Antibiotic susceptibility of coagulase-negative staphylococci isolated from goats' milk

The antibiotic susceptibility of 70 strains of coagulase-negative staphylococci (CNS) isolated during the 2001 lactating period from the milk of dairy goats, was evaluated. The antibiotics tested were benzylpenicillin, cloxacillin, amoxicillin, amoxicillin plus clavulanic acid, cephalonium and cefoperazone, erythromycin and tylmicosin, kanamycin and tetracycline. Minimum inhibitory concentration (MIC) measurements showed that all beta-lactams (except cefoperazone) were effective against Staphylococcus epidermidis and Staphylococcus caprae, whereas the other antibiotics were either less effective or showed no activity. Other CNS species showed very variable sensitivity to the antibiotics; testing would be required before therapy for the clinical control of goat mammary infections.