فراوانی ژن‌های tst، entBو entC در میان نمونه‌های بالینی استافیلوکوک اورئوس جدا شده ازبیماران بستری دربیمارستان‌های آموزشی قزوین

Abstract Background: Staphylococcus aureus is one of the most common infectious bacterial pathogens. TSST-1 and enterotoxins are the major virulence factors of this organism which are superantigens and cause the toxic shock syndrome. The toxin-encoding genes are located on pathogenicity islands with the ability to move to non-toxigenic strains. This study was done to determine the frequency of the most common genes (tst, entB and entC) that cause toxic shock syndromes, in clinical isolates of Staphylococcus aureus collected from university affiliated hospitals in Qazvin. Materials and methods: In this descriptive study, a total of 65 isolates of Staphylococcus aureus were collected from hospitalized patients over a period of 9 months. All isolates were initially identified using standard biochemical tests and then were confirmed by detection of the femA gene which is intrinsic for Staphylococcus aureus. PCR assay was performed for detection of tst , entB and entC genes. Results: Of 65 isolates, 22 isolates (33.4%) were positive for tst, entB and entC genes. Among them, 18 isolates (27.6%) were positive for tst, 2 (3%) for entB and 2 (3%) for entC genes. 2 isolates (3%) were also positive for both tst and entC genes. Conclusion: Presence of the toxic shock syndrome toxins genes in clinical isolates of Staphylococcus aureus is significant in the studied hospitals. Considering the clinical significance of these isolates and their potential to cause serious disease, strategies to prevent the spread of these pathogens is urgently needed. Keywords: Staphylococcus aureus, tst, entB, entC, toxic shock syndrome.