author(s)
B Puvarajan

abstract
Staphylococcus aureus has been described as one of the most important mastitis pathogens in cattle and Coagulase-negative Staphylococci (CoNS) recognized as etiologic agent associated with intramammary infections (IMI) of dairy animals in most of the developing countries. Keeping in mind the poorman’s cow, this study was conducted to isolate and identify the main staphylococcal species causing caprine mastitis in 28 smaller goat farms located in Cauvery Delta Region viz., Thiruvarur, Thanjavur, Trichy and part of Pudukottai district of Tamilnadu. Out of the 54 mastitis milk samples collected, 45 staphylococcal isolates were identified (83.3%) on the basis of cultural and biochemical features as well as by genus specific PCR. Then species level identification of staphylococcal isolates was carried out using analysis of the etb gene at 226 bp. Overall, four different species of CoNS were identified as: 25 Staphylococcus aureus (55.5%), 13 Staphylococcus chromogenes (28.8%), 5 Staphylococcus hyicus (11.1%), 2 Staphylococcus hominis 4%). Although the role of S. aureus as an etiological agent of caprine mastitis has been elucidated previously where as studies on the relative importance of specific CoNS in caprine mastitis have not been undertaken in this Cauvery Delta Zone of Tamilnadu. This study demonstrated that S. aureus and S. chromogenes were predominant and thus be considered as emerging pathogens causing mastitis in this region and the etb gene PCR detection will be an useful tool for identifying staphylococcal isolates derived from subclinical goat mastitis at species level. Moreover this study will pave way for an overview on distribution of CoNS species of staphylococcus in this region.