Pandemic human-associated extended-spectrum β-lactamase-producing Escherichia coli lineages of ST38, ST131 and ST141 identified in Viennese dogs.

OBJECTIVES

To assess the prevalence of ESBL Enterobacteriaceae among dogs attending a veterinary clinic in Vienna, characterize the isolates in terms of antimicrobial resistance, virulence and phylogenetic relationships.

METHODS

Faecal samples of 88 dogs were streaked on selective plates, species were identified by MALDI-ToF MS, tested for resistance by a combination disk test and VITEK 2®, whole genome-sequenced, bioinformatically genotyped, phylogenetically analysed and screened for resistance and virulence genes.

RESULTS

ESBL Escherichia coli carriage rate was 14.8% (95% CI: [8.1-23.9]). No carbapenem resistance was found, but 53.8% of the isolates were classified genotypically as multi-drug resistant. Phylogenetic analyses revealed that half of the isolates belonged to animal and environment-associated phylogroups, while another half was human-associated, and included high-risk international clones of ST38, ST131 and ST141, which clustered primarily with human isolates. All isolates harboured various virulence-associated genes, including four isolates that encoded exotoxins, of which two were from the pandemic ST131 and emerging ST141 lineages.

CONCLUSIONS

Dogs in Vienna carry ESBL E. coli with high rates of multi-drug resistance and virulence, and a highly diverse population structure that includes pandemic human-associated lineages.