北京市房山区羊梨形虫病流行病学调查

EPIDEMIOLOGICAL SURVEY ON OVINE PIROPLASMOSIS AT BEIJING SUBURB

为了解北京郊区羊梨形虫病的流行情况，本研究采用形态学检测，同时结合使用梨形虫18S rRNA基因通用引物进行PCR与直接测序法，对来自北京市房山郊区某养殖场的120只山羊及15只绵羊全血样本进行检测。结果发现血涂片中梨形虫检测阳性率为95．0％，其中吕氏泰勒虫Theileria luwenshuni于山羊中检出115例阳性，阳性率95．8％；于绵羊中检出6只阳性；未发现其他泰勒虫以及巴贝斯虫的感染。本研究首次对北京周边地区进行羊梨形虫分子流行病学研究，发现房山地区为吕氏泰勒虫流行区，并且发现山羊对吕氏泰勒虫可呈现长期带虫感染。

The objective of this study is to investigate the existence of ovine and caprine theileriosis and to identify the pathogens in the countryside of Beijing. Firstly, peripheral blood smears from goats and sheep collected from Fangshan D. Beijing suburb were examined under microscope to ensure the infection of Piroplasmia and the genomic DNA was extracted from blood of goats and sheep and amplified using common primers targeting to 18S rRNA of Theileria spp. and Babesia spp. respectively for screening. Then, three sets of Theileria-specific primers targeting Theileria luwenshuni, Theileria uilenbergi, Theileria ovis, three common theileria parasites in China's Mainland, were applied to distinguish different theileria infections and nearly full-length of 18S rRNA gene sequences from four randomly selected positive goats were obtained and used for phylogenetical analysis. Results of this study showed high prevalence of T. luwenshuni infection （95. 8% ） in this farm but T. uilenbergi, T. ovis and Babesia spp. were not detected. Conclusion of our study is that countryside of Beijing is an endemic area of T. luwenshuni. The data will be useful for guiding the prevention and control of ovine and caprine theileriosis in this area .