随着细菌对抗生素的耐药性日益严重，新型的抗细菌感染治疗策略已经成为全球研究热点。研究证明了III型分泌系统（T3SS）及其分泌的效应蛋白在革兰氏阴性细菌致病过程中具有关键作用，并成为抗毒力治疗策略的作用靶标。沙门氏菌是一类常见的革兰氏阴性细菌，为人兽共患病病原。本课题组前期研究发现肉桂醛在不影响沙门氏菌生长的浓度下，可以减少T3SS效应蛋白的含量，也能提高小鼠感染沙门氏菌的生存率。为此，本项目以鼠伤寒沙门氏菌为研究对象，采用LC-MS，Western-blot，RT-PCR等技术，从肉桂醛对沙门氏菌T3SS效应蛋白、效应蛋白编码基因及其调节因子的改变等方面开展研究，寻找肉桂醛的作用靶标，阐明其作用机制。通过建立细胞感染和动物感染保护模型评价肉桂醛体内活性，阐明肉桂醛治疗沙门氏菌感染的机制。为肉桂醛抗沙门氏菌感染的应用提供理论依据，同时为T3SS抑制剂的研发提供候选结构。

Growing resistance to antibiotics has spread very rapidly, directly affected the control of bacterial infections. Novel therapeutic strategy against bacterial infection has become a focus of global attention. Many studies showed that the type III secretion system (T3SS) and its effectors of Gram-negative bacteria play crucial roles in pathogenic progress. T3SS, an essential virulence element of Salmonella spp., is a source of antivirulence strategies target. Salmonella are the most popular zoonotic pathogen bacteria in global with serious harm to the development of husbandry and the human health. We found that cinnamaldehyde reduced the content of T3SS-mediated secretion proteins in the culture without affecting the growth of bacteria in Salmonella. Cinnamaldehyde also protected mice from Salmonella typhimurium-induced death. Salmonella typhimurium will used in this project. We will study the changes in T3SS-1 effectors amounts and its regulatory gens expression using LC-MS, Western-blot and RT-PCR. These results will illuminate the mechanisms and targets of of cinnamaldehyde inhibited Salmonella T3SS. Cell and animal infection models will use to investigate the protection and treatment effects of Salmonella infection by cinnamaldehyde. This research provides a theoretic basis for the treatment mechanism of cinnamaldehyde used in Salmonella infections, but also provides a new structure for development of T3SS inhibitor.