BLR&D Research Career Scientist Award Application

项目摘要/摘要 我们研究的首要目标是了解疾病的分子基础。 由肠道细菌病原体引起，并利用这一知识开发 将使退伍军人受益的治疗剂。我们的一个主要焦点是 实验室是研究艰难梭菌的细菌病原体，它能引起 与医疗保健相关的感染，并已被世界卫生组织指定为“紧急威胁” 疾病控制和预防中心。艰难梭菌感染的危险因素 感染包括年龄超过65岁、抗生素治疗和酸抑制剂的使用； 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，艰难梭菌在图森的感染率 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 窝藏与流行有关的病原体的“超强毒力”菌株。我们有 详细描述艰难VA菌株，发现新的毒力策略 受雇于这些生物，使用尖端基因组分析跟踪它们的进化 并传播，并向医生提供反馈，以努力减少 感染。 我们还在探索分子机制方面取得了一些创新性进展。 艰难梭菌通过这种方式致病。对于这些努力，我们广泛使用了MASS 全球分析各种菌株以辨别其独特之处的光谱技术 潜在的毒力。此外，我们采用了并大大改进了最近的 对艰难梭菌进行基因操作以了解其毒力的方法； 这使得我们能够敲除或限制各种基因的表达。超越了 我们发现艰难梭菌毒素与疾病有关的开创性工作 非毒素因子的关键作用包括鞭毛、荚膜多糖和 毒力中的超氧化物还原酶。我们还使用了质谱学来了解 宿主细胞的相应变化。 最后，基于我们对艰难梭菌如何附着在宿主肠道的理解， 我们最近设计并设计了一种新型的、安全的“合成生物”制剂来表达C. 粘附性难治菌。在动物感染模型中，该试剂能够完全阻断 艰难梭菌感染和疾病。这个产品，它的第一代完全是 由我们目前的VA Merit奖支持，现在受临时专利保护，并且 目前正在紧锣密鼓地进一步完善。预计该代理将成为 预防艰难梭菌感染的有效、安全、“首创”的非抗生素选择 退伍军人，以及所有易受影响的个人。

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.