3个马群感染马泰勒虫的分子病原学调查

Investigation of Molecular Etiology of Theileria equi Infection in Three Herds

试验采用显微镜观察、PCR和竞争性酶联免疫吸附试验（competitive enzyme-linked immunosorbentassay,cELISA）等方法对贵州矮马、西南马和伊犁马的马泰勒虫病的感染状况进行研究。结果显示,从32份新鲜的血液涂片中,观察到形态完整的马泰勒虫（Theileria equi）虫体,检出率12.5%。从贵州矮马、西南马及伊犁马3个马群血液总DNA中都检测到马泰勒虫的18SrRNA基因片段,与已知序列的同源性为97%～100%;相比之下,贵州矮马与伊犁马的阳性率相近,分别为76.62%和73.81%,西南马较低,仅为33.33%。另外,经cELISA检测,与伊犁马（31.71%）相比,贵州矮马和西南马血液中抗马泰勒虫抗体的阳性率较低,分别为24.68%和12.12%,并与两个马群的血液理化指标存在一定的联系：与中性细胞数量、γ-谷氨酰转移酶和肌酸激酶的含量呈弱正相关;与红细胞、白细胞、血小板、淋巴细胞数量及血红蛋白含量呈弱负相关。这些研究结果提示3个马群中均存在较高比例的马泰勒虫感染。

To explore the prevalence of Theileriaequi（T.equi）infection in horse in Guizhou province,the antibody level and 18 SrRNA gene were detected from blood samples of Guizhou pony,Southwest horse and Yili horse using competitive ELISA and PCR methods.Giemsa-stained blood smear was prepared to observe T.equi in red blood cells.Intact protozoans of T.equi were observed in red blood cells of horses at Giemsa-stained slide smears with a detection rate of12.5%.The 18 SrRNA gene fragment of T.equi was detected in Guizhou pony,Southwest horse and Yili horse,and the consistent rates with the known nucleotide sequence were 97%to 100%.The PCR result indicated that the positive rates of T.equi in Guizhou pony（76.62%）and Yili horse（73.81%）were similar,which were higher than that in Southwest horse（33.33%）.Furthermore,the antibody levels against T.equi in Guizhou pony（24.68%）and Southwest horse（12.12%）were lower than that in Yili horse（31.71%）.A weak correlation between the antibody level and the blood physicochemical indexes was calculated from Guizhou pony and Southwest horse,including weak positive correlations with neutrophils numbers,gamma-glutamyl transferaseand creatine kinase levels,and weak negative correlations with the numbers of red blood cell,white blood cell,platelet and lymphocyte and contents of hemoglobin.It suggested that a higher proportion of T.equi infection present in three herds.