Key Laboratory of Veterinary Parasitology of Gansu Province, State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.
Exp Parasitol. 2010 Dec;126(4):476-81. doi: 10.1016/j.exppara.2010.05.024. Epub 2010 Jun 1.
Theileria sergenti and Theileria sinensis are closely related members of benign Theileria species found in cattle and yaks in China. They are morphologically indistinguishable. A polymerase chain reaction (PCR) targeting major piroplasm surface protein of T. sergenti and T. sinensis was developed in this study. The newly developed oligonucleotide primer set was able to specifically amplify the DNA of T. sinensis and in conjunction with primers for T. sergenti and these two species could be detected and distinguished. Specificity testing also revealed that there was no cross-reaction with the other tick-borne diseases Theileria annulata, Babesia ovata, Anaplasma marginale as well as bovine white blood cells. Phylogenetic analysis based on the MPSP gene sequences confirmed the specificity of PCR assays. The sensitivity of the methods was 0.1pg DNA for the T. sergenti PCR and 1pg DNA for T. sinensis PCR. Two hundred and thirty-six field blood samples from of cattle and yaks were collected from five different geographical regions in China where benign Theileria species have been found. T. sergenti was found in all five provinces but was absent from one county in Gansu Province. T. sinensis was only found in Gansu Province. In both counties in Gansu where the parasites co-existed, mixed infections were detected. Our results indicate that the PCR methods developed in this study are suitable for the detection and differentiation of T. sergenti and T. sinensis.
绵羊泰勒虫和中国黄牛及牦牛中的无侵袭性泰勒虫是亲缘关系密切的良性泰勒虫，形态上无法区分。本研究针对绵羊泰勒虫和无侵袭性泰勒虫主要表面蛋白基因（MPSP）设计并建立了聚合酶链式反应（PCR）检测方法。新设计的引物组能特异性地扩增无侵袭性泰勒虫的 DNA，与绵羊泰勒虫的引物组合使用，可以同时检测和区分这两种泰勒虫。特异性试验也显示，该方法与其他蜱传疾病（环形泰勒虫、卵形巴贝斯虫、边缘无浆体）以及牛白细胞均无交叉反应。基于 MPSP 基因序列的系统进化分析证实了 PCR 检测方法的特异性。该方法对绵羊泰勒虫的检测灵敏度为 0.1pg DNA，对无侵袭性泰勒虫的检测灵敏度为 1pg DNA。从中国五个不同地理区域的 236 份牛和牦牛的野外血液样本中，检测到了绵羊泰勒虫。这五种寄生虫在五个省份都有发现，但在甘肃省的一个县却没有。无侵袭性泰勒虫仅在甘肃省被发现。在甘肃共存的两个县，检测到了混合感染。研究结果表明，本研究中建立的 PCR 方法适合绵羊泰勒虫和无侵袭性泰勒虫的检测和区分。
