Classification and antimicrobial susceptibilities of enterococcus species isolated from apparently healthy food-producing animals in Japan.

A total of 1024 enterococci were recovered from faeces of healthy animals from 178 cattle, 178 pig and 156 broiler farms. Enterococcus faecium was the predominant species recovered (35.8%), followed by E. faecalis (31.3%) and E. hirae (25.6%). Oxytetracycline resistance was most frequently found among E. faecalis (85.9%), E. faecium (58.8%) and E. hirae (48.1%). Resistance rates to almost all antimicrobials were higher in E. faecalis than E. faecium and E. hirae. Isolates from cattle were more susceptible to the antimicrobials studied than those from pigs and broilers. VanA- or VanB-type vancomycin-resistant enterococci have not been found since the ban of avoparcin use 5 years ago.