High-level mupirocin resistance in Gram-positive bacteria isolated from diseased companion animals.

The purpose of this study was to investigate the high-level mupirocin resistance (HLMR) in Gram-positive bacteria isolated from companion animals. A total of 931 clinical specimens were collected from diseased pets. The detection of mupirocin-resistant bacteria and plasmid-mediated mupirocin resistance genes were evaluated by antimicrobial susceptibility tests, polymerase chain reactions, and sequencing analysis. Four-hundred and six (43.6%) bacteria were isolated and 17 (4.2%), including 14 staphylococci and 3 Corynebacterium were high-level mupirocin-resistant (MICs, ≥ 1,024 ug/mL) harboring mupA. Six staphylococci of HLMR strains had plasmid-mediated mupA-IS257 flanking regions. The results show that HLMR bacteria could spread in veterinary medicine in the near future.