Department of Zoology, Abdul Wali Khan University, Mardan, 2320, Pakistan.
Department of Biosciences, COMSATS University Islamabad (CUI), Park Road, Chak Shahzad, Islamabad, Pakistan.
Exp Parasitol. 2020 May;212:107872. doi: 10.1016/j.exppara.2020.107872. Epub 2020 Mar 9.
Theileriosis is a widespread and economically important disease of small ruminants in Pakistan. Ruminants are the intermediate hosts in the lifecycle of Theileria spp., with ticks of the family Ixodidae being the definitive hosts. To better understand the distribution and prevalence of theileriosis in Pakistan, a molecular survey was performed in small ruminants from the Lower Dir district of the Khyber Pakhtunkhwa province. A total of 200 healthy sheep and goats were screened from Maidan, Samar Bagh and Munda districts of district Dir Lower, Pakistan during December (2017) to April (2018). DNA samples were screened through nested PCR using universal primers. The amplified 492-498 bp amplicon was subjected to RLB analysis which was based on the hypervariable of the 18S rRNA gene to test for the presence of genotypes of Theileria in blood samples. A phylogeny was constructed to determine the species of Theileria genotypes. Nested PCR results indicated 53.5% prevalence of one or more Theileria genotypes in the blood of the host animal. From RLB assay, 27 animals (13.5%) showed infection with only a single species of Theileria while 80 animals (40%) showed coinfection by multiple Theileria spp. Based on the 18S rRNA phylogeny, the unknown genotype is of the species Theileria luwenshuni and is closely related to Chinese isolates. The present finding is the first report on molecular diagnosis of Theileria luwenshuni in small ruminants in Pakistan.
泰勒虫病是巴基斯坦小反刍动物中一种广泛存在且具有重要经济意义的疾病。反刍动物是泰勒虫属生命周期中的中间宿主，而硬蜱科的蜱是确定的宿主。为了更好地了解巴基斯坦泰勒虫病的分布和流行情况，在巴基斯坦开伯尔-普赫图赫瓦省低迪尔地区的小反刍动物中进行了分子调查。2017 年 12 月至 2018 年 4 月，从巴基斯坦低迪尔区迈丹、萨马尔巴格和蒙达区共筛查了 200 只健康绵羊和山羊。使用通用引物通过巢式 PCR 对 DNA 样本进行筛查。扩增的 492-498 bp 扩增子通过基于 18S rRNA 基因高变区的 RLB 分析来检测血液样本中是否存在泰勒虫基因型。构建系统发育树以确定泰勒虫基因型的物种。巢式 PCR 结果表明，宿主动物血液中存在一种或多种泰勒虫基因型的比例为 53.5%。从 RLB 检测结果来看，27 只动物（13.5%）仅感染了一种泰勒虫，而 80 只动物（40%）则同时感染了多种泰勒虫。基于 18S rRNA 系统发育，未知基因型属于卢氏泰勒虫种，与中国分离株密切相关。本研究是巴基斯坦小反刍动物中卢氏泰勒虫分子诊断的首次报道。
