中文摘要：

为了探讨ompR、spiA、rpoS、ompR-spiA、ompR-rpoS基因缺失株成为肠炎沙门茵减毒候选活疫苗的可能性，构建了3株rpoS、ornpR-spiA、ornpR-rpoS基因缺失株，通过口服方式把5株ompR、spiA、rpoS、ompR-spiA、ompR-rpoS基因缺失株接种BALB／c小鼠进行毒力测定和免疫保护性测定。结晶紫染色定量法显示，这5株基因缺失株生物被膜的形成能力显著降低；毒力测定显示，它们的半数致死量比野生株的高10000倍，双基因缺失株的毒力更弱。血清抗体水平测定表明，各基因缺失株可诱导机体产生较高的IgG抗体，并于注射后第3周达到高峰；攻毒后ompR、spiA、rpoS、ompR-spiA和ompR—rpoS基因缺失株的免疫保护率分别为62．5％、50．OoA、50．0％、50．0％和37．5％。结果表明，ompR基因缺失株可作为肠炎沙门茵减毒活疫苗的候选株。

英文摘要：

To develop a live attenuated vaccine against Salmonella enteritidis ,we constructed single or double deletion mutants with deletions of rpoS, ompR-rpoS or ompR-spiA genes of S. enteritidis, and their virulence and immunogenicity were evaluated. Compared with the wild-type strain, all five mutants re- vealed deficiency in biofilm formation determined by crystal violet staining,and an increased LDso （10 000- fold） in a mouse model, of which the double mutants were more attenuated than the single mutants. Fur- thermore,when mice were orally immunized with these mutants,the mutants induced the higher IgG anti- bodies,which reached the peak 3 weeks post-immunization. When the immunized mice were infected with the wild-type strain, 4 weeks post-immunization, the protection rates induced by the ompR, spiA, rpoS,om- pR-rpoS or ompR-spiA mutants were 62. 5%, 50. 0%, 50. 0%, 37. 5% and 50. 0%, respectively. These results showed that the ompR mutant may be a potential live vaccine candidate against S. enteritidis.