Molecular analysis of Salmonella typhi host specificity

伤寒沙门氏菌宿主特异性的分子分析

• 批准号: 251114-2006
• 负责人: Daigle, France
• 金额: $ 2.98万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2006
• 资助国家: 加拿大
• 起止时间: 2006-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=337420
• 关键词: Molecular; analysis; Salmonella; typhi; host

Salmonella enterica causes of a large variety of diseases in humans and animals. Understanding pathogenic mechanisms of S. enterica serovar Typhi, the etiologic agent of typhoid fever, is limited by lack of virulence in laboratory animals. Typhi is a host-adapted serovar that is specific for humans. Our long-term objective is to better understand the molecular mechanisms by which Salmonella causes infection and disease in humans. We will focus our research on understanding Typhi host specificity with extensive use of human and murine cell culture models to elucidate differences in bacterial gene expression and survival within cells from these two different host species. Specifically, we will conduct studies to establish a genetic basis for the host specificity of Typhi by : (1) characterizing Typhi specific genes expressed in macrophages that are absent from the serovar Typhimurium genome and (2) identification of Typhi genes that are specifically expressed in only one type of host cells. In these studies, we will employ newly developed molecular genetic tools, such as selective capture of transcribed sequences (SCOTS) a technique currently in use by our research group, that identifies bacterial genes expressed in vivo. We will also use an original approach using GFP (green fluorescent protein) gene fusions and cytofluorometry (FACS). This project will involve the generation of mutant strains using defined deletion mutations with suicide vectors and the use of a broad range of methods of microbial genetics, molecular biology, biochemistry, immunology, cell biology, and microscopy. It is anticipated that the research proposed in this application will contribute to our understanding of the means by which Typhi colonizes, invades and overcomes host defenses and causes enteric fever. This information should lead to strategies, including the development of vaccines to reduce likelihood of Salmonella colonization and infection.

肠道沙门氏菌引起人类和动物的多种疾病。了解S.伤寒的病原体肠型血清型伤寒由于在实验室动物中缺乏毒力而受到限制。伤寒是一种适应宿主的血清型，对人类特异。我们的长期目标是更好地了解沙门氏菌引起人类感染和疾病的分子机制。我们将集中我们的研究，了解伤寒宿主特异性与广泛使用的人类和小鼠细胞培养模型，以阐明细菌基因表达和细胞内的生存从这两个不同的宿主物种的差异。具体而言，我们将进行研究，以建立伤寒宿主特异性的遗传基础：（1）表征在巨噬细胞中表达的伤寒特异性基因，这些基因不存在于鼠伤寒血清型基因组中;（2）鉴定仅在一种类型的宿主细胞中特异性表达的伤寒基因。在这些研究中，我们将采用新开发的分子遗传学工具，如转录序列的选择性捕获（SCOTS），这是我们研究小组目前使用的一种技术，可以识别体内表达的细菌基因。我们还将使用一种使用GFP（绿色荧光蛋白）基因融合和细胞荧光测定法（FACS）的原始方法。该项目将涉及使用定义的缺失突变与自杀载体和微生物遗传学，分子生物学，生物化学，免疫学，细胞生物学和显微镜广泛的方法的使用的突变株的生成。预计本申请中提出的研究将有助于我们了解伤寒菌定植、侵入和克服宿主防御并引起肠热病的方式。这些信息应导致战略，包括疫苗的开发，以减少沙门氏菌定植和感染的可能性。