Shumaila Naz, Farhana Riaz Chaudhry, Dilawar Abbas Rizvi, Muhammad Ismail
Department of Zoology, Faculty of Sciences, Pir Mehr Ali Shah Arid Agriculture University Rawalpindi, 46300 Rawalpindi, Pakistan.
Institute of Dermatology, Military Hospital, 46300 Rawalpindi, Pakistan.
Trop Biomed. 2018 Sep 1;35(3):796-803.
Scabies occurs in human due to the burrowing ectoparasite Sarcoptes scabiei var. hominis resulting in intense itching and inflammation, and manifesting as a skin allergy. Limited information is available about the genetic diversity of S. scabiei in human. In this study, we characterized S. scabiei var. hominis using nuclear marker ITS-2, mitochondrial marker 16S and microsatellite markers. To examine the extent of the genetic variation, individual mite gDNA was first amplified using ITS-2, 16S and microsatellite primers by PCR, later amplicons were sequenced directly and analysed by MEGA 7. Sequence analysis of ITS2 showed no host segregation and geographical isolation, whereas 16S indicated presence of both hosts adapted and geographically segregated populations of S. scabiei. Results of microsatellites revealed polymorphism as allelic variability between and within the populations studied. The different varieties of Sarcoptes mites belong to different host species and geographic regions recommended that Sarcoptes mites are genetically isolated. This is the first report on the molecular characterization of S. scabiei var. hominis from Pakistan. Additionally, genetic studies including a greater number of specimens are required to comprehend the molecular epidemiology of Sarcoptes mite in Pakistan.
疥疮是由人疥螨这种掘穴性体外寄生虫引起的,会导致剧烈瘙痒和炎症,表现为皮肤过敏。关于人疥螨的遗传多样性,目前可用信息有限。在本研究中,我们使用核标记ITS-2、线粒体标记16S和微卫星标记对人疥螨进行了特征分析。为了检测遗传变异程度,首先通过PCR使用ITS-2、16S和微卫星引物扩增单个螨的基因组DNA,随后对扩增子进行直接测序,并通过MEGA 7进行分析。ITS2的序列分析显示不存在宿主隔离和地理隔离,而16S表明存在适应宿主和地理隔离的人疥螨种群。微卫星结果显示在所研究的种群之间和种群内部存在等位基因变异的多态性。不同种类的疥螨属于不同的宿主物种和地理区域,这表明疥螨在遗传上是隔离的。这是关于来自巴基斯坦的人疥螨分子特征的首次报告。此外,需要进行包括更多标本的遗传研究,以了解巴基斯坦疥螨的分子流行病学。