Background and Objective: Staphylococcus aureus is a leading etiologic agent of sinusitis, and it is notorious for its multiple virulence factors and genes encoding antibiotic resistance. Molecular screening of those genes is important for elucidating its pathogenic role and for helping clinically effective intervention. In this study, the important virulence and resistance genes of S. aureus among the SSSS patients was determined by PCR.
Methods: Out of 100 clinical specimens collected from patients with sinusitis, 48 strains were confirmed as S. aureus by both cultural media and biochemical tests and over VITEK 2 system. Genomic DNA was used for PCR to amplify 16S rRNA gene, mecA, ermA, ermB, ermC (erythromycin resistance genes), and fnbA, fnbB, hlg, tst (virulence genes). The PCR products were examined by means of agarose gel electrophoresis.
Results: All 48 isolates were positive for the 16S rRNA and mecA genes indicating identification of the bacterium and methicillin resistance. Of the macrolide resistance genes ermA and ermC were found in 50% of the isolates and the ermB in 12.5%. Regarding virulence genes, fnbA was detected in 70.83%, hlg and tst in 66.66% and fnbB in 50% of isolates.
Conclusion: Molecular characterization of S. aureus isolates from sinus infections uncovered a high prevalence of methicillin resistance and virulence factors, especially fnbA, hlg, and tst. PCR-based detection was proved to be efficient and dependable to provide rapid diagnosis of clinically important genes to the field of molecular epidemiological surveillance and antimicrobial stewardship.