Journal of Pure and Applied MicrobiologyVol. 2 No. 2

Detection of Staphylococcus aureus Enterotoxins (SES) in Foodstuffs by ELISA

N. Rahimifard, Sh. Shoeibi et al.

¹Food and Drug Laboratory Research center (FDLRC), Tehran, Iran. ²Food and Drug Control Laboratories (FDCLs), Ministry of Health (MOH), Tehran, Iran. ³Immunology Department, Pasteur Institute of Iran, Tehran, Iran. 4Microbiology Department, Faculty of Medicine, Tehran University of Medical Sciences(TUMS), Tehran, Iran.

Received on 28 May 2008 and accepted on 30 July 2008

 

ABSTRACT

Staphylococcal enterotoxication results from ingestion of foods containing 1 of 11 immunologically distinct enterotoxins, A, B, C1, C2, C3, D, E, F, G, H and I. Staphylococcus aureus is heat-labile and it’s enterotoxins are heat-stable1,2,3, due to presumption enterotoxins culture results for viable bacteria are not sufficient to prove food safety for consumption. In this study we examined the presence of Staphylococcus aureus and staphylococcal enterrotoxins(SEs) in 60 samples of ready to use foodstuffs that should be free of this organism,obtained from samples were suspected to have foodborne pathogens and referred to FDCLs of Iran. Viable bacteria were detected by culture, and simultaneously enterotoxins by ELISA, using commercial kit for the detection of A, B, C, D, E, F and G enterotoxins, after extraction and purification from the food substrate. Staphylococcus aureus were detected by enrichment method10. Giolitti cantoni broth was used as enrichment media and Baird Parker agar as selective media. 27 samples were positive in routine culture method and in 38 samples enterotoxins were found by ELISA method. All enterotoxin-positive samples had enterotoxin A and 21 of them enterotoxin B too. Based on the results, the culture method for detection of food contamination is not a definite reliable method, and ELISA method could be preferred, in this respect.

Keywords : Staphylococcus aureus, Enterotoxins (SES), Foodstuff, ELISA.