The Investigation of Frequency of sea,sec and tst genes in Staphylcoccus aureus isolated from Clinical sources in Karaj

Background and Aim : Staphylococcus aureus is a common nosocomial and community-acquired pathogen. This bacterium has different virulence factors and provides conditions for invading the host by secreting various toxins, including superantogenic enterotoxins. Among them, various types of enterotoxins and toxins of toxic shock syndrome have a high role in pathogenesis. The aim of this study was to investigate the frequency of sea, sec and tst genes in Staphylococcus aureus isolates isolated from clinical sources in Karaj.Methods : This descriptive-analytical study was performed on ۱۰۰ Staphylococcus aureus isolates, which were identified and confirmed by biochemical methods. Then, antibiogram test was performed by disk diffusion agar method according to CLSI ۲۰۱۹ instructions and PCR method was used to identify sea, sec and tst genes. Results : The results showed that the highest resistance to antibiotics penicillin, ceftazidime, tetracycline, erythromycin, cefoxitin, ciprofloxacin, oxacillin, clindamycin, respectively ۹۲%, ۸۲%, ۴۷%, ۴۳%, ۳۸%, ۳۶%, ۳۴%, ۳۳% and also the lowest resistance were related to gentamicin, trimethoprim, sulfamethoxazole, chloramphenicol with ۲۳%, ۱۶%, ۴%, respectively, and no vancomycin-resistant isolates were observed. PCR results also showed that۸۶% of the isolates contained at least one of the sea, sec and tst genes, of which ۷۹% contained the sea gene, ۵% contained the sec gene and ۴۳% of the isolates had the tst gene.Conclusion : The spread of antibiotic resistance in patients and patients referred to clinical sources which has increased due to improper use of antibiotics and inappropriate prescription of such drugs and Also, the high prevalence of sea, sec and tst gene expression in Staphylococcus aureus strains in hospitals can be a serious warning and danger to public health. Given the clinical importance of these isolates and their threatening role in public health, it is necessary to pay more attention to them.

Keywords:

Staphylococcus aureus , Antibiotic resistance , Staphylococcal enterotoxins , Toxic shock syndrome syndrome