Genetics of Salmonella Resistance to the Inflammatory Response in the Gut

沙门氏菌对肠道炎症反应的耐药性遗传学

• 批准号: 7911674
• 负责人: HELENE L ANDREWS-POLYMENIS
• 金额: $ 19.39万
• 依托单位: TEXAS A&M UNIVERSITY HEALTH SCIENCE CTR
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-11 至 2012-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7911674
• 关键词: Animal Model; Animals; Antimicrobial Resistance; Bacteria; Bacterial Genes; Candidate Disease Gene; Cattle; Cause of Death; Cells; Cistrons; Clinical; Collection; Complement; Defect; Defensins; Development; Diarrhea; Disadvantaged; Disease; Enteral; Environment; Epithelial; Epithelial Cells; Event; Exhibits; Face; Flushing; Foundations; Future; Gastroenteritis; Gastrointestinal tract structure; Gene Deletion; Genes; Genetic; Genetic Screening; Goals; Hour; Human; Immune response; Immunocompromised Host; In Vitro; Individual; Infection; Infiltration; Inflammation; Inflammatory; Inflammatory Response; Inflammatory disease of the intestine; Intestines; Leukocyte L1 Antigen Complex; Libraries; Livestock; Methods; Modeling; Molecular; Mucous Membrane; Organism; Parasites; Pathology; Persons; Process; Production; Proteins; Public Health; Relative (related person); Resistance; Salmonella; Salmonella enterica; Salmonella infections; Screening procedure; Serotyping; Staging; Study models; Symptoms; System; Texas; Therapeutic Intervention; United States; Universities; Virus; Work; antimicrobial; base; deletion library; experience; foodborne; foodborne illness; human disease; intestinal epithelium; killings; lambda Spi-1; mutant; neutrophil; new technology; novel; pathogen; public health relevance; response; transmission process

DESCRIPTION (provided by applicant): Non-typhoidal Salmonella, including serotype Typhimurium (STm) are food-borne bacterial pathogens that cause ~1.4 million cases of diarrheal disease annually in the United States and hundreds of millions of cases worldwide. In the intestine, STm induces a strong neutrophilic inflammatory response and the production of antimicobial compounds by intestinal epithelial cells. In the face of this inflammatory response the numbers of STm in the intestine increase sharply, while the intestinal microflora of the host are dramatically reduced. The objective of this proposal is to identify the bacterial factors that allow STm to resist being killed by antimicrobials produced by the intestinal epithelium. The calf is the natural model of diarrheal STm infection that is most similar to human disease in clinical signs, host responses, and intestinal pathology. We have developed a forward genetic system to make screening for mutants feasible in ligated ileal loops in calves, a model developed at Texas A&M. We have generated a collection of over 1000 targeted deletion strains in STm, including mutants in all "Salmonella-specific" genes and we have developed microarray-based methods to screen this entire collection of mutants as a single pool. We have already confirmed the use of this system for forward genetic screening in animal infection. In AIM-1 we will screen the mutant pool in calf ligated ileal loops to identify mutants sensitive to intestinal epithelial cell-derived antimicrobials. In AIM-2 we will verify and complement these mutants in competitive infections in ligated ileal loops in calves. In AIM-3 we will determine which of these genes are important for resistance to the purified antimicrobials calprotectin and enteric 2-defensin, antimicrobials known to be produced by the intestinal epithelium during inflammation. This project is a first step toward a comprehensive determination of the molecular mechanism of the bacterial genes involved in the response to inflammation in the gut. PUBLIC HEALTH RELEVANCE: Salmonella is a leading cause of food borne illness, causing ~1.4 million cases of diarrheal disease per year and is the single most common cause of death from food-borne illnesses associated with viruses, parasites or bacteria in the US primarily in immunocompromised persons. The genes and mechanisms used by non-typhoidal Salmonellae to survive in the face of a host inflammatory response in the intestine are not well understood. These mechanisms allow Salmonellae to establish a niche in the intestine during infection, and they are shed from this niche in fecal material from infected persons and livestock continuing the cycle of transmission. Development of a better understanding of the genes and mechanisms involved in this important stage of infection is critical to breaking the cycle of transmission of this organism. This work will have a direct impact on public health.

描述(申请人提供)：非伤寒沙门氏菌，包括血清型鼠伤寒沙门氏菌(STM)是食源性细菌性病原体，每年在美国导致约140万例腹泻疾病，在全世界造成数亿例。在肠道中，STM诱导强烈的中性粒细胞炎症反应，并由肠上皮细胞产生抗真菌化合物。面对这种炎症反应，肠道中的STM数量急剧增加，而宿主的肠道微生物区系却急剧减少。这项建议的目的是确定使STM抵抗由肠道上皮产生的抗菌剂杀死的细菌因素。 小牛是腹泻STM感染的自然模型，在临床症状、宿主反应和肠道病理上与人类疾病最相似。我们已经开发了一种正向遗传系统，使在小牛结扎的回肠环中筛选突变是可行的，这是德克萨斯A&M开发的一个模型。我们已经在STM中产生了1000多个靶向缺失菌株的集合，包括所有“沙门氏菌特异性”基因的突变，我们已经开发了基于微阵列的方法来将整个突变集合作为一个池进行筛选。我们已经确认使用该系统进行动物感染的正向遗传筛查。 在AIM-1中，我们将在小牛结扎的回肠环中筛选突变体库，以鉴定对肠上皮细胞衍生抗菌剂敏感的突变体库。 在AIM-2中，我们将验证和补充这些突变体在小牛回肠结扎环竞争感染中的作用。 在AIM-3中，我们将确定这些基因中的哪些对于抵抗纯化的抗菌素钙保护素和肠道2-防御素是重要的，这些抗菌素是已知在炎症过程中由肠道上皮产生的。 该项目是全面确定参与肠道炎症反应的细菌基因分子机制的第一步。公共卫生相关性：沙门氏菌是食源性疾病的主要原因，每年导致约140万例腹泻疾病，是美国与病毒、寄生虫或细菌相关的食源性疾病最常见的死亡原因，主要发生在免疫功能低下的人中。非伤寒沙门氏菌在肠道中面对宿主炎症反应时生存所使用的基因和机制尚不清楚。这些机制使沙门氏菌在感染期间在肠道中建立了一个生态位，并从这个生态位中从感染者和牲畜的粪便物质中排出，继续传播循环。更好地了解感染这一重要阶段所涉及的基因和机制，对于打破这种有机体的传播循环至关重要。这项工作将对公众健康产生直接影响。

项目成果

Contribution of the type VI secretion system encoded in SPI-19 to chicken colonization by Salmonella enterica serotypes Gallinarum and Enteritidis.

• DOI: 10.1371/journal.pone.0011724
• 发表时间: 2010-07-22
• 期刊: PloS one
• 影响因子: 3.7
• 作者: Blondel CJ;Yang HJ;Castro B;Chiang S;Toro CS;Zaldívar M;Contreras I;Andrews-Polymenis HL;Santiviago CA
• 通讯作者: Santiviago CA

Only one of the two type VI secretion systems encoded in the Salmonella enterica serotype Dublin genome is involved in colonization of the avian and murine hosts.

• DOI: 10.1186/1297-9716-45-2
• 发表时间: 2014-01-09
• 期刊: Veterinary research
• 影响因子: 4.4
• 作者: Pezoa D;Blondel CJ;Silva CA;Yang HJ;Andrews-Polymenis H;Santiviago CA;Contreras I
• 通讯作者: Contreras I