肠炎沙门菌rfbG基因缺失株的构建及其生物学特性研究

目的 探究rfbG基因对肠炎沙门菌毒力的影响,评价肠炎沙门菌缺失rfbG基因后作为减毒活疫苗的潜力。方法 利用自杀质粒介导的同源重组技术,无痕构建肠炎沙门菌Z11ΔrfbG缺失株,并对其生物学特性进行分析。结果 成功构建肠炎沙门菌Z11ΔrfbG缺失株,与野生株相比,缺失株Z11ΔrfbG生化特性没有发生变化,在LB液体培养基中生长速率较慢;缺失株生物被膜形成能力显著弱于野生株,其感染J774A.1细胞后,产生的细胞毒性亦显著低于野生株。此外,缺失株可与吖啶橙溶液发生凝集,但与O₉血清不发生凝集。结论 rfbG基因缺失显著降低了肠炎沙门菌Z11的毒力,且缺失株符合粗糙型菌株的特点,Z11ΔrfbG不仅具有作为沙门菌减毒活疫苗或载体的潜质,也具有作为DIVA疫苗的潜力,为肠炎沙门菌减毒活疫苗的开发研究奠定了基础。

Construction and biological characteristics of Salmonella enteritidis with rfbG gene deletion

The aim was to explore the effect of rfbG on the virulence of Salmonella Enteritidis and evaluate its potential as a live attenuated vaccine. Salmonella Enteritidis Z11ΔrfbG was constructed using a homologous recombination technique mediated by the suicide plasmid, and its biological characteristics were analyzed. Z11ΔrfbG was successfully constructed, and there was no difference in biochemical characteristics between Z11ΔrfbG and the wild strain. The growth rate of Z11ΔrfbG was slower in LB liquid medium. The ability of the deletion strain to form biofilm was significantly weaker than that of the wild strain. The cytotoxicity of the deletion strain after infection of J774A.1 cells was significantly lower than that of the wild strain. In addition, the deletion strain could agglutinate with acridine orange solution but not with O9 serum. The rfbG deletion significantly reduced the virulence of Salmonella enteritidis Z11, and the deletion strain had the characteristics of rough strains. Z11ΔrfbG not only has potential as a live attenuated vaccine or carrier of Salmonella, but also as a DIVA vaccine, which lays the foundation for research on live attenuated vaccines for Salmonella enteritidis.