Aghayan Sargis, Gevorgian Hasmik, Ebi Dennis, Atoyan Hripsime A, Addy Francis, Mackenstedt Ute, Romig Thomas, Wassermann Marion
Chair of Zoology, Yerevan State University, Yerevan, Armenia.
Scientific Center of Zoology and Hydroecology, NAS RA, Yerevan, Armenia; National Institute of Health, Moh Ra, Yerevan, Armenia.
Vet Parasitol. 2019 Apr;268:21-31. doi: 10.1016/j.vetpar.2019.02.009. Epub 2019 Mar 1.
Fasciolosis, a food- and waterborne infection caused by the trematodes Fasciola hepatica and F. gigantica, is recognized by WHO as a neglected zoonotic disease. Whereas F. hepatica is distributed worldwide in cooler climates, F. gigantica occurs mainly in the tropics of Africa and Asia. The southern Caucasus, with Armenia, is one of the most northern regions where both species occur and may produce hybrids. In this study, livestock in central Armenia was surveyed for fasciolosis, the causative species were determined and the genetic diversity of both species was estimated. Total prevalence in sheep (1794), cattle (324) and goats (9) was 21.2%, 15.7% and 44.4%, respectively. After morphological identification and sequencing of a mitochondrial (nad1) and a nuclear marker gene (28S rRNA), 62 collected specimens were allocated to F. hepatica (n = 55) and F. gigantica (n = 7). Intraspecific diversity was evaluated for the complete nad1 gene, resulting in 29 haplotypes of F. hepatica and six haplotypes of F. gigantica. Diversity was higher among F. gigantica than F. hepatica in the Armenian sample set, a difference that was confirmed analyzing available sequences for both species worldwide. Maximum genetic distance between haplotypes in global networks was 49 nucleotide steps for F. gigantica compared to 15 for F. hepatica. In the available sample sets, F. hepatica showed higher diversity in western Asia and the Middle East compared to Europe and eastern Asia, while for F. gigantica loosely structured clusters comprising mainly western/southern Asian and African haplotypes could be identified. A distinct clade comprising haplotypes from Zambia was basal in the phylogenetic tree. Biogeographical implications of these data are discussed.
肝片吸虫病是一种由肝片吸虫和巨片吸虫这两种吸虫引起的食源性和水源性感染疾病，被世界卫生组织认定为一种被忽视的人畜共患疾病。肝片吸虫分布于全球气候较凉爽的地区，而巨片吸虫主要出现在非洲和亚洲的热带地区。南高加索地区，包括亚美尼亚，是这两种吸虫都有出现且可能产生杂交种的最北部地区之一。在本研究中，对亚美尼亚中部的家畜进行了肝片吸虫病调查，确定了致病物种，并估计了这两种吸虫的遗传多样性。绵羊（1794只）、牛（324头）和山羊（9只）的总体患病率分别为21.2%、15.7%和44.4%。经过形态学鉴定以及线粒体（nad1）和核标记基因（28S rRNA）测序后，62个采集的样本被鉴定为肝片吸虫（n = 55）和巨片吸虫（n = 7）。对完整的nad1基因评估种内多样性，结果显示肝片吸虫有29个单倍型，巨片吸虫有6个单倍型。在亚美尼亚样本组中，巨片吸虫的多样性高于肝片吸虫，这一差异在分析全球这两种吸虫的可用序列时得到了证实。全球网络中单倍型之间的最大遗传距离，巨片吸虫为49个核苷酸步长，而肝片吸虫为15个核苷酸步长。在可用样本组中，与欧洲和东亚相比，肝片吸虫在西亚和中东地区表现出更高的多样性，而对于巨片吸虫，可以识别出主要由西亚/南亚和非洲单倍型组成的结构松散的聚类。一个由赞比亚单倍型组成的独特分支位于系统发育树的基部。本文讨论了这些数据的生物地理学意义。
