Prevalence of Biofilm Formation and Detection of PSM B Gene in Clinical Isolates of Staphylococcus aureus

Background and objectives: Staphylococcus aureus is a frequent cause of hospital- and community-associated infections on a global scale. This organism is responsible for causing an extensive range of diseases and many of them are capable of biofilm formation for their survival. By this method, treatment of them with antibiotics become very difficult and antibiotic resistance is another rising concern. Material and Methods: The clinical samples were collected and examined for Staphylococcus aureus by microbiological and biochemical tests. Then, the biofilm formation in Staphylococcus aureus isolates was detected by microtiter plate. Using SYBR Green Real-Time PCR, the expression of PSM was determined. Results: A total of 60 strains of Staphylococcus aureus were isolated from clinical isolates. Of them, 47 strains (78.3%) were identified biofilm producing and the others were considered negative for biofilm formation. After real-time PCR testing to detect PSM, it was determined that 100% of the strains were positive for biofilms and PSM genes. The results of phenotypic and genotypic tests of biofilm were closely related to each other and the expression of PSM B gene was 80%. It was found that 100% of strains were biofilm producing and PSM B gene was present in 78.3% (47 strains) of them. Conclusion: The prevalence of biofilm production in Staphylococcus aureus strains isolated from clinical samples was high, so it is highly important to monitor the prevalence of these organisms in hospitals and community as well as their antimicrobial resistance.