Antibiogram and aetiological agents isolated from milk samples from cattle with mastitis.
In the region of Marília, SP, Brazil, 133 milk samples from cows infected with bovine mastitis were analysed. The following microorganisms were isolated: Staphylococcus aureus (39.8%), Coliaerogenes (24.1%), haemolytic Streptococcus b (8.3%), Coagulase negative Staphylococcus (6.7%), haemolytic Streptococcus a (6%), Pseudomonas spp (4.5%), Klebsiella (3.7%), Corynebacterium, and unidentified non-haemolytic Streptococcus and Gram positive Bacillus (2.3% each). In antibiotic sensitivy tests, netilmicin (81%), gentamicin (71.2%) and amicacin (67%) were the most effective drugs. Lincomicin (13.9%), ampicillin (11.8%) and penicillin (9.3%) were the least effective.