Division of Foodborne, Waterborne and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
Infect Genet Evol. 2013 Mar;14:111-9. doi: 10.1016/j.meegid.2012.11.021. Epub 2012 Dec 19.
The population structure of Enterocytozoon bieneusi was examined by multilocus sequence typing (MLST) of 64 specimens from AIDS patients in Peru, Nigeria, and India and five specimens from captive baboons in Kenya using a combination of the ribosomal internal transcribed spacer (ITS) and four microsatellite and minisatellite markers. Parasites in different geographic locations (Peru, India, and Nigeria) all had strong and significant linkage disequilibrium (LD) and only limited recombination, indicative of a clonal population structure in E. bieneusi from each location. When isolates of various geographical areas were treated as a single population, phylogenetic analysis and substructural analysis using STRUCTURE found no evidence for the existence of geographically segregated sub-populations. Nevertheless, both analyses revealed the presence of two major genetically isolated groups of E. bieneusi: one (sub-population 1) contained all isolates of the anthroponotic ITS genotype A, whereas the other (sub-population 2) harbored isolates of multiple ITS genotypes with zoonotic potential. This was also supported by FST analysis. The measurement of LD and recombination rates indicated that sub-population 2 had a clonal population structure, whereas sub-population 1 had an epidemic population structure. The data confirmed the existence of genetic sub-populations in E. bieneusi that may be transmitted differently in humans.
本研究采用多位点序列分型（MLST）技术，对来自秘鲁、尼日利亚和印度的 64 例艾滋病患者以及肯尼亚 5 例圈养狒狒的肠道内杯状细胞内原生动物（Enterocytozoon bieneusi）进行了基因结构分析，该技术结合了核糖体内部转录间隔区（ITS）和 4 个微卫星和小卫星标记。结果显示，来自不同地理区域（秘鲁、印度和尼日利亚）的寄生虫均具有强烈且显著的连锁不平衡（LD），仅存在有限的重组，表明 E. bieneusi 在每个地点都具有克隆种群结构。当将来自不同地理区域的分离株视为一个单一群体时，基于 STRUCTURE 的系统发育分析和亚结构分析均未发现存在地理隔离亚群的证据。然而，这两种分析都揭示了存在两个主要的遗传隔离 E. bieneusi 群体：一个（亚群 1）包含所有具有人际传播潜力的 ITS 基因型 A 的分离株，而另一个（亚群 2）则含有多种具有动物源性传播潜力的 ITS 基因型的分离株。FST 分析也支持这一结果。LD 和重组率的测量表明，亚群 2 具有克隆种群结构，而亚群 1 具有流行种群结构。数据证实了 E. bieneusi 中存在遗传亚群，这些亚群可能在人类中以不同的方式传播。
