With the increasing human animal bond, cross-species bacterial transmission has become a concern among pet owners, veterinarians, and public health officials. Improved epidemiologic understanding of bacterial sharing may help minimize this risk. The goals of this study were to determine the prevalence of fecal E. coli sharing between dogs and their owners and to analyze potential epidemiological risk factors involved in inter-host transfer.
Fecal swabs and a survey were collected from 61 healthy dog and human owner pairs and a control group. Three representative E. coli colonies were isolated from each fecal sample. Pulse field gel electrophoresis (PFGE) using restriction endonuclease XbaI was performed on DNA from each isolate, and similarity matrices were used to compare profiles within households. Surveys questioned frequency of behaviors including sleeping in the same bed, kissing on the face, washing hands after petting and before feeding, disposal of feces, drinking out of toilets, and time spent awake together. Chi-square and Mann-Whitney analysis were used to compare fingerprint and survey results.
A wide array of E. coli PFGE profiles was observed in all groups. Fecal E. coli isolates from only one dog-owner pair had identical profiles. Isolates from twelve other dog-owner pairs had >90% fingerprint similarity. No behaviors surveyed were found statistically more often in households with >90% fecal E. coli similarity than households without similar strains.
Although sharing of genetically similar fecal E. coli is uncommon between dogs and their owners, proper hygiene should be encouraged to minimize potential transmission.