Molecular epidemiological study on emerging enteric infections in Asia

亚洲新发肠道感染的分子流行病学研究

基本信息

批准号：
14256004
负责人：
NISHIBUCHI Mitsuaki
金额：
$ 21.38万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

We studied the DNA fingerprints of new pandemic strains of Vibrio parahaemolyticus isolated in Thailand and Vietnam by using the pulsed field gel electrophoresis(PFGE) method. The results indicated that strains harbored in molluscan bivalves are responsible for infection in Thailand and that clear transition of O3:K6 serotype to O1:K25,etc. occurred in Vietnam. The nucleotide sequences of 11 genes in 60 pandemic strains representing the isolates in various Asian countries were combined and analyzed. The result indicated that O3:K6,O4:K68, and O1:KUT strains are phylogenetically related and possible ancestral strains of the pandemic strains were found.Of the 20 ctx^+ Vibrio cholerae strains isolated from the seafoods in Malaysia 15 strains belonged to the new serotype (O139). These strains and ctx^+ V.cholerae strains isolated in India and Bangladesh and from international travelers were subjected to the PFGE-dendrogram analysis. The phylogenetic relationship among these strains suggested that Malaysian O139 strains were introduced from the Bengal area in two separate occasions. The nucleotide sequences of five genes of 79 strains of V.cholerae including the above strains were determined and analyzed by a multilocus sequence typing approach. The result supported the phylogenetic relationship of the strains obtained by the PFGE method.Our study on Escherichia coli O157 suggested this organism is widely distributed in Asian environment. However, considerable number of the environmental strains produced very little amount of Stx2. This was due at least in part to the change in the DNA sequence around the Q gene. This genetic change and the fact that very few patients infected by E.coli O157 are reported in Asian countries appear to be related.

我们通过使用脉冲场凝胶电泳（PFGE）方法研究了在泰国和越南分离出的新大流血菌株的DNA指纹。结果表明，软体动物双壳类动物中含有的菌株是泰国感染的原因，并且O3：K6血清型向O1：K25等明确过渡。发生在越南。在各种亚洲国家中代表分离株的60个大流行菌株中11个基因的核苷酸序列被合并和分析。结果表明，发现了O3：K6，O4：K68和O1：KUT菌株在系统发育上是相关的，并且发现了大流行菌株的可能的祖先菌株。从马来西亚15菌株中属于新的Sertype（O139）中，从马来西亚15株中从海鲜中分离出的20 ctx^+ Vibrio cholerae菌株（O139）。在印度和孟加拉国分离的这些菌株和CTX^+ V.胆碱菌株以及国际旅行者进行了PFGE-DENDROGRAM分析。这些菌株之间的系统发育关系表明，马来西亚O139菌株是从孟加拉地区引入的，两次是单独的场合。确定并通过多焦点序列分型方法确定并分析了79个菌株的五个基因的五个基因的核苷酸序列。结果支持通过PFGE方法获得的菌株的系统发育关系。我们对大肠杆菌O157的研究表明，这种生物在亚洲环境中广泛分布。但是，大量的环境菌株产生的STX2很少。这至少部分归因于Q基因周围的DNA序列的变化。这种遗传变化以及在亚洲国家中据报道，很少有被大肠杆菌O157感染的患者的事实似乎是相关的。