Characterization of virulent Escherichia coli in healthy pet dog feces: Implications for public health

Abstract

The characterization of Escherichia coli that colonizes pets is necessary to maintain animal health and to reduce the chance of transmission to owners. In this study, we investigated the incidence of potentially virulent E. coli inhabiting healthy pet dogs as a risk of infection to pet owners. Antibiotic-resistant E. coli isolated from freshly passed dog feces were whole-genome sequenced using Illumina chemistry and classified into pathogenic lineages using pathogen-specific markers. The antimicrobial resistance genes (ARGs), virulence-associated genes (VAGs), and plasmids were respectively predicted using the ResFinder, VirulenceFinder, and PlasmidFinder. Of the 32 isolates, 13 carried resistance genes such that four, six, and 11 contained β-lactam (blaTEM), aminoglycoside [aac-6(Ib7)/ant-3(Iia)/aph-3(Ib)/aph-6(Id)] and tetracycline (tet) resistance genes, respectively. The IncF plasmids were most prevalent (n=12, 38.71%) but the highly self-conjugative IncN plasmids occurred simultaneously with the plasmid-borne [quinolones (QnrS1/QnrB7) and sulfonamide (sul3)] ARGs in ≥ 2 E. coli. One E. coli each was classified as avian pathogenic E. coli, atypical enteropathogenic E. coli, enterotoxigenic E. coli, Shiga toxin-producing enteroaggregative E. coli, and enteroaggregative E. coli. Pet feces should be carefully handled because they contain virulent and drug-resistant E. coli.