Li Wei, Wan Qiang, Yu Qinlei, Yang Yuqi, Tao Wei, Jiang Yanxue, Xiao Lihua
College of Veterinary Medicine, Northeast Agricultural University, 59 Mucai street, Harbin, Heilongjiang, 150030, China.
Jilin Provincial Animal Disease Control Center, 4510 Xi'an Road, Changchun, Jilin, 130062, China.
Parasitol Res. 2016 Jul;115(7):2899-904. doi: 10.1007/s00436-016-5069-3. Epub 2016 Apr 20.
Enterocytozoon bieneusi is an obligate intracellular protozoan parasite that infects a wide range of mammal hosts and birds. Previous genotypic surveys were limited to measure the polymorphisms at the ribosomal internal transcribed spacer (ITS) that evolved slowly. Data on population structure are available only on E. bieneusi isolates from primates. This study explored the genotypic and phylogenetic characteristics of four mini- and microsatellites and performed a population genetic analysis in 39 E. bieneusi isolates of potentially zoonotic ITS genotype D from farmed foxes and raccoon dogs in China. Sequence polymorphisms facilitated determination of six, two, four, and five genotypes at markers MS1, MS3, MS4, and MS7, respectively. Patterns of phylogeny revealed different levels of diversity within and among the genetic markers. Clear genotypic and phylogenetic divergences between E. bieneusi isolates of ITS genotype D from fur animals and humans were observed at individual markers. Complete linkage disequilibrium and very limited recombination in subsequent population genetic analysis supported a clonal structure for E. bieneusi population from fur animals (FID). Phylogenetic analysis, genetic network, and measures of F ST and gene flow demonstrated population differentiation of FID from two known human E. bieneusi populations HID (with a clonal structure) and HIA (with an epidemic structure). The data indicated an ideal resolving power of MLST compared to the previously widely used ITS genotyping and confirmed the clonal nature and population differentiation of E. bieneusi in various hosts.
微小隐孢子虫是一种专性细胞内原生动物寄生虫，可感染多种哺乳动物宿主和鸟类。以往的基因分型调查仅限于测量进化缓慢的核糖体内部转录间隔区（ITS）的多态性。关于种群结构的数据仅来自灵长类动物的微小隐孢子虫分离株。本研究探索了四个微卫星和小卫星的基因分型和系统发育特征，并对来自中国养殖狐狸和貉的39株具有潜在人畜共患病风险的ITS基因型D的微小隐孢子虫分离株进行了群体遗传分析。序列多态性分别在标记MS1、MS3、MS4和MS7上确定了六种、两种、四种和五种基因型。系统发育模式揭示了遗传标记内部和之间不同程度的多样性。在单个标记上观察到来自毛皮动物和人类的ITS基因型D的微小隐孢子虫分离株之间存在明显的基因分型和系统发育差异。在随后的群体遗传分析中，完全连锁不平衡和非常有限的重组支持了来自毛皮动物的微小隐孢子虫群体（FID）的克隆结构。系统发育分析、遗传网络以及FST和基因流测量表明FID与两个人类微小隐孢子虫群体HID（具有克隆结构）和HIA（具有流行结构）存在群体分化。数据表明，与先前广泛使用的ITS基因分型相比，多位点序列分型具有理想的分辨能力，并证实了微小隐孢子虫在不同宿主中的克隆性质和群体分化。
