Quantitative analysis of various virulance genes (PVL, LukED, γ-hemoliz) by real-time PCR of Staphylococcus aureus strains isolated from bovine mastitis

In 98 Staphylococcus aureus (S. aureus) strains isolated from bovine mastitis, presence/absence of virulence genes such as Panton-Valentine leukocidin (PVL), γ-hemolysis and LukED and quantitative analysis were conducted by Real-Time PCR. According to Real-Time PCR PVL, γ-hemolysis and LukED genes of 98 S. aureus strains were found as 70.40%, 90.81% and 66.32%, respectively. As a result of the quantitative analysis of virulence genes according to strains, they are grouped into 3 groups as 40<-10,000, 10,000-100,000 and 100,000< IU/ml considering viral gene amount. The amount of PVL gene among these groups was determined as 27.55%, 9.18% and 32.65% respectively, and γ-hemolysis as 48.97%, 39.79% and 2.04% and LukED as 45.91%, 14.28% and 6.12%. As a result, in S. aureus strains isolated from bovine mastitis the prevalence of these virulence genes were higher. Therefore it is deduced that PVL, γ-hemolysis and LukED may be important virulence factors in the pathogenesis of S. aureus.