鸡白痢沙门菌sifA基因缺失株的构建及其生物学特性的研究

Construction of a Salmonella pullorum S06004ΔsifA strain and study on its biological characteristics

为研究sifA基因对鸡白痢沙门菌致病性的影响,采用λ-red同源重组系统构建鸡白痢沙门菌S06004株的sifA基因缺失株S06004ΔsifA,同时构建该基因缺失株的回补株S06004ΔsifA(pBR322-sifA),并对该缺失株的生长特性、生化特性、遗传稳定性和毒力等生物学特性进行了研究。PCR和测序鉴定结果表明,成功构建了sifA基因缺失株S06004ΔsifA和该基因缺失株的回补株S06004ΔsifA(pBR322-sifA);生物学特性研究结果显示,sifA基因的缺失不影响鸡白痢沙门菌的生长特性和生化特性,且该缺失株具有良好的遗传稳定性,但其对3日龄雏鸡的LD50升高了39.3倍。本研究获得的减毒鸡白痢沙门菌sifA基因缺失株S06004ΔsifA为进一步研究鸡白痢沙门菌sifA基因的功能奠定了基础。

In order to define the pathogenicity ofΔsifA gene to Salmonella pullorum,the mutant S06004ΔsifA was successfully constructed by theλ-red recombinant.Meanwhile,its complementary strain S06004ΔsifA(pBR322-sifA)was successfully constructed.Then the biological characteristics showed that the growth property and biochemical properties of S06004ΔsifA were consistent with those of its parent strain S06004 and complementary strain S06004ΔsifA(pBR322-sifA).The mutant S06004ΔsifAhad good genetic stability.The chicken lethal test showed that the LD50 of the S06004ΔsifA was 39.3times higher than that of the parent strain S06004,and the virulence was also restored by complementary strain.In conclusion,this study provided basic data for further study of the functions of the sifAgene.