# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 1980 | 0 | 0.9985 | Genotypic analyses of IncHI2 plasmids from enteric bacteria. Incompatibility (Inc) HI2 plasmids are large (typically > 200 kb), transmissible plasmids that encode antimicrobial resistance (AMR), heavy metal resistance (HMR) and disinfectants/biocide resistance (DBR). To better understand the distribution and diversity of resistance-encoding genes among IncHI2 plasmids, computational approaches were used to evaluate resistance and transfer-associated genes among the plasmids. Complete IncHI2 plasmid (N = 667) sequences were extracted from GenBank and analyzed using AMRFinderPlus, IntegronFinder and Plasmid Transfer Factor database. The most common IncHI2-carrying genera included Enterobacter (N = 209), Escherichia (N = 208), and Salmonella (N = 204). Resistance genes distribution was diverse, with plasmids from Escherichia and Salmonella showing general similarity in comparison to Enterobacter and other taxa, which grouped together. Plasmids from Enterobacter and other taxa had a higher prevalence of multiple mercury resistance genes and arsenic resistance gene, arsC, compared to Escherichia and Salmonella. For sulfonamide resistance, sul1 was more common among Enterobacter and other taxa, compared to sul2 and sul3 for Escherichia and Salmonella. Similar gene diversity trends were also observed for tetracyclines, quinolones, β-lactams, and colistin. Over 99% of plasmids carried at least 25 IncHI2-associated conjugal transfer genes. These findings highlight the diversity and dissemination potential for resistance across different enteric bacteria and value of computational-based approaches for the resistance-gene assessment. | 2024 | 38684834 |
| 1974 | 1 | 0.9984 | Plasmid-associated antimicrobial resistance and virulence genes in Escherichia coli in a high arctic reindeer subspecies. OBJECTIVES: In extreme environments, such as the Arctic region, the anthropogenic influence is low and the presence of antimicrobial-resistant bacteria is unexpected. In this study, we screened wild reindeer (Rangifer tarandus platyrhynchus) from the Svalbard High Arctic Archipelago for antimicrobial-resistant Escherichia coli and performed in-depth strain characterisation. METHODS: Using selective culturing of faecal samples from 55 animals, resistant E. coli were isolated and subjected to minimum inhibitory concentration (MIC) determination, conjugation experiments and whole-genome sequencing. RESULTS: Twelve animals carried antimicrobial-resistant E. coli. Genomic analysis showed IncF plasmids as vectors both for resistance and virulence genes in most strains. Plasmid-associated genes encoding resistance to ampicillin, sulfonamides, streptomycin and trimethoprim were found in addition to virulence genes typical for colicin V (ColV)-producing plasmids. Comparison with previously reported IncF ColV plasmids from human and animal hosts showed high genetic similarity. The plasmids were detected in E. coli sequence types (STs) previously described as hosts for such plasmids, such as ST58, ST88 and ST131. CONCLUSION: Antimicrobial-resistant E. coli were detected from Svalbard reindeer. Our findings show that successful hybrid antimicrobial resistance-ColV plasmids and their host strains are widely distributed also occurring in extreme environmental niches such as arctic ecosystems. Possible introduction routes of resistant bacterial strains and plasmids into Svalbard ecosystems may be through migrating birds, marine fish or mammals, arctic fox (Vulpes lagopus) or via human anthropogenic activities such as tourism. | 2021 | 34216807 |
| 1982 | 2 | 0.9984 | Comamonas resistens Co-Producing GES-5 and OXA-17 in Urban Wastewater as a Potential Novel Disseminator of Clinically Relevant β-Lactamases. Comamonas species have been isolated from different sources, with Comamonas testosteroni and Comamonas resistens commonly related to human diseases and multidrug resistance, respectively. During a surveillance study to monitor carbapenem resistance in bacteria from wastewater samples in Brazil, a carbapenem-resistant strain, named M13, was obtained and identified as C. resistens (ANI 98.90%, dDDH 94.60%) by genomic analysis, being a species distinct from C. testosteroni. It exhibited multidrug resistance and presented small inhibition zones around disks containing novel β-lactams and β-lactam-β-lactamase inhibitor combinations. Comparative genomics showed significant single nucleotide polymorphism divergence between M13 and other C. resistens genomes, suggesting geographically driven genomic diversity. Strain M13 uniquely harbored genes related to antimicrobial resistance and metal tolerance as follows: bla(GES-5) (carbapenem resistance), bla(OXA-17) (third-generation cephalosporin resistance), mer operon (mercury tolerance), and pco operon (copper tolerance). The bla(GES-5) and bla(OXA-17) genes were located on distinct plasmids that lacked conjugative genes but contained mobilization elements, indicating the potential for horizontal transfer. Unlike C. resistens strains from China, M13 strain may have acquired clinically relevant antimicrobial resistance genes via interactions with Brazilian microbial communities. These findings highlight the relevance of monitoring Comamonas species as potential reservoirs and disseminators of clinically relevant antimicrobial resistance genes and underscore the need for environmental monitoring of carbapenem-resistant strains. | 2025 | 40719913 |
| 5738 | 3 | 0.9984 | Unveiling the Genomic Landscape of Understudied Salmonella enterica Serovars from Poultry and Human: Implications for Food Safety. Despite the bacteria of the genus Salmonella are pathogens of zoonotic importance, the factors associated with some serovars genetic diversity remain unclear. We investigated genotypic profiles of antimicrobial resistance, plasmid replicons, and virulence factors in 301 S. enterica genomes from human and animal sources, supplemented by ten sequenced genomes from fecal samples of laying hens in Brazil. Many antimicrobial resistance genes have been detected across various Salmonella serovars; with a limited number of unique resistance genes predicted in poultry isolates compared to human isolates. Specifically, among the 52 antimicrobial resistance genes identified, 48% were shared between poultry and human isolates, while 21.1% were exclusive to poultry isolates and 30.7% were exclusive to human isolates. Chromosomal mutations in the gyrA and parC genes were also predicted. To the best of our knowledge, this is the first work to report S. Braenderup carrying the SPI-10. SGI-1 was detected in a few isolates of S. Schwarzengrund from poultry and the CS54 island was solely noticed in genomes referring to the serovars S. Saintpaul and S. Braenderup. Among the serovars analyzed, S. Saintpaul showed the lowest plasmid diversity. A total of 161 (161/271) virulence genes were common to all serovars, the remaining genes were exclusively identified within specific serovars, revealing a distinct distribution pattern within the S. enterica population. Overall, our study brings to light the genetic potential of Salmonella serovars frequently neglected in poultry production, which threatens public health, particularly due to multidrug-resistant profiles against active principles used to treat human infections. | 2025 | 40327155 |
| 1981 | 4 | 0.9984 | Detecting Class 1 Integrons and Their Variable Regions in Escherichia coli Whole-Genome Sequences Reported from Andean Community Countries. Various genetic elements, including integrons, are known to contribute to the development of antimicrobial resistance. Class 1 integrons have been identified in E. coli isolates and are associated with multidrug resistance in countries of the Andean Community. However, detailed information on the gene cassettes located on the variable regions of integrons is lacking. Here, we investigated the presence and diversity of class 1 integrons, using an in silico approach, in 2533 whole-genome sequences obtained from EnteroBase. IntFinder v1.0 revealed that almost one-third of isolates contained these platforms. Integron-bearing isolates were associated with environmental, food, human, and animal origins reported from all countries under scrutiny. Moreover, they were identified in clones known for their pathogenicity or multidrug resistance. Integrons carried cassettes associated with aminoglycoside (aadA), trimethoprim (dfrA), cephalosporin (blaOXA; blaDHA), and fluoroquinolone (aac(6')-Ib-cr; qnrB) resistance. These platforms showed higher diversity and larger numbers than previously reported. Moreover, integrons carrying more than three cassettes in their variable regions were determined. Monitoring the prevalence and diversity of genetic elements is necessary for recognizing emergent patterns of resistance in pathogenic bacteria, especially in countries where various factors are recognized to favor the selection of resistant microorganisms. | 2024 | 38786123 |
| 1815 | 5 | 0.9984 | Clinically relevant antibiotic resistance in Escherichia coli from black kites in southwestern Siberia: a genetic and phenotypic investigation. Wild birds including raptors can act as vectors of clinically relevant bacteria with antibiotic resistance. The aim of this study was to investigate the occurrence of antibiotic-resistant Escherichia coli in black kites (Milvus migrans) inhabiting localities in proximity to human-influenced environments in southwestern Siberia and investigate their virulence and plasmid contents. A total of 51 E. coli isolates mostly with multidrug resistance (MDR) profiles were obtained from cloacal swabs of 35 (64%, n = 55) kites. Genomic analyses of 36 whole genome sequenced E. coli isolates showed: (i) high prevalence and diversity of their antibiotic resistance genes (ARGs) and common association with ESBL/AmpC production (27/36, 75%), (ii) carriage of mcr-1 for colistin resistance on IncI2 plasmids in kites residing in proximity of two large cities, (iii) frequent association with class one integrase (IntI1, 22/36, 61%), and (iv) presence of sequence types (STs) linked to avian-pathogenic (APEC) and extra-intestinal pathogenic E. coli (ExPEC). Notably, numerous isolates had significant virulence content. One E. coli with APEC-associated ST354 carried qnrE1 encoding fluoroquinolone resistance on IncHI2-ST3 plasmid, the first detection of such a gene in E. coli from wildlife. Our results implicate black kites in southwestern Siberia as reservoirs for antibiotic-resistant E. coli. It also highlights the existing link between proximity of wildlife to human activities and their carriage of MDR bacteria including pathogenic STs with significant and clinically relevant antibiotic resistance determinants. IMPORTANCE Migratory birds have the potential to acquire and disperse clinically relevant antibiotic-resistant bacteria (ARB) and their associated antibiotic resistance genes (ARGs) through vast geographical regions. The opportunistic feeding behavior associated with some raptors including black kites and the growing anthropogenic influence on their natural habitats increase the transmission risk of multidrug resistance (MDR) and pathogenic bacteria from human and agricultural sources into the environment and wildlife. Thus, monitoring studies investigating antibiotic resistance in raptors may provide essential data that facilitate understanding the fate and evolution of ARB and ARGs in the environment and possible health risks for humans and animals associated with the acquisition of these resistance determinants by wildlife. | 2023 | 37310717 |
| 2604 | 6 | 0.9984 | Acquisition and dissemination of cephalosporin-resistant E. coli in migratory birds sampled at an Alaska landfill as inferred through genomic analysis. Antimicrobial resistance (AMR) in bacterial pathogens threatens global health, though the spread of AMR bacteria and AMR genes between humans, animals, and the environment is still largely unknown. Here, we investigated the role of wild birds in the epidemiology of AMR Escherichia coli. Using next-generation sequencing, we characterized cephalosporin-resistant E. coli cultured from sympatric gulls and bald eagles inhabiting a landfill habitat in Alaska to identify genetic determinants conferring AMR, explore potential transmission pathways of AMR bacteria and genes at this site, and investigate how their genetic diversity compares to isolates reported in other taxa. We found genetically diverse E. coli isolates with sequence types previously associated with human infections and resistance genes of clinical importance, including bla(CTX-M) and bla(CMY). Identical resistance profiles were observed in genetically unrelated E. coli isolates from both gulls and bald eagles. Conversely, isolates with indistinguishable core-genomes were found to have different resistance profiles. Our findings support complex epidemiological interactions including bacterial strain sharing between gulls and bald eagles and horizontal gene transfer among E. coli harboured by birds. Results suggest that landfills may serve as a source for AMR acquisition and/or maintenance, including bacterial sequence types and AMR genes relevant to human health. | 2018 | 29743625 |
| 2633 | 7 | 0.9984 | Tracking bla(CTX-M) transmission through transposable elements in uropathogenic and commensal E. coli. AIM: To investigate the nucleotide sequences associated with transposable elements carrying bla(CTX-M) allelic variants as potential markers for the transmission of antimicrobial resistance genes between domestic animals, humans and the environment. MATERIALS & METHODS: We conducted whole-genome sequencing and analyzed the nucleotide sequences of most abundant bla(CTX-M) allelic variants (bla(CTX-M-27), bla(CTX-M-55), and bla(CTX-M-65)) in commensal Escherichia coli (n = 20) from household members in Quito and uropathogenic E. coli (UPEC) (n = 149) isolated from nine clinics in Quito, Ecuador. RESULTS: The Ecuadorian commensal E. coli and UPEC displayed identical nucleotide sequences surrounding the bla(CTX-M) gene and the synteny was similar to those found in other parts of the world; however phylogenetic analysis indicated that the genetic environments in Ecuadorian isolates were unique. CONCLUSION: These findings suggest that the nucleotide sequences flanking the bla(CTX-M) genes may be useful for resolving ARG transmission pathways, especially inter-regional analyses. | 2025 | 39880589 |
| 5739 | 8 | 0.9983 | Emergence and Comparative Genome Analysis of Salmonella Ohio Strains from Brown Rats, Poultry, and Swine in Hungary. Rats are particularly important from an epidemiological point of view, because they are regarded as reservoirs for diverse zoonotic pathogens including enteric bacteria. This study is the first to report the emergence of Salmonella serovar Ohio in brown rats (Rattus norvegicus) and food-producing animals in Hungary. We first reveal the genomic diversity of the strains and their phylogenomic relationships in the context of the international collection of S. Ohio genomes. This pathogen was detected in 4.3% (4/92) of rats, captured from multiple sites in Hungary. A whole-genome-based genotype comparison of S. Ohio, Infantis, Enteritidis, and Typhimurium strains showed that 76.4% (117/153) of the virulence and antimicrobial resistance genes were conserved among these serovars, and none of the genes were specific to S. Ohio. All S. Ohio strains lacked virulence and resistance plasmids. The cgMLST phylogenomic comparison highlighted a close genetic relationship between rat and poultry strains of S. Ohio from Hungary. These strains clustered together with the international S. Ohio genomes from aquatic environments. Overall, this study contributes to our understanding of the epidemiology of Salmonella spp. in brown rats and highlights the importance of monitoring to minimize the public health risk of rodent populations. However, further research is needed to understand the route of infection and evolution of this serovar. | 2024 | 39201506 |
| 2630 | 9 | 0.9983 | Characterization of bla(NDM-5)-and bla(CTX-M-199)-Producing ST167 Escherichia coli Isolated from Shared Bikes. Shared bikes as a public transport provide convenience for short-distance travel. Whilst they also act as a potential vector for antimicrobial resistant (AR) bacteria and antimicrobial resistance genes (ARGs). However, the understanding of the whole genome sequence of AR strains and ARGs-carrying plasmids collected from shared bikes is still lacking. Here, we used the HiSeq platform to sequence and analyze 24 Escherichia coli isolated from shared bikes around Metro Stations in Beijing. The isolates from shared bikes showed 14 STs and various genotypes. Two blaNDM-5 and blaCTX-M-199-producing ST167 E. coli have 16 resistance genes, four plasmid types and show >95% of similarities in core genomes compared with the ST167 E. coli strains from different origins. The blaNDM-5- or blaCTX-M-199-carrying plasmids sequencing by Nanopore were compared to plasmids with blaNDM-5- or blaCTX-M-199 originated from humans and animals. These two ST167 E. coli show high similarities in core genomes and the plasmid profiles with strains from hospital inpatients and farm animals. Our study indicated that ST167 E. coli is retained in diverse environments and carried with various plasmids. The analysis of strains such as ST167 can provide useful information for preventing or controlling the spread of AR bacteria between animals, humans and environments. | 2022 | 36009901 |
| 1859 | 10 | 0.9983 | Transcontinental Dissemination of Enterobacterales Harboring bla(NDM-1) in Retail Frozen Shrimp. The global food trade provides a means of disseminating antimicrobial resistant (AMR) bacteria and genes. Using selective media, carbapenem-resistant species of Enterobacterales (Providencia sp. and Citrobacter sp.), were detected in a single package of imported frozen shrimp purchased from a grocery store in Ohio, USA. Polymerase chain reaction confirmed that both isolates harbored bla(NDM-1) genes. Following PacBio long read sequencing, the sequences were annotated using the NCBI Prokaryotic Genome Annotation Pipeline. The bla(NDM-1) genes were found in IncC plasmids, each with different antimicrobial resistance island configuration. We found that the bla(NDM-1) AMR islands had close relationships with previously reported environmental, food, and clinical isolates detected in Asia and the United States, highlighting the importance of the food chain in the global dissemination of antimicrobial resistance. | 2025 | 38563789 |
| 1656 | 11 | 0.9983 | Characterisation of Commensal Escherichia coli Isolated from Apparently Healthy Cattle and Their Attendants in Tanzania. While pathogenic types of Escherichia coli are well characterized, relatively little is known about the commensal E. coli flora. In the current study, antimicrobial resistance in commensal E. coli and distribution of ERIC-PCR genotypes among isolates of such bacteria from cattle and cattle attendants on cattle farms in Tanzania were investigated. Seventeen E. coli genomes representing different ERIC-PCR types of commensal E. coli were sequenced in order to determine their possible importance as a reservoir for both antimicrobial resistance genes and virulence factors. Both human and cattle isolates were highly resistant to tetracycline (40.8% and 33.1%), sulphamethazole-trimethoprim (49.0% and 8.8%) and ampicillin (44.9% and 21.3%). However, higher proportion of resistant E. coli and higher frequency of resistance to more than two antimicrobials was found in isolates from cattle attendants than isolates from cattle. Sixteen out of 66 ERIC-PCR genotypes were shared between the two hosts, and among these ones, seven types contained isolates from cattle and cattle attendants from the same farm, suggesting transfer of strains between hosts. Genome-wide analysis showed that the majority of the sequenced cattle isolates were assigned to phylogroups B1, while human isolates represented phylogroups A, C, D and E. In general, in silico resistome and virulence factor identification did not reveal differences between hosts or phylogroups, except for lpfA and iss found to be cattle and B1 phylogroup specific. The most frequent plasmids replicon genes found in strains from both hosts were of IncF type, which are commonly associated with carriage of antimicrobial and virulence genes. Commensal E. coli from cattle and attendants were found to share same genotypes and to carry antimicrobial resistance and virulence genes associated with both intra and extraintestinal E. coli pathotypes. | 2016 | 27977751 |
| 4969 | 12 | 0.9983 | Comparative Genomic Analysis of Campylobacter Plasmids Identified in Food Isolates. Campylobacter is one of the leading bacterial causes of gastroenteritis worldwide. It frequently contaminates poultry and other raw meat products, which are the primary sources of Campylobacter infections in humans. Plasmids, known as important mobile genetic elements, often carry genes for antibiotic resistance, virulence, and self-mobilization. They serve as the main vectors for transferring genetic material and spreading resistance and virulence among bacteria. In this study, we identified 34 new plasmids from 43 C. jejuni and C. coli strains isolated from retail meat using long-read and short-read genome sequencing. Pangenomic analysis of the plasmid assemblies and reference plasmids from GenBank revealed five distinct groups, namely, pTet, pVir, mega plasmids (>80 kb), mid plasmids (~30 kb), and small plasmids (<6 kb). Pangenomic analysis identified the core and accessory genes in each group, indicating a high degree of genetic similarity within groups and substantial diversity between the groups. The pTet plasmids were linked to tetracycline resistance phenotypes in host strains. The mega plasmids carry multiple genes (e.g., aph(3')-III, type IV and VI secretion systems, and type II toxin-antitoxin systems) important for plasmid mobilization, virulence, antibiotic resistance, and the persistence of Campylobacter. Together, the identification and comprehensive genetic characterization of new plasmids from Campylobacter food isolates contributes to understanding the mechanisms of gene transfer, particularly the spread of genetic determinants of virulence and antibiotic resistance in this important pathogen. | 2025 | 39858976 |
| 5729 | 13 | 0.9983 | Virulome and genome analyses identify associations between antimicrobial resistance genes and virulence factors in highly drug-resistant Escherichia coli isolated from veal calves. Food animals are known reservoirs of multidrug-resistant (MDR) Escherichia coli, but information regarding the factors influencing colonization by these organisms is lacking. Here we report the genomic analysis of 66 MDR E. coli isolates from non-redundant veal calf fecal samples. Genes conferring resistance to aminoglycosides, β-lactams, sulfonamides, and tetracyclines were the most frequent antimicrobial resistance genes (ARGs) detected and included those that confer resistance to clinically significant antibiotics (blaCMY-2, blaCTX-M, mph(A), erm(B), aac(6')Ib-cr, and qnrS1). Co-occurrence analyses indicated that multiple ARGs significantly co-occurred with each other, and with metal and biocide resistance genes (MRGs and BRGs). Genomic analysis also indicated that the MDR E. coli isolated from veal calves were highly diverse. The most frequently detected genotype was phylogroup A-ST Cplx 10. A high percentage of isolates (50%) were identified as sequence types that are the causative agents of extra-intestinal infections (ExPECs), such as ST69, ST410, ST117, ST88, ST617, ST648, ST10, ST58, and ST167, and an appreciable number of these isolates encoded virulence factors involved in the colonization and infection of the human urinary tract. There was a significant difference in the presence of multiple accessory virulence factors (VFs) between MDR and susceptible strains. VFs associated with enterohemorrhagic infections, such as stx, tir, and eae, were more likely to be harbored by antimicrobial-susceptible strains, while factors associated with extraintestinal infections such as the sit system, aerobactin, and pap fimbriae genes were more likely to be encoded in resistant strains. A comparative analysis of SNPs between strains indicated that several closely related strains were recovered from animals on different farms indicating the potential for resistant strains to circulate among farms. These results indicate that veal calves are a reservoir for a diverse group of MDR E. coli that harbor various resistance genes and virulence factors associated with human infections. Evidence of co-occurrence of ARGs with MRGs, BRGs, and iron-scavenging genes (sit and aerobactin) may lead to management strategies for reducing colonization of resistant bacteria in the calf gut. | 2022 | 35298535 |
| 1595 | 14 | 0.9983 | Anthropogenic antibiotic resistance genes mobilization to the polar regions. Anthropogenic influences in the southern polar region have been rare, but lately microorganisms associated with humans have reached Antarctica, possibly from military bases, fishing boats, scientific expeditions, and/or ship-borne tourism. Studies of seawater in areas of human intervention and proximal to fresh penguin feces revealed the presence of Escherichia coli strains least resistant to antibiotics in penguins, whereas E. coli from seawater elsewhere showed resistance to one or more of the following antibiotics: ampicillin, tetracycline, streptomycin, and trim-sulfa. In seawater samples, bacteria were found carrying extended-spectrum β-lactamase (ESBL)-type CTX-M genes in which multilocus sequencing typing (MLST) showed different sequence types (STs), previously reported in humans. In the Arctic, on the contrary, people have been present for a long time, and the presence of antibiotic resistance genes (ARGs) appears to be much more wide-spread than was previously reported. Studies of E coli from Arctic birds (Bering Strait) revealed reduced susceptibility to antibiotics, but one globally spreading clone of E. coli genotype O25b-ST131, carrying genes of ESBL-type CTX-M, was identified. In the few years between sample collections in the same area, differences in resistance pattern were observed, with E. coli from birds showing resistance to a maximum of five different antibiotics. Presence of resistance-type ESBLs (TEM, SHV, and CTX-M) in E. coli and Klebsiella pneumoniae was also confirmed by specified PCR methods. MLST revealed that those bacteria carried STs that connect them to previously described strains in humans. In conclusion, bacteria previously related to humans could be found in relatively pristine environments, and presently human-associated, antibiotic-resistant bacteria have reached a high global level of distribution that they are now found even in the polar regions. | 2016 | 27938628 |
| 1777 | 15 | 0.9983 | Inter-phylum circulation of a beta-lactamase-encoding gene: a rare but observable event. Beta-lactamase-mediated degradation of beta-lactams is the most common mechanism of beta-lactam resistance in Gram-negative bacteria. Beta-lactamase-encoding genes can be transferred between closely related bacteria, but spontaneous inter-phylum transfers (between distantly related bacteria) have never been reported. Here, we describe an extended-spectrum beta-lactamase (ESBL)-encoding gene (bla(MUN-1)) shared between the Pseudomonadota and Bacteroidota phyla. An Escherichia coli strain was isolated from a patient in Münster (Germany). Its genome was sequenced. The ESBL-encoding gene (named bla(MUN-1)) was cloned, and the corresponding enzyme was characterized. The distribution of the gene among bacteria was investigated using the RefSeq Genomes database. The frequency and relative abundance of its closest homolog in the global microbial gene catalog (GMGC) were analyzed. The E. coli strain exhibited two distinct morphotypes. Each morphotype possessed two chromosomal copies of the bla(MUN-1) gene, with one morphotype having two additional copies located on a phage-plasmid p0111. Each copy was located within a 7.6-kb genomic island associated with mobility. bla(MUN-1) encoded for an extended-spectrum Ambler subclass A2 beta-lactamase with 43.0% amino acid identity to TLA-1. bla(MUN-1) was found in species among the Bacteroidales order and in Sutterella wadsworthensis (Pseudomonadota). Its closest homolog in GMGC was detected frequently in human fecal samples. This is, to our knowledge, the first reported instance of inter-phylum transfer of an ESBL-encoding gene, between the Bacteroidota and Pseudomonadota phyla. Although the gene was frequently detected in the human gut, inter-phylum transfer was rare, indicating that inter-phylum barriers are effective in impeding the spread of ESBL-encoding genes, but not entirely impenetrable. | 2024 | 38441061 |
| 1722 | 16 | 0.9983 | Genomic Characteristics and Molecular Epidemiology of Multidrug-Resistant Klebsiella pneumoniae Strains Carried by Wild Birds. This study aimed to explore the relationship between wild birds and the transmission of multidrug-resistant strains. Klebsiella pneumoniae was isolated from fresh feces of captured wild birds and assessed by the broth microdilution method and comparative genomics. Four Klebsiella pneumoniae isolates showed different resistance phenotypes; S90-2 and S141 were both resistant to ampicillin, cefuroxime, and cefazolin, while M911-1 and S130-1 were sensitive to most of the 14 antibiotics tested. S90-2 belongs to sequence type 629 (ST629), and its genome includes 30 resistance genes, including bla(CTX-M-14) and bla(SHV-11), while its plasmid pS90-2.3 (IncR) carries qacEdelta1, sul1, and aph(3')-Ib. S141 belongs to ST1662, and its genome includes a total of 27 resistance genes, including bla(SHV-217). M911-1 is a new ST, carrying bla(SHV-1) and fosA6, and its plasmid pM911-1.1 (novel) carries qnrS1, bla(LAP-2), and tet(A). S130-1 belongs to ST3753, carrying bla(SHV-11) and fosA6, and its plasmid pS130-1 [IncFIB(K)] carries only one resistance gene, tet(A). pM911-1.1 and pS90-2.3 do not have conjugative transfer ability, but their resistance gene fragments are derived from multiple homologous Enterobacteriaceae strain chromosomes or plasmids, and the formation of resistance gene fragments (multidrug resistance region) involves interactions between multiple mobile element genes, resulting in a complex and diverse resistance plasmid structure. The homologous plasmids related to pM911-1.1 and pS90-2.3 were mainly from isolated human-infecting bacteria in China, namely, K. pneumoniae and Escherichia coli. The multidrug-resistant K. pneumoniae isolates carried by wild birds in this study had drug resistance phenotypes conferred primarily by multidrug resistance plasmids that were closely related to human-infecting bacteria. IMPORTANCE Little is known about the pathogenic microorganisms carried by wild animals. This study found that the multidrug resistance phenotype of Klebsiella pneumoniae isolates carried by wild birds was mainly attributed to multidrug resistance plasmids, and these multidrug resistance plasmids from wild birds were closely related to human-infecting bacteria. Wild bird habitats overlap to a great extent with human and livestock habitats, which further increases the potential for horizontal transfer of multidrug-resistant bacteria among humans, animals, and the environment. Therefore, wild birds, as potential transmission hosts of multidrug-resistant bacteria, should be given attention and monitored. | 2023 | 36840587 |
| 4970 | 17 | 0.9983 | Massive analysis of 64,628 bacterial genomes to decipher water reservoir and origin of mobile colistin resistance genes: is there another role for these enzymes? Since 2015, new worrying colistin resistance mechanism, mediated by mcr-1 gene has been reported worldwide along with eight newly described variants but their source(s) and reservoir(s) remain largely unexplored. Here, we conducted a massive bioinformatic analysis of bacterial genomes to investigate the reservoir and origin of mcr variants. We identified 13'658 MCR-1 homologous sequences in 494 bacterial genera. Moreover, analysis of 64'628 bacterial genomes (60 bacterial genera and 1'047 species) allows identifying a total of 6'651 significant positive hits (coverage >90% and similarity >50%) with the nine MCR variants from 39 bacterial genera and more than 1'050 species. A high number of MCR-1 was identified in Escherichia coli (n = 862). Interestingly, while almost all variants were identified in bacteria from different sources (i.e. human, animal, and environment), the last variant, MCR-9, was exclusively detected in bacteria from human. Although these variants could be identified in bacteria from human and animal sources, we found plenty MCR variants in unsuspected bacteria from environmental origin, especially from water sources. The ubiquitous presence of mcr variants in bacteria from water likely suggests another role in the biosphere of these enzymes as an unknown defense system against natural antimicrobial peptides and/or bacteriophage predation. | 2020 | 32249837 |
| 1776 | 18 | 0.9983 | Broad-Host Dissemination of Plasmids Coharboring the fos Operon for Fructooligosaccharide Metabolism with Antibiotic Resistance Genes. The fos operon encoding short-chain fructooligosaccharide (scFOS) utilization enables bacteria of the family Enterobacteriaceae to grow and be sustained in environments where they would struggle to survive. Despite several cases of the detection of the fos operon in isolates of avian and equine origins, its global distribution in bacterial genomes remains unknown. The presence of the plasmid-harbored fos operon among resistant bacteria may promote the spread of antibiotic resistance. A collection of 11,538 antimicrobial-resistant Enterobacteriaceae isolates from various sources was screened for the fosT gene encoding the scFOS transporter. Out of 307 fosT-positive isolates, 80% of them originated from sources not previously linked to fosT (humans, wastewater, and animals). The chromosomally harbored fos operon was detected in 163/237 isolates subjected to whole-genome sequencing. In the remaining 74 isolates, the operon was carried by plasmids. Further analyses focusing on the isolates with a plasmid-harbored fos operon showed that the operon was linked to various incompatibility (Inc) groups, including the IncHI1, IncF-type, IncK2, IncI1, and IncY families. Long-read sequencing of representative plasmids showed the colocalization of fos genes with antibiotic resistance genes (ARGs) in IncHI1 (containing a multidrug resistance region), IncK2 (bla(TEM-1A)), IncI1 [sul2 and tet(A)], and IncY [aadA5, dfrA17, sul2, and tet(A)] plasmids, while IncF-type plasmids had no ARGs but coharbored virulence-associated genes. Despite the differences in the locations and structures of the fos operons, all isolates except one were proven to utilize scFOSs. In this study, we show that the fos operon and its spread are not strictly bound to one group of plasmids, and therefore, it should not be overlooked. IMPORTANCE It was believed that members of the family Enterobacteriaceae are unable to grow under conditions with short-chain fructooligosaccharides as the only source of carbon. Nevertheless, the first Escherichia coli isolate from chicken intestine was able to utilize these sugars owing to the chromosomally harbored fos operon. Studies on E. coli isolates from horses discovered the horizontal transfer of the fos operon on IncHI1 plasmids along with genes for antibiotic resistance. The first plasmid detected was pEQ1, originating from the feces of a hospitalized horse in the Czech Republic. Follow-up studies also revealed the dissemination of the IncHI1 plasmid-harbored fos operon in the Netherlands, Germany, Denmark, and France among healthy horses. Despite several cases of detection of the fos operon, its global distribution in bacterial genomes remains unknown. The fos operon possibly plays a role in the adaptation of plasmids among resistant bacteria and therefore may promote the spread of antibiotic resistance. | 2023 | 37578374 |
| 1983 | 19 | 0.9983 | Aeromonas species isolated from aquatic organisms, insects, chicken, and humans in India show similar antimicrobial resistance profiles. Aeromonas species are Gram-negative bacteria that infect various living organisms and are ubiquitously found in different aquatic environments. In this study, we used whole genome sequencing (WGS) to identify and compare the antimicrobial resistance (AMR) genes, integrons, transposases and plasmids found in Aeromonas hydrophila, Aeromonas caviae and Aeromonas veronii isolated from Indian major carp (Catla catla), Indian carp (Labeo rohita), catfish (Clarias batrachus) and Nile tilapia (Oreochromis niloticus) sampled in India. To gain a wider comparison, we included 11 whole genome sequences of Aeromonas spp. from different host species in India deposited in the National Center for Biotechnology Information (NCBI). Our findings show that all 15 Aeromonas sequences examined had multiple AMR genes of which the Ambler classes B, C and D β-lactamase genes were the most dominant. The high similarity of AMR genes in the Aeromonas sequences obtained from different host species point to interspecies transmission of AMR genes. Our findings also show that all Aeromonas sequences examined encoded several multidrug efflux-pump proteins. As for genes linked to mobile genetic elements (MBE), only the class I integrase was detected from two fish isolates, while all transposases detected belonged to the insertion sequence (IS) family. Only seven of the 15 Aeromonas sequences examined had plasmids and none of the plasmids encoded AMR genes. In summary, our findings show that Aeromonas spp. isolated from different host species in India carry multiple AMR genes. Thus, we advocate that the control of AMR caused by Aeromonas spp. in India should be based on a One Health approach. | 2022 | 36532495 |