摘要
目的了解大肠埃希菌分离株eaeA基因的多态性。方法对不同来源的60株大肠埃希菌分离株的eaeA基因进行聚合酶链反应扩增后直接测序,测序结果在NCBI中进行BLASTn比对,根据比对相似性判定eaeA基因的型别。将获得型别的序列与GenBank中肠致病性大肠埃希菌(Enteropathogenic Escherichia coli,EPEC)和肠出血性大肠埃希菌(Enterohemorrhagic Escherichia coli,EHEC)代表性菌株型别的序列用Neighbor-joining法构建系统发生树,分析其进化关系。结果所有EHEC分离株的eaeA基因均为γ型,且序列完全一致。EPEC分离株的eaeA基因型以β1型为主,同时存在ε,κ,ι2,θ型。结论 EHEC分离株的eaeA基因相对保守,型别单一,而EPEC分离株的eaeA基因表现出较大的多态性。
Objective To understand the genotypes of the eaeA gene of Escherichia coli （EHEC/EPEC） isolates in China. Methods The eaeA genes of 60 isolates of Escherichia coli were amplified by using polymerase chain reaction （PCR）. The products were sequenced and analyzed with BLASTn, and the subtype was identified according to their similarity. Phylogenetic tree was constructed based on the eaeA gene sequences. Results Genotype ~/was found in the eaeA genes, with identical sequences, of all 43 EHEC isolates, however, the genotypes of eaeA genes were diverse in 17 EPEC isolates and 131 was the most common genotype（70. 6% ）, followed by K（ll. 6% ） , e（5.8% ）, t2（5.8% ）and 0 （5.8%）. Conclusion Based on the sequence analysis of intimin gene family, we found genetic diversity in EPEC isolates and genetic conservativeness in EHEC isolates.
出处
《疾病监测》
CAS
2012年第2期93-96,共4页
Disease Surveillance
基金
国家"艾滋病和病毒性肝炎等重大传染病防治"科技重大专项(No.2008ZX10004-009)~~
