Spread of multidrug-resistant Escherichia coli within domestic aggregates (humans, pets, and household environment)

Advances in veterinary medicine have been associated with recourse to antimicrobial therapies, which favors the emergence of resistant bacteria, potentially able to spread globally. The aim of the present study was to elucidate the manner in which shared environments between pets receiving antimicrobial treatments and their owners could contribute to the spread of antimicrobial drug-resistant Escherichia coli. Three domestic aggregates, including pets, owners, and household environment were studied. Each core pet had a history of previous antimicrobial therapies. Overall, 231 E. coli isolates were recovered from pets' feces, urine, oral secretion, skin, and fur; and owners' hands and stool swabs. Commonly touched household objects and surfaces (light switches, door knobs, TV remote control, mobile phones, banister, refrigerator door handle, kitchen floor, pet beds, leash, food, and water recipients) were also sampled. All strains were analyzed by antimicrobial susceptibility testing. Subsequently, some isolates were selected for Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction and Pulsed-Field Gel Electrophoresis analyses, to evaluate their genetic relatedness. Antimicrobial susceptibility tests displayed 20 different phenotypic patterns with an important representation of multidrug-resistant ones (75.0%). The 3 core dogs presented multidrug-resistant E. coli clones disseminated over various body sites. In 2 of 3 domestic aggregates, A and B, clonal disseminations among animals, owners, and household surfaces were also observed. Results confirmed the dissemination of multidrug-resistant E. coli within and through the household environment, highlighting the relevance of pets in the community spread of antimicrobial resistance.