ABSTRACT
The purpose of this study was to determine the in-vitro susceptibility pattern of 72 Staphylococcus aureus strains, isolated from bovine mastitic milk. The calves were reared on 10 dairy farms in the state of São Paulo, Brazil. These strains were tested by the standardized disc diffusion method. The highest susceptibility was to gentamicin (98.6%) and erytromycin (98.6%), followed by streptomycin (94.4%), oxacillin (84.7%), novobiocin (73.4%), vancomycin (72.2%), ampicillin (4.2%) and penicillin (2.8%). Results showed that 72 (100%) strains were resistant to at least 2 antibiotics and chemotherapeutics. None of the active principles, acting alone, was effective against any of the strains tested.
KEY WORDS
Stahylococcus aureus
; bovine mastitis; antimicrobial