SIMPLE METHOD FOR DETECTION OF CLOSTRIDIUM-BOTULINUM TYPE-A TO F-NEUROTOXIN GENES BY POLYMERASE CHAIN-REACTION

A polymerase chain reaction (PCR)-based method was established to dete ct each type of neurotoxin genes of Clostridium botulinum types A to F by employing the oligonucleotide primer sets corresponding to special regions of the light chains of the neurotoxins. In this procedure, th e PCR products were easily confirmed by restriction enzyme digestion p rofiles, and as little as 2.5 pg of template DNAs from toxigenic strai ns could be detected. The specific PCR products were obtained from tox igenic C. botulinum types A to F, a type E toxin-producing C. butyricu m strain, and a type F toxin-producing C. baratii strain, but no PCR p roduct was detected in nontoxigenic strains of C. botulinum and other clostridial species. The neurotoxin genes were also detected in food p roducts of a seasoned dry salmon and a fermented fish (Izushi) which h ad caused type E outbreaks of botulism. Therefore, it is concluded tha t this PCR-based detection method can be used for the rapid diagnosis of botulism.