Molecular epidemiological analysis to assess the influence of pet-ownership in the biodiversity of Staphylococcus aureus and MRSA in dog- and non-dog-owning healthy households.

It has been suggested that zoonotic transmission of Staphylococcus aureus (SA) and methicillin-resistant S. aureus (MRSA) can occur between owners and their pets within the same household. However, the influence that pet-ownership could have in the biodiversity of SA/MRSA strains circulating among owners is not fully understood. The objective of this study was to perform a molecular epidemiological analysis to evaluate and compare the biodiversity of SA/MRSA strains in dog-owning and non-dog-owning healthy households within the same community. Antimicrobial resistance, SCCmec type, USA type and clonality were assessed. Overall, 33·1% (165/499) of human subjects carried SA and 2·8% (14/499) carried MRSA. Among dogs, 7·1% (8/113) carried SA but none were MRSA positive. No difference was detected in the diversity index of SA/MRSA pulsotypes between dog-owning and non-dog-owning households; but, a marked variation was still observed in the pulsotypes circulating in each type of household. Additionally, simultaneous carriage of the same SA pulsotype in owner(s) and dog was observed in 57% of households with positive humans and pets. These results demonstrate that dogs can indeed participate in the circulation of SA/MRSA pulsotypes within a home and that the presence of a pet does not seem to favour certain strains within their household.