Prevalence of sea, seb, tsst, and mecA Genes in Staphylococcus aureus Isolated from Shrimps Sold in Seafood Retailers in Tehran, Iran

Background: Staphylococcus aureus, a Gram-positive bacterium, is the most prevalent food-borne pathogen in most regions of the world. The current study was carried out with the aim of S. aureus isolation from shrimps sold in Tehran, Iran. Furthermore, the genes of mecA as indicator of methicillin-resistant S. aureus, sea, seb, and tsst encoding enterotoxins were studied in the S. aureus isolates. Methods: Totally, 150 fresh and 150 frozen shrimp samples were collected from seafood retailers in Tehran. Isolation of S. aureus from the samples was carried out using conventional methods. The target genes were identified using polymerase chain reaction technique. Data were statistically analyzed using SPSS v. 11.5 software. Results: Out of 150 fresh and 150 frozen samples, 84 samples (28%) were contaminated with S. aureus. The contamination rate in fresh samples (22%) was significantly (p<0.05) lower than in frozen samples (34%). Totally, prevalence rates of sea, seb, tsst, and mecA genes in the isolates were 39.3, 15.5, 4.8, and 28.6%, respectively showing significant (p<0.05) differences. Conclusion: High prevalence rates of enterotoxigenic and also antibiotic resistance genes in S. aureus isolated from shrimp samples in the current study highlighted worries about risk of staphylococcal food poisoning in Iranian shrimp consumers.