STUDY THE PREVALENCE OF HBL AND NHE COMPLEXES IN ISOLATED BACILLUS CEREUS FROM SOME PASTEURIZED MILK AND CHEESE SAMPLES OF IRAN

Background and Aim:Bacillus cereus is human opportunistic pathogen which can cause diarrhoeal and emetic types of food poisoning. The haemolysin BL (HBL), and non-haemolytic enterotoxin (NHE) are three-component toxin proteins which is produced with this bacterium. B. cereus is frequently detected in variety food products including dairy.Methods: A total of 40 samples of pasteurized full fat milk and cheeses were collected from markets in Iran. The samples were cultured in PEMPA. Following the biochemical tests, the bacterial colonies were identified by PCR. Then B. cereus isolates were checked for NHE and HBL complex genes by specific primers using PCR.Results:Results showed that 15 samples of 40 were contaminated with B. cereus. The NHE complex genes were found in 5 samples while HBL complex have seen in 3 samples.The results of this study have shown that NHE and HBL complex have seen in approx. 20% of dairy in which are lower than those reported by othersConclusion:PCR is a reliable method for differentiation between non-enterotoxigenic and enterotoxigenic isolates of B. cereus. Enhancing awareness about virulence and prevalence of genes involved in food poisoning would be effective in the prevention of food poisoning.

Keywords:

Bacillus cereus , Dairy , NHE and HBL complex , PCR