Characterization of Coagulase Negative Staphylococci from Mastitis

Of late, coagulase negative staphylococci (CoNS) as a group have become the most common bacteria associated with bovine mastitis in many countries and are described as "emerging mastitis pathogens". The present study was carried out with the objective of isolation, identification and study of antimicrobial resistance patterns of CoNS associated with bovine mastitis in Southern India.The high incidence of the CoNS in milk samples in the study area signifies their possible role as emerging mastitis pathogens in mastitis. Of the 10 species targeted by multiplex-PCR, S. epidermidis, S. chromogenes and S. sciuri were the major CoNS detected. Coagulase negative variants of S. aureus were also detected by PCR. The study also indicated the existence of methicillin resistance in CoNS isolates of bovine origin and the possibility of the CoNS acting as reservoir of the antibiotic resistant genes including aminoglycosides resistant genes. This finding emphasizes the need for targeting CoNS, besides several other species, in routine diagnosis and for the development of therapeutic or prophylactic measures for the control of bovine mastitis, caused by CoNS, in India.