Identification and antimicrobial susceptibility of coagulase-negative Staphilococci from bovine mastitis

PELLEGRINO, M.; VISSIO, C; MAGNANO, V.; FROLA I.; DUCRÓS, E.; LARRIESTRA, A.; RASPANTI, C.

San Miguel de Tucumán, Tucumán

Congreso; XLV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Celular (SAIB); 2009

Sociedad Argentina de Investigación en Bioquímica y Biología Celular

Coagulase-negative staphylococci (CNS ) as a group are increasingly seen as important mastitis pathogens. In several recent prevalence studies, CNS were the most frequently isolated udder pathogens from bovine milk samples with high somatic cell count (SCC). To assess the pathogenic significance of individual CNS species and to develop species-specific management practices, accurate species identification is needed. The aims of this study were to identify the most common CNS involved in bovine mastitis and to analize their susceptibility to antimicrobials commonly used for mastitis therapy. A total of 131 CNS isolated from bovine milk in dairy basin of Villa María, Argentine, were identified using a conventional phenotypic method. Sensitivity was determined by Kirby-Bauer method. Results indicated that S. chromogenes was the predominant specie (41.7%), followed by S. haemolyticus (15.7%). In this study we demonstrated that milk from cows with intramammary infection (IMI) cause by CNS had significantly high SCC. Moreover the high resistance to penicillin and ampicillin associated to most prevalent species found in this study emphasize the importance of identification of CNS when IMI are present.