伤寒杆菌耐药质粒pR_(ST98)毒力基因spv的序列测定

DNA Sequencing of Virulence Gene spv on the Salmonella typhi Multidrug Resistance Plasmid pR_(ST98)

目的 对伤寒杆菌多重耐药质粒 pRST98的毒力基因spv进行克隆及核酸序列测定。 方法 为区分毒力基因存在于细菌染色体还是位于耐药质粒 pRST98,先分离提取耐药质粒 pRST98,再以该质粒为模板 ,将自行设计的引物经多聚酶链式反应 (PCR)扩增目的基因 ,装入克隆载体 pGEM TEASY进行核酸序列测定。 结果 PCR反应得到spv基因的spvR和spvB片段 ,其ORF大小分别为 894bp和 1776bp ,核酸序列测定后进行生物信息学分析。结论 伤寒杆菌多重耐药质粒pRST98除编码细菌抗药性外 ,还具有与细菌毒力相关的基因 ,该质粒是一种具有双重功能的“嵌合型”质粒。

Objective To clone and sequence the virulence gene spv presented on Salmonella typhi multidrug resistance plasmid pR ST98 . Methods The spv gene was amplified by PCR(Polymerase Chains Reaction),and then ligated to plasmid vector pGEM-T EASY.The open reading frame(ORF) spvR and spvB were sequenced. Results The ORF of spvR sized 894bp,and spvB was 1776bp.The aquired DNA data was then analysed by bio_informatics. Conclusion Except for the ability to encode the drug resistance,the Salmonella typhi plasmid pR ST98 might also encode virulence.PCR and DNA sequencing results presented in this study support a mosaic-like structure for pR ST98