Mitochondrial DNA in the environment: towards the development of better animal-specific markers for fecal source tracking

环境中的线粒体 DNA：开发更好的动物特异性标记物用于粪便来源追踪

• 批准号: RGPIN-2016-06061
• 负责人: Villemur, Richard
• 金额: $ 2.77万
• 依托单位: Institut national de la recherche scientifique
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 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=667803
• 关键词: Mitochondrial; DNA; environment; towards; development

Numerous sources can contribute to fecal contamination of water and soil. As many waterborne pathogenic microorganisms are associated with fecal pollution, monitoring such contamination in water quality assessments is of great importance for public health. Indeed, fecal pollution of surface water and groundwater can have a great impact on public health (drinking water) and local economy (agriculture and recreational activities). The microbiological quality of water is primarily monitored using fecal indicator organisms, such as coliforms. However, these indicators do not identify the source of the fecal matter. Several fecal source tracking (FST) methods have been developed to address the issue of host-specific contributions to fecal contamination. Host-specific genetic markers detected by PCR methods indicate the presence of fecal contamination from specific animal species. Most of these genetic markers rely on the presence of microorganisms in the intestinal (fecal) matter that are associated with specific animal host. Despite their number, none of these markers are completely and sufficiently specific and sensitive. Therefore, it is essential to develop novel genetic markers and innovative methods for FST.*** Recently developed FST genetic markers rely on the important release of colonic epithelium cells in the intestinal lumen. These cells contain numerous copies of mitochondria with their genome (mtDNA). In the early 2000s, my team has been the first group to develop mtDNA-based FST markers; such markers are now used by other groups. mtDNA sequences are highly species-specific; substantial differences in mtDNA can be found between closely related species. Building on these sequence variations, we designed species-specific primers that can be used for PCR. We and others have demonstrated that mtDNA from human, bovine and porcine are present and detectable in untreated domestic sewage, agricultural soil runoff, swine farm effluents and water from rivers with known pollution sources. Despite the successful detection of mtDNA in environmental samples, the detection of such markers can be challenging in environmental water and soil. This problem stems from our lack of knowledge on the dynamics of mtDNAs in the environment.*** The overall aim of this research program is to characterize the fate of mtDNAs in various water and soil environments with the ultimate goal of developing improved mtDNA detection as a robust FST method. The aims of the research program will address the fate and transport of animal-specific mtDNA markers in various environmental situations well controlled in laboratory settings as well as in experimental field plots. The development of improved animal-specific markers identifying the exact sources of fecal matter is essential for implementing effective preventive or remedial strategies.**

许多来源都可能导致粪便污染水和土壤。由于许多水生病原微生物与粪便污染有关，因此在水质评价中监测此类污染对公众健康至关重要。事实上，地表水和地下水的粪便污染会对公共卫生（饮用水）和当地经济（农业和娱乐活动）产生重大影响。水的微生物质量主要是利用粪便指示生物，如大肠菌群进行监测。然而，这些指标不能识别粪便的来源。已经开发了几种粪便来源追踪（FST）方法来解决宿主特异性对粪便污染的贡献问题。通过PCR方法检测到的宿主特异性遗传标记表明存在特定动物物种的粪便污染。大多数这些遗传标记依赖于肠道（粪便）物质中与特定动物宿主相关的微生物的存在。尽管它们的数量，这些标志物中没有一个是完全和足够的特异性和敏感性。因此，开发FST的新型遗传标记和创新方法至关重要。* 最近开发的FST遗传标记依赖于结肠上皮细胞在肠腔中的重要释放。这些细胞含有大量的线粒体及其基因组（mtDNA）。在21世纪初，我的团队是第一个开发基于mtDNA的FST标记的团队;这些标记现在被其他团队使用。线粒体DNA序列具有高度的物种特异性;在密切相关的物种之间可以发现线粒体DNA的实质性差异。基于这些序列变异，我们设计了可用于PCR的种特异性引物。我们和其他人已经证明，来自人类，牛和猪的mtDNA存在于未经处理的生活污水，农业土壤径流，养猪场废水和已知污染源的河流中。尽管在环境样品中成功检测到mtDNA，但在环境水和土壤中检测此类标记物可能具有挑战性。这个问题源于我们对环境中线粒体DNA的动态缺乏了解。* 该研究计划的总体目标是描述mtDNA在各种水和土壤环境中的命运，最终目标是开发改进的mtDNA检测作为一种强大的FST方法。该研究计划的目标将解决动物特异性mtDNA标记物在实验室环境和实验田中控制良好的各种环境条件下的命运和运输。开发改进的动物特异性标记物，以确定粪便物质的确切来源，对于实施有效的预防或补救策略至关重要。