Insertion of E.coli type III secretion system proteins into host cell plasma membrane

肠出血性（EHEC）和肠致病性（EPEC）大肠杆菌是革兰氏阴性病原体，其引起广泛的水传播和食源性传染病。 这些病原体通常与严重的疟疾发作有关，很少与更多的死亡有关，如2000年在安大略省沃克顿暴发中观察到的病例。 EHEC和EPEC已经进化出称为III型分泌系统（TTSS）的专门分子机器，更常被称为分子针。 TTSS是一种高效的分子结构，旨在将来自细菌的蛋白质直接注入形成小肠衬里的上皮靶细胞的细胞质区室。 TTSS由两组蛋白质组成，称为：i）转运子，其功能是在膜上打孔并将细菌附着到宿主细胞上，以及ii）效应子，其在注射到宿主细胞中时触发显著的结构变化，使肠道渗漏并促进细菌入侵。 这项工作的目的是了解如何EHEC和EPEC细菌穿透宿主细胞膜，并成为锚定。 这些研究的长期目标是在分子水平上了解这一过程，目的是利用这些知识制定治疗或消除这些食物和水骨细菌引起的感染的策略。

Enterohemorrhagic (EHEC) and enteropathogenic (EPEC) Escherichia coli are Gram negative pathogens that are responsible for a wide spectrum of water borne and food borne infectious diseases. These pathogens are typically associated with severe diarrheal episodes and more rarely in more death, as in the cases observed in the Walkerton, ON outbreak in 2000. EHEC and EPEC have evolved specialized molecular machines called the type III secretions system (TTSS), more commonly known as the molecular needle. The TTSS is a highly efficient molecular structure designed to inject proteins from bacteria directly into the cytoplasmic compartment of epithelial target cells that form the lining of the small intestine. TTSS consists of two groups of proteins called; i) translocators that function to punch a hole in membrane and attaching bacteria to the host cell and ii) effectors which when inject into the host cell trigger marked structural changes that make the intestine leaky and facilitate invasion by bacteria. The objective of this work is to understand how EHEC and EPEC bacteria penetrate the host cell membrane and become anchored. The long term goal of these studies is to understand this process at the molecular level with the aim of using this knowledge to develop strategies for treatment or elimination of infections caused by these food and water bone bacteria.