Characterization of Staphylococcus sp isolates from milk of cross bred cows on the day of drying

The dry period is a crucial phase in the lactation cycle of a dairy cow. It is a time of nutritional, metabolic and mammary change that will profoundly impact health and productitvity in next lactation. It is during the first and last 2weeks of the dry period that is when the teat canal kertain plug is forming and then dissolving that the cow is especially susceptible to new infections. The currnt study was conducted with am aim to isolate and charecterize Staphylococcus sp from milk of crossbred dairy cows on the date of drying. Two hundred and eighty one samples were collected from crooss bred dairy cows on the date of drying. Two hundred Staphylococcus isolates were obtained from the tested samples and a comparitive study was performed with regard to biofilm formation on CRA, haemolysis, coagulase production and methicillin resistance. Out of 200 Staphylococcus isolates, 6% were coagulase positive, 21.5% isolates haemolysed sheep blood agar, 77.5% of isolates were biofilm producers, and 82.5% of isolates were methicilin resisstant. Present study showed phenotypic relation between the biofilm production and methicillin resistance i.e., 86.6% of the methicillin resistant isolates were biofilm producers on CRA. The present study therefore shows high prevalence of methicillin resistance and biofilm forming ability in Staphylococcus sps in milk at the time of drying, understanding of which is essential to design better therapeutic measures against mastitis.