Short communication: Fluoroquinolone susceptibility of Staphylococcus aureus strains isolated from caprine clinical mastitis in southeast Spain

The antibiotic susceptibility of 32 strains of Staphylococcus aureus isolated from the mastitic milk of dairy goats was evaluated. The antibiotics tested were 3 fluoroquinolones that have been developed especially for use in veterinary medicine: danofloxacin, marbofloxacin, and orbifloxacin. Minimum inhibitory concentration (MIC) tests were performed according to the microdilution broth method. The MIC90 (concentration at which 90% inhibition is achieved) values obtained were 0.5, 1, and 1 mg/L for danofloxacin, marbofloxacin, and orbifloxacin, respectively. Danofloxacin was the most active fluoroquinolone tested against Staph. aureus strains isolated from milk; however, specific testing is required before using these drugs as therapy for the control of clinical mammary infections in goats.