Zoology Department, College of Science, King Saud University, Riyadh, Saudi Arabia.
Zoology Department, Faculty of Science, Cairo University, Cairo, Egypt.
Lett Appl Microbiol. 2020 Oct;71(4):377-385. doi: 10.1111/lam.13335. Epub 2020 Jun 22.
Sarcocystosis is a parasitic disease caused by an intracellular protozoan parasite Sarcocystis belonging to the phylum Apicomplexa. These parasites have a requisite two-host life cycle. Recently, there are many Sarcocystis species that identified morphologically. In the present study, diaphragmatic muscle samples from the domestic horse (Equus caballus) were examined for Sarcocystis infection. The natural infection with sarcocysts was recorded to be 62·5% for only microcysts in the infected muscles. Molecular analysis using the 18S rRNA gene was conducted to swiftly and accurately identify the recovered species. Studies on the expression of the 18S rRNA gene have confirmed that the present parasite isolates belong to the Sarcocystis genus. The sequence data showed significant identities (>80%) with archived gene sequences from species within the Sarcocystidae family, and a dendrogram showing the phylogenetic relationship was constructed. The most closely related species were the previously described Sarcocystis fayeri and Sarcocystis bertrami. The current data showed that the present species was identified as S. fayeri and deposited in GenBank (accession number MF614956.1). This study highlights the importance of the genetic data in the exact taxonomy within sarcocystid species.
肉孢子虫病是一种由肉孢子虫属（Sarcocystis）的细胞内原生动物寄生虫引起的寄生虫病，属于顶复门（Apicomplexa）。这些寄生虫有一个必需的两宿主生命周期。最近，已经鉴定出许多形态上相似的肉孢子虫物种。在本研究中，检查了家马（Equus caballus）的膈肌肌肉样本是否感染了肉孢子虫。仅在感染肌肉中的微囊虫中记录到 62.5%的天然感染。使用 18S rRNA 基因的分子分析进行了快速而准确的鉴定。对 18S rRNA 基因表达的研究证实，目前分离的寄生虫属于肉孢子虫属。序列数据显示与来自肉孢子虫科（Sarcocystidae）内物种的存档基因序列具有高度相似性（>80%），并构建了显示系统发育关系的系统发育树。最密切相关的物种是先前描述的 Sarcocystis fayeri 和 Sarcocystis bertrami。目前的数据表明，目前的物种被鉴定为 S. fayeri，并已在 GenBank 中注册（登录号 MF614956.1）。本研究强调了遗传数据在肉孢子虫物种内准确分类中的重要性。
