Identification of the classical enterotoxin genes of Staphylococcus aureus in various foods by multiplex PCR assay

Abstract

Background: An annual update of information about the prevalence of Staphylococcus aureus and staphylococcal enterotoxins (SEs) genes is required in every geographic area. Aims: This study was conducted to investigate the prevalence of the bacterium and type of associated enterotoxin genes in different food samples, using multiplex polymerase chain reaction (PCR) assay. Methods: In order to achieve these goals, 310 samples, divided into three groups (dairy products, meat, and traditional sweets groups), were collected. After determination of the prevalence of S. aureus, the existence of 16s rRNA, sea, seb, sec, sed, and see genes were evaluated using multiplex PCR assay. Results: Staphylococcus aureus was isolated from 103 (33%) samples. Furthermore, the meat category had the most contamination rate of S. aureus. Additionally, the kebab samples (61.5%) were the most contaminated products, followed by hamburger (47.3%), and ice cream (33.8%). Of these 103 S. aureus isolates, 72 isolates (69.9%) harbored at least one type of the classical SEs genes. The prevalence of the type A enterotoxin gene was detected higher than the other SEs genes. Conclusion: The results indicated that inappropriate handling of the samples in the preparation and processing steps, especially for the meat products, can lead to the spread of more bacteria. The relatively high prevalence of some classical enterotoxin genes in the isolates revealed the potential power of this bacterium to produce enterotoxins, which can lead to food-poisoning.