新疆南疆绵羊泰勒虫病分子流行病学调查

Molecular epidemiological survey of Theileria spp.in sheep from southern Xinjiang

目的了解新疆南疆绵羊的泰勒虫感染情况及其种类分布特征。方法基于泰勒虫通用引物和种特异性引物,采用PCR法检测该区域绵羊血液标本中的泰勒虫,并进行序列分析。结果 637份血液标本PCR检测泰勒虫阳性400份,总感染率为62.79%。其中,莎车县、英吉沙县和泽普县绵羊的泰勒虫感染率均为100%,不同采样点绵羊的泰勒虫感染率比较差异有统计学意义(χ~2=220.87,P<0.01);散养和圈养绵羊的泰勒虫感染率分别为72.62%(358/493)和29.17%(42/144),差异有统计学意义(χ~2=90.06,P<0.01);夏季和冬季绵羊的泰勒虫感染率分别为44.01%(125/284)和77.90%(275/353),差异有统计学意义(χ~2=90.06,P<0.01)。经种特异性引物PCR扩增和序列比对,400个泰勒虫阳性样品中,399个为绵羊泰勒虫,1个为环形泰勒虫,未检出尤氏泰勒虫和吕氏泰勒虫。结论新疆南疆绵羊的泰勒虫病流行严重,感染虫种主要为绵羊泰勒虫,应加强对该地区泰勒病的防控。

Objective To ascertain the prevalence and distribution characteristics of Theileriaspp.in sheep from the Southern Xinjiang Uyghur Autonomous Region. Methods Blood samples from sheep were examined using a nested polymerase chain reaction（PCR）based on universal primers and species-specific primers,and sequences of Theileriaspp.were analyzed. Results Of 637 blood samples,400 were positive for Theileriaspp.The overall rate of infection with Theileriaspp.was 62.79%.The rate of infection with Theileriaspp.differed significantly among sampling sites（P〈0.01）,with the highest rate of infection of 100%in Yarkant County,Yengisar County,and Poskam Country.The prevalence of the parasite differed significantly by the way in which sheep were fed and the season（P〈0.01）.Seventy-twopoint-six percent（358/493）of grazing sheep and 29.17%（42/144）of sheep fed in pens tested positive.Forty-four-pointzero-one percent（125/284）of all sheep tested positive in summer and 77.90%（275/353）tested positive in winter.Based on amplification of species-specific primers and sequencing,399 of 400 samples contained T.ovis while the remainder contained T.annulata.T.luwenshuni and T.uilenbergi were not detected. Conclusion This study indicated that sheep in southern Xinjiang are seriously infected with Theileria spp.and that T.ovis was the most common species.Therefore,control of malignant ovine theileriosis should be enhanced in that region.