中文摘要：

目的对犬粪中的疑似环孢子虫卵囊进行形态学和分子鉴定。方法对首次在犬粪中发现的疑似环孢子虫卵囊的形状、大小、抗酸染色、孢子化和自发荧光等形态特征进行了观察。根据GenBank已发表的环孢子虫序列设计并合成3条引物，对犬源环孢子虫18S rDNA部分序列进行巢氏PCR扩增，将扩增产物纯化并克隆至载体pMD19-T，挑选阳性克隆测序并进行同源性及系统进化分析。结果该疑似环孢子虫卵囊与人的环孢子虫卵囊形态特征相似，扩增的18SrDNA片段大小为715bp，与预期目的片段一致。序列同源性和系统发育分析显示该犬源环孢子虫与环孢子虫间的相似性最高，系统进化树中处于同一分支。结论首次从犬粪中发现的疑似环孢子虫卵囊可以确定为环孢子虫。

英文摘要：

The morphological and molecular identifications of Cyclospora-like oocysts of dogs were underwent in the present study, in which the morphological characteristics of the Cyclospora-like oocysts firstly found in the stool samples of dogs, such as shape, size, acid-fast staining,sporulation and auto-fluorescene, were observed. According to the published sequence of the rDNA gene of Cyclospora in GenBank, 3 primers were designed and were used to amplify part of the 18S rDNA gene of dog-associated Cyclospora-like organism by nested PCR. The amplicons were purified and cloned into vector pMD19T. Then, the positive clones screened were sequenced and subjected to sequence homology and phylogenetic analysis. It was found that the morphological charactertistics of the Cyclospora-like oocysts in dogs were similar to that of the human Cyclospoa oocysts and the size of the amplified fragment of 18S rDNA was proved to be 715 bp, that was identical to that of the target fragment. Based on the results of sequence homology and phylogenetic analysis, the dog-associated Cyclospora-like organism was identified as the Cyclospora species.