表达猪链球菌溶血素基因的减毒沙门氏菌的构建及鉴定

将猪链球菌溶血素（suilysin，SLY）基因克隆入原核表达栽体pBV220，将重组质粒再导入减毒鼠伤寒沙门氏菌SV4089株，经PCR和酶切鉴定，构建成携带猪链球菌溶血素基因的重组减毒鼠伤寒沙门氏菌。结果表明：该减毒株具有相对安全性；用酶切和PCR鉴定法证实在无抗生素存在的条件下携带重组质粒的减毒株比较稳定；SDS-PAGE显示SLY能在宿主菌中进行表达。该结果为进一步研究制备猪链球菌口服活疫苗奠定了基础。

Construction and Identification of a Recombinant Attenuated Salmonella Expressing Streptococcus suis sly Gene

Sly gene of Streptococcus suis was cloned into a procaryotic expression plasmid pBV220, and the identified recombinant was then used to transform an attenuated Salmonella typhimurium SV4089. Identified by PCR and restriction enzyme digestion, a recombinant live attenuated Salmonella typhimurium vaccine strain expressing S. suis sly gene was constructed. The results showed that recombinant vaccine strain was relatively safe and the recombinant plasmid pBV220/sly was stable within the host strain by PCR and restriction enzyme digestion. SLY was expressed in the recombination strains. This work will help lo develop an oral recombinant live vaccine against S suis.