Prevalence and risk analysis of mobile colistin resistance and extended-spectrum β-lactamase genes carriage in pet dogs and their owners: a population based cross-sectional study

Mobile colistin resistance gene mcr-1 and extended-spectrum β-lactamase gene blaCTX-M are highly prevalent in human – and pet-derived bacteria. Isolation of identical strains of mcr-1-positive Escherichia coli (MCRPEC) or blaCTX-M-positive E. coli (CTX-MPEC) from pets and humans highlighted the potential for co-colonization of antibiotic-resistant bacteria which can be a risk for dissemination of resistance genes. In this study, the prevalence of mcr-1 and blaCTX-M carriage from rectal swabs in 299 families (dogs and their owners) were 2.7 and 5.3%, respectively. We identified a significant association of mcr-1 carriage between dogs and their owners. Whilst antibiotic use in the previous three months was associated with blaCTX-M carriage in dogs. Only one instance of dog and owner carrying identical CTX-MPEC was observed. Although the prevalence of identical strains in one family is rare, the huge number of dog ownership worldwide suggest that this threat should not be underestimated.