中文摘要：

根据OenBank上已发表的环孢子虫（Cyclospora）rDNA序列设计并合成1对引物，利用PCR技术时首次在牛体内发现的形态学特征与人环孢子虫（Cyclospora cayetanensis）极为相似的牛源环孢子虫的ITS-1＋序列进行了扩增。将PCR扩增出的片段纯化后，克隆至pGEM—TEasy载体后进行序列测定，并利用NCBI在线BLAST程序对测序结果进行了同源性比较和序列分析。分析结果显示，扩增的ITS-1＋大小为865bp的片段，包含18S部分序列（371bp）、ITS-1全序列（385bp）和5．8S部分序列（109bp）。序列同源性分析表明，该牛源环抱子虫为艾美尔科原虫，但不同于目前已知的各种艾美尔科原虫，可能是一种新发现的原虫。

英文摘要：

According to the published sequence of the rDNA gene of Cyclospora in GenBank,a pair of primers was designed to amplify the ITS-1 ＋ region of the Cyclospora-like species from dairy cattle by PCR. The amplicons was cloned into pGEM-T Easy vector. The insert was successfully sequenced,and the result revealed that the insert was 856 bp in length and consisted of partial 18S,5.8S and complete ITS-1 DNA sequences. The dairy cattle-associated Cyclospora-like species was identified as a protozoa which belongs to Eimeriidae based on the partial 18S and 5.8S DNA sequences. It may be a new species since it has a specific ITS-1 sequence.