The objective of the investigation was to evaluate the in vitro antimicrobial sensibility of 291 isolates of Staphylococcus spp., taken from the mammary glands of dairy cows with subclinical mastitis in the regions of Metropolitan Recife (A), Agreste (B) and Zona da Mata (C) in the state of Pernambuco, Brazil. From the 291 isolates, 170 (58.4%) were identified as negative coagulase Staphylococcus (SCN), 84 (28.9%) as Staphylococcus aureus, and 37 (12.7%) as positive coagulase Staphylococcus (SCP). To study sensitivity to antimicrobials, the diffusion in disks method was used with 16 antimicrobial drugs commonly employed in the treatment of mastitis. The most efficient antibiotic in vitro was the combination of neomicine + bacitracine + tetracycline with percentages of 98.4%, 99.3%, and 89.7% for the A, B, and C regions, respectively. The least efficient was ampicillin, which was resistant to 56.5% of the isolates taken from region A, 72.8% from region B, and 71.8% from region C. These results indicate the need for periodic testing of sensitivity in vitro, as these variations can compromise the treatment of animals as well as control programs for bovine mastitis caused by Staphylococcus spp.
Milk; mastitis; antimicrobial sensitivity; Staphylococcus spp
