Skip to main content
NCBI home page
Scientific Reports logoLink to Scientific Reports
. 2026 Feb 12;16:8583. doi: 10.1038/s41598-026-38191-6

Antimicrobial resistance of Escherichia coli in Hungarian wild rats and characterization of a CTX-M-1 type ESBL plasmid

Ama Szmolka 1,✉, Gabriella Locsmándi 2, Anita Makó 1, Adél Kiss 3, Ákos Gellért 1, László Egyed 1
PMCID: PMC12976303  PMID: 41673084

Abstract

This study presents a comprehensive analysis of antimicrobial resistance in E. coli from brown rats (Rattus norvegicus), focusing on the occurrence and genetic basis of resistance and characterizing an ESBL-producing E. coli strain with a fully resolved CTX-M-1 plasmid. 25.6% of 90 brown rats carried AMR E. coli strains, with 8.9% displaying multidrug resistance. The predominant resistance pattern was combined resistance to ampicillin (17.8%) and tetracycline (12%), with plasmid-associated resistance genes blaTEM−1 and tet(A)/tet(B). The study identified the first ESBL-producing E. coli strain (88/Ec2) in an urban rat in Hungary, harboring the gene blaCTX−M−1 on an approximately 92 kb IncI1 plasmid pCTX-M-1_88/Ec2. Comparative plasmid analysis showed 98% structural similarity to CTX-M-1 plasmids from human-derived pathogens. Strain 88/Ec2 was serotyped as O168:H38 and assigned to a novel sequence type, ST17982. Phylogenetically, it exhibits a central relationship to human CTX-M E. coli lineages, suggesting a shared genomic background with globally disseminated, human epidemic E. coli lineages. These findings highlight the role of urban brown rats as reservoirs and potential vectors of antimicrobial resistance within the One Health framework and advocate for enhanced surveillance of AMR in urban wildlife to better understand and mitigate the zoonotic transfer of resistance genes.

Supplementary Information

The online version contains supplementary material available at 10.1038/s41598-026-38191-6.

Keywords: CTX-M-1 plasmid, Core genome MLST, Plasmid replicon type, Escherichia coli, Rat, ST17982

Subject terms: Genetics, Microbiology, Molecular biology

Introduction

Antimicrobial resistance (AMR) of Escherichia coli poses a significant challenge in the context of public health and the One Health approach, particularly due to its prevalence across diverse ecological niches, including wildlife populations1–3.

Wild Rattus species, such as brown rats (Rattus norvegicus) and black rats (Rattus rattus), are of particular concern due to their role as potential reservoirs and vectors for diverse zoonotic pathogens4–6. These rodents frequently inhabit environments shared with humans and/or livestock, including urban, industrial, and agricultural settings, thereby facilitating the transmission of AMR bacteria at the interface of human-animal-environment interactions7. This zoonotic importance highlights the need to study AMR in E. coli strains isolated from wild rat populations, as these rodents may serve as reservoirs for commensal AMR bacteria capable of disseminating resistance genes to human and animal pathogens1,8,9.

The rise of AMR in E. coli is a pressing concern, driven by the over- and inappropriate use of antibiotics in both human and veterinary medicine as well as in agriculture10. Multidrug-resistant (MDR) E. coli strains and their plasmids encoding resistance mechanisms of public health-priority such as extended-spectrum β-lactamase (ESBL) or colistin have become widespread both in human settings and livestock industry11–13. Plasmids of IncF and IncI1 type are the key drivers of multidrug resistance among enteric pathogens across different ecological niches and contribute to the emergence and epidemic success of high-risk clonal lineages, including ST131 and ST1193 among E. coli populations14,15. Within the food chain, pESI-like plasmids represent the most striking example of epidemic IncI plasmids, playing a decisive role in the global spread of Salmonella Infantis in the poultry industry16,17. Modern molecular epidemiology increasingly employs whole genome-based methodologies such as the core genome Multi-Locus Sequence Typing (cgMLST)18, to reveal the genomic diversity and phylogenetic relationships of plasmidic E. coli strains. This approach is also helpful in elucidating their potential contribution to the global AMR crisis.

The close proximity of rats to human populations coupled with their adaptability to diverse habitats, makes them an important subject for the study of zoonotic AMR bacteria, with special emphasis on the prevalence of plasmid-mediated resistance mechanisms. Unfortunately, research on AMR E. coli strains isolated from wild rodents, particularly rats, reveals significant knowledge gaps. This is due to the limited number of comprehensive data on plasmid associated AMR genes, critical in urban environments where rats may live close to humans.

To address this limitation, we aimed to provide a comprehensive insight into the antimicrobial resistance diversity of E. coli strains isolated from rats across diverse habitats in Hungary. By analyzing multiple cohabiting intestinal isolates of E. coli from individual rats, this research seeks to elucidate the diversity and distribution of antimicrobial resistance patterns within the E. coli population colonizing these rodents in order to assess their zoonotic potential in Hungary.

Materials and methods

Ethics statement

This study protocol was approved (no. MÁB-VMRI-2022/03) by the Institutional Ethics Committee of HUN-REN Veterinary Medical Research Institute for the sampling of rats and the storage and use of their tissues. All sampling procedures involving rats were carried out in accordance with the Hungarian Animal Protection Act (Act 28/1998, § 3, 11 and 12) and the European Directive on the protection of animals used for scientific purposes (Directive 2010/63/EU, 22 September 2010). The study was performed in accordance with ARRIVE guidelines.

Establishment of a comprehensive collection of cohabiting E. coli isolates from wild rats

This study is based on an initial collection of approx. 700 E. coli isolates derived from the large intestine of 90 clinically healthy brown and black rats, Rattus norvegicus (n = 82) and Rattus rattus (n = 8). A described earlier19, the animals were captured and sampled between 2021 and 2024 at various sampling sites across Hungary, predominantly in public and industrial areas as well as farm environments (Fig. 1). Briefly, captured animals were anaesthetized with a combination of xylazine hydrochloride (Sedaxylan injection, EUROVET ANIMAL HEALTH B.V., Bladel, The Netherlands) and tiletamine hydrochloride–zolazepam (Zoletil 100 injection, Virbac, Carros, France). Following anaesthesia, the animals were placed in a CO₂ chamber and euthanized by overdose. Euthanasia was performed by a veterinarian in compliance with all relevant professional, ethical, animal welfare and biosafety regulations. After euthanasia, the large intestine was aseptically removed and stored at − 20 °C until laboratory processing and bacterial isolation.

Fig. 1.

Fig. 1

Open in a new tab

The comprehensive collection of cohabiting E. coli (n = 696) isolated from brown and black rats (Rattus norvegicus and Rattus rattus) from various environments in Hungary between 2021 and 2024. Each intestinal sample (Ring 2) is characterized by multiple (n = 4–8), randomly selected E. coli strains (Ring 3). Black arrows indicate the samples from which AMR E. coli strains were successfully isolated.

Multiple cohabiting E. coli strains were isolated from each large intestinal sample, to increase sensitivity of detection and explore the diversity of antimicrobial resistance patterns at the level of individual samples (Fig. 1). For this, 1 g of intestinal content was enriched in 10 ml Luria Bertani (LB) broth (Merck KGaA), and incubated for 18 h at 37 °C. Next, 10 µl of overnight LB culture was streaked onto Chromocult® Coliform agar plates (Merck KGaA). Following overnight incubation (18 h, 37 °C) eight individual colonies resembling E. coli were randomly selected to represent each sample. Molecular confirmation of these colonies was carried out by multiplex PCR based on the simultaneous presence of the E. coli marker genes lacZ (beta-galactosidase) and uidA (beta-glucuronidase)20.

Selection of a core collection of E. coli strains with representative resistance phenotypes

The AMR phenotype of the comprehensive collection of 696 E. coli strains was determined using disc diffusion (Kirby-Bauer) method against 11 antibiotic compounds selected to detect resistance phenotypes typically associated with mobile genetic elements, including plasmids. Accordingly, the strains were tested to ampicillin (AMP-10 µg), ciprofloxacin (CIP-5 µg), cefotaxime (CTX-5 µg), chloramphenicol (CHL-30 µg), gentamicin (GEN-10 µg), meropenem (MEM-10 µg), nalidixic acid (NAL-30 µg), sulfonamide compounds (SUL-300 µg), tetracycline (TET-30 µg), trimethoprim (TMP-5 µg), and tobramycin (TOB-10 µg) (Bio-Rad Laboratories).

Antibiotic susceptibility testing was performed in accordance with the guidelines and interpretation standards of the European Committee on Antimicrobial Susceptibility Testing21. Strains with intermediate zone diameters were interpreted as susceptible, whereas multidrug resistance was defined as simultaneous resistance to at least three antibiotic classes. The E. coli strain ATCC 25,922 was used as a reference.

Antimicrobial resistance phenotyping allowed for the selection of a core collection of 155 E. coli strains, curated by isolating one representative strain per identified resistance phenotype from each sample, thereby reducing the collection while maintaining the phenotypic diversity. E. coli strains of the core collection were stored at − 80 °C in LB containing 10% glycerol.

Identification of plasmid-associated resistance genes by quantitative real-time PCR (qPCR)

To assess the presence of antimicrobial resistance genes (ARGs), qPCR was performed on 30 AMR E. coli strains. These strains were selected from the core collection of cohabiting AMR E. coli to represent the diversity of AMR phenotypes identified in the 23 rat samples where AMR E. coli was detected. Genomic DNA was extracted from fresh bacterial colonies, which were resuspended in 200 µl of Buffer AVE Elution buffer (RNase-free water with 0.04% NaN3, INDICAL Bioscience), using the A&A Biotechnology MagnifiQ™ Pathogen 96 instant kit, following the manufacturer’s instructions.

We employed the multiplex TaqMan qPCR assay developed by Pholwat et al.22, with minor modification to the primers and corresponding TaqMan probes, as presented in Table S1. It is noteworthy that the qPCR system did not encompass the full spectrum of E. coli ARGs as reported in Pholwat’s study. Here we focused on identifying the genetic basis of E. coli AMR/MDR phenotypes detected in this study. A standard 10-fold dilution series of positive control E. coli strains was used for optimizing qPCR detection efficiency, without the intention of quantification. The qPCR was performed using a BIO-RAD PCR system (Bio-Rad Laboratories). Primer/probe sets, with final concentrations of 0.4 µM for primers and 0.2 µM for probes, were assayed in a 20 µl PCR mixture containing 10 µl of 2X PCRBIO HS Taq Mix, (PCR Biosystem Inc., Pennsylvania, USA), 4 µl of nuclease free water, and 2 µl of genomic DNA. The cycling conditions included an initial denaturation at 95˚C for 2 min, followed by 40 cycles of denaturation at 95˚C for 5 s and annealing/extension at 62˚C for 30 s.

Whole genome sequencing and reconstruction of the ESBL plasmid CTX-M-1

The genome sequence of the E. coli strain 88/Ec2 carrying an ESBL plasmid of the CTX-M-1 type was determined by whole genome sequencing (WGS) (Eurofins Biomi Ltd.) using the Illumina MiSeq sequencing platform. The CTX-M-1 plasmid sequence was reconstructed through nanopore sequencing of the strain on the GridION platform, using the GridION Mk1 device. The basecaller used was Dorado (Oxford Nanopore Technologies, https://github.com/nanoporetech/dorado). Raw Nanopore reads were quality- and length-filtered using NanoFilt (https://github.com/wdecoster/nanofilt). Assembly of the long reads was performed using Flye (https://github.com/mikolmogorov/Flye), and polishing was done with Medaka (https://github.com/nanoporetech/medaka). The entire process was implemented in an in-house automated bioinformatics pipeline, which included multiple quality control checkpoints. The final filtered nanopore dataset was used in a hybrid assembly with Illumina paired-end reads using Unicycler v0.5.1 in bold mode. During the hybrid assembly, Unicycler first assembled the Illumina reads with SPAdes v4.2.0, selecting a wide k-mer range (27 to 127) based on the median short-read length (251 bp), and performed depth-based contig filtering. Long reads were incorporated using a miniasm-based scaffolding approach, followed by multiple rounds of consensus polishing with Racon v1.5.0. The final assembly graph was further refined through bridge construction and integration of high-quality single-copy contigs from the short-read assembly, resulting in a high-contiguity hybrid genome reconstruction. The CTX-M-1 plasmid was fully resolved as a complete circular plasmid sequence.

The genome of the CTX-M-1 plasmid was annotated with the Rapid Annotations using Subsystems Technology (RAST) server v2.023. The genome sequences of the strain Ec88/2, including the complete sequence of the CTX-M-1 plasmid pCTXEc88/2, have been deposited in BioProject PRJNA1303976.

Whole genome-based prediction of the antimicrobial resistance and virulence genotypes and phylogenetic analysis

The integrated web-base genotyping platforms of the Center for Genomic Epidemiology (CGE), such as the ResFinder 4.7.224,25, VirulenceFinder 2.0.525–27 and PlasmidFinder 2.125,28 were used for the in silico identification of the acquired antimicrobial resistance and virulence genes (ARGs and VGs) as well as for plasmid typing based on the replicon type. The serotype of the strain Ec88/2 was identified using SerotypeFinder v.2.0.129. The assembled contigs were used for these analyses, with minimum thresholds for sequence identity and length coverage of 95% and 80%, respectively.

The phylogenetic relation of the CTX-M-1 strain 88/Ec2 was determined using core genome multilocus sequence typing (cgMLST) in the context of a curated collection of CTX-M E. coli retrieved from the Bacterial and Viral Bioinformatics Resource Center (BV-BRC, https://www.bv-brc.org/). These complete and high-quality E. coli genomes represented various human sources (Table S2). Phylogenetic analysis based on both MLST and cgMLST were performed using Ridom SeqSphere+ software v9.0830. The sequence types (STs) were determined by MLST, which relies on the polymorphism of the seven housekeeping genes included in the Warwick MLST scheme for E. coli. The core gene set was determined by blasting all E. coli genome sequences against the E. coli reference strain K-12 MG1655 (GenBank accession no. NC_000913).

Results

Antimicrobial resistance phenotypes of cohabiting E. coli strains from wild rats in Hungary

In total 696 E. coli strains were isolated from 90 large intestinal samples, predominantly representing brown rats (Rattus norvegicus) of clinically healthy status. Most of these animals were captured in public, industrial, and agricultural settings (Fig. 1). To increase sensitivity of detection and to reveal AMR diversity within individual rats, each sample was represented by multiple (4–8) E. coli isolates, which were designated as cohabiting strains.

Antimicrobial resistance phenotyping revealed that 25.6% (n = 23) of the rat samples contained AMR E. coli strains. Among these, E. coli strains displaying MDR phenotypes were detected in eight samples most of them (n = 5) representing animals from urban areas. Notably, all AMR E. coli strains were isolated from brown rats, with none of the black rat samples testing positive for AMR E. coli. E. coli strains exhibiting plasmid-associated AMR phenotypes, such as resistance to ampicillin, tetracycline, and nalidixic acid, were most frequently detected (in 11.7–17.8% of the rat samples). Furthermore, a strain of E. coli exhibiting resistance to cefotaxime was identified in one sample (1.1%) derived from an urban brown rat. In contrast, the vast majority (74.4%) of the captured rats were found to lack AMR E. coli strains (Fig. 2).

Fig. 2.

Fig. 2

Open in a new tab

The prevalence of wild rat samples colonized by AMR E. coli strains. Abbreviations for antimicrobials: Amp: ampicillin; Tet: tetracycline; Nal: nalidixic acid; Sul: sulfonamides; Tmp: trimethoprim; Cip: ciprofloxacine; Chl: chloramphenicol; Ctx: cefotaxime.

In total, 86 cohabiting AMR E. coli strains were isolated from the 23 brown rat samples, each displaying resistance to at least one antimicrobial agent (Fig. S1). From each intestinal sample, it was possible to isolate one pansensitive E. coli strain alongside at least one cohabiting E. coli with various AMR/MDR patterns. Among the cohabiting E. coli strains isolated from the same sample, resistance to ampicillin, tetracycline and nalidixic acid was the most prevalent phenotype. MDR E. coli strains were isolated from eight samples, with the Amp-Tet-Nal-Sul phenotype, conferring resistance to ampicillin, sulfonamides, tetracycline and nalidixic acid, being the most frequently detected (Fig. S1).

Identification of antimicrobial resistance genes associated with mobile genetic elements

To characterize the diversity of ARGs associated with these AMR phenotypes, the subset of 30 AMR E. coli strains from the core collection underwent ARG genotyping using qPCR. It is noteworthy that we focused on identifying the genetic basis of E. coli AMR/MDR phenotypes detected in this study. Accordingly, ARGs associated with mobile genetic elements, conferring resistance to the following antibiotic classes were targeted: β-lactams, tetracyclines, fluoroquinolones, phenicols, sufonamides, and trimethoprim, respectively (Table S1).

qPCR analysis revealed the predominant presence of the β-lactamase and tetracycline resistance genes blaTEM−1 and tet(A)/tet(B) in 93.4% and 63.4% of the E. coli strains, respectively. The trimethoprim and sulfonamide resistance genes dfraA12, sul1 and sul2 were detected in 23.4% of the strains. The phenicol resistance gene floR was identified in two samples (6.7%) while the ESBL gene blaCTX−M1 was detected in one E. coli strain (88/Ec2) isolated from an urban brown rat. Notably, 20 of the 30 E. coli exhibited coexistance of the blaTEM−1 and tet(A)/tet(B) genes, with some strains also harboring the sul and dfr genes (Fig. 3).

Fig. 3.

Fig. 3

Open in a new tab

The circular map illustrating the AMR genotypes of the 30 selected isolates from the core collection of cohabiting E. coli strains derived from brown rats (Rattus norvegicus). Abbreviations for antimicrobials: Amp: ampicillin; Tet: tetracycline; Nal: nalidixic acid; Sul: sulfonamides; Tmp: trimethoprim; Cip: ciprofloxacine; Chl: chloramphenicol; Ctx: cefotaxime.

Genomic features of an ESBL E. coli isolated from rats in Hungary and the analysis of its plasmid pCTX-M-1_88/Ec2

An in silico whole-genome sequence (WGS) analysis was performed to predict the sequence type, serotype, and plasmid replicon types, as well as to identify acquired resistance and virulence genes in order to reveal the genomic context of the gene blaCTX−M−1 in the strain 88/Ec2, which was identified as ESBL-positive.

WGS-based genotyping identified this E. coli strain as serotype O168:H38, and revealed that it represents a novel sequence type, ST17982. The whole-genome analysis and contig assembly yielded four chromosomal contigs and four plasmidic contigs, characterized by replicon types FIIB, FII, I1 and Col (PRJNA1303976). The VirulenceFinder identified the coexistence of chromosomal virulence genes, that are universal among most E. coli strains. These include as astA (heat-stable enterotoxin), fimH (type 1 fimbria adhesion), hlyE (hemolysin) and lpfA (long polar fimbriae). None of these virulence genes were associated with any of the plasmids. The E. coli strain 88/Ec2 exhibited resistance to ampicillin and cefotaxime, conferred by the ESBL gene blaCTX−M−1, located on a 91,929 bp plasmid of IncI1 type, designated as pCTX-M-1_88/Ec2 (PRJNA1303976). Consistent with the in silico prediction of antimicrobial resistance and virulence genes, as well as plasmid replicon types, the analysis of the plasmid genome indicated that this IncI1 plasmid exclusively harbours the blaCTX−M−1 gene (Figs. 3 and 4).

Fig. 4.

Fig. 4

Open in a new tab

The genome map and sequence comparison of the plasmid pCTX-M-1_88/Ec2 (91,929 bp) identified in an E. coli strain from brown rat (Rattus norvegicus). The figure integrates the genome map of plasmid pCTX-M-1_88/Ec2, created using SnapGene software (www.snapgene.com), and the sequence comparison with plasmids pLC0541_17 and pECOH8, derived from human strains of Salmonella and E. coli, respectively. This comparison was generated using the Blast Ring Image Generator (BRIG)31.

To reveal the host and source diversity associated with plasmids carrying the blaCTX−M−1 gene, a BLASTn analysis was performed. Comparative analysis of plasmid genomes identified two CTX-M-1 plasmids that map to pCTX-M-1_88/Ec2 with a query coverage of 98% and a pairwise identity of 99.9% (Fig. 4). Accordingly, plasmid pLC0541_17 and plasmid pECOH8 were identified in Salmonella Napoli and E. coli strains respectively, both of human origin. These plasmids derived from Salmonella and E. coli, shared an identical genomic architecture to that of the rat E. coli plasmid. This similarity encompasses all genomic regions related to specific plasmid functions, including the pil and tra regions, involved in plasmid conjugation and transfer. Additionally, the presence of the blaCTX−M−1 gene in association with the transposase of insertion sequence ISEcp1 was identified in all three plasmids. Conversely, the IsnD enzyme gene associated with the insertion sequence IS2 was identified as a unique feature of the rat E. coli plasmid in this comparison (Fig. 4).

Phylogenetic relationships and genomic diversity of the rat CTX-M E. coli in comparison to human strains

To compare genomic diversity and reveal the phylogenetic relation between the rat-derived E. coli strain 88/Ec2 and human E. coli strains, a curated database collection (BV-BRC) of CTX-M E. coli strains was established. The STs of the database strains were identified by MLST based on the whole-genome sequences. The search of the BV-BRC database identified 437 CTX-M type E. coli strains of human origin, isolated between 2001 and 2024, including the Hungarian strain 88/Ec2 under study (Table S2). The collection encompassed a global distribution of CTX-M E. coli, with strains derived from 50 countries. The majority of these strains, 26.1% and 18.9% were isolated in China and the USA respectively. With the exception of the Hungarian strain 88/Ec2, none of the E. coli strains in the database were isolated from rat sources.

According to the results of the MLST analysis, the tested CTX-M E. coli strains were grouped into 91 STs. Among these, ST131, ST410, ST167, ST405 and ST38 accounted for 50% of the strains, with ST131 being the most prevalent (Fig. 5). Most E. coli strains associated with these STs were characterized by the presence of the blaCTX−M alleles 15, 14 and 27. Only three human E. coli strains, derived from Switzerland, the USA, Hungary were identified as CTX-M-1, and were assigned to distinct STs, namely ST40, ST224 and ST17982 respectively. Notably, ST17982 is considered as novel genetic lineage for E. coli.

Fig. 5.

Fig. 5

Open in a new tab

Phylogenetic diversity of the Hungarian E. coli strain from a brown rat (Rattus norvegicus) in comparison to human strains of CTX-M E. coli (2001 and 2024). The Minimum Spanning Tree was constructed to present the phylogenetic relationships among 437 E. coli strains isolated from humans based on the sequence type (ST), namely on the polymorphism of seven housekeeping genes. Distinct strains within the nodes are separated by grey lines. The node colour is indicative: red represents the Hungarian rat E. coli strain 88/Ec2; yellow indicates STs included in cgMLST analysis; grey indicates STs comprising more than four E. coli strains, but not included in cgMLST.

The MLST phylogeny positioned the Hungarian rat CTX-M-1 E. coli (ST17982) centrally among numerous genetic lineages, with a maximum genetic distance of six alleles from major STs, such as ST131, ST410, ST38 and ST678 (Fig. 5). To enhance the understanding of genomic diversity within these related genetic lineages, a cgMLST analysis was performed on 215 CTX-M-positive E. coli strains, based on the polymorphism of 1898 core genes, using the strain E. coli K-12 MG1655 as the reference genome. The phylogenetic analysis of the core genome revealed that E. coli genomes are organized into four major clusters according to their sequence types (Fig. 6). Clusters 1 and 3 represented the predominant sequence types ST410 and ST131, exhibiting the most homogenous core genome sequences. Conversely, strains of ST38, ST354 and ST648 were grouped within Cluster 2, showing the most significant genomic diversity. While the Hungarian rat ST17982 strain 88/Ec2 and the Swiss human E. coli strains of CTX-M-1 type grouped with CTX-M-15 and CTX-M-55 strains in Cluster 4, they express distinct genomic backgrounds.

Fig. 6.

Fig. 6

Open in a new tab

Core genome diversity of a selected set of CTX-M E. coli strains from humans and a brown rat (Rattus norvegicus) in relation to sequence type (ST). The Neighbor Joining Tree showing the genomic diversity of 215 E. coli strains, was constructed based on the polymorphism of 1898 target genes of the core genome. Core genes were identified by blasting all genome sequences against the reference strain E. coli K-12 MG1655 (GenBank accession no. NC_000913). Black arrows indicate the Hungarian and the Swiss ESBL E. coli strains of the CTX-M-1 type.

Discussion

The One Health approach underscores the interconnectedness of human, animal, and environmental health, with a particular focus on addressing antimicrobial resistance in complex zoonotic bacteria such as MDR E. coli, with a high genomic plasticity and potential to colonize a wide range of host species and habitats1,32. As synanthropic rodents, wild rats exemplify this interconnectedness by potentially contaminating shared environments with pathogenic bacteria and facilitating the genomic dynamics of antimicrobial resistance in E. coli strains.

Therefore, understanding the diversity of AMR genotypes in E. coli populations from wild rats is crucial for identifying AMR mechanisms that could have significant implications for human health. This study presents one of the few comprehensive analyses of antimicrobial resistance in E. coli from brown rats (Rattus norvegicus) in Central Europe and represents the first in Hungary. It highlights the occurrence and genetic background of antimicrobial resistance and characterizes an ESBL-producing E. coli strain, with a fully resolved CTX-M-1 plasmid. By elucidating the phylogenetic relatedness of this strain with E. coli genomes representing various human sources, we aim to contribute to the understanding of the global significance of E. coli antimicrobial resistance in wild rodent populations within the One Health concept.

Rats from urban and agricultural environments can host multiple species of AMR bacteria, predominantly E. coli, exhibiting a large diversity of resistance mechanisms. Our survey of AMR in Rattus species indicated that a substantial proportion (25.6%) of brown rats, particularly those captured in urban/public areas in Hungary, carried AMR E. coli strains, with 8.9% of them displaying multidrug resistance. This prevalence of AMR is consistent with findings in urban rat populations of other countries, although the abundance of AMR E. coli varies by geographic region and environment9,33–35. These and our studies suggest that human-associated environments remain hotspots for the maintenance and dissemination of antimicrobial resistance. In line with these studies, the predominant resistance pattern detected was combined resistance to ampicillin (17.8%) and tetracycline (12%). Genotyping of 30 representative AMR E. coli strains revealed that plasmid-associated resistance genes blaTEM−1 and tet(A)/tet(B) were present in approximately 93% and 60% of the strains respectively. These genes are frequently identified in wild rodent populations, as reported in the aforementioned studies, and are considered among the most widespread in E. coli and multiple MDR enteric pathogens, posing a threat to both animal and public health36–38. The high prevalence of these common plasmid-mediated AMR patterns in rat E. coli populations reflects selective pressures from antibiotic use in agricultural and urban settings. In fact, E. coli from wild rats could be regarded as indicators of antimicrobial pressures present in their environments. The Hungarian wild rat population exhibits the absence of resistance to aminoglycosides and fluoroquinolones, alongside a low prevalence of resistance to phenicols. This may be attributed to a limited exposure of their environment to these antibiotic classes, in contrast to the higher prevalence and diversity of AMR detected in more intensively farmed or urbanized habitats in other countries. Accordingly, recent AMR surveys conducted on rodents from urban and farm settings, increasingly identified the presence of E. coli strains harboring high-priority resistance mechanisms, including ESBL, fluoroquinolone or even colistin resistances33,34,39–41.

Rodents, particularly rats, are increasingly recognized as reservoirs for ESBL-producing E. coli, potentially facilitating the zoonotic transmission of antimicrobial resistance between humans and other animals. A significant finding of this study is the first identification of an ESBL-producing E. coli strain (88/Ec2) in an urban rat in Hungary, which harbors the ESBL gene blaCTX−M−1 on an approximately 90 kb plasmid. The emergence CTX-M enzymes represent one of the most widespread ESBLs in E. coli. From the One Health perspective, particular attention is directed towards CTX-M-1, CTX-M-14 and CTX-M-15 type ESBLs, which are globally disseminated regardless of host origin and geographical region13,42. While CTX-M-14 and CTX-M-15 remain to be the major types identified in humans, CTX-M-1 is widely distributed among animals in Europe and is regarded as the most frequently detected ESBL among rats. In contrast to the overall moderate prevalence (10–20%) of the ESBL gene blaCTX−M−1 observed in brown rats43,44, the detection of this gene in a single rat sample (1.1%) reflects a low, but notable occurrence of the ESBL CTX-M-1 in the Hungarian rat population. This prevalence does not align with the generally higher proportion (> 20%) of E. coli resistant to third-generation cephalosporins found in human clinical settings and in food-producing animals in Hungary45–47. The discrepancy may indicate a reduced incidence of rat infestation within the aforementioned human clinical and food-producing animal environments.

The global success of CTX-M E. coli considerably relies on the wide distribution of specific plasmids or genetic lineages. The blaCTX-M-1 gene in the rat E. coli strain 88/Ec2 was borne on an IncI1 plasmid (pCTX-M-1_88/Ec2) of about 92 kb. Comparative analysis showed that it exhibits 98% structural similarity to CTX-M-1 plasmids from human-derived pathogens: pLC0541_17 from Salmonella Napoli48 and pECOH8 from human E. coli (unpublished; HG739083). All three plasmids share the same genomic architecture, including the conjugative transfer region, and the ISEcp1–blaCTX-M-1 transposition unit, ISEcp1 being recognized as the predominant insertion sequence associated with blaCTX−M mobility49. This finding underscores the interspecies transfer of plasmids and reinforces previous studies that IncI1 plasmids are key drivers for dissemination of blaCTX−M−1 among animal and human hosts. These plasmids exhibit minimal fitness cost, facilitating their persistence even without selective pressure14,50,51.

In comparison to other host species, there is limited research specifically focused on the characterization of CTX-M-1 plasmids in ESBL-producing E. coli in urban rats, particularly from a molecular epidemiological perspective. Studies on plasmid epidemiology, including those involving rodents have demonstrated that both IncF and IncI1 plasmids facilitate the efficient transfer of the blaCTX−M−1 gene between commensal and pathogenic E. coli across humans, animals, and the environment9,33,52. Consequently, our findings support the concept that wild rats may act as incidental but epidemiologically relevant links within the plasmid-mediated resistance gene network.

Moreover, the complete resolution of this rat E. coli plasmid pCTX-M-1_88/Ec2 provides a significant genomic resource for elucidating the intra- and interspecies mobility of the blaCTX−M−1 gene in future research. The isolation of multiple cohabiting strains from individual samples underlines, that single rats are simultaneously carrying both pansensitive and resistant E. coli strains. This complexity of AMR ecology within a single animal also presents a unique opportunity to experimentally investigate the dissemination and potential evolution of antimicrobial resistance plasmids at the micro-community level.

Strain 88/Ec2 was serotyped as O168:H38 and assigned to sequence type ST17982, representing a novel genetic lineage not previously reported. The E. coli O168:H38 serotype is not linked to any known outbreaks, specific pathotypes, or virulence factors such as Shiga toxins. This is consistent with our findings, which reveal that no virulence genes with public health implications were identified in this CTX-M-1 E. coli strain. Nevertheless, urban rats can host E. coli that combine ESBL resistance with virulence genes, characteristic to extraintestinal pathogenic E. coli (ExPEC) belonging to widespread sequence types. A comprehensive phylogenomic study on ESBL E. coli in peridomestic rats in Hong Kong demonstrates that urban rats can harbor diverse CTX-M E. coli lineages, including CTX-M-14, -15, -55 and − 65) strains, which are assigned to high-risk ExPEC lineages such as ST131, ST1193, ST69 and ST7339. Both ST131 and ST1193 are regarded as major drivers of antimicrobial resistance, with their epidemic success likely attributed to the combination of diverse CTX-M and virulence genes15. The finding of Günther et al.9 on the identification of the association of ST95 E. coli with an ESBL-producing ExPEC strain belonging to one of the most virulent ExPEC lineages ST95, underscores the potential zoonotic implications of ESBL-producing ExPEC strains in rat populations. Similarly, Sano et al.53 concluded that urban wildlife in Brazil may serve as reservoirs for WHO-priority CTX-M E. coli, acting as hotspots for spreading clinically relevant resistances.

Phylogenetically, the Hungarian rat 1 E. coli strain 88/Ec2 (O168:H38, ST17982) exhibits a central relationship to human CTX-M E. coli lineages, with genetic distances of up to six alleles from dominant sequence types such as ST131, ST410 and ST38, while maintaining a distinct core genome profile. This profile clusters with CTX-M-1, CTX-M-15 and CTX-M-55 E. coli strains. This phylogenetic proximity suggests that this novel rat E. coli strain shares a substantial genomic background with globally disseminated, often human-adapted E. coli lineages. Such clonal intersections are increasingly recognized, as synanthropic rodents may acquire or circulate E. coli clonal lineages that reflect those found in humans and livestock. Consequently, ST17982 represents a previously uncharacterized branch of this broad CTX-M lineage, underscoring the diversity and potential One Health significance of ESBL E. coli in wildlife.

Conclusions

This study presents the first comprehensive analysis of antimicrobial resistance in E. coli from brown rats (Rattus norvegicus) in Hungary. It underscores the occurrence and genetic basis of antimicrobial resistance and characterizes an ESBL-producing E. coli strain, with a fully resolved CTX-M-1 plasmid pCTX-M-1_88/Ec2. Our findings highlight the role of urban brown rats as reservoirs and potential vectors of antimicrobial resistance within the One Health framework. However commensal AMR E. coli of the Hungarian rat population does not pose a greater threat to humans than those reported in the few international studies. The identification of a novel ESBL-producing E. coli strain with the IncI1/blaCTX−M−1/ST17982 genotype in Hungary seem to represent a novel and potentially emerging lineage of E. coli with indication that this or closely related plasmids could be circulating between strains of Salmonella spp. and E. coli of different animal hosts. These findings advocate for enhanced surveillance of AMR in urban wildlife, particularly in human-associated environments, to better understand and mitigate the zoonotic transfer of resistance genes. Future research should focus on the zoonotic potential and molecular epidemiology of this novel ESBL E. coli lineage. Its CTXM-1 plasmid would require more extended molecular monitoring and experimental host adaptation studies of ESBL E coli in brown rats, as well as determination of mobility of CTX-M-1 plasmids in vitro and in vivo.

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary Material 1 (192.5KB, pdf)
Supplementary Material 2 (64.4KB, xlsx)
Supplementary Material 3 (54.2KB, xlsx)

Author contributions

Conceptualization, A.S.; methodology, L.E., A.S., A.M., G.L. and A.K.; software, A.S. and Á.G.; data evaluation, A.S., G.L. and Á.G.; writing—original draft preparation, A.S., and Á.G. All authors have read and agreed to the published version of the manuscript.

Funding

Open access funding provided by HUN-REN Veterinary Medical Research Institute. This research was funded by the K 137798 grant of the National Research, Development and Innovation Office. Additional support was provided by the Ministry of Innovation and Technology of Hungary (legal successor: Ministry of Culture and Innovation of Hungary) from the National Research, Development and Innovation Fund, financed under the TKP2021-EGA-01 funding schemes of the National Research, Development and Innovation Office.

Data availability

The datasets generated for this study are available in BioProject PRJNA1303976.

Competing interests

The authors declare no competing interests.

Footnotes

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

References

  • 1.EFSA and ECDC. The European union summary report on antimicrobial resistance in zoonotic and indicator bacteria from humans, animals and food in 2022–2023. EFSA J.23, 4523 (2025). [DOI] [PMC free article] [PubMed]
  • 2.Li, X., Mowlaboccus, S., Jackson, B., Cai, C. & Coombs, G. W. Antimicrobial resistance among clinically significant bacteria in wildlife: an overlooked one health concern. Int. J. Antimicrob. Agents. 64, 107251 (2024). [DOI] [PubMed] [Google Scholar]
  • 3.Samreen, Ahmad, I., Malak, H. A. & Abulreesh, H. H. Environmental antimicrobial resistance and its drivers: a potential threat to public health. J. Glob Antimicrob. Resist.27, 101–111 (2021). [DOI] [PubMed] [Google Scholar]
  • 4.Devanathan, N. et al. Synanthropic rodents and shrews are reservoirs of zoonotic bacterial pathogens and act as sentinels for antimicrobial resistance spillover in the environment: a study from Puducherry, India. One Heal. 18, 100759 (2024). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 5.Cock, M. P. et al. Increased rat-borne zoonotic disease hazard in greener urban areas. Sci. Total Environ.896, 165069 (2023). [DOI] [PubMed] [Google Scholar]
  • 6.Badger-Emeka, L. et al. An investigation of potential health risks from zoonotic bacterial pathogens associated with farm rats. Environ. Heal Insights. 14, 1178630220942240 (2020). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 7.Dominguez, J. E. et al. Rats as sources of multidrug-resistant Enterobacteriaceae in animal production environments. Zoonoses Public. Heal. 70, 627–635 (2023). [DOI] [PubMed] [Google Scholar]
  • 8.Uea-Anuwong, T. et al. Antimicrobial resistance in bacteria isolated from peridomestic rattus species: a scoping literature review. One Heal. 16, 100522 (2023). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 9.Guenther, S. et al. Frequent combination of antimicrobial multiresistance and extraintestinal pathogenicity in Escherichia coli isolates from urban rats (Rattus norvegicus) in Berlin, Germany. PLoS ONE. 7, e50331 (2012). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 10.Tang, K. W. K., Millar, B. C. & Moore, J. E. Antimicrobial resistance (AMR). Br. J. Biomed. Sci.80, 11387 (2023). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 11.Mandujano-Hernández, A. et al. The global rise of ESBL-producing Escherichia coli in the livestock sector: a five-tear overview. Animals14, 2490 (2024). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 12.Szmolka, A. et al. Emergence and genomic features of a mcr-1 Escherichia coli from Duck in Hungary. Antibiotics12, 1519 (2023). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 13.Ewers, C., Bethe, A., Semmler, T., Guenther, S. & Wieler, L. H. Extended-spectrum β-lactamase-producing and AmpC-producing Escherichia coli from livestock and companion animals, and their putative impact on public health: a global perspective. Clin. Microbiol. Infect.18, 646–655 (2012). [DOI] [PubMed] [Google Scholar]
  • 14.Foley, S. L., Kaldhone, P. R., Ricke, S. C. & Han, J. Incompatibility group I1 (IncI1) plasmids: their Genetics, Biology, and public health relevance. Microbiol. Mol. Biol. R85, 145236 (2021). [DOI] [PMC free article] [PubMed]
  • 15.Pitout, J. D. D., Peirano, G., Chen, L., DeVinney, R. & Matsumura, Y. Escherichia coli ST1193: following in the footsteps of E. coli ST131. Antimicrob. Agents Chemother.66, e00511–e00522 (2022). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 16.Szmolka, A., Wami, H. & Dobrindt, U. Comparative genomics of emerging lineages and mobile resistomes of contemporary broiler strains of Salmonella infantis and E. coli. Front. Microbiol.12, 642125 (2021). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 17.Aviv, G. et al. A unique megaplasmid contributes to stress tolerance and pathogenicity of an emergent Salmonella enterica serovar infantis strain. Environ. Microbiol.16, 977–994 (2014). [DOI] [PubMed] [Google Scholar]
  • 18.Kimura, B. Will the emergence of core genome MLST end the role of in Silico MLST? Food Microbiol.75, 28–36 (2018). [DOI] [PubMed] [Google Scholar]
  • 19.Szmolka, A., Lancz, Z. S., Rapcsák, F. & Egyed, L. Emergence and comparative genome analysis of Salmonella Ohio strains from brown Rats, Poultry, and swine in Hungary. Int. J. Mol. Sci.25, 8820 (2024). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 20.Bej, A. K., McCarty, S. C. & Atlas, R. M. Detection of coliform bacteria and Escherichia coli by multiplex polymerase chain reaction: comparison with defined substrate and plating methods for water quality monitoring. Appl. Environ. Microbiol.57, 2429–2432 (1991). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 21.The European Committee on Antimicrobial Susceptibility Testing (EUCAST). Breakpoint tables for interpretation of MICs and zone diameters. Version 15.0. (2025). https://www.eucast.org.
  • 22.Pholwat, S. et al. Genotypic antimicrobial resistance assays for use on E. coli isolates and stool specimens. PLoS ONE. 14, e0216747 (2019). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 23.Aziz, R. K. et al. The RAST server: rapid annotations using subsystems technology. BMC Genom. 9, 75 (2008). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 24.Bortolaia, V. et al. ResFinder 4.0 for predictions of phenotypes from genotypes. J. Antimicrob. Chemother.75, dkaa345 (2020). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 25.Camacho, C. et al. BLAST+: architecture and applications. BMC Bioinform.10, 421 (2009). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 26.Tetzschner, A. M. M., Johnson, J. R., Johnston, B. D., Lund, O. & Scheutz, F. Silico genotyping of Escherichia coli isolates for extraintestinal virulence genes by use of Whole-Genome sequencing data. J. Clin. Microbiol.58, e01269–e01220 (2020). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 27.Joensen, K. G. et al. Real-time whole-genome sequencing for routine typing, surveillance, and outbreak detection of verotoxigenic Escherichia coli. J. Clin. Microbiol.52, 1501–1510 (2014). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 28.Carattoli, A. et al. In Silico detection and typing of plasmids using plasmidfinder and plasmid multilocus sequence typing. Antimicrob. Agents Chemother.58, 3895–3903 (2014). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 29.Joensen, K. G., Tetzschner, A. M. M., Iguchi, A., Aarestrup, F. M. & Scheutz, F. Rapid and easy In Silico serotyping of Escherichia coli isolates by use of Whole-Genome sequencing data. J. Clin. Microbiol.53, 2410–2426 (2015). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 30.Jünemann, S. et al. Updating benchtop sequencing performance comparison. Nat. Biotechnol.31, 294–296 (2013). [DOI] [PubMed] [Google Scholar]
  • 31.Alikhan, N. F., Petty, N. K., Zakour, N. L. B. & Beatson, S. A. BLAST ring image generator (BRIG): simple prokaryote genome comparisons. BMC Genom. 12, 402 (2011). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 32.Aslam, B. et al. Antibiotic resistance: one health one world outlook. Front. Cell. Infect. Microbiol.11, 771510 (2021). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 33.Guyomard-Rabenirina, S. et al. Antimicrobial resistance in wildlife in Guadeloupe (French West Indies): distribution of a single blaCTX–M–1/IncI1/ST3 plasmid among humans and wild animals. Front. Microbiol.11, 1524 (2020). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 34.Huy, H. L. et al. Antibiotic-resistant Escherichia coli isolated from urban rodents in Hanoi, Vietnam. J. Vet. Méd Sci.82, 653–660 (2020). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 35.Himsworth, C. G. et al. Prevalence and characteristics of Escherichia coli and Salmonella spp. In the feces of wild urban Norway and black rats (Rattus norvegicus and rattus rattus) from an Inner-city neighborhood of Vancouver, Canada 7. J. Wildl. Dis.51, 589–600 (2015). [DOI] [PubMed] [Google Scholar]
  • 36.Laborda, P. et al. Wildlife and antibiotic resistance. Front. Cell. Infect. Microbiol.12, 873989 (2022). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 37.Sonola, V. S., Katakweba, A., Misinzo, G. & Matee, M. I. Molecular epidemiology of antibiotic resistance genes and virulence factors in Multidrug-Resistant Escherichia coli isolated from Rodents, Humans, Chicken, and household soils in Karatu, Northern Tanzania. Int. J. Environ. Res. Public. Heal. 19, 5388 (2022). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 38.Poirel, L. et al. Antimicrobial resistance in Escherichia coli. Microbiol. Spectr.6, 2563. 10.1128/microbiolspec.arba-0026-2017 (2018). [DOI] [PMC free article] [PubMed]
  • 39.Uea-Anuwong, T. et al. Antimicrobial resistance and phylogenetic relatedness of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli in peridomestic rats (Rattus norvegicus and rattus tanezumi) linked to City areas and animal farms in Hong Kong. Environ. Res.251, 118623 (2024). [DOI] [PubMed] [Google Scholar]
  • 40.Onanga, R. et al. Prevalence of extended-spectrum β-lactamases in E. coli of rats in the region North East of Gabon. Vet. Med. Int.2020, 5163493 (2020). [DOI] [PMC free article] [PubMed]
  • 41.Desvars-Larrive, A. et al. Urban brown rats (Rattus norvegicus) as possible source of multidrug-resistant Enterobacteriaceae and meticillin-resistant Staphylococcus spp., Vienna, Austria, 2016 and 2017. Eurosurveillance24, 1900149 (2019). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 42.Bevan, E. R., Jones, A. M. & Hawkey, P. M. Global epidemiology of CTX-M β-lactamases: temporal and geographical shifts in genotype. J. Antimicrob. Chemother.72, 2145–2155 (2017). [DOI] [PubMed] [Google Scholar]
  • 43.Ho, P. L. et al. Clonal diversity of CTX-M-producing, multidrug-resistant Escherichia coli from rodents. J. Méd Microbiol.64, 185–190 (2015). [DOI] [PubMed] [Google Scholar]
  • 44.Guenther, S. et al. Is fecal carriage of Extended-Spectrum-β-Lactamase-Producing Escherichia coli in urban rats a risk for public health? Antimicrob. Agents Chemother.57, 2424–2425 (2013). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 45.Kerek, Á., Szabó, Á. & Jerzsele, Á. Antimicrobial susceptibility profiles of commensal Escherichia coli isolates from chickens in Hungarian poultry farms between 2022 and 2023. Antibiotics13, 1175 (2024). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 46.Tóth, K., Tóth, Á., Kamotsay, K., Németh, V. & Szabó, D. Population snapshot of the extended-spectrum β-lactamase-producing Escherichia coli invasive strains isolated from a Hungarian hospital. Ann. Clin. Microbiol. Antimicrobials10.21203/rs.3.rs-535213/v1 (2021). [DOI] [PMC free article] [PubMed]
  • 47.Balázs, B. et al. Occurrence of Escherichia coli producing extended spectrum β-lactamases in food-producing animals. Acta Vet. Hung.69, 211–215 (2021). [DOI] [PubMed] [Google Scholar]
  • 48.Clément, M. et al. Whole-genome sequence of the first extended-spectrum β-lactamase-producing strain of Salmonella Enterica subsp. enterica serovar Napoli. Microbiol. Resour. Announc.7, 5623. 10.1128/mra.00973-18 (2018). [DOI] [PMC free article] [PubMed]
  • 49.Poirel, L., Decousser, J. W. & Nordmann, P. Insertion sequence ISEcp1B is involved in expression and mobilization of a blaCTX-M β-Lactamase gene. Antimicrob. Agents Chemother.47, 2938–2945 (2003). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 50.Gruel, G. et al. High prevalence of blaCTXM–1/IncI1-Iγ/ST3 plasmids in Extended-Spectrum β-Lactamase-Producing Escherichia coli isolates collected from domestic animals in Guadeloupe (French West Indies). Front. Microbiol.13, 882422 (2022). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 51.de Been, M. et al. Dissemination of cephalosporin resistance genes between Escherichia coli strains from farm animals and humans by specific plasmid lineages. PLoS Genet. 10, e1004776 (2014). [DOI] [PMC free article] [PubMed]
  • 52.Schaufler, K. et al. Clinically relevant ESBL-Producing K. pneumoniae ST307 and E. coli ST38 in an urban West African rat population. Front. Microbiol.9, 150 (2018). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 53.Sano, E. et al. One health clones of multidrug-resistant Escherichia coli carried by synanthropic animals in Brazil. One Heal. 16, 100476 (2023). [DOI] [PMC free article] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

Supplementary Material 1 (192.5KB, pdf)
Supplementary Material 2 (64.4KB, xlsx)
Supplementary Material 3 (54.2KB, xlsx)

Data Availability Statement

The datasets generated for this study are available in BioProject PRJNA1303976.

Articles from Scientific Reports are provided here courtesy of Nature Publishing Group

RESOURCES