Mitchell Gillian, Zadoks Ruth N, Skuce Philip J
Moredun Research Institute, Pentlands Science Park, Penicuik, United Kingdom.
Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Camden, NSW, Australia.
Front Vet Sci. 2021 Mar 4;7:605259. doi: 10.3389/fvets.2020.605259. eCollection 2020.
Rumen fluke are parasitic trematodes that affect domestic and wild ruminants across a wide range of countries and habitats. There are 6 major genera of rumen fluke and over 70 recognized species. Accurate species identification is important to investigate the epidemiology, pathophysiology and economic impact of rumen fluke species but paramphistomes are morphologically plastic, which has resulted in numerous instances of misclassification. Here, we present a universal approach to molecular identification of rumen fluke species, including different life-cycle stages (eggs, juvenile and mature fluke) and sample preservation methods (fresh, ethanol- or formalin-fixed, and paraffin wax-embedded). Among 387 specimens from 173 animals belonging to 10 host species and originating from 14 countries on 5 continents, 10 rumen fluke species were identified based on ITS-2 intergenic spacer sequencing, including members of the genera , and . Pairwise comparison of ITS-2 sequences from this study and GenBank showed >98.5% homology for 80% of intra-species comparisons and <98.5% homology for 97% of inter-species comparisons, suggesting that some sequence data may have been entered into public repositories with incorrect species attribution based on morphological analysis. We propose that ITS-2 sequencing could be used as a universal tool for rumen fluke identification across host and parasite species from diverse technical and geographical origins and form the basis of an international reference database for accurate species identification.
瘤胃吸虫是一种寄生性吸虫，在许多国家和不同栖息地影响着家养和野生反刍动物。瘤胃吸虫有6个主要属和70多个已确认的物种。准确的物种鉴定对于研究瘤胃吸虫的流行病学、病理生理学和经济影响很重要，但双口吸虫在形态上具有可塑性，这导致了许多错误分类的情况。在此，我们提出一种通用方法，用于瘤胃吸虫物种的分子鉴定，包括不同的生命周期阶段（卵、幼虫和成熟吸虫）以及样本保存方法（新鲜、乙醇或福尔马林固定以及石蜡包埋）。在来自5大洲14个国家、属于10个宿主物种的173只动物的387个样本中，基于ITS-2基因间隔区测序鉴定出10种瘤胃吸虫，包括 属、 属和 属的成员。本研究的ITS-2序列与GenBank的成对比较显示，80%的种内比较同源性>98.5%，97%的种间比较同源性<98.5%，这表明一些基于形态学分析的序列数据可能已被错误地归入公共数据库。我们建议ITS-2测序可作为一种通用工具，用于鉴定来自不同技术和地理来源的宿主和寄生虫物种中的瘤胃吸虫，并形成一个用于准确物种鉴定的国际参考数据库的基础。
