摘要：Infant botulism is a neuromuscular paralysis caused by the botulinum neurotoxin (BoNT) produced in the intestines after the germination and outgrowth of ingested spores of the anaerobic spore-forming bacterium Clostridium botulinum . In Japan, 24 cases of infant botulism have been reported. From 1986 to 1989, 12 cases occurred, all with a history of honey feeding before onset of symptoms. Since 1990, a further 12 cases have occurred, but none has had a history of honey feeding and the origin remains unidentified in most cases. To understand the background of these cases, we determined the genetic characteristics of the C. botulinum associated with type A and type B infant botulism in Japan. Accordingly, the isolates were divided genetically by origin (honey feeding or not) and period. A type B isolate associated with a case in Osaka City in 2005 was considered to be a new BoNT/B subtype. We also established new genotyping methods for C. botulinum type A and type B, multiplex PCR assays for boNT/A gene cluster typing and boNT/B subtyping, which will be useful for epidemiological studies of C. botulinum and the infectious diseases that they cause.
