Identification of Bacillus cereus emetic toxin gene from Meat Curry (#227)
Bacillus cereus is a spore forming bacterium that produces toxins that cause vomiting or diarrhoea. Symptoms are generally mild and short-lived up to 24 hours. B. cereus is commonly found in the environment as well as a variety of foods. Spores are able to survive harsh environments including normal cooking temperatures. B. cereus is one of predominant found foodborne pathogen in many countries e.g. Malaysia. Two major types of food poisoning caused by B. cereus, emetic (vomiting) and diarrheal, have been described in several hospitals in Malaysia. The vomiting type is affected by a small cyclic heat-stable peptide (cereulide), and the diarrheal disease is caused by three different enterotoxins (HBL, NHE, cytK). The objective of this study was to identify B. cereus using biochemical test and emetic toxin-producing of B. cereus, specifically BHL by targeting a specific gene hblD. A total of twenty seven samples of meat curry from nine random restaurants around Selangor, Malaysia were used in this study. Mannitol egg yolk polymyxin (MYP) is a selective medium and confirmatory biochemical tests were used to isolate B. cereus. The biochemical test was used to detect B. cereus and the samples examine for the presence of hblD gene by polymerase chain reaction (PCR). The results showed all samples were identified as B. cereus, the morphology observation showed Gram-positive, rod-shaped and motility differs between the samples. In particular, all samples were positive for the production of the enzyme catalase, fermentation of glucose ,hydrolyzes of starch and reduction of nitrate and negative for hydrogen sulphide gas, and the breakdown of amino-acid tryptophan. These findings represent an example of how genomics and biochemical could rapidly help public health experts responding not only to clearly identified select agent but also to agents with similar pathogenic potentials.