Relman D A, Schmidt T M, Gajadhar A, Sogin M, Cross J, Yoder K, Sethabutr O, Echeverria P
Department of Medicine, Stanford University School of Medicine, California, USA.
J Infect Dis. 1996 Feb;173(2):440-5. doi: 10.1093/infdis/173.2.440.
A coccidian organism assigned to the genus Cyclospora has been increasingly recognized in association with prolonged diarrhea in humans throughout the world. Confusion surrounds the taxonomy of this fastidious organism, despite the availability of morphology and sporulation characteristics. The small subunit rRNA coding region from cyclosporan oocysts purified from a human fecal specimen was amplified and sequenced. The same sequence was present in specimens from 8 other patients with cyclosporan oocysts but absent in specimens from asymptomatic subjects and from cryptosporidiosis patients. Phylogenetic analysis of rDNA sequences reveals that the human-associated Cyclospora is closely related to members of the Eimeria genus. These results allow predictions concerning Cyclospora host specificity, life cycle, and epidemiology as well as the development of a specific polymerase chain reaction-based diagnostic assay.
一种归属于环孢子属的球虫类生物体，在世界各地与人类长期腹泻相关联的情况日益受到关注。尽管已有形态学和孢子形成特征，但这种苛求生物体的分类学仍存在混淆。从一份人类粪便标本中纯化出的环孢子虫卵囊的小亚基核糖体RNA编码区被扩增并测序。在另外8例有环孢子虫卵囊的患者标本中存在相同序列，但在无症状受试者和隐孢子虫病患者的标本中不存在。核糖体DNA序列的系统发育分析表明，与人类相关的环孢子虫与艾美耳属的成员密切相关。这些结果有助于对环孢子虫的宿主特异性、生命周期和流行病学进行预测，以及开发基于聚合酶链反应的特异性诊断检测方法。
