Severe Enteric Disease: Pathogenesis and Response

描述(申请人提供)：传染性肠道疾病是世界各地的主要健康问题。这项申请旨在建立马里兰大学肠道研究调查网络(ERIN)合作研究中心(CRC)，以调查肠道疾病的重要临床、发病机制和宿主反应问题。这次结直肠癌的重点是志贺氏菌。和致泻性大肠杆菌(DEC)，这是全球肠道多中心研究(GEMS)中从腹泻病死亡病例中分离出的最常见的细菌病原体。GEM正在非洲和南亚的7个地点进行，是迄今为止对5岁以下儿童腹泻疾病进行的最大规模的研究。临床标本和来自GEMS的细菌分离以及这项研究产生的假说将通过各种方法进一步检验，包括细菌致病分析、肠道生理学研究、粪便适应性免疫和免疫标记、细菌基因组学、微生物群和人类SNP分析。提出了三个多组成部分、高集成度的项目。项目1将侧重于DEC和志贺氏菌感染的发病机制。将确定从致死性腹泻病例、非致命性感染和对照中分离的肠致病性大肠杆菌(EPEC)菌株的基因组序列。基因组分析中潜在的EPEC毒力因子将使用各种分析方法和模型进一步表征，以研究发病机制。一种最初在志贺氏菌中发现但也存在于DEC中的肠毒素将被进一步鉴定。在项目2中，将研究宿主反应的不同方面，包括感染野生型和突变志贺氏菌和DEC菌株的肠道组织的生理学研究，以及GEMS患者粪便标本中免疫球蛋白和细胞因子水平的表征。项目3将使用GEMS的临床标本来调查临床方面，以确定患者先前与腹泻疾病易感性相关的基因中的SNPs，使用微生物组和实验室联合感染研究细菌之间的相互作用，以及从致命性和非致命性疾病分离的志贺氏菌菌株的泛基因组研究。

DESCRIPTION (provided by applicant): Infectious enteric diseases are major health problem throughout the world. This application seeks to establish the University of Maryland Enterics Research Investigational Network (ERIN) Cooperative Research Center (CRC) to investigate important clinical, pathogenesis, and host response Issues of enteric disease. The particular enteric pathogens that will be the focus of this CRC are Shigella spp. and diarrheagenic E. coli (DEC), which were implicated as the bacterial pathogens most frequently isolated from fatal cases of diarrheal disease in the Global Enteric Multicenter Study (GEMS). The GEMS is being conducted at 7 sites in Africa and South Asia and is the largest study ever conducted of diarrheal disease in children under the age of 5. Clinical specimens and bacterial isolates from GEMS as well as hypotheses arising from this study will be further examined using a variety of approaches including bacterial pathogenesis assays, intestinal physiology studies, fecal adaptive immunity and immunological markers, bacterial genomics, microbiomes, and human SNP analysis. Three multi-component and highly integrated projects are proposed. Project 1 will focus on the pathogenesis of DEC and Shigella infections. Genome sequences of enteropathogenic E. coli (EPEC) strains isolated from lethal cases of diarrhea, from non-lethal infections and from controls will be determined. Potential EPEC virulence factors implicated in the genomic analysis will be further characterized using a variety of assays and models to study pathogenesis. An enterotoxin originally discovered in Shigella but also present in DEC will be further characterized. In Project 2, different aspects of host response will be studied, including physiology studies of intestinal tissue infected with wild type and mutant Shigella and DEC strains, as well as the characterization of fecal immunoglobulin and cytokine levels in stool specimens from GEMS patients. Project 3 will investigate clinical aspects using clinical specimens from GEMS to determine patient SNPs in genes previously associated with susceptibility to diarrheal disease, bacterial interactions using microbiome and laboratory co-infection studies, and studies on the pangenomics of Shigella strains isolated from lethal and non-lethal disease.