Stucki U, Braun R, Roditi I
Institut für allgemeine Mikrobiologie, University of Bern, Switzerland.
Exp Parasitol. 1993 Feb;76(1):68-75. doi: 10.1006/expr.1993.1008.
The oocysts of Eimeria tenella, one of the most pathogenic of several species causing chicken coccidiosis, are difficult to distinguish microscopically from several other infective Eimeria species. One copy of a gene coding for 5S ribosomal RNA has been cloned from E. tenella and sequenced. A coding region of 120 nucleotides and an intergenic region of 608 nucleotides together make up a 5S rRNA repeat unit, of which there are many copies tandemly repeated in the genome. The intergenic region is species-specific and sequences derived from it can be used for species identification by polymerase chain reaction (PCR). The PCR procedure described here is particularly sensitive, with fewer than 10 oocysts sufficing to give a positive result. This method may also be useful for the identification by PCR of other cyst-forming parasites.
柔嫩艾美耳球虫是引起鸡球虫病的几种致病性最强的球虫之一，其卵囊在显微镜下很难与其他几种感染性艾美耳球虫物种区分开来。已从柔嫩艾美耳球虫中克隆并测序了一个编码5S核糖体RNA的基因拷贝。120个核苷酸的编码区和608个核苷酸的基因间隔区共同构成一个5S rRNA重复单元，基因组中有许多拷贝串联重复。基因间隔区具有物种特异性，从中获得的序列可用于通过聚合酶链反应（PCR）进行物种鉴定。这里描述的PCR程序特别灵敏，少于10个卵囊就足以给出阳性结果。该方法也可能有助于通过PCR鉴定其他形成包囊的寄生虫。
