PCR AND GENE PROBE IDENTIFICATION OF BOTULINUM NEUROTOXIN-A, NEUROTOXIN-B, NEUROTOXIN-E, AND NEUROTOXIN-G PRODUCING CLOSTRIDIUM SPP AND EVALUATION IN FOOD SAMPLES

A degenerate primer pair was selected to amplify specifically a 260-bp DNA fragment from Clostridium botulinum types A, B, E, F, and G, and five individual probes allowed identification of each toxinotype by hy bridization of the PCR products. The 72 strains of different Clostridi um species tested and 11 other bacterial species commonly found in foo d samples gave an amplification product. This assay was able to detect 1 C. botulinum type A or B and 10 C. botulinum type E strains per rea ction. With 184 artificially contaminated food samples, after an 18-h enrichment step, the sensitivity was 10 bacteria per g of sample and t he correlation with the mouse bioassay reached 95.6%.