肺炎链球菌是社区获得性肺炎的主要病原菌，也是导致儿童和老年人死亡的主要诱因。万古霉素耐受菌株的出现，严重影响相关感染性疾病的治疗，但其抗生素耐受的分子机制尚不明确。肺炎链球菌双组分系统TCS11与其万古霉素耐受相关，通过生物信息学分析发现TCS11基因簇在各种血清型菌株中普遍存在，而反转录PCR提示该基因簇相邻基因共同转录形成一个操纵子单元。为深入解析TCS11具体作用机制，本项目拟对肺炎链球菌TIGR4中TCS11各基因进行敲除及过表达，通过分析野生型、敲除和过表达菌株生长特性及其转录组的改变，发掘下游靶基因；采用EMSA实验分析RR蛋白与其靶基因的相互作用，结合5'RACE和启动子活性分析，确定其关键结合元件；构建肺炎链球菌肺炎小鼠模型，体内验证其在万古霉素耐受中的作用。本项目的实施将明确肺炎链球菌TCS11在万古霉素耐受中的作用和调控机制，为肺炎链球菌相关疾病的治疗提供理论基础。

Streptococcus pneumoniae is one of the main causes for community-acquired pneumonia and a main reason for the death of the children and the elderly. Emergence of vancomycin tolerance strains seriously affects the treatment of related infectious diseases. However, the molecular mechanism of antibiotic tolerance remains to be elucidated. The two-component system TCS11 was related with pneumococcal vancomycin tolerance, and we found that TCS11 gene cluster was ubiquitous in different serotype strains. The genes of TCS11 cluster were co-transcription in the same operon. To elucidate the mechanism of TCS11 regulation, we will construct gene knockout and overexpression strains of pneumococcal two-component system genes, and explore the specific genes regulated by TCS11 through analyzing the growth characteristics and transcriptome sequencing of the strains. To determine its key binding elements, EMSA will be used to analyze the interaction of TCS11 RR with the promoters of its target genes, 5'RACE and the promoter activity analysis will be utilized. Mouse model of pneumococcal pneumoniae will be constructed to verify the role of TCS11 in vancomycin tolerance in vivo. This study would clarify the function and transcriptional regulation mechanism of pneumococcal TCS11 in its vancomycin tolerance, and could be the theoretical basis for the treatment of pneumococcal related diseases.