Aptamer-based surface plasmon resonance detection of legionella pneumophila in water systems ****************

基于适体的表面等离子体共振检测水系统中的嗜肺军团菌 ****************

• 批准号: 521532-2018
• 负责人: Tabrizian, Maryam
• 金额: $ 11.61万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Strategic Projects - Group
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=666371
• 关键词: Aptamer; based; surface; plasmon; resonance

Legionnaires' disease is caused by the bacterium Legionella pneumophila (Lp). Many water systems, such as cooling towers and hot water distribution systems, are potentially contaminated by Lp. Production of aerosols by such systems enables the transmission of Lp to humans. Many outbreaks of this disease are reported each year. For example, Quebec City suffered from a major outbreak in 2012. Surveillance of water systems is crucial for limiting infection risks and outbreaks. Detection of Lp in water systems is currently performed by culturing or qPCR. These methods are expensive and tedious, and in the case of culturing, take up to two weeks to perform. In collaboration with Magnus Chemical Ltd, we propose to develop a novel detection method based on the recognition of Lp by aptamers, short DNA sequences that folds into structures binding specifically to a target. The aptamers will be developed using the "Systemic Evolution of Ligands through EXponential enrichment" (SELEX) technique. Specificity and versatility of the aptamers will be tested against a diversity of Lp isolates and other bacterial species frequently isolated form water systems. The best aptamers will be immobilized on the surface of a Surface Plasmon Resonance biosensor (SPR) prism and their ability to detect Lp in man-made water samples will be evaluated. The system will then be optimized by modifying the surface chemistry and by using a second aptamer coupled to gold nanoparticle in a "sandwich assay" to amplify the signal and improve the limit of detection (LOD). To further lower the LOD, a Lab-on-a-Chip strategy will be developed for the Lp enrichment in water samples. The aim is to reach a LOC of 10-100 CFU Lp /ml (maintenance levels). Next, the novel detection method will be tested with real water samples and compared to the current detection methods. This project should allow the development of a novel detection strategy that could be miniaturized and used to monitor the presence of Lp in water systems in a continuous manner. At term, this project will improve timely response to initiate treatment of water systems to minimize risk of Legionnaires' disease.**************************

军团病是由嗜肺军团菌 (Lp) 引起的。许多供水系统，例如冷却塔和热水分配系统，都可能受到液化石油气的污染。此类系统产生的气溶胶能够将 Lp 传播给人类。每年都有许多这种疾病爆发的报道。例如，魁北克市在 2012 年遭受了一次重大疫情爆发。供水系统的监测对于限制感染风险和疫情爆发至关重要。目前，水系统中 Lp 的检测是通过培养或 qPCR 进行的。这些方法昂贵且繁琐，并且在培养的情况下，需要长达两周的时间才能完成。我们与 Magnus Chemical Ltd 合作，提议开发一种基于适配体对 Lp 的识别的新型检测方法，适配体是短 DNA 序列，可折叠成与靶标特异性结合的结构。适配体将使用“通过指数富集进行配体的系统进化”（SELEX）技术来开发。适配体的特异性和多功能性将针对多种 Lp 分离株和经常从水系统中分离出来的其他细菌物种进行测试。最好的适配体将被固定在表面等离子共振生物传感器 (SPR) 棱镜的表面上，并且将评估它们检测人造水样中 Lp 的能力。然后，将通过修改表面化学并在“三明治测定”中使用与金纳米颗粒偶联的第二个适配体来放大信号并提高检测限（LOD）来优化系统。为了进一步降低 LOD，我们将开发芯片实验室策略来富集水样中的 Lp。目标是达到 10-100 CFU Lp /ml（维持水平）的 LOC。接下来，我们将用真实的水样对这种新型检测方法进行测试，并与现有的检测方法进行比较。该项目应允许开发一种新颖的检测策略，该策略可以小型化并用于连续监测水系统中 Lp 的存在。从长远来看，该项目将改善及时响应，启动水系统处理，以尽量减少军团病的风险。 *************************