Detection of Host Response In Clostridium Difficile Infection

艰难梭菌感染中宿主反应的检测

• 批准号: 8859073
• 负责人: Jian-Ping Jin
• 金额: $ 24.4万
• 依托单位: NORTHSHORE UNIVERSITY HEALTHSYSTEM
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8859073
• 关键词: Anaerobic Bacteria; Antibiotics; Antibodies; Archives; Biological Assay; Biological Markers; Campylobacter; Cessation of life; Clinical; Clinical Microbiology; Clostridium difficile; Colitis; Communicable Diseases; Communities; Community-Acquired Infections; Cytoskeleton; Data; Detection; Development; Diagnosis; Diagnostic; Diagnostic tests; Diarrhea; Disease; Enteral; Epithelial; Epithelial Cells; Escherichia coli; Etiology; Evaluation; Feces; Food; Generations; Goals; Gold; Health Care Costs; Health care facility; Healthcare; Hospital Costs; Hospitals; Immune response; Immunocompromised Host; Incidence; Individual; Infection; Inflammatory Bowel Diseases; Intestines; Laboratories; Large Intestine; Lead; Measures; Methodology; Methods; Morbidity - disease rate; Muscle; Organism; Parasites; Patient Care; Patients; Proteins; Protocols documentation; Pseudomembranous Colitis; Records; Recovery; Reproduction spores; Research; Research Project Grants; Salmonella; Sampling; Series; Shigella; Signs and Symptoms; Specificity; Specimen; Symptoms; Testing; Toxic Megacolon; Toxin; Tropomyosin; Uncertainty; Universities; Virulent; base; clinically significant; cost; design; enteric pathogen; high risk; improved; industry partner; mortality; next generation; novel; novel diagnostics; pathogen; patient population; protocol development; prototype; public health relevance; research clinical testing; response marker

 DESCRIPTION (provided by applicant): The aim of this research application is to develop a paradigm shift in diagnostic testing for a globally important, yet poorly diagnosed, healthcare-associated infectious disease, namely Clostridium difficile infection (CDI). CDI results from infection of the bowel by C. difficile, a Gram-positive, spore-forming, obligate anaerobic bacterium. It can cause (diarrheal) illness ranging from moderate diarrhea to severe colitis (toxic megacolon) with a high risk of death. For the last two decades CDI has re-emerged in healthcare facilities with nearly a 10- fold increase in mortality and significant excess healthcar cost. Current CDI diagnostics is limited to detection of the organism and/or its toxin product(s) i conjunction with clinical symptoms, and does not differentiate infected from simply colonized patients, thus leading to inaccurate diagnosis as well as antibiotic mis/overuse. To overcome these limitations and resolve uncertainty of CDI diagnosis, a ground-breaking concept for CDI diagnosis will be developed and evaluated during this research project. The project rationale is that C. difficile toxin B mechanism of action causes cytoskeletal disruption of colonic epithelial cells with release of non- muscle tropomyosin (Tm). Our hypothesis is that increased levels of Tm, a major protein in colonic epithelial cytoskeleton, in the patient's stool indicates a specific host response to CDI and can be used as a diagnostic target signifying active infection from C. difficile. The application objective is to develop and evaluate Tm detection in stool specimens as a biomarker for clinically significant manifestations of CDI. To accomplish it, we will pursue two specific aims: 1) Determine the feasibility of clinically appropriate fecal Tm detection. This aim will be accomplished by performing multiple tasks - generation of Tm specific antibodies, optimization of Tm recovery method from stool specimens, Tm detection protocol development and optimization utilizing controls mimicking CDI negative and positive specimens, and testing for potential interferences. 2) Evaluate fecal Tm as a CDI specific host response marker on specimens obtained from clinically diverse patient populations. For that, CDI positive and negative clinical specimens will be utilized for Tm detection and data comparison to clinical and microbiological records of the same specimens. The records are available due to access and use of remnant samples from the clinical microbiology laboratory. The specificity of CDI diagnostics will be validated on stool specimens from patients with diarrhea due to other enteric bacterial pathogens (E. coli, Salmonella, Shigella spp, and Campylobacter), parasites, antibiotic-associated diarrhea (not due to infection), and bowel disorders like inflammatory bowel disease. This proposed concept has great potential to allow development of a novel diagnostic application for CDI. It will serve as an example for the next generation of infectious disease diagnostics measuring host response instead of detecting pathogens or their products. Our long term goal is to improve patient care by delivering a host response CDI test ready for development with an industry partner, such as TechLab(r), Inc., as a commercial assay that can undergo FDA clearance trials.

 描述（由申请人提供）：本研究申请的目的是针对一种全球重要但诊断不佳的医疗保健相关传染病，即艰难梭菌感染 (CDI)，开发诊断测试的范式转变。 CDI 是由艰难梭菌（一种革兰氏阳性、产孢子、专性厌氧细菌）肠道感染引起的。它可引起（腹泻）疾病，从中度腹泻到严重结肠炎（中毒性） 巨结肠）具有很高的死亡风险。在过去的二十年里，CDI 在医疗机构中重新出现，死亡率增加了近 10 倍，医疗费​​用也显着超额。目前的 CDI 诊断仅限于结合临床症状检测微生物和/或其毒素产物，并且不能区分感染者和单纯定植患者，从而导致诊断不准确以及抗生素误用/过度使用。为了克服这些局限性并解决 CDI 诊断的不确定性，本研究项目将开发和评估 CDI 诊断的突破性概念。该项目的基本原理是，艰难梭菌毒素 B 的作用机制会导致结肠上皮细胞的细胞骨架破坏，并释放非肌肉原肌球蛋白 (Tm)。我们的假设是，患者粪便中 Tm（结肠上皮细胞骨架中的一种主要蛋白质）水平升高表明存在特定的 宿主对 CDI 的反应，可用作表明艰难梭菌活动性感染的诊断目标。应用目标是开发和评估粪便标本中的 Tm 检测，作为 CDI 临床显着表现的生物标志物。为了实现这一目标，我们将追求两个具体目标：1) 确定临床上适当的粪便 Tm 检测的可行性。这一目标将通过执行多项任务来实现 - 生成 Tm 特异性抗体、优化粪便样本中的 Tm 回收方法、利用模拟 CDI 阴性和阳性样本的对照开发和优化 Tm 检测方案，以及测试潜在干扰。 2) 对从临床不同患者群体获得的样本评估粪便 Tm 作为 CDI 特异性宿主反应标志物。为此，CDI阳性和阴性临床标本将用于Tm检测以及与相同标本的临床和微生物记录的数据比较。由于访问和使用了临床微生物实验室的剩余样本，因此可以获得这些记录。 CDI 诊断的特异性将通过其他肠道细菌病原体（大肠杆菌、沙门氏菌、志贺氏菌属和弯曲杆菌）、寄生虫、抗生素相关性腹泻（非感染引起）和肠道疾病（如炎症性肠病）引起的腹泻患者的粪便标本进行验证。这个提出的概念具有开发 CDI 新型诊断应用的巨大潜力。它将作为下一代传染病诊断的一个例子，测量宿主反应而不是检测病原体或其产物。我们的长期目标是通过提供宿主反应 CDI 测试来改善患者护理，该测试可与 TechLab(r), Inc. 等行业合作伙伴一起开发，作为可以接受 FDA 许可试验的商业化验。