Establishment of a novel multiplex PCR assay and detection of toxigenic strains of the species in the Bacillus cereus group

• Published in: Journal of food protection Vol. 68; no. 10; pp. 2123 - 2130
• Main Authors: Yang, I.C, Shih, D.Y.C, Huang, T.P, Huang, Y.P, Wang, J.Y, Pan, T.M
• Format: Journal Article
• Language: English
• Published: Des Moines, IA International Association of Milk, Food and Environmental Sanitarians 01.10.2005
• Subjects: Bacillus cereus; Bacillus cereus - classification; Bacillus cereus - isolation & purification; Bacillus cereus - metabolism; Bacillus mycoides; bacterial contamination; Base Sequence; Biological and medical sciences; enterotoxins; Enterotoxins - analysis; Enterotoxins - biosynthesis; food contamination; Food industries; Food Microbiology; food pathogens; Fundamental and applied biological sciences. Psychology; General aspects; Methods of analysis, processing and quality control, regulation, standards; microbial detection; Phylogeny; polymerase chain reaction; Polymerase Chain Reaction - methods; soil bacteria; Species Specificity; Taq Polymerase; toxigenic strains; Assay; Polymerase chain reaction; Bacillus cereus; Analysis method; Bacillales; Bacteria; Control method; Bacillaceae; Molecular biology; Detection; Species; Strain
• ISSN: 0362-028X; 1944-9097
• DOI: 10.4315/0362-028X-68.10.2123

Five different enterotoxins and one emetic toxin of Bacillus cereus have been characterized. To amplify all of the enterotoxin and emetic-specific sequences of the species in the B. cereus group, a multiplex PCR with 12 primer pairs was established. In developing the assay method, a common terminal sequence at the 3' ends of all primers was chosen and a hot start Taq polymerase was used to overcome primer dimer formation. The assay was successfully applied to analyze the toxigenic potential of 162 food-poisoning and food-related strains. Results showed that there were 10 toxigenic patterns for all the test strains. All of the B. cereus strains carried at least one toxin gene. More than 70% of Bacillus mycoides strains carried no known toxin genes. The toxin profiles and toxin genes of B. mycoides strains were significantly different from B. cereus strains (P < 0.05), although the two species were closely related. The results suggest that many B. mycoides strains might be less prone to cause food poisoning. They also indicate the importance of detecting the toxin genes together with the detection of the species in the B. cereus group.