BLR&D Research Career Scientist Award Application

项目总结/摘要 我们研究的首要目标是了解疾病的分子基础 引起的肠道细菌病原体，并利用这一知识， 治疗药物，将有利于退伍军人群体。我们的一个主要重点是 实验室是细菌病原体的研究，艰难梭菌，这导致 卫生保健相关感染，并已被指定为“紧急威胁”， 疾病控制和预防中心。对获得C.艰难 感染包括年龄超过65岁、抗生素治疗和使用抑酸剂;这 风险因素的组合使退伍军人特别容易受到感染。 我们正在进行的流行病学研究表明，C。图森的艰难感染率 弗吉尼亚州（和其他亚利桑那州）的医院高于全国平均水平，许多患者 携带病原体的“高毒力”细菌相关菌株。我们有 特征性VA C.艰难菌株的详细资料，发现了新的毒力策略 这些生物所使用的，使用尖端的基因组分析来跟踪它们的进化 传播，并向医生提供反馈，以减少 感染. 我们在探索分子机制方面也取得了一些创新性进展 其中C. difficile引起疾病。为了这些努力，我们广泛使用了质量 光谱分析技术，以全球分析各种菌株，以辨别其独特的 毒力潜力此外，我们还采用并大大改进了最近的 方法学基因操作C.艰难梭菌，以了解其毒力; 这使我们能够敲除或限制各种基因的表达。超出 开创性的工作揭示了C.艰难梭菌毒素有助于疾病，我们已经发现 非毒素因子包括鞭毛、荚膜多糖和 超氧化物还原酶毒性。我们还用质谱分析法来了解 宿主细胞的相应变化。 最后，在我们对C.艰难梭菌附着在宿主肠道上， 我们最近设计并制造了一种新的，安全的“合成生物”制剂来表达C。 艰难粘附素在感染的动物模型中，该试剂能够完全阻断 C.艰难的感染和疾病。该产品的第一代完全 由我们目前的VA优异奖支持，现在受到临时专利的保护， 目前正在加紧进一步完善。预计代理人将是一名 有效、安全、“同类第一”的非抗生素选择，以预防C.艰难梭菌感染 退伍军人，以及所有易受影响的人。

Project Summary/Abstract The overarching goal of our research is to understand the molecular basis of disease caused by enteric bacterial pathogens, and to leverage this knowledge to develop therapeutic agents that will benefit the Veteran population. A major focus of our laboratory is the study of the bacterial pathogen, Clostridium difficile, which causes healthcare-associated infections, and has been designated an “Urgent Threat” by the Centers for Disease Control and Prevention. The risk factors for acquiring C. difficile infection include age over 65 years, antibiotic treatment, and use of acid-suppressors; this combination of risk factors makes Veterans especially vulnerable to infection. Our ongoing epidemiological studies show that C. difficile infection rates in the Tucson VA (and other Arizona) hospitals are above the national average, and that many patients harbor `hyper-virulent' epidemic-associated strains of the pathogen. We have characterized VA C. difficile strains in detail, uncovered novel virulence strategies employed by these organisms, used cutting-edge genome analyses to track their evolution and spread, and provided feedback to physicians in an effort to reduce incidence of infections. We have also made several innovative advances in exploring the molecular mechanisms by which C. difficile causes disease. For these efforts, we have extensively used mass spectrometry techniques to globally analyze various strains to discern their unique virulence potential. Further, we have adopted, and greatly improved, recent methodologies to genetically manipulate C. difficile in order to understand its virulence; this has allowed us to knock out, or limit the expression of, various genes. Beyond the pioneering work revealing that C. difficile toxins contribute to disease, we have uncovered key roles for non-toxin factors including flagella, capsular polysaccharides and superoxide reductase in virulence. We have also used mass spectrometry to understand corresponding changes in host cells. Finally, building on our understanding of how C. difficile attaches to the host intestine, we recently designed and engineered a novel, safe “synthetic biologic” agent to express C. difficile adhesins. In an animal model of infection, the agent was able to completely block C. difficile infection and disease. This product, the first generation of which is fully supported by our current VA Merit award, is now protected by a provisional patent, and is currently under intensive further refinement. It is anticipated that the agent will be an effective, safe, “first-in-kind” non-antibiotic option to prevent C. difficile infection in Veterans, as well as all susceptible individuals.