中文摘要：

[目的]为研究与Lpf菌毛合成相关的lpfC基因对肠炎沙门菌致病性的影响。[方法]利用自杀质粒介导的同源重组技术构建肠炎沙门菌C50041株的lpfC基因缺失株C50041ΔlpfC,并进行PCR和测序鉴定。同时,将lpfC基因克隆至质粒pBR322并电转入缺失株中,构建回复株C50041ΔlpfCR。比较野生株C50041、缺失株C50041ΔlpfC及回复株C50041ΔlpfCR的基本生物学特性。[结果]成功构建了缺失株C50041ΔlpfC及回复株C50041ΔlpfCR,且lpfC基因的缺失不影响C50041的生长特性和生化特性。该缺失株具有良好的遗传稳定性,但缺失株对BALB/c小鼠的LD50是野生株的2倍。[结论]lpfC基因的缺失使肠炎沙门菌对BALB/c小鼠的毒力降低,为进一步研究肠炎沙门菌Lpf菌毛的功能奠定了基础。

英文摘要：

[Objective]To study the role of lpfC gene which encodes a putative outer membrane usher for Lpf fimbrial assembly of Salmonella enteritidis in pathogenesis.[Methods]We constructed a lpfC mutant of Salmonella Enteritidis strain C50041 via suicide plasmid p GMB151,and its complementary strain C50041 ΔlpfCR in this study.Then the biological characteristics and virulence were determined.[Results]Among the three strains,there are no obviously differences in growth property and biochemical properties,while pass-generation test showed that hereditary property ofC50041 ΔlpfC was stable.However,the mouse lethal test showed that the LD50 of the C50041 ΔlpfC was 2 times than that of the parent strain C50041.[Conclusion]This study provided basic data for further study of the functions of the lpfC gene,and make a significant contribution to study the Lpf fimbriae function of Salmonella enteritidis.