Detection of enterotoxin targeted entFM and hblA genes by inoculating Bacillus cereus (Strain BC1) into ready-to-eat food (RTF) and drink samples using polymerase chain reaction (PCR)

Detection of enterotoxin by targeting entFM and hblA genes in Bacillus cereus BC1 strain inoculated into ready to eat food (RTF) and drink samples using polymerase chain reaction (PCR) was conducted. The B. cereus BC1 strain was confirmed as a Bacillus diarrhoeal enterotoxin (BDE) when tested by a commercially available Enzyme-linked immunosorbent assay-BDE immunoassay (ELISA-BDE immunoassay, TECRA). In the specificity study, both enterotoxin genes were detected on chromosomal DNA of B. cereus BC1 strain by showing a specific band of 1269 bp (entFM) and 874 bp (hblA), respectively. However, none of the target genes were detected for the other 15 genomic DNA bacteria (B. cereus (ATCC 11779), B. subtilis (ATCC 6633), Campylobacter jejuni (ATCC 29428), C. coli (Jabatan Kimia Malaysia, JKM), Clostridium perfringen (ATCC 13124), Enterobacter sakazaki (ATCC 51329), Escherichia coli (ATCC 43888), E. coli (ATCC 11735), Legionella pneumophila (ATCC 33152), Listeria monocytogenes (ATCC 35967), Salmonella typhi (IMR), S. enteritidis (ATCC 13076), S. typhimurium (ATCC 14028), Shigella flexeneri (ATCC 12022) and Vibrio cholerae bengal (Institute Medical Research (IMR), Malaysia) examined. The detection limit of both genes was 0.1 ng of genomic DNA. Thus, in the presence study it is evidence that the PCR analysis targeting enterotoxin of entFM and hblA genes are suitable and useful in detecting enterotoxic B. cereus in RTFs and drinks contaminated sample.