艰难梭菌引起抗感染免疫的主要致病因子及其基因功能的研究进展

Clostridium difficile virulence factors inducing anti-infection response and its gene functions

艰难梭菌是医院感染性腹泻中最常见的病原菌之一,在过去10年中,由于ribotyping 027型等高毒菌株的出现,全球艰难梭菌感染相关性疾病发病率显著上升,已经成为欧美许多国家法定传染病必报的监测病原。致病艰难梭菌的毒力因子主要包括A毒素和B毒素,刺激机体发生免疫应答。除外A、B毒素,少数艰难梭菌还产生二元毒素。本文对近年来艰难梭菌引起机体抗感染免疫的相关致病因子及其基因功能的最新研究进展进行了回顾和总结,并重点探讨了主要致病因子A毒素和B毒素结构功能及基因表达调控特征,包括构建A、B毒素分子模型,致病基因编码区多态性特征,以及负向调控因子tcdC的变异及影响,对未来疫苗靶位点的筛选以及艰难梭菌致病机制中信号转导研究具有指导意义。

Clostridium difficile is one of the most common causes for hospital acquired diarrhea. During the past decade, incidence of Clostridium difficile associated disease has significantly increased worldwide coincident with emerging of hypervirulent strain ribotyping 027, and this microorganism has been included into monitoring pathogens of national notable disease in several western countries. Hosts immune responses to virulence factors, mainly toxin A and toxin B produced by toxigenic strains, directly influence the development of disease. Further more, a number of strains express an additional toxin termed binary toxin. In this paper, we retrospect and summarize the latest advancement of the gene functions of Clostridium difficile virulence factors inducing anti- infection response, and primarily discuss the characteristics of molecular model and gene regulation of toxin A and toxin B, which will be a basis for study on screen of possible vaccine antigen target and signal transduction in pathogenic mechanism of Clostridium diifficile.