福氏志贺菌主动外排基因acrB的克隆与序列分析

以福氏志贺菌2a型菌株基因组为模板,经PCR扩增得acrB基因,将该基因克隆到pMD18-T Vector载体,将重组质粒进行PCR和酶切鉴定及序列测定.结果表明:测定序列与Genbank收录的福氏志贺菌参考序列同源性为99.7%,与大肠杆菌的acrB基因序列比较分析,序列同源性在98%~99%之间,说明志贺菌主动外排基因acrB在碱基序列和编码的氨基酸序列上均与大肠杆菌有很高的同源性,它可能是志贺菌引起多重耐药的主要原因.

Cloning and sequence analysis of activite efflux gene acrB of Shigella flexneri 2a

To identify the sequence of the active efflux gene acrB in Shigella flexneri 2a and analyze its sequence,the whole acrB gene was amplified by PCR from Shigella flexneri 2a genome DNA.The acrB gene was ligated with pMD18-T vector and transformed into competent cell DH5.Identification of recombinant vector was conducted by PCR and restriction enzyme digestion.Sequence analysis indicated that the sequence of acrB gene of Shigella flexneri 2a shared 99.8 % homology with the reference sequence of Shigella flexneri(Genebank No.NC_004337) and shared 98 %～99 % homology were detected in comparison with E.coli.The active efflux gene acrB of Shigella flexneri 2a showed high homology in bases,encoding amino acids with E.coli and it was possible that Shigella flexneri was resistant to multiple antibiotics.