Detection of virulence associated factors from Staphylococcus aureus isolated from bovine mastitis

Abstract

A total of 53 bacterial isolates obtained from bovine mastitis and positive to catalase, and 23S rRNA ribotyping tests were analyzed for production virulence factor viz. mannitol fermentation, Coagulase production, lipase activity, DNase activity, slime production assay and haemolysin production. Out of 53 isolates, 53 (100%), 49 (92.45%), 29 (54.72%), 44 (83.02%) and 42 (79.25%) isolates were found positive for mannitol fermentation, Coagulase production, lipase activity, DNase activity and slime production respectively. Out of 53 isolates, alpha, beta, gamma and alpha-beta haemolysin production were observed in 18 (33.96%), 26 (49.06%), 4 (7.55%) and 5 (9.43%) isolates respectively. Further the isolates were subjected to genotypic evaluation of virulence associated Coa and spa genes. Polymorphism was recorded in Coa and spa genes. Amplification of the spa gene revealed 200, 270 and 296 bp size amplicons while 723, 812 and 1000 bp amplicons found in Coa gene amplification. Out of 53 isolates, 36 (67.92%) and 32 (60.38%) isolates were found positive for spa and Coa genes respectively.