Polymorphism in coa and spa virulence genes in staphylococcus aureus of camel skin origin

Abstract

The present study was undertaken with a view to identify S. aureus organisms isolated from camel skin wounds by ribotyping and to study polymorphism in their two virulence genes viz. coa and spa, responsible for production of coagulase and protein A, respectively. All the 15 isolates in the study were ribotyped targeting 23S rRNA gene using species specific primers wherein a species specific amplicon of 1250 bp was produced. The polymerase chain reaction targeting coa gene produced only single amplicon in each isolate but of variable sizes. The frequency of amplicon of 600 bp was highest followed by amplicons of 710, 760 and 850 bp. The PCR amplification of X-region of spa gene produced amplicons of seven different sizes viz. 160, 180, 200, 260, 280, 300 and 500 bp with calculated number of 5, 6, 7, 9, 10, 11 and 19 repeats, respectively. Out of 15 isolates 14 produced only single amplicon whereas one isolate produced two amplicons of 200 and 500 bp size. In the present study most of the isolates possessed seven repeats of 24 bp in variable X-region of spa gene. The present investigation revealed presence of both pathogenic and nonpathogenic strains of S. aureus with polymorphism in both the virulence genes.