Common Mastitis Pathogens in Milk Samples of HF Crossbred Cattle

Mastitis is the most imperative economic problem faced by dairy producers all over the world. Inflammation of the mammary gland is called mastitis. The present study was undertaken to identify the incidence rate for five major pathogens viz., Staphylococcus aureus (S. aureus), Staphylococcus epidermidis (S. epidermidis), Streptococcus agalactiae (S. agalactiae), Streptococcus dysgalactiae (S. dysgalactiae) and Escherichia coli (E. coli) in the milk samples collected from Bangalore and Kolar district by PCR based microorganism detection technique. A total of 214 composite milk samples were screened by CMT and then PCR-based detection of pathogens for the samples was carried out. In this methodology, 30 ml of milk sample was strained to remove milk somatic cells and further centrifuged at 1000 x g for 15 min to discard the fat layer. The results revealed the presence of S. aureus in 28.5 per cent of the total animals screened, S. epidermis was identified in 15.42 per cent of cases. E. coli followed and the incidence rate was 13.55 per cent with regard to E. coli. S. agalactiae and S. dysgalactiae were identified in 10.28 per cent and 3.74 per cent of the cases respectively. None of the pathogens considered in this study were detected in 117 milk samples, these samples were also observed to be normal for CMT. The results correlate with the results of another study where PCR-based detection of mastitis pathogens in bulk tank milk samples revealed the highest incidence rate for S. aureus followed by S. epidermidis and E. coli in areas around Bangalore dist. The present study supported the fact that PCR-based identification of mastitis-causing pathogens from milk is a rapid and reliable method to reveal the exact bacterial etiology of mastitis.