大肠杆菌-钩端螺旋体重组穿梭质粒pGKINVA的构建及重组钩体的筛选

目的 构建大肠杆菌-钩体穿梭质粒pGKINVA,并重组于钩体PatocⅠ株,为进一步确定钩体invA基因的功能奠定基础.方法 将invA基因克隆于pGKble24载体,PCR、限制性内切酶双酶切及测序鉴定重组穿梭质粒pGKINVA.质粒pGKINVA经电穿孔法转化无毒钩体PatocⅠ株,并筛选重组钩体菌株.结论 从钩体基因组中克隆出长558 bp的invA基因,定向插入pGKble24构建重组穿梭质粒pGKINVA,抗生素及蓝/白斑筛选和测序鉴定并获得正确的重组质粒后,电穿孔法转化钩体PatocⅠ株,在Korthof固体培养基生长并抗生素筛选、PCR鉴定出重组钩体菌株.结论 成功构建重组大肠杆菌-钩端螺旋体穿梭质粒pGKINVA,并筛选出2个重组钩体菌株,将有助于进一步阐明invA基因在钩体体内中的功能分析.

Construction of Recombinant E.coli-L.interrogans Shuttle Plasmid pGKINVA and Screening Recombinant Leptospira Strains

OBJECTIVE: To further investigate pathogenic function of invA in Leptospira, recombinant L. biflexa-Escherichia coli shuttle vector pGKINVA was constructed, and electropored into L. biflexa strain Patoc I . METHODS: The invA gene was cloned into shuttle vector pGKble24 to construct a recombinant L. biflexa-Escherichia coli shuttle vector pGKINVA. The recombinant vectors were electropored into L. biflexa serovar Patoc strain Patoc I . RESULTS: A 558 bp invA was amplified from L. interrogans serovars Lai strain 017 and ligated with Aat II and Xma I digested pGKble24. After screening by kanamycin and blue/white color, the recombinant pGKINVA was obtained and sequenced. Subsequently, the recombinant pGKINVA was electropored into L. biflexa strain Patoc I. The selected mutants were identified by PCR. CONCLUSION: Recombinant L. biflexa-Escherichia coli shuttle vector with invA insert was constructed and two strains of pGKINVA transformed Leptospira were obtained. These pGKINVA transformed Leptospira strains would provid an experimental model to investigate potential pathogenic functions of invA in vivo.