the prevalence study of staphylococcal enterotoxin genes from clinical samples of patients by multiplex pcr in ahwaz hospitals.

background: several virulence factors have been described in pathogenesis of staphylococcus aureus strains. staphylococcal enterotoxins(ses) that is one of the most factors, are belonging to important members of bacterial superantigens. superantigens are defined by their ability to stimulate cytokine release from both t cells and macrophages. 13 different ses are known that their function is not only as gastrointestinal toxins but also as superantigens.aim: the aim of this study was to evaluate the prevalence of ses genes in isolates from patients in ahwaz hospitals.material: this study was performed on 1280 clinical samples from patients who were referred to the four hospitals in ahwaz. samples were collected from urine, blood, skin chips and sputum of patients. staphylococcus aureus isolates were identified by routine bacteriological methods. genomic dna was extracted by phenol-chloroform method. the sets of enterotoxin genes(sea-sei) were amplified by multiplex pcr. pcr products were analyzed by electrophoresis.results: in this study 231 staphylococcus aureus were isolated from urine , blood, skin chips and spatum samples. 89(39%) strains had enterotoxin gene. the frequency of sea (17%), seg (15%), sec (6%), sed and seh (5.6%), seb (5.1%) and sei (9.5%) were reported. there was no see gene among isolates. the study of genes simultaneously showed that the frequency of two genes and three genes were 20% and 17 %. conclusion: given the importance of nosocomial staphylococcus aureus infections and the role of ses as superantigen in the development of various diseases, study of these genes in clinical specimen is necessary.