State Key Laboratory of Veterinary Etiological Biology, National Professional Laboratory for Echinococcosis, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, Gansu Province, PR China.
Department of Clinical Medicine and Surgery, University of Agriculture, Faisalabad, Pakistan.
Infect Genet Evol. 2020 Nov;85:104481. doi: 10.1016/j.meegid.2020.104481. Epub 2020 Jul 28.
Taenia hydatigena is a cestode of veterinary importance. Infection with the metacestode larval stage results in cysticercosis, which poses a serious challenge to the livestock industry worldwide. Globally, there are numerous reports on cysticercosis caused by T. hydatigena in sheep and goat but a lack of data on the prevalence and genetic diversity exists for Pakistan. We designed this study to provide an insight into the disease status as well as investigate the genetic variation among the recovered isolates based on the mitochondrial cox1 gene. In this study, we examined small ruminants (sheep and goats) slaughtered in Faisalabad in eastern Punjab province of Pakistan for T. hydatigena metacestodes and described the population structure and genetic variation using the cytochrome c oxidase subunit 1 (cox1) mitochondrial gene. Overall, a prevalence of 4.40% (goat =4.67% sheep = 4.07%) from a total of 2225 small ruminant carcasses (sheep = 983, goats = 1242) was observed. Based on the NCBI BLAST search and Bayesian phylogeny, the identity of all isolates was confirmed via their nucleotide sequences. The diversity indices indicated a high haplotype and a low nucleotide diversity with 43 haplotypes from 98 isolates. The results also show the existence of unique haplotypes of T. hydatigena in Pakistan as demonstrated by the significant negative values of Tajima's D and Fu's Fs neutrality test suggesting a recent population expansion. The median-joining network of the partial cox1 sequence dataset showed the existence of two main haplotypes detected in both sheep and goat populations. This study shows that the prevalence of cycticercosis due to T. hydatigena is below 5% in sheep and goats in Faisalabad, Punjab, Pakistan. The molecular analysis of the partial cox1 gene also indicates a high degree of genetic variation with the existence of rare haplotypes. These findings represent a preliminary report on the prevalence and genetic variation of T. hydatigena in Pakistan and serve as baseline information for future studies on the prevalence and population structure of T. hydatigena in the country.
细粒棘球绦虫是一种具有重要兽医意义的绦虫。感染其幼虫阶段即包虫囊蚴会导致囊尾蚴病，这对全球的畜牧业构成了严重挑战。在全球范围内，有许多关于绵羊和山羊感染细粒棘球绦虫导致囊尾蚴病的报告，但巴基斯坦缺乏关于该病流行率和遗传多样性的数据。我们设计了这项研究，旨在深入了解该疾病的现状，并基于线粒体 cox1 基因研究回收分离株的遗传变异。在这项研究中，我们检查了巴基斯坦旁遮普省东部费萨拉巴德屠宰的小反刍动物（绵羊和山羊）中的细粒棘球绦虫包虫囊，并描述了种群结构和遗传变异，使用的是细胞色素 c 氧化酶亚基 1（cox1）线粒体基因。总的来说，从总共 2225 个小反刍动物尸体（绵羊 983 个，山羊 1242 个）中观察到细粒棘球绦虫包虫囊的总流行率为 4.40%（山羊为 4.67%，绵羊为 4.07%）。根据 NCBI BLAST 搜索和贝叶斯系统发育，所有分离株的核苷酸序列证实了其身份。多样性指数表明，高单倍型和低核苷酸多样性，98 个分离株中有 43 个单倍型。结果还表明，巴基斯坦存在细粒棘球绦虫的独特单倍型，这是由 Tajima 的 D 和 Fu 的 Fs 中性检验的显著负数值证明的，这表明最近种群扩张。部分 cox1 序列数据集的中位数连接网络显示，在绵羊和山羊种群中均检测到两个主要单倍型。本研究表明，在巴基斯坦费萨拉巴德，绵羊和山羊的细粒棘球蚴囊尾蚴病的流行率低于 5%。cox1 基因部分序列的分子分析也表明存在高度遗传变异，存在罕见单倍型。这些发现代表了巴基斯坦细粒棘球绦虫流行率和遗传变异的初步报告，为该国未来研究细粒棘球绦虫的流行率和种群结构提供了基线信息。
