2型猪链球菌菌毛蛋白编码基因SSU0474生物学特性分析  

Construction and characterization of pilus backbone gene SSU0474 knock-out mutant of Streptococcus suis serotype 2

作　　者：廖辉[1,2] 陈红娜[1] 王长军[1] 潘秀珍[1] 唐家琪[1] 

机构地区：[1]南京军区军事医学研究所,江苏南京210002 [2]解放军第四五四医院血液肿瘤科

出　　处：《中国公共卫生》2013年第4期524-527,共4页Chinese Journal of Public Health

基　　金：国家自然科学基金(30730081;30972638;81071317;31170124;81171527;81172794);江苏省自然科学基金(BK2009042;BK2010025;BK2010114;BK2010113);南京军区医学科技创新课题(09Z040)

摘　　要：目的构建2型猪链球菌中国强毒株05ZYH33菌毛蛋白编码基因SSU0474缺失突变株,并对其生物学特性进行分析。方法利用同源重组原理构建SSU0474缺失突变株,PCR及RT-PCR对筛选的突变株进行验证,革兰染色和电镜比较突变株SSU0474与野毒株之间的差异,小鼠实验进一步比较突变株的毒力变化。结果引物特异性PCR证实SSU0474基因缺失突变株构建成功;革兰染色结果显示突变株和野毒株染色特性差异无统计学意义,SSU0474基因的缺失未明显影响细菌的生长速率;电镜结果表明突变株SSU0474细胞壁明显变薄,细菌菌毛样附属结构缺失;小鼠毒力实验结果提示突变株SSU0474的毒力明显下降。结论本研究成功获得菌毛蛋白编码基因SSU0474缺失突变株,并对该基因的生物学特性进行了初步探讨,为系统研究2型猪链球菌中国强毒株05ZYH33菌毛的生物学功能提供依据。Objective To construct pilus backbone gene SSU0474 knock-out mutant of a strong virulent strain of Strepococcus suis serotype 2 （S.suis 2） （05ZYH33） isolated in China and to analyze its biological characteristics. Methods The pilus backbone gene SSU0474 knock-out mutant strain was constructed with homologic recombination method and the mutant strains were identified with PCR and reverse transciption PCR. Gram＇ s stain and electroic microscope observation were used to examine the difference bwtween SSU 0474 mutant srain and wild strain. The virulent change of the mutant strain was tested with experiment in mice. Results Results of biological characteristics showed that there were no differences in dyeing properties and growth kinetics between the mutant SSU0474 strain and the wild type strain 05ZYH33. The abolishment of the SSU0474 expression had influence on cell wall upon cultivation in standard laboratory in vitro assay. Furthermore, mutants were impaired in virulence when evaluated in a murine model of S. suis 2. Conclusion These results suggest that SSU0474 plays an important role in the S. suis 2 05ZYH33, which laid the foundation for the study of the mechanisms of pilus assembly and biological function in the S. suis 2.

关 键 词：2型猪链球菌 菌毛蛋白 SSU0474基因敲除 生物学特性 

分 类 号：R378[医药卫生—病原生物学]