Pets as potential carriers of multidrug-resistant Enterococcus faecium of significance to public health.

Enterococci are important opportunistic pathogens for humans and animals and have recently become one of the leading causes of nosocomial infections, raising concerns about their virulence and antimicrobial traits. This study describes a multidrug-resistant Enterococcus faecium isolated from a case of feline urinary tract infection. This strain was characterized for virulence and antimicrobial resistance markers, phylogenetic group and sensitivity to antimicrobial agents used routinely in veterinary and human practice. Other than virulence traits, the isolate harboured a variety of antimicrobial-resistance genes and chromosomal mutations, the combination of which conferred resistance to almost all of the antimicrobial compounds tested. Interestingly, this strain harboured mutations in the quinolone resistance-determining regions never been described in E. faecium and conferring resistance to all the quinolones tested. The combination of these resistance features, together with its virulence traits, makes this strain an example of a potentially dangerous pathogen that could easily spread in veterinary hospitals and perhaps to the environment and to humans, seriously compromising patient outcomes.