Capsular typing of Staphylococcus aureus isolates from cattle and goat mastitis by PCR targeting cap5K and cap8K genes

Abstract

The capsular typing of Staphylococcus aureus of bovine and caprine origin was carried out by polymerase chain reaction using primers specific for cap5K and cap8K genes. From cattle mastitis 60% of S. aureus were found to possess cap5K gene responsible for production of CP5 capsule and 20% of the isolates possessed cap8K gene responsible for biosynthesis of CP8 capsule. The rest 20% isolates did not produce amplicon with these primers and were considered non-CP5 and non-CP8 isolates. From goats, 30% of the isolates showed presence of cap5K gene and 20% of the isolates exhibited presence of cap 8K gene whereas 50% of the isolates were non-typable for cap5K or cap 8K genes. No polymorphism was observed in cap5K and cap8K genes observed by restriction fragment length polymorphism (RFLP) and by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) analysis suggesting that the K genes of cap5 and cap8 gene cluster were highly conserved.