鸡白痢沙门菌S06004株致病岛-2缺失株的构建及其生物学特性

Construction and characterization of Salmonella Pathogenicity Island 2 (SPI-2) deletion mutant of Salmonella Pullorum S06004

摘要:

摘要:【目的】了解致病岛-2(Salmonella Pathogenicity Island 2，SPI-2)对鸡白痢沙门菌致病性的影响，初步探讨研制安全有效的鸡白痢沙门菌减毒株的可行性。【方法】采用λ-red 同源重组系统构建鸡白痢沙门菌S06004株的SPI-2(约40 kb)缺失株S06004ΔSPI2。并与野生型相比较，对该缺失株的生长特性、生化特性、遗传稳定性和致病性等基本生物学特性进行鉴定。【结果】成功构建SPI-2缺失株S06004ΔSPI2，SPI-2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，其对2日龄雏鸡的LD50是野生株的252 倍。【结论】SPI-2的缺失引起鸡白痢沙门菌毒力的明显下降，这为进一步研究鸡白痢沙门菌SPI-2的功能及制备减毒疫苗奠定了基础。

Abstract:

Abstract:［Objective］To research the pathogenicity of Salmonella Pathogenicity Island 2 (SPI-2) deletion mutant of Salmonella Pullorum and preliminary explore the feasibility of developing safe attenuated Salmonella Pullorum candidate vaccine strain.［Methods］TheSPI-2 (－40 kb) deletion mutant of Salmonella Pullorum S06004 was constructed using the λ-red recombinant system． Then the biological characteristics such as growth rate，biochemical properties，genetic stability and virulence were evaluated between the deletion mutant strain S06004ΔSPI2 and its parent strain S06004．［Results］S06004ΔSPI2 was successfully constructed． The growth rate and biochemical properties of S06004ΔSPI2 were consistent with those of its parent strain S06004．The mutant was stable with the deletion of SPI-2．Chicken lethal test showed that the LD50 of S06004ΔSPI2 was 252 times higher than the parent strain S06004．［Conclusion］The virulence of S06004ΔSPI2 was obviously attenuated．This study provided basic data for further study of the functions of SPI-2，and implied its potential to develop attenuated Salmonella vaccine.