# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 1661 | 0 | 1.0000 | Novel mcr-3 variant, encoding mobile colistin resistance, in an ST131 Escherichia coli isolate from bloodstream infection, Denmark, 2014. A novel variant of the plasmid-borne colistin resistance gene mcr-3 was detected on an IncHI2 plasmid in an ST131 CTX-M-55-producing Escherichia coli isolate from a Danish patient with bloodstream infection in 2014. The discovery of novel plasmid-borne genes conferring resistance to colistin is of special interest since colistin has reemerged as an important drug in the treatment of infections with multidrug-resistant Gram-negative bacteria. | 2017 | 28797324 |
| 1689 | 1 | 0.9998 | Occurrence and Characteristics of Mcrs among Gram-Negative Bacteria Causing Bloodstream Infections of Infant Inpatients between 2006 and 2019 in China. The aim of this study was to determine the occurrence of mobilized colistin resistance (mcr) genes in Gram-negative bacteria causing bloodstream infections of child inpatients in China. Bacteria were collected between 2006 and 2019 in a maternal and child health hospital, and mcr genes were screened by PCR. Five of 252 isolates were mcr-positive, including one mcr-1-positive colistin-resistant Escherichia coli isolate, two mcr-9-positive colistin-susceptible Salmonella enterica isolates, and two mcr-9-positive colistin-susceptible Enterobacter hormaechei isolates. These were obtained from two neonate and three infant patients admitted between 2009 and 2018. The E. coli isolate was obtained from a neonate aged 20 min, suggestive of a possible mother-to-neonate transmission. The five mcr-positive isolates were multidrug resistant, and two S. enterica and one E. hormaechei isolate showed a hypervirulent phenotype compared to a hypervirulent Klebsiella pneumoniae type strain in a Galleria mellonella infection model. The mcr-1 gene was carried by an IncX4-type pA1-like epidemic plasmid, and the mcr-9 gene was detected on IncHI2/2A-type novel plasmids co-carrying multiple resistance genes. The four IncHI2/2A-type plasmids shared a backbone and a high similarity (≥77% coverage and ≥ 90% nucleotide identity), suggesting that they were derived from a common ancestor with cross-species transmission and have circulated locally over a long period. The conjugation assay showed that the mcr-1-encoding plasmid and one mcr-9-encoding plasmid were self-transmissible to E. coli with high conjugation frequencies. Our findings demonstrate that mcr genes have disseminated in the community and/or hospitals, mediated by epidemic/endemic plasmids over a long period. The study shows that continuous monitoring of mcr genes is imperative for understanding and tackling their dissemination. IMPORTANCE Antimicrobial resistance, especially the spread of carbapenemase-producing Enterobacteriaceae (CPE), represents one of the largest challenges to One Health coverage of environmental, animal, and human sectors. Colistin is one of the last-line antibiotics for clinical treatment of CPE. However, the emergence of the mobilized colistin resistance (mcr) gene largely threatens the usage of colistin in the clinical setting. In this study, we investigated the existence of mcr genes in 252 Gram-negative bacteria collected between 2006 and 2019 which caused bloodstream infections of child inpatients in China. We found a high prevalence of mcr carriage among children inpatients in the absence of professional exposure, and mcr might have widely disseminated in the community via different routes. This study emphasizes the importance of rational use of colistin in the One Health frame, and highlights both the urgent need for understanding the prevalence and dissemination of mcr genes in different populations and the importance of effective measures to control their spread. | 2022 | 35138190 |
| 1667 | 2 | 0.9998 | Colistin Resistance Gene mcr-8 in a High-Risk Sequence Type 15 Klebsiella pneumoniae Isolate from Kenya. The emergence and rise of mobile colistin resistance genes are of great global concern due to the ease of transfer of resistance to other bacteria. This report describes the genome of a colistin- and multidrug-resistant Klebsiella pneumoniae isolate bearing mcr-8, obtained from a hospitalized patient in Kenya. | 2020 | 32972937 |
| 1527 | 3 | 0.9998 | Emergence of an Escherichia coli strain co-harbouring mcr-1 and bla(NDM-9) from a urinary tract infection in Taiwan. OBJECTIVES: Multidrug-resistant bacteria have become a serious threat worldwide. In particular, the coexistence of carbapenemase genes and mcr-1 leaves few available treatment options. Here we report a multidrug-resistant Escherichia coli isolate harbouring both mcr-1 and bla(NDM-9) from a patient with a urinary tract infection. METHODS: Antimicrobial susceptibility and resistance genes of the E. coli isolate were characterised. Furthermore, the assembled genome sequences of mcr-1- and bla(NDM-9)-carrying plasmids were determined and comparative genetic analysis with closely related plasmids was carried out. RESULTS: Three contigs were assembled comprising the E. coli chromosome and two plasmids harbouring mcr-1 (p5CRE51-MCR-1) and bla(NDM-9) (p5CRE51-NDM-9), respectively. Whole-genome sequencing revealed that the two antimicrobial resistance genes are located on individual plasmids. CONCLUSIONS: The emergence of coexistence of carbapenemase genes and mcr-1 in Enterobacteriaceae highlights a serious threat to antimicrobial therapy. | 2019 | 30312830 |
| 1660 | 4 | 0.9998 | Emergence of Plasmid-Mediated Fosfomycin-Resistance Genes among Escherichia coli Isolates, France. FosA, a glutathione S-transferase that inactivates fosfomycin, has been reported as the cause of enzymatic resistance to fosfomycin. We show that multiple lineages of FosA-producing extended spectrum β-lactamase Escherichia coli have circulated in France since 2012, potentially reducing the efficacy of fosfomycin in treating infections with antimicrobial drug-resistant gram-negative bacilli. | 2017 | 28820368 |
| 1686 | 5 | 0.9998 | Resistome of carbapenem- and colistin-resistant Klebsiella pneumoniae clinical isolates. The emergence and dissemination of carbapenemases, bacterial enzymes able to inactivate most β-lactam antibiotics, in Enterobacteriaceae is of increasing concern. The concurrent spread of resistance against colistin, an antibiotic of last resort, further compounds this challenge further. Whole-genome sequencing (WGS) can play a significant role in the rapid and accurate detection/characterization of existing and emergent resistance determinants, an essential aspect of public health surveillance and response activities to combat the spread of antimicrobial resistant bacteria. In the current study, WGS data was used to characterize the genomic content of antimicrobial resistance genes, including those encoding carbapenemases, in 10 multidrug-resistant Klebsiella pneumoniae isolates from Pakistan. These clinical isolates represented five sequence types: ST11 (n = 3 isolates), ST14 (n = 3), ST15 (n = 1), ST101 (n = 2), and ST307 (n = 1). Resistance profiles against 25 clinically-relevant antimicrobials were determined by broth microdilution; resistant phenotypes were observed for at least 15 of the 25 antibiotics tested in all isolates except one. Specifically, 8/10 isolates were carbapenem-resistant and 7/10 isolates were colistin-resistant. The blaNDM-1 and blaOXA-48 carbapenemase genes were present in 7/10 and 5/10 isolates, respectively; including 2 isolates carrying both genes. No plasmid-mediated determinants for colistin resistance (e.g. mcr) were detected, but disruptions and mutations in chromosomal loci (i.e. mgrB and pmrB) previously reported to confer colistin resistance were observed. A blaOXA-48-carrying IncL/M-type plasmid was found in all blaOXA-48-positive isolates. The application of WGS to molecular epidemiology and surveillance studies, as exemplified here, will provide both a more complete understanding of the global distribution of MDR isolates and a robust surveillance tool useful for detecting emerging threats to public health. | 2018 | 29883490 |
| 1897 | 6 | 0.9998 | Plasmid-based replicon typing: Useful tool in demonstrating the silent pandemic of plasmid-mediated multi-drug resistance in Enterobacterales. BACKGROUND: Multi-drug resistant Enterobacterales increasingly isolated in hospital settings have a significant impact on therapy and overall treatment costs. Conjugative plasmids carrying relevant resistance genes have been described as the most frequent mechanism of acquisition and spread of resistance. PCR-based replicon typing (PBRT) is a method for plasmid identification and incompatibility typing which helps detect the presence of plasmid families in these bacteria. This study was undertaken to provide an insight into the prevalence of resistance plasmids in MDR Enterobacterales in our tertiary care setting. METHODS: A selection of one hundred multi-drug resistant Enterobacterale isolates sourced from clinical samples were subjected to PCR-based replicon typing. RESULTS: A total of 21 plasmid replicon types were detected from 85% of the isolates out of the 28 families described in literature. Majority of the isolates (54%) showed three or more replicons. IncF was the most frequent plasmid family detected with FIA being the most common replicon type (43%) followed by FII (29%) and FIB (28%) replicons. Among the IncX plasmid family, X3 replicon was the commonest (14%). IncF and IncX plasmid families are known to carry a large spectrum of resistance genes. CONCLUSION: The presence of these plasmids engenders emergent steps to be taken for prevention of their transmission in the form of strict infection control measures in the hospital and adoption of novel methods of plasmid curing to eliminate the plasmids from these organisms rendering them susceptible to the currently used antimicrobials. | 2025 | 40463599 |
| 1684 | 7 | 0.9998 | Plasmid-encoded gene duplications of extended-spectrum β-lactamases in clinical bacterial isolates. INTRODUCTION: The emergence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae is an urgent and alarming One Health problem. This study aimed to investigate duplications of plasmid-encoded ESBL genes and their impact on antimicrobial resistance (AMR) phenotypes in clinical and screening isolates. METHODS: Multi-drug-resistant bacteria from hospitalized patients were collected during routine clinical surveillance from January 2022 to June 2023, and their antimicrobial susceptibility patterns were determined. Genotypes were extracted from long-read whole-genome sequencing data. Furthermore, plasmids and other mobile genetic elements associated with ESBL genes were characterized, and the ESBL genes were correlated to ceftazidime minimal inhibitory concentration (MIC). RESULTS: In total, we identified four cases of plasmid-encoded ESBL gene duplications that match four genetically similar plasmids during the 18-month surveillance period: five Escherichia coli and three Klebsiella pneumoniae isolates. As the ESBL genes were part of transposable elements, the surrounding sequence regions were duplicated as well. In-depth analysis revealed insertion sequence (IS)-mediated transposition mechanisms. Isolates with duplicated ESBL genes exhibited a higher MIC for ceftazidime in comparison to isolates with a single gene copy (3-256 vs. 1.5-32 mg/L, respectively). CONCLUSION: ESBL gene duplications led to an increased phenotypic resistance against ceftazidime. Our data suggest that ESBL gene duplications by an IS-mediated transposition are a relevant mechanism for how AMR develops in the clinical setting and is part of the microevolution of plasmids. | 2024 | 38469349 |
| 1725 | 8 | 0.9998 | Letter to the Editor: Escherichia fergusonii Harboring IncHI2 Plasmid Containing mcr-1 Gene-A Novel Reservoir for Colistin Resistance in Brazil. Emergence of colistin-resistant bacteria harboring mobile colistin resistance genes (mcr genes) pose a threat for food-producing animals and humans. In this article, we aim to highlight the emergence of Escherichia fergusonii as an important new reservoir to mcr-1-harboring plasmid in poultry production. Three strains closely related were isolated from cloacal swabs. Their genome contains four plasmids, including a 182,869 bp IncHI2 plasmid harboring the colistin resistance gene mcr-1. These results will contribute to our understanding of plasmid-mediated mcr-1 gene presence and transmission in E. fergusonii. | 2021 | 33001761 |
| 1746 | 9 | 0.9997 | New Multidrug-Resistant Salmonella enterica Serovar Anatum Clone, Taiwan, 2015-2017. In 2011, a Salmonella enterica serovar Anatum clone emerged in Taiwan. During 2016-2017, infections increased dramatically, strongly associated with emergence and spread of multidrug-resistant strains with a plasmid carrying 11 resistance genes, including bla(DHA-1). Because these resistant strains infect humans and food animals, control measures are urgently needed. | 2019 | 30561315 |
| 1670 | 10 | 0.9997 | KPC-2-producing Klebsiella pneumoniae isolated from a Czech patient previously hospitalized in Greece and in vivo selection of colistin resistance. Carbapenemase-producing Gram-negative bacteria peak clinical interest due to their ability to hydrolyze most β-lactams, including carbapenems; moreover, their genes spread through bacterial populations by horizontal transfer. Bacteria with acquired carbapenemase have sporadically been reported in the Czech Republic, so far only in Enterobacteriaceae and Pseudomonas aeruginosa. In this study, we described the first finding of a KPC-2-producing strain of Klebsiella pneumoniae, which was isolated from a surgical wound swab, decubitus ulcer, and urine of a patient previously hospitalized in Greece. The patient underwent various antibiotic therapies including a colistin treatment. However, after approximately 20 days of the colistin therapy, the strain developed a high-level resistance to this drug. All the isolates were indistinguishable by pulsed field gel electrophoretic analysis and belonged to the international clone ST258, which is typical of KPC-producing K. pneumoniae isolates. The bla (KPC-2) gene was located on a Tn4401a transposon variant. The OmpK35 and OmpK36 genes analysis performed due to the high resistance level of the strains to β-lactams exhibited no changes in their sequence or in their expression when compared with carbapenem-susceptible isolates. | 2011 | 21818609 |
| 2068 | 11 | 0.9997 | Genetic characterization of plasmid-mediated fluoroquinolone efflux pump QepA among ESBL-producing Escherichia coli isolates in Mexico. Antimicrobial resistance is a major global public health problem, with fluoroquinolone-resistant strains of Escherichia coli posing a significant threat. This study examines the genetic characterization of ESBL-producing E. coli isolates in Mexican hospitals, which are resistant to both cephalosporins and fluoroquinolones. A total of 23 ESBL-producing E. coli isolates were found to be positive for the qepA gene, which confers resistance to fluoroquinolones. These isolates exhibited drug resistance phenotypes and belonged to specific sequence types and phylogenetic groups. The genetic context of the qepA gene was identified in a novel genetic context flanked by IS26 sequences. Mating experiments showed the co-transfer of qepA1 and chrA determinants alongside bla(CTX-M-15) genes, emphasizing the potential for these genetic structures to spread among Enterobacterales. The emergence of multidrug-resistant Gram-negative bacteria carrying these resistance genes is a significant clinical concern for public healthcare systems. | 2023 | 37702924 |
| 886 | 12 | 0.9997 | Detection of Plasmid-Mediated Resistance against Colistin in Multi-Drug-Resistant Gram-Negative Bacilli Isolated from a Tertiary Hospital. The aim of this study was to determine the prevalence of plasmid-mediated colistin resistance mcr-1 to mcr-5 genes among colistin and multi-drug-resistant Gram-negative bacilli strains isolated from patients in a tertiary hospital in Toluca, Mexico. The presence of mcr genes among the 241 strains collected was assessed by PCR. In the case of mcr-carrying E. coli, further PCR tests were performed to determine the presence of bla(CTX-M) and whether the strains belonged to the O25b-ST131 clone. Conjugation experiments were also carried out to assess the horizontal transmission of colistin resistance. A total of twelve strains (5.0%), of which four were E. coli; four were P. aeruginosa; three were K. pneumoniae, and one E. cloacae, were found to be resistant to colistin. Of these strains, two E. coli isolates were found to carry mcr-1, and Southern blot hybridization demonstrated its presence on an approximately 60 kb plasmid. Both mcr-1-carrying E. coli strains were found to co-express bla(CTX-M), belong to the O25b-ST131 clone, and horizontally transmit their colistin resistance. The results of this study confirm the presence of plasmid-mediated colistin resistance in hospitalized patients in Mexico and demonstrated that the multi-drug-resistant O25b-ST131 E. coli clone can acquire mcr genes and transmit such resistance traits to other bacteria. | 2023 | 37630556 |
| 1575 | 13 | 0.9997 | Widespread transfer of resistance genes between bacterial species in an intensive care unit: implications for hospital epidemiology. A transferable plasmid encoding SHV-12 extended-spectrum beta-lactamase, TEM-116, and aminoglycoside resistance was responsible for two sequential clonal outbreaks of Enterobacter cloacae and Acinetobacter baumannii bacteria. A similar plasmid was present among isolates of four different bacterial species. Recognition of plasmid transfer is crucial for control of outbreaks of multidrug-resistant nosocomial pathogens. | 2005 | 16145160 |
| 1669 | 14 | 0.9997 | Antimicrobial Resistance and Comparative Genome Analysis of Klebsiella pneumoniae Strains Isolated in Egypt. Klebsiella pneumoniae is an important human pathogen in both developing and industrialised countries that can causes a variety of human infections, such as pneumonia, urinary tract infections and bacteremia. Like many Gram-negative bacteria, it is becoming resistant to many frontline antibiotics, such as carbapenem and cephalosporin antibiotics. In Egypt, K. pneumoniae is increasingly recognised as an emerging pathogen, with high levels of antibiotic resistance. However, few Egyptian K. pneumoniae strains have been sequenced and characterised. Hence, here, we present the genome sequence of a multidrug resistant K. pneumoniae strain, KPE16, which was isolated from a child in Assiut, Egypt. We report that it carries multiple antimicrobial resistance genes, including a bla(NDM-1) carbapenemase and extended spectrum β-lactamase genes (i.e., bla(SHV-40), bla(TEM-1B), bla(OXA-9) and bla(CTX-M-15)). By comparing this strain with other Egyptian isolates, we identified common plasmids, resistance genes and virulence determinants. Our analysis suggests that some of the resistance plasmids that we have identified are circulating in K. pneumoniae strains in Egypt, and are likely a source of antibiotic resistance throughout the world. | 2021 | 34576775 |
| 1602 | 15 | 0.9997 | Molecular survey of mcr1 and mcr2 plasmid mediated colistin resistance genes in Escherichia coli isolates of animal origin in Iran. OBJECTIVES: The emergence of colistin-resistant Enterobacteriaceae from human and animal sources is one of the major public health concerns as colistin is the last-resort antibiotic for treating infections caused by multidrug-resistant Gram-negative bacteria. We aimed to determine the prevalence of the prototype widespread colistin resistance genes (mcr-1 and mcr-2) among commensal and pathogenic Escherichia coli strains isolated from food-producing and companion animals in Iran. RESULTS: A total of 607 E. coli isolates which were previously collected from different animal sources between 2008 and 2016 used to uncover the possible presence of plasmid-mediated colistin resistance genes (mcr-1 and mcr-2) by PCR. Overall, our results could not confirm the presence of any mcr-1 or mcr-2 positive E. coli among the studied isolates. It is concluded that despite the important role of food-producing animals in transferring the antibiotic resistance, they were not the main source for carriage of mcr-1 and mcr-2 in Iran until 2016. This study suggests that the other mcr variants (mcr-3 to mcr-9) might be responsible for conferring colistin resistance in animal isolates in Iran. The possible linkage between pig farming industry and high level of mcr carriage in some countries needs to be clarified in future prospective studies. | 2021 | 33757569 |
| 1629 | 16 | 0.9997 | Molecular detection of colistin resistance genes (mcr-1 to mcr-5) in human vaginal swabs. OBJECTIVE: Colistin resistance has emerged worldwide and has been threatening the efficacy of one of the last-resort antimicrobials used for treatment of multidrug resistant Gram-negative bacteria. While five colistin resistance genes (mcr-1, mcr-2, mcr-3, mcr-4 and mcr-5) have been described, few data are available on the prevalence of mcr-genes other than mcr-1 in human samples. RESULTS: In this study, the presence of five currently described colistin resistance genes (mcr 1-5) in vaginal swabs of women undergoing infertility evaluation was reported. Most samples were found to be positive for the mcr-4 (12.7%), followed by two for the mcr-2 (1.5%), two for the mcr-3 (1.5%), one for the mcr-1 (0.7%), and one for the mcr-5 (0.7%). Phylogenetic comparison demonstrated identical (mcr-1, mcr-2, mcr-3, mcr-5) or similar (mcr-4) nucleotide sequences of human samples and those of animal origins from the same city, suggesting the potential transmission of mcr genes from animals to humans. This is the first detection of mcr-2, mcr-4 and mcr-5 genes in human samples, and warrants further research to determine the spread of the mcr genes and elucidate the full epidemiology of colistin resistance genes in humans. | 2018 | 29463301 |
| 1842 | 17 | 0.9997 | Emergence of mcr-9.1 in Extended-Spectrum-β-Lactamase-Producing Clinical Enterobacteriaceae in Pretoria, South Africa: Global Evolutionary Phylogenomics, Resistome, and Mobilome. Extended-spectrum-β-lactamase (ESBL)-producing Enterobacteriaceae are critical-priority pathogens that cause substantial fatalities. With the emergence of mobile mcr genes mediating resistance to colistin in Enterobacteriaceae, clinicians are now left with few therapeutic options. Eleven clinical Enterobacteriaceae strains with resistance to cephems and/or colistin were genomically analyzed to determine their resistomes, mobilomes, and evolutionary relationships to global strains. The global phylogenomics of mcr genes and mcr-9.1-bearing genomes were further analyzed. Ten isolates were ESBL positive. The isolates were multidrug resistant and phylogenetically related to global clones but distant from local strains. Multiple resistance genes, including bla (CTX-M-15) bla (TEM-1), and mcr-9.1, were found in single isolates; ISEc9, IS19, and Tn3 transposons bracketed bla (CTX-M-15) and bla (TEM-1) Common plasmid types included IncF, IncH, and ColRNAI. mcr-9 was of close sequence identity to mcr-3, mcr-5, mcr-7, mcr-8, and mcr-10. Genomes bearing mcr-9.1 clustered into six main phyletic groups (A to F), with those of this study belonging to clade B. Enterobacter species and Salmonella species are the main hosts of mcr-9.1 globally, although diverse promiscuous plasmids disseminate mcr-9.1 across different bacterial species. Emergence of mcr-9.1 in ESBL-producing Enterobacteriaceae in South Africa is worrying, due to the restricted therapeutic options. Intensive One Health molecular surveillance might discover other mcr alleles and inform infection management and antibiotic choices.IMPORTANCE Colistin is currently the last-resort antibiotic for difficult-to-treat bacterial infections. However, colistin resistance genes that can move from bacteria to bacteria have emerged, threatening the safe treatment of many bacterial infections. One of these genes, mcr-9.1, has emerged in South Africa in bacteria that are multidrug resistant, further limiting treatment options for clinicians. In this work, we show that this new gene is disseminating worldwide through Enterobacter and Salmonella species through multiple plasmids. This worrying observation requires urgent action to prevent further escalation of this gene in South Africa and Africa. | 2020 | 32430406 |
| 1664 | 18 | 0.9997 | Emergence of colistin resistance in Enterobacter aerogenes from Croatia. A colistin-resistant Enterobacter aerogenes [study code 12264] was isolated from the tracheal aspirate of a 71-year-old male patient in the General Hospital [GH] in Pula, Croatia. The patient was previously treated in University Hospital Centre in Rijeka with colistin in order to eradicate Acinetobacter baumannii isolate, susceptible only to colistin and tigecycline. Genes encoding ESBLs [bla(TEM), bla(SHV), bla(CTX-M), bla(PER-1)] were screened by PCR. The strain was shown to possess bla(CTX-M-15) and bla(TEM-1) genes. To asses genes possibly involved in resistance to colistin the chromosomal enconding mgrB gene and the plasmid-mediated mcr-1 and mcr-2 genes were screened as described previously. Mcr-1 and mcr-2 genes were not detected and mgrB gene presented a wild-type sequence. PCR-based Replicon typing method [PBRT] conducted on an E. aerogenes isolate, showed that the strain carried an IncN plasmid. Adaptive mechanisms such as changes of the bacterial cell outer membrane that cause porin decrease or presence of an efflux pump, due to selection pressure exerted by the therapeutic administration of colistin, could be responsible for the development of colistin resistance in our strain, as recently reported in E. aerogenes from France. Due to effective infection control measures, the colistin-resistant strain did not spread to other patients or hospital wards. This is the first report of an ESBL-producing, colistin-resistant E. aerogenes in clinically relevant samples such as endotracheal aspirate and blood culture, showing the presence of this rare resistance profile among Gram-negative bacteria. | 2018 | 29063811 |
| 1630 | 19 | 0.9997 | One Health study of mobile colistin resistance (mcr) in Salmonella enterica in Canada, 2017-2022. Colistin is a last-resort treatment for highly drug-resistant bacterial infections. Of 47,184 Salmonella isolates collected from 2017 to 2022 in Canada from human and animal/food sources, mobile colistin resistance (mcr) variants conferring colistin resistance were detected exclusively in humans (n = 15). These variants were mcr-1.1 (n = 7), mcr-3.1 (n = 5), mcr-3.2 (n = 2), and mcr-1.2 (n = 1). The most common mcr-containing serotypes were I 4,[5],12:i:- (n = 8) and Typhimurium (n = 3). The proportion of Salmonella carrying mcr genes remains low in Canada (0.03%). IMPORTANCE: Colistin can be used in combination with other drugs as salvage therapy for extensively drug-resistant infections. If mobile colistin resistance (mcr) becomes widely disseminated in Enterobacterales, colistin will no longer be an option for salvage therapy in otherwise untreatable infections. While colistin is not commonly used to treat human Salmonella infections, Salmonella represents an important reservoir of mcr genes that may be transmitted to other gram-negative bacteria. Our aim was to determine the occurrence of mcr genes in Salmonella isolates collected from humans, food animals, and retail meats in Canada. | 2025 | 40387317 |