and Virulence Platforms, CRISPR-Cas Systems and Phylogeny of Commensal E. coli from Wildlife. Commensal bacteria act as important reservoirs of virulence and resistance genes. However, existing data are generally only focused on the analysis of human or human-related bacterial populations. There is a lack of genomic studies regarding commensal bacteria from hosts less exposed to antibiotics and other selective forces due to human activities, such as wildlife. In the present study, the genomes of thirty-eight E. coli strains from the gut of various wild animals were sequenced. The analysis of their accessory genome yielded a better understanding of the role of the mobilome on inter-bacterial dissemination of mosaic virulence and resistance plasmids. The study of the presence and composition of the CRISPR/Cas systems in E. coli from wild animals showed some viral and plasmid sequences among the spacers, as well as the relationship between CRISPR/Cas and E. coli phylogeny. Further, we constructed a single nucleotide polymorphisms-based core tree with E. coli strains from different sources (humans, livestock, food and extraintestinal environments). Bacteria from humans or highly human-influenced settings exhibit similar genetic patterns in CRISPR-Cas systems, plasmids or virulence/resistance genes-carrying modules. These observations, together with the absence of significant genetic changes in their core genome, suggest an ongoing flow of both mobile elements and E. coli lineages between human and natural ecosystems. | 2021 | 34063152 |
| 3406 | 18 | 0.9998 | Environmental and Pathogenic Carbapenem Resistant Bacteria Isolated from a Wastewater Treatment Plant Harbour Distinct Antibiotic Resistance Mechanisms. Wastewater treatment plants are important reservoirs and sources for the dissemination of antibiotic resistance into the environment. Here, two different groups of carbapenem resistant bacteria-the potentially environmental and the potentially pathogenic-were isolated from both the wastewater influent and discharged effluent of a full-scale wastewater treatment plant and characterized by whole genome sequencing and antibiotic susceptibility testing. Among the potentially environmental isolates, there was no detection of any acquired antibiotic resistance genes, which supports the idea that their resistance mechanisms are mainly intrinsic. On the contrary, the potentially pathogenic isolates presented a broad diversity of acquired antibiotic resistance genes towards different antibiotic classes, especially β-lactams, aminoglycosides, and fluoroquinolones. All these bacteria showed multiple β-lactamase-encoding genes, some with carbapenemase activity, such as the bla(KPC)-type genes found in the Enterobacteriaceae isolates. The antibiotic susceptibility testing assays performed on these isolates also revealed that all had a multi-resistance phenotype, which indicates that the acquired resistance is their major antibiotic resistance mechanism. In conclusion, the two bacterial groups have distinct resistance mechanisms, which suggest that the antibiotic resistance in the environment can be a more complex problematic than that generally assumed. | 2021 | 34572700 |
| 3440 | 19 | 0.9998 | Global dissemination of the beta-lactam resistance gene blaTEM-1 among pathogenic bacteria. Antibiotic resistance presents a burgeoning global health crisis, with over 70 % of pathogenic bacteria now exhibiting resistance to at least one antibiotic. This study leverages a vast dataset of 618,853 pathogenic bacterial genomes from the NCBI pathogen detection database, offering comprehensive insights into antibiotic resistance patterns, species-specific profiles, and transmission dynamics of resistant pathogens. We centered our investigation on the beta-lactam resistance gene blaTEM-1, found in 43,339 genomes, revealing its extensive distribution across diverse species and isolation sources. The study unveiled the prevalence of 15 prominent antibiotic resistance genes (ARGs), including those conferring resistance to beta-lactam, aminoglycoside, and tetracycline antibiotics. Distinct resistance patterns were observed between Gram-positive and Gram-negative bacteria, indicating the influence of phylogeny on resistance dissemination. Notably, the blaTEM-1 gene demonstrated substantial prevalence across a wide array of bacterial species (8) and a high number of isolation sources (11). Genetic context analysis revealed associations between blaTEM-1 and mobile genetic elements (MGEs) like transposons and insertion sequences. Additionally, we observed recent horizontal transfer events involving clusters of blaTEM-1 genes and MGEs underscore the potential of MGEs in facilitating the mobilization of ARGs. Our findings underscore the importance of adopting a One Health approach to global genomic pathogen surveillance, aiming to uncover the transmission routes of ARGs and formulate strategies to address the escalating antibiotic resistance crisis. | 2025 | 39824112 |