Data from: A combined parasitological-molecular approach for non-invasive characterization of parasitic nematode communities in wild hosts

Most hosts are concurrently or sequentially infected with multiple parasites; thus, fully understanding interactions between individual parasite species and their hosts depends on accurate characterization of the parasite community. For parasitic nematodes, noninvasive methods for obtaining quantitative, species-specific infection data in wildlife are often unreliable. Consequently, characterization of gastrointestinal nematode communities of wild hosts has largely relied on lethal sampling to isolate and enumerate adult worms directly from the tissues of dead hosts. The necessity of lethal sampling severely restricts the host species that can be studied, the adequacy of sample sizes to assess diversity, the geographic scope of collections and the research questions that can be addressed. Focusing on gastrointestinal nematodes of wild African buffalo, we evaluated whether accurate characterization of nematode communities could be made using a noninvasive technique that combined conventional parasitological approaches with molecular barcoding. To establish the reliability of this new method, we compared estimates of gastrointestinal nematode abundance, prevalence, richness and community composition derived from lethal sampling with estimates derived from our noninvasive approach. Our noninvasive technique accurately estimated total and species-specific worm abundances, as well as worm prevalence and community composition when compared to the lethal sampling method. Importantly, the rate of parasite species discovery was similar for both methods, and only a modest number of barcoded larvae (n = 10) were needed to capture key aspects of parasite community composition. Overall, this new noninvasive strategy offers numerous advantages over lethal sampling methods for studying nematode–host interactions in wildlife and can readily be applied to a range of study systems.

多数宿主会同时或先后感染多种寄生虫；因此，要充分明确单一寄生虫物种与其宿主间的互作关系，有赖于对寄生虫群落的精准表征。针对寄生线虫（parasitic nematodes）而言，在野生动物体内获取定量且物种特异性的感染数据的非侵入式方法往往可靠性欠佳。因此，野生宿主胃肠道线虫群落的表征工作，在很大程度上依赖于致死性采样（lethal sampling）——即直接从死亡宿主的组织中分离并计数成虫。致死性采样的必要性，严重限制了可开展研究的宿主物种、评估物种多样性所需的样本量充足性、样本采集的地理范围，以及可探究的研究问题。本研究以野生非洲水牛的胃肠道线虫为研究对象，评估了结合传统寄生虫学方法与分子条形码技术（molecular barcoding）的非侵入式手段，能否实现线虫群落的精准表征。为验证该新方法的可靠性，我们将致死性采样得到的胃肠道线虫丰度、感染率、物种丰富度及群落组成的估算值，与本研究采用的非侵入式方法得到的估算值进行了对比。相较于致死性采样方法，本研究的非侵入式手段可精准估算线虫总丰度、物种特异性线虫丰度，以及线虫感染率与群落组成。值得注意的是，两种方法的寄生虫物种发现速率相近，且仅需少量带有条形码标记的幼虫（n = 10）即可捕捉寄生虫群落组成的核心特征。总体而言，在野生动物线虫-宿主互作研究中，这一新型非侵入式策略相较于致死性采样方法具备诸多优势，且可便捷地应用于多种研究体系。