Distribution of staphylococcal enterotoxin A gene among Staphylococcus aureus isolates from traditional white–brined cheese

Subject Areas : Journal of Comparative Pathobiology

Kh  Mohammadi, ¹ (ندارد)

Received: 2014-06-04 Accepted : 2014-09-19 Published : 2015-01-21

Keywords: Traditional White–Brined Chees, Staphylococcus aureus, Gene, Enterotoxin, Multiplex PCR,

Abstract :

The consumption of food containing staphylococcal enterotoxins is regularly identified as thecause of intoxication. Enterotoxin A is considered as the most common toxin in staphylococcus–related food poisoning. The purpose of this study was to determine the prevalence of S. aureusin traditional white–brined cheese and distribution of enterotoxin A gene (sea) among them. Atotal of 120 samples was examined and S. aureus was isolated from 11 (9.1%) of the samples.According to the results, load of S. aureus was estimated from 1.5×101 to 8.6×104 cfu/g. Nosample was in the critical cell density of >105 cfu/g. From each sample, five suspected colonieswere confirmed by biochemical tests. S. aureus isolates were further identified based on 23SrRNA, themonuclease and enterotoxin A genes using multiplex PCR. Based on multiplex PCRresults all 55 isolates were identified as S. aureus. The enterotoxin A gene (sea) was detected in6 (10.9%) of the isolates. In conclusion, S. aureus and sea gene was found in traditional white–brined cheese. It seems that if the favorable growth conditions are provided, S. aureus couldproliferate and produce enterotoxin and could be regarded as a potential risk for human health.