Li Wei, Xiao Lihua
Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, Harbin, China.
College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
Front Genet. 2019 Apr 2;10:307. doi: 10.3389/fgene.2019.00307. eCollection 2019.
Microsporidia comprise a large class of unicellular eukaryotic pathogens that are medically and agriculturally important, but poorly understood. There have been nearly 1,500 microsporidian species described thus far, which are variable in biology, genetics, genomics, and host specificity. Among those, is the well-known species responsible for the most recorded cases of human microsporidian affections. The pathogen can colonize a broad range of mammals and birds and most of the animals surveyed share some genotypes with humans, posing a threat to public health. Based on DNA sequence analysis of the ribosomal internal transcribed spacer (ITS) and phylogenetic analysis, several hundreds of genotypes have been defined and clustered into different genetic groups with varied levels of host specificity. However, single locus-based typing using ITS might have insufficient resolution to discriminate among isolates with complex genetic or hereditary characteristics and to assess the elusive reproduction or transmission modes of the organism, highlighting the need for exploration and application of multilocus sequence typing (MLST) and population genetic tools. The present review begins with a primer on microsporidia and major microsporidian species, briefly introduces the recent advances on ITS genotyping and phylogeny, summarizes recent MLST and population genetic data, analyzes the inter- and intragroup host specificity at the MLST level, and interprets the public health implications of host specificity in zoonotic or cross-species transmission of this ubiquitous fungus.
微孢子虫是一大类单细胞真核病原体，在医学和农业方面都很重要，但人们对其了解甚少。迄今为止，已描述了近1500种微孢子虫物种，它们在生物学、遗传学、基因组学和宿主特异性方面存在差异。其中， 是导致人类微孢子虫感染病例记录最多的著名物种。这种病原体可寄生于多种哺乳动物和鸟类，大多数被调查的动物与人类共享一些基因型，对公共卫生构成威胁。基于核糖体内部转录间隔区（ITS）的DNA序列分析和系统发育分析，已定义了数百种 基因型，并将其聚类为具有不同宿主特异性水平的不同遗传组。然而，使用ITS进行的基于单一位点的分型可能分辨率不足，无法区分具有复杂遗传或遗传特征的 分离株，也无法评估该生物体难以捉摸的繁殖或传播模式，这突出了探索和应用多位点序列分型（MLST）和群体遗传工具的必要性。本综述首先介绍了微孢子虫和主要微孢子虫物种的基本知识，简要介绍了 ITS基因分型和系统发育的最新进展，总结了最近的MLST和群体遗传数据，分析了MLST水平上的组间和组内宿主特异性，并解释了这种普遍存在的真菌在人畜共患病或跨物种传播中宿主特异性对公共卫生的影响。
