Rinder H, Katzwinkel-Wladarsch S, Thomschke A, Löscher T
Department of Infectious Diseases and Tropical Medicine, Klinikum Innenstadt, University of Munich, Germany.
Tokai J Exp Clin Med. 1998 Dec;23(6):433-7.
Microsporidia are obligate intracellular, spore-forming protozoa and are regarded as newly emerging pathogens . Enterocytozoon spp. as well as Encephalitozoon spp. are recognized as major aetiological agents in chronic diarrhoea of immnunocompromised patients. The detection and differentiation of strains within microsporidial species is a prerequisite for the elucidation of their hitherto unknown reservoirs and their mode of transmission . In Enterocytozoon bieneusi, the most prevalent human-pathogenic microsporidium, 6 different genotypes of the internal transcribed spacer (ITS) of the rRNA gene are known so far, with 12 polymorphic sites . This pathogen has infrequently been detected in 2 animal hosts only, pigs and rhesus macaques, and only the genotype of the latter has also been found in a human patient, too. Encephalitozoon cuniculi has a wider confirmed spectrum of animal hosts, but only one polymorphic site is known in the ITS, differing in 3 different numbers of a tetranucleotide repeat. Therefore, further genomic targets may have to be characterized, too. Few data are available on strain differentiation in Encephalitozoon intestinalis and E. hellem.
微孢子虫是专性细胞内、形成孢子的原生动物，被视为新出现的病原体。肠孢子虫属以及脑孢子虫属被认为是免疫功能低下患者慢性腹泻的主要病原体。微孢子虫物种内菌株的检测和区分是阐明其迄今未知的宿主和传播方式的先决条件。在最常见的人致病性微孢子虫——比氏肠孢子虫中，目前已知rRNA基因内部转录间隔区（ITS）有6种不同基因型，存在12个多态性位点。这种病原体仅在两种动物宿主——猪和恒河猴中偶尔被检测到，并且仅在一名人类患者中也发现了后者的基因型。兔脑炎微孢子虫已确认的动物宿主范围更广，但在ITS中仅已知一个多态性位点，其在一个四核苷酸重复序列的数量上有3种不同情况。因此，可能还必须对其他基因组靶点进行表征。关于肠脑炎微孢子虫和海伦脑炎微孢子虫的菌株区分，现有数据很少。
