致病性大肠埃希菌O2、O（78）及融合双价弱毒菌株O（2,78）（Chl^rNor^r）ompA基因的克隆及序列分析

目的 应用PCR扩增大肠埃希菌O2、O78及融合双价弱毒菌株O2,78的外膜蛋白A（ompA）基因,并进行克隆。方法 根据GenBank中人源大肠埃希菌K-12的ompA核苷酸序列设计特异引物,应用PCR对大肠埃希菌O2、O78及融合双价弱毒菌株O2,78的ompA基因进行体外扩增、克隆和序列分析。结果 O2、O78和O2,78经PCR获得的ompA基因片段大小为1 041 bp,与理论值相符;经过克隆和测序分析,该基因的核苷酸序列均由2 271 nt组成,编码1个由346个氨基酸组成的前外膜蛋白A,三菌株ompA基因核苷酸序列与GenBank提供的已知基因序列比较,同源性均为100%。结论 本研究成功克隆了大肠埃希菌ompA基因全长。

Gene cloning and sequence analysis of enteropatuogenic Escherichia coli （EPEC） O2, OTs and ompA from integration bivalent attenuated strain of O2, 7s （Chl＇Nor＇） strains

Objective To amplify clone and sequence ompA of Escherichia coli O2, OTs and their fusion bivalent attenu ated strain O2.75 （Chl＇Nor＇）. Methods Specific primers were designed according to the nucleotide sequence of the outer membrane protein gene A （ompA） of E. coli K-12 , and the PCR was used in amplifying, cloning and sequence analysis of E. coli O2, O75 and O2, 75 （Chl＇Nor＇） strains of ompA genes. Results The size of O2, O75 and O2.75 ompA gene fragment obtained by PCR was 1 041 bp, which was in line with the theoretical value. After cloning and sequencing analysis, the nucleotide sequence of the gene consist of 2 271 bp composition, coding one from the 346 amino acid composition of the former outer membrane protein A. Comparing the three strains ompA gene nucleotide sequence with the sequences of known genes provided by GenBank, they are 100% homology. Conclusion The full-length of ompA was successfully cloned in this study.