Antimicrobial resistance, virulence profiles, and phylogenetic groups of fecal Escherichia coli isolates: a comparative analysis between dogs and their owners in Japan

In this study, fecal Escherichia coli isolates (n=188) from 34 dog-owner pairs and 26 healthy control humans (2 isolates per individual) were tested for susceptibility to 6 antimicrobials and screened for virulence genes. Genetic diversity between canine and owner isolates was evaluated by pulsed-field gel electrophoresis (PFGE). Canine isolates exhibited significantly different rates of resistance to four and two antimicrobials, compared to control and owner isolates, respectively. Of the genes examined, the prevalence of sfa, hly, and cnf genes in canine isolates were higher than in control isolates, but not than in owner isolates. These results suggest that characteristics of owner isolates are somewhat similar to canine isolates, compared to isolates from non-dog owners. In addition, PFGE analysis revealed that transfer of E. coli between owners and their dogs had occurred within 3/34 (8.8%) households. Considering the effects of dog ownership on the population of E. coli isolates from owners, further epidemiological studies are required.