Department of Microbiology, Wakayama Medical University School of Medicine, 811–1 Kimiidera, Wakayama 641–0012, Japan.
Microbes Environ. 2012;27(4):343-9. doi: 10.1264/jsme2.me12002. Epub 2012 Apr 14.
Recent advances in understanding the genetics of enterotoxigenic Clostridium perfringens, including whole genome sequencing of a chromosomal cpe strain and sequencing of several cpe-carrying large plasmids, have led to the development of molecular approaches to more precisely investigate isolates involved in human gastrointestinal diseases and isolates present in the environment. Sequence-based PCR genotyping of the cpe locus (cpe genotyping PCR assays) has provided new information about cpe-positive type A C. perfringens including: 1) Foodborne C. perfringens outbreaks can be caused not only by chromosomal cpe type A strains with extremely heat-resistant spores, but also less commonly by less heat-resistant spore-forming plasmid cpe type A strains; 2) Both chromosomal cpe and plasmid cpe C. perfringens type A strains can be found in retail foods, healthy human feces and the environment, such as in sewage; 3) Most environmental cpe-positive C. perfringens type A strains carry their cpe gene on plasmids. Moreover, recent studies indicated that the cpe loci of type C, D, and E strains differ from the cpe loci of type A strains and from the cpe loci of each other, indicating that the cpe loci of C. perfringens have remarkable diversity. Multi-locus sequence typing (MLST) indicated that the chromosomal cpe strains responsible for most food poisoning cases have distinct genetic characteristics that provide unique biological properties, such as the formation of highly heat-resistant spores. These and future advances should help elucidate the epidemiology of enterotoxigenic C. perfringens and also contribute to the prevention of C. perfringens food poisoning outbreaks and other CPE-associated human diseases.
近年来，人们对肠毒素型产气荚膜梭菌的遗传学研究取得了进展，包括对染色体 cpe 菌株进行全基因组测序以及对几个携带 cpe 的大质粒进行测序，这使得人们能够开发出分子方法，更精确地研究与人类胃肠道疾病相关的分离株以及存在于环境中的分离株。cpe 基因座的基于序列的 PCR 基因分型（cpe 基因分型 PCR 检测）为 cpe 阳性 A 型产气荚膜梭菌提供了新的信息，包括：1）食源性病原体产气荚膜梭菌的爆发不仅可以由具有极强耐热孢子的染色体 cpe 型 A 菌株引起，也可以由耐热性稍差的形成孢子的质粒 cpe 型 A 菌株引起；2）染色体 cpe 和质粒 cpe A 型产气荚膜梭菌都可以在零售食品、健康人的粪便和环境中（如污水）发现；3）大多数环境中 cpe 阳性的 A 型产气荚膜梭菌菌株将其 cpe 基因携带在质粒上。此外，最近的研究表明，C、D 和 E 型菌株的 cpe 基因座与 A 型菌株的 cpe 基因座以及彼此的 cpe 基因座不同，表明产气荚膜梭菌的 cpe 基因座具有显著的多样性。多位点序列分型（MLST）表明，引起大多数食物中毒病例的染色体 cpe 菌株具有独特的遗传特征，赋予其独特的生物学特性，例如形成高度耐热的孢子。这些和未来的进展应该有助于阐明肠毒素型产气荚膜梭菌的流行病学，也有助于预防产气荚膜梭菌食物中毒的爆发和其他与 CPE 相关的人类疾病。
