致病性耶尔森菌外膜蛋白A基因多态性研究

发布时间：2018-06-07 23:49

本文选题：致病性耶尔森菌 + 基因多态性分析　；参考：《中国疾病预防控制中心》2013年硕士论文

【摘要】：鼠疫耶尔森菌(Yersinia pestis)、小肠结肠炎耶尔森菌(Yersinia enterocolitica, Y.e)与假结核耶尔森菌(Yersinia pseudotuberculosis, Y.p)是对人类具有致病性的病原体,它们都属于耶尔森菌属的G菌。鼠疫耶尔森菌是烈性传染病鼠疫的病原体；小肠结肠炎耶尔森菌是引起人类小肠结肠炎的病原菌,还可以引起一些后遗症如结节性红斑、反应性关节炎、心内膜炎等,甚至可引起败血症而死亡。而假结核耶尔森菌存在于多种动物肠道内,人类感染较少,主要通过进食污染的食物而感染。目前,关于革兰氏阴性肠道杆菌的外膜蛋白A的研究已经证明了外膜蛋白A是一种多功能的蛋白,同时作为一类主要的抗原成分,参与适应性免疫应答。同时我们的研究已经证明了小肠结肠炎耶尔森菌的外膜蛋白A具有很强的免疫原性。鼠疫耶尔森菌的外膜蛋白A也已经被证明具有免疫原性,并对鼠疫耶尔森菌的感染具有保护作用。为了更好的在基因水平上对这三种致病性耶尔森菌的外膜蛋白A进行研究,本研究对318株小肠结肠炎耶尔森菌、97株假结核耶尔森菌及45株鼠疫耶尔森菌的ompA基因进行了检测,同时进行了序列分析。还对318株小肠结肠炎耶尔森菌的p-ompA基因进行了检测与测序分析。测序结果表明：全部170致病性小肠结肠炎耶尔森菌及含有ystB基因的84株生物1A型菌株都携带p-ompA和ystB基因,不携带ompA基因64株生物1A型菌株仅有部分单独携带p-ompA(7株)和ompA(22株)基因,同时证实p-ompA基因和ystB基因在致病性小肠结肠炎耶尔森菌中具有高度保守性,在生物1A型菌株中这两个基因分布与ystB基因高度相关,且序列具有多态性,在不携带ompA基因的生物1A型菌株中,p-ompA和ompA基因只携带其中之一,而没有同时携带这两个基因的菌株。聚类分析显示致病性菌株序列类型较少,很保守,而非致病菌株的序列类型呈多样性。全部的鼠疫耶尔森菌及假结核耶尔森菌的ompA基因都表现出高度保守性,并且全部菌株都含有p-ompA基因。通过对这三种致病性耶尔森菌的外膜蛋白A基因的多态性研究,可以提示外膜蛋白A基因是致病性耶尔森菌的保守基因,同时外膜蛋白A可能是致病性耶尔森菌致病相关的蛋白,该研究可为进一步研究致病性耶尔森菌外膜蛋白A的功能提供基础。而小肠结肠炎耶尔森菌的ompA基因的保守性与p-ompA基因相似,提示基因也可能是小肠结肠炎耶尔森菌的功能相关基因。
[Abstract]:Yersinia pestism, Yersinia enterocolitica (Y.e) and Yersinia pseudotuberculosis (Y.p) are pathogenic pathogens of Yersinia, which belong to G of Yersinia genus. Yersinia pestis is the pathogen of plague, and Yersinia enterocolitica is the pathogen of human enterocolitis. It can also cause some sequelae such as erythema nodosum, reactive arthritis, endocarditis, etc. It can even cause sepsis and death. But Yersinia pseudotuberculosis exists in the intestines of many animals, and human beings have less infection, mainly through eating contaminated food. Studies on the outer membrane protein A of Gram-negative enterobacterial bacteria have proved that outer membrane protein A is a multifunctional protein and is a major antigen component involved in adaptive immune response. At the same time, our study has demonstrated that Yersinia enterocolitica has strong immunogenicity. The outer membrane protein A of Yersinia pestis has also been proved to be immunogenicity and has a protective effect on the infection of Yersinia pestis. In order to study the outer membrane protein A of these three pathogenic Yersinia strains at the gene level, the ompA genes of 97 Yersinia enterocolitica strains and 45 Yersinia pestis strains were detected. At the same time, the sequence analysis was carried out. The p-ompA gene of 318 strains of Yersinia enterocolitica was detected and sequenced. The sequencing results showed that all 170 pathogenic Yersinia enterocolitica strains and 84 biotype 1A strains containing ystB gene carried p-ompA and ystB genes. OmpA gene was not carried in 64 strains of biological strain 1A (p-ompA(7 strain) and ompA(22 strain (only partially). It was also confirmed that p-ompA gene and ystB gene were highly conserved in Yersinia enterocolitica. The distribution of these two genes was highly correlated with the ystB gene, and the sequence was polymorphic. The p-ompA and ompA genes carried only one of them in the strain without ompA gene, but there was no strain carrying the two genes at the same time. Cluster analysis showed that the sequence types of pathogenic strains were few and conserved, while the sequence types of non-pathogenic strains were diverse. All Yersinia pestis and Yersinia pseudotuberculosis ompA genes were highly conserved, and all strains contained p-ompA gene. By studying the polymorphism of the outer membrane protein A gene of these three pathogenic Yersinia strains, it can be concluded that the outer membrane protein A gene is a conserved gene of pathogenic Yersinia. At the same time, outer membrane protein A may be the pathogenicity related protein of pathogenic Yersinia, and this study may provide a basis for further study on the function of outer membrane protein A of pathogenic Yersinia. The conserved nature of the ompA gene of Yersinia enterocolitica is similar to that of the p-ompA gene, suggesting that the gene may also be a functional related gene of Yersinia enterocolitica.
【学位授予单位】：中国疾病预防控制中心
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R378.61

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