Microorganisms that cause mastitis were isolated in a herd of sheep and their sensitivity to antimicrobials was tested. Twenty-one sheep had their mammary glands monitored during lactation. Eighty-eight milk sample from CMT-positive sheep were analyzed in order to isolate the etiologic agent of mastitis. Coagulase negative Staphylococcus were isolated from 29.5% of samples. Ampicillin and penicillin were the antimicrobials with higher number of resistant strains. The importance of coagulase negative staphylococci has been demonstrated, especially S. lentus and S. sciuri as a cause of ovine mastitis.
coagulase negative; mastitis; sheep; Staphylococcus
