Development and application of an eDNA method to detect and quantify a pathogenic parasite in aquatic ecosystems.
Development and application of an eDNA method to detect and quantify a pathogenic parasite in aquatic ecosystems.
复制标题
DOI：
10.1890/14-1530.1
复制
发表时间：
2015-06
期刊：
影响因子：
--
通讯作者：
Whyard S
中科院分区：
文献类型：
--
作者：
Huver JR;Koprivnikar J;Johnson PT;Whyard S
基于环境中发现的生物DNA（eDNA）的方法越来越多地用于生态研究和生物多样性调查，作为传统实地调查方法的替代方法。这种基于DNA的技术主要用于确定自由生活的生物体的存在，但在检测和量化环境中的传染性病原体方面具有很大的潜力，这对于评估疾病风险是必要的。我们开发了一种eDNA方法来研究吸虫Ribeiroia ondattera的分布和丰度，Ribeiroia ondattera是一种致病性寄生虫，已知会导致北美两栖动物畸形。除了将这种eDNA方法与经典的宿主尸检进行比较之外，我们还检查了R.在不同的降解条件（时间和温度）下，本试验对R. ondatestrium，能够检测低至14 fg的这种寄生虫的DNA（1/2500的一个单一的感染阶段）从现场水样。与两栖类宿主尸检结果比较，定量PCR结果的一致性达90%以上。从15个现场检测到的疟原虫，也是宿主感染丰度的重要预测因子。在25 °C下21天后，在实验室样品中仍然可以检测到DNA，这表明我们的方法对现场条件具有鲁棒性。通过比较eDNA与传统调查方法在确定病原体存在和丰度方面的优缺点，我们发现与eDNA方法相关的较低成本和工作量提供了许多优势。替代工具的开发对于疾病生态学至关重要，因为野生动物管理和保护工作需要可靠地建立和监测病原体。
Approaches based on organismal DNA found in the environment (eDNA) have become increasingly utilized for ecological studies and biodiversity inventories as an alternative to traditional field survey methods. Such DNA-based techniques have been largely used to establish the presence of free-living organisms, but have much potential for detecting and quantifying infectious agents in the environment, which are necessary to evaluate disease risk. We developed an eDNA method to examine the distribution and abundance of the trematode Ribeiroia ondatrae, a pathogenic parasite known to cause malformations in North American amphibians. In addition to comparing this eDNA approach to classical host necropsy, we examined the detectability of R. ondatrae in water samples subject to different degradation conditions (time and temperature). Our test exhibited high specificity and sensitivity to R. ondatrae, capable of detecting as little as 14 fg of this parasite’s DNA (1/2500th of a single infectious stage) from field water samples. Compared to our results from amphibian host necropsy, quantitative PCR was ∼ 90% concordant with respect to R. ondatrae detection from 15 field sites and was also a significant predictor of host infection abundance. DNA was still detectable in lab samples after 21 days at 25 °C, indicating that our method is robust to field conditions. By comparing the advantages and disadvantages of eDNA versus traditional survey methods for determining pathogen presence and abundance in the field, we found that the lower costs and effort associated with eDNA approaches provide many advantages. The development of alternative tools is critical for disease ecology as wildlife management and conservation efforts require reliable establishment and monitoring of pathogens.