PCR assay a new approach for detection of enterotoxins

Abstract

B. cereus group is considered as a potential problem, since it can contaminate many dairy products. In this study, three primer sets were selected to simultaneously detect two different species of the B. cereus group by using triple – primer PCR. The triple–primer PCR in this study were synthesized using the CER, CES and groEL genes for the detection of emetic toxin producing strains and another specific primer for the detection of diarrheal toxin (groEL gene only). Results indicated that all the diarrheal enterotoxin producing B. cereus strains showed a presence of groEL gene, while CER and CES genes were completely absent. Out of the six B. cereus strains tested for the production of diarrheal and emetic enterotoxins by using triple–primer PCR technique, three diarrheal enterotoxin producing strains were only detected. On the other hand, all six B. cereus strains had limited ability to produce emetic toxin. All diarrheal enterotoxin producing B. mycoides strains showed presence of groEL gene, but CER and CES genes were not detected in any of the B. mycoides tested strains. Consequently, four B. mycoides strains were tested for the production of diarrheal and emetic enterotoxins by using triple–primer PCR technique, only two strains showed diarrheal enterotoxin producing strains. In contrary all B. mycoides tested strains had limited ability to produce emetic toxin.