Frequency analysis of adhesin genes cna, fnbA and fnbB in Staphylococcus aureus isolates from sheep mastitis

Different virulence factors are involved in Staphylococcus aureus pathogenesis. Surface proteins such as collagen- (cna) and fibronectin-binding proteins (fnB) are important factors in adhesion and invasion of S. aureus. Therefore، the aim of this study was to investigate the presence of cna، fnbA and fnbB genes in collection of S. aureus isolates from clinical and subclinical sheep mastitis. In this study 45 isolates were identified as S. aureus by standard biochemical as well as amplification of species-specific thermonucleasegene (nuc). Then، isolates were analyzed for the presence of cna، fnbA and fbnBadhesion genes using specific primers by polymerase chain reaction (PCR). A 279-bp DNA fragment was synthesized from all of the S. aureus isolates following the amplification of species-specific gene (nuc). Interestingly، 43 (95. 55%) isolates were found to be cna positive. From the 45 studied isolates، 39 and 35 were harbored the fnbA and fbnB genes، respectively. According to the large diffusion of cna، fnbAand fbnB genes among the studied isolates، it can be conclude that CBP، FnBPA and FnBPB encoded by the mentioned genes were presumably effective in pathogenesis of mastitis caused by S. aureus and isolates likely express receptors for matrix proteins such as collagen and fibronectin. This encourages the development of new strategies to prevent mastitis، based on antagonist ligands able to interact with surface adhesions and block it specific binding with matrix proteins.