Long-term pet ownership promotes resistome similarity between cats and their owners

Pet ownership offers physical and mental health benefits, but the risks of antibiotic resistance genes (ARGs) transmission between pets and humans remain underexplored. In this study, we used metagenomics analysis of fecal samples to compare resistome profiles among four groups: owned cats and their owners, and caged cats and non-cat owners. Our findings show significant similarities in gut microbial composition, ARGs, and mobile genetic elements (MGEs) between owned cats and their owners, identifying 73 shared core ARGs and 80 shared MGEs. In contrast, caged cats and non-cat owners shared only 30 ARGs and 73 MGEs. Long-term contact was positively correlated with a higher number of shared ARGs (from 20 + to 60 + ) and MGEs (from 10 + to 40 + ), as well as increased resistome risk (2.47- to 4.92-fold) between pet cats and owners. The gut microbiota played a key role in shaping the ARGs and MGEs profiles, with Escherichia coli and Klebsiella pneumoniae identified as primary carriers, each genome harboring 20 to 62 ARGs and 6 to 29 MGEs. ARGs transfer events were more frequent between pet cats and their owners than in other groups. These findings underscore a potential risk of shared antimicrobial resistance between companion animals and humans within the studied population in China.