云南省腾冲市牛羊感染梨形虫的分子流行病学调查

Molecular epidemiological investigation of Piroplasma infection in cattle and sheep in Tengchong,Yunnan Province

为了解腾冲市牛、羊感染梨形虫的流行情况,本研究选择腾冲市11个乡镇为采样点,采集牛、羊血液样本,采用分子生物学方法,扩增包括泰勒虫属和巴贝斯虫属在内的梨形虫科18S rRNA基因约1600 bp片段,阳性产物进行测序,根据序列同源性比对和遗传进化分析,进行虫种鉴定。共采集758头牛、羊的血样,检出阳性207头,总阳性率27.31%。其中牛、羊阳性率分别为45.02%(149/331)、13.58%(58/427)。11个乡镇的牛均有检出,6个乡镇的羊有阳性。检出虫种包括巴贝斯虫(Babesia)和泰勒虫(Theileria)两属共13种,均为蜱传血液原虫,泰勒虫占82.13%(170/207),巴贝斯虫占17.87%(37/207)。巴贝斯虫种类包括:狍巴贝斯虫(B.capreoli)、猎户巴贝斯虫(B.venatorum)、双芽巴贝斯虫(B.bigemina)、牛巴贝斯虫(B.bovis)、微小巴贝斯虫(B.microti)等5种;泰勒虫种类包括:吕氏泰勒虫(T.luwenshuni)、环形泰勒虫(T.annulata)、水牛泰勒虫(T.buffeli)、东方泰勒虫(T.orientalis)、瑟氏泰勒虫(T.sergenti)、绵羊泰勒虫(T.ovis)、附膜泰勒虫(T.velifera)和一种新的未命名泰勒虫共8种。牛感染6种泰勒虫和4种巴贝斯虫,羊感染3种泰勒虫和2种巴贝斯虫。该结果表明腾冲市养殖的牛羊存在梨形虫病的广泛流行,且虫种丰富,具有较高的多样性特征,需加强防范。

To understand the status of Piroplasma infection in cattle and sheep in the Tengchong area of Yunnan Province so as to provide scientific basis for the prevention of animal epidemics and to promote the development of animal husbandry in the arrea,blood samples were collected from cattle and sheep in 11 villages and towns there.The 18S rRNA gene sequence of the Piroplasma family was amplified by using PCR.Positive PCR products were sequenced.The species of Piroplasma were identified by homology comparison and phylogenetic analysis.Of the 758 blood samples collected from cattle and sheep,27.31%(207/758)were positive;the positive rates in cattle and sheep were 45.02%(149/331)and 13.58%(58/427),respectively.A total of 13 species of tick-borne blood protozoa under the Babesia genera and Theileria genera were detected.The positive rates of the two genera were 82.13%(170/207)and 17.87%(37/207),respectively.The species of Babesia detected in the study included B.capreoli,B.venatorum,B.bigemina,B.bovis,and B.microti.The species of Theileria detected in the study included T.luwenshuni,T.annulata,T.buffeli,T.orientalis,T.sergenti,T.ovis,T.velifera and a novel species.Six species of Theileria and four species of Babesia were detected in cattle,and three species of Theileria and two species of Babesia were detected in sheep.Piroplasmosis was endemic in cattle and sheep in Tengchong with high diversities which calls for more effective prevention of the disease in Tengchong.