Treating animal bites: susceptibility of Staphylococci from oral mucosa of cats.

Infected wounds determined by cats' bites represent high costs to public health, and their adequate treatment relies on the knowledge of the antimicrobial susceptibility of bacterial agents found in the oral microbiota. Members of the genus Staphylococcus sp. belong to the microbiota of the oral mucosa of cats and are frequently involved in secondary infections of these wounds. This study aimed to evaluate the antimicrobial susceptibility of Staphylococcus species isolated from oral mucosa of cats. Samples were collected from 200 clinically healthy cats and processed by standard bacteriological methods and tested for susceptibility to a panel of 16 antimicrobials. A total of 212 staphylococci isolates were obtained from 141 of the 200 cats (70.5%), and more than one colony was recognized in 53 cases. Coagulase-negative species were most frequently found (89.6%) distributed among Staphylococcus xylosus (50.9%), Staphylococcus felis (27.4%), Staphylococcus simulans (6.1%) and Staphylococcus sciuri (5.2%). Coagulase-positive species (10.4%) were distributed among Staphylococcus aureus (4.7%) and Staphylococcus intermedius group (SIG) (5.7%). Regarding to antimicrobial resistance, 178 isolates (83.9%) were resistant to at least one antimicrobial, and rifampicin showed the best results with 100% of sensitive strains. Conversely, high rates of resistance were observed for penicillin and tetracycline (56.1%). The 212 staphylococci isolates and 30 (14.1%) strains were resistant to methicillin (on the disc susceptibility test) and may be preliminarily considered as methicilin-resistant staphylococci. In conclusion, this study reports important rates of antimicrobial resistance among the species of Staphylococcus isolated from clinical specimens of cats, which must be considered for the treating of cats' bites in humans.