Molecular characterisation of virulence genes in Staphylococcus aureus associated with clinical bovine mastitis

Abstract

Staphylococcus aureus is the most frequently isolated pathogen from bovine mastitis including subclinical, clinical, and chronic infections. Virulence factors possessed by S. aureus aid in causing infection and inflammation by producing toxins and proteins, which are responsible for the pathogenesis of the disease. In the current study out of 51 animals presented with clinical mastitis, S. aureus was isolated from the milk of 18 animals. S. aureus was confirmed by genus and species level identification using polymerase chain reaction. Molecular characterization of selected virulence genes including thermonuclease (nuc) and Panton Valentine Leucocidin (PVL) was performed in all the S. aureus isolates. Presence of nuc gene was observed in all the isolates (100 %) of S. aureus. No isolates were found to be positive for the presence of PVL gene. Profiling the virulence genes is an important tool for epidemiological studies of mastitis, which can be employed for the prevention and control of the disease.

Keywords

• mastitis
• staphylococcus aureus
• virulence genes