Occurrence of ESBL-Producing Escherichia coli ST131, Including the H30-Rx and C1-M27 Subclones, Among Urban Seagulls from the United Kingdom.

Antimicrobial resistance is a public health concern. Understanding any role that urban seagulls may have as a reservoir of resistant bacteria could be important for reducing transmission. This study investigated fecal Escherichia coli isolates from seagulls (herring gulls and lesser black-backed gulls) to determine the prevalence of extended-spectrum cephalosporin-resistant (ESC-R) and fluoroquinolone-resistant E. coli among gull species from two cities (Taunton and Birmingham) in the United Kingdom (UK). We characterized the genetic background and carriage of plasmid-mediated resistance genes in extended-spectrum ß-lactamase (ESBL)-producing E. coli obtained from these birds. Sixty ESC-R E. coli isolates were obtained from 39 seagulls (39/78, 50%), of which 28 (28/60, 46.7%) were positive for plasmid-mediated CTX-M and/or AmpC ß-lactamase resistance genes. Among these, blaCTX-M-15, blaCTX-M-14, and blaCMY-2 predominated. Three isolates belonging to the B2-ST131 clone were detected, of which two harbored blaCTX-M-15 (typed to C2/H30Rx) and one harbored blaCTX-M-27 and was typed to C1/H30-R (recently described as the C1-M27 sublineage). The plasmid-mediated quinolone resistance (PMQR) gene carriage prevalence (11.7%) consisted of aac(6')-Ib-cr and qnrB genes. No carbapenem or colistin resistance genes were detected. Urban seagulls in the UK are colonized and can spread major antimicrobial-resistant E. coli isolates harboring ESBL and PMQR determinants, including clinically important strains such as the pandemic clone B2-ST131 and the C1-M27 subclade. This is the first report of ST131-C1-M27 subclade in wildlife in the UK and in seagulls worldwide.

Diversity, Virulence, and Clinical Significance of Extended-Spectrum ß-Lactamase- and pAmpC-Producing Escherichia coli From Companion Animals.

Escherichia coli are opportunistic pathogens with the potential to cause a variety of infections in both humans and animals and in many cases have developed antimicrobial resistance. In this study, we characterized extended-spectrum cephalosporin resistant (ESCR) E. coli isolates from diseased companion animals (dogs, cats, and horses) and related the results to clinical findings. ESCR E. coli clinical isolates obtained over a 6-year period were screened for extended-spectrum ß-lactamase (ESBL) and/or plasmid mediated AmpC (pAmpC) and virulence markers likely to be associated with extraintestinal pathogenic E. coli (ExPEC). ESBL and/or pAmpC genetic determinants were identified in 79.9% of the ESCR E. coli isolates with bla CTX-M genes being the most common ESBL genotype of which bla CTX-M-15, bla CTX-M-14, and bla CTX-M-55 were the most prevalent. In addition, bla CMY -2 was the most common genotype identified amongst pAmpC producing isolates. Phylogenetic group typing showed that B2 was the most prevalent phylogroup among the ESCR E. coli isolates, followed by the closely related phylogroups D and F which are also associated with extra-intestinal infections. ESCR was also identified in phylogroups commonly regarded as commensals (B1, A, and C). Virulence factor (VF) scores >2 were mostly present amongst isolates in phylogroup B2. Higher virulence scores were found in isolates lacking ESBL/pAmpC resistance genes compared with those carrying both genes (p < 0.05). Five of phylogroup B2 isolates, were typed to the pandemic virulent O25b-ST131 clone and three ST131 isolates carrying bla CTX-M-15 belonged to the subclade C2/H30Rx whilst one isolate carrying bla CTX-M-27 typed to the recently described sub-clade C1-M27. MLST typing also identified other sequence types commonly associated with infections in humans (ST410, ST10, and ST648). Most ESCR E. coli isolates obtained in pure growth were cultured from normally sterile body sites (mostly from urinary tract infections, UTIs) whilst only a small proportion were obtained from body sites populated with commensal flora (p < 0.0001). Our study has shown that ExPEC ESBL/pAmpC producing E. coli isolates are common amongst companion animal isolates and are associated with colonization and infection. In addition, their isolation from a normally sterile site is likely to be clinically significant and warrants antimicrobial treatment.