中文摘要：

目的研究组氨酸三聚体蛋白（histidinetriadprotein，Htp）在2型猪链球菌（Streptococcussuis2，S．suis2）05ZYH33中的定位，以及sortaseA（srtA）基因缺失对该蛋白表达的影响。方法通过生物软件分析Htp氨基酸序列的分子特征；以纯化的Htp重组蛋白为免疫原，免疫新西兰兔，获得兔抗Htp抗血清；利用westernblotting和ELISA检测该抗体的特异性和效价；以抗Htp抗体为工具通过流式细胞术验证Htp在菌体表面的定位，并比较05ZYH33和srtA基因敲除突变株AsrtA菌体表面Htp的表达量b结果生物软件预测发现Htp存在信号肽和跨膜序列，具备表面蛋白的特征；流式细胞分析发现Htp定位于S．suis2表面；AsrtA菌体表面Htp的量明显少于野生型菌株。结论本研究明确了Htp在S．suis2菌体表面的定位并发现srtA基因敲除后细菌表面的Htp有所减少，为进一步研究Htp在猪链球菌致病过程中发挥的功能及其调控机制奠定了基础。

英文摘要：

Objective To determine the localization of histidine triad protein （Htp） on Streptococcus suis 2 （ S. suis 2） and the effect of disruption of sortase A （srtA） gene on the expression level of Htp. Methods Antiserum against Htp was prepared by immunizing rabbit with recombinant Htp. Bioinformatics analysis was adopted to evaluate the amino acid sequence characteristic of Htp. Flow cytometry was applied to localize Htp on S. suis 2 bacteria. Results Bioinformatics analysis demonstrated that Htp had the characteristic of cell surface protein with signal sequence and transmembrane sequence. Flow cytometry showed the localization of Htp was on the surface of S. suis 2 and the expression level of Htp on cell surface decreased by deletion of srtA. Conclusions Htp is located on the cell surface of S. suis 2. The results provide a foundation for further investigation of the rote of Htp in the infection of S. suis 2.