Prevalence of Staphylococcus aureus carriage among dogs and their owners

Case reports have indicated transmission of Staphylococcus aureus between humans and pets. We investigated associations between level of contact between dog and owner, and S. aureus colonization. In a cross-sectional study, nasal carriage and antibiotic susceptibility of S. aureus was determined for 830 dogs and 736 owners. Relatedness of isolates was investigated using antibiograms and pulsed-field gel electrophoresis (PFGE). Associations between carriage and demographics or amount of contact between owners and dogs were documented. S. aureus was isolated in 24% of humans and 8.8% of dogs. Antibiotic resistance was significantly more common in canine isolates. Of 17 owner/dog colonized pairs, six were indistinguishable by PFGE. Colonization of dogs was not associated with close human contact, but was strongly associated with health-care occupations (OR 3.29, 95% CI 1.49-7.26, P=0.002). In outbreak situations health-care workers' pets should be considered as a source of S. aureus. High rates of resistance indicate increased monitoring of antibiotic use in veterinary practice is needed.