Laboratory of Veterinary Parasitology, Faculty of Agriculture, Iwate University, Ueda, Morioka, Japan; Faculty of Animal Science and Veterinary Medicine, Thai Nguyen University of Agriculture and Forestry, Quyet Thang Commune, Thai Nguyen City, Viet Nam.
National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
Infect Genet Evol. 2021 Jul;91:104806. doi: 10.1016/j.meegid.2021.104806. Epub 2021 Mar 17.
The adult stage of Explanatum explanatum has economic importance in the production of ruminants, especially water buffaloes. This species has been widely reported in the Indian sub-continent. Recently, molecular analyses to reveal the dispersal route of this species were performed in Bangladesh, Nepal, and India. In the present study, we focused on E. explanatum distributed in Sri Lanka. A total of 52 flukes were collected from water buffaloes in Sri Lanka and identified as E. explanatum based on the internal transcribed spacer 2 (ITS2) region of nuclear ribosomal DNA. Analysis of the mitochondrial NADH dehydrogenase subunit 1 (nad1) gene from DNA samples detected 18 haplotypes, and five of them were identical to those from the Indian E. explanatum. The pairwise fixation index value indicated that the Sri Lankan population had a comparatively closer relationship with the Indian population than with the Bangladeshi or Nepalese populations. The Sri Lankan population showed significantly lower genetic variability than the Indian population, suggesting that the Indian population was the ancestor of the Sri Lankan population. The movement of host ruminants, including water buffaloes, was probably involved in the introduction of the fluke into Sri Lanka. The results of our study provide useful information for elucidating the geographic origin of E. explanatum distributed in the Indian subcontinent.
膨胀口吸虫的成虫阶段在反刍动物（特别是水牛）的生产中具有经济重要性。该物种在印度次大陆被广泛报道。最近，在孟加拉国、尼泊尔和印度进行了分子分析，以揭示该物种的传播途径。在本研究中，我们专注于分布在斯里兰卡的膨胀口吸虫。从斯里兰卡的水牛中总共收集了 52 条吸虫，并根据核核糖体 DNA 的内部转录间隔区 2（ITS2）区域将其鉴定为膨胀口吸虫。从 DNA 样本中分析线粒体 NADH 脱氢酶亚单位 1（nad1）基因检测到 18 种单倍型，其中 5 种与印度的膨胀口吸虫相同。成对固定指数值表明，与孟加拉国或尼泊尔种群相比，斯里兰卡种群与印度种群的亲缘关系更近。与印度种群相比，斯里兰卡种群的遗传变异明显较低，表明印度种群是斯里兰卡种群的祖先。包括水牛在内的宿主反刍动物的迁移可能导致该吸虫进入斯里兰卡。我们的研究结果为阐明分布在印度次大陆的膨胀口吸虫的地理起源提供了有用的信息。
