Citrobacter rodentium is a mouse-specific pathogen commonly used to model infection by human Enteropathogenic Escherichia coli, an important cause of infant diarrhea and mortality worldwide. In the early phase of infection, C. rodentium overcomes competition by the gut microbiota for successful replication. Then, the pathogen uses a type three secretion system (T3SS) to inject effector proteins into intestinal epithelial cells and induce metabolic and inflammatory conditions that promote colonization of the intestinal epithelium. C. rodentium also elicits highly coordinated innate and adaptive immune responses in the gut that regulate pathogen colonization and eradication. In this review, we highlight recent work on the regulation and function of the C. rodentium T3SS, the mechanisms employed by the pathogen to evade competition by the microbiota, and the function of the host immune response against infection.

柠檬酸杆菌是一种小鼠特异性病原体，通常用于模拟人类肠道致病性大肠杆菌的感染，这是全球婴儿腹泻和死亡率的重要原因。在感染的早期阶段，C. rodentium克服了肠道微生物群的竞争以成功复制。然后，病原体使用一种 3 型分泌系统 (T3SS) 将效应蛋白注入肠上皮细胞并诱导代谢和炎症条件，从而促进肠上皮的定植。C. 啮齿目还在肠道中引发高度协调的先天性和适应性免疫反应，调节病原体定植和根除。在这篇综述中，我们重点介绍了啮齿类杆菌T3SS 的调控和功能、病原体逃避微生物群竞争的机制以及宿主免疫反应对感染的功能的近期工作。