广西奶牛隐孢子虫病的流行病学调查

为了调查广西奶牛隐孢子虫病的流行情况,采用饱和蔗糖溶液漂浮法和改良抗酸染色法对广西9个奶牛场和4个奶牛个体养殖户的1 612头份粪样进行隐孢子虫卵囊的检测,并以基于18SrRNA基因的PCR-RFLP技术对分离的隐孢子虫卵囊进行种类鉴定。结果显示,7个奶牛场发现存在隐孢子虫感染,隐孢子虫阳性粪样为189头份,总感染率为11.72%(189/1 612)。在感染的年龄段上,1～6月龄犊牛的隐孢子虫感染率为21.3%,显著高于7～12月龄的青年牛(9.6%)和大于1岁龄的成年牛(3.8%)(P<0.01)。感染季节以冬季感染较高,但与夏季感染结果相比差异不显著(P>0.05)。PCR-RFLP分析显示,分离的7个隐孢子虫株均为安氏隐孢子虫。调查表明,广西奶牛隐孢子虫虫株以安氏隐孢子虫为主,感染率与河南、江苏、安徽、吉林等省份相似。

Epidemiological investigation of cryptosporidiosis in dairy cattle in Guangxi,China

To investigate the prevalence of cryptosporidiosis in dairy cattle in Guangxi Province,Cryptosporidium oocysts were collected by the Sheater’s sugar flotation technique and the modified acid-fast stain method from 1 612 fecal samples which were collected from nine Holstein dairy cattle farms and four individual Holstein dairy cattle farms.The Cryptosporidium oocysts were then identified using the PCR-RFLP based on the 18S rRNA gene.Results showed that the infection rate of Cryptosporidium was 11.72%(189/1 612),distributed in seven Holstein dairy cattle farms.The infection rate of Cryptosporidium in 1-6-month-old cattle was 21.3%,which was significantly higher than that in 7-12-month-old cattle(9.6%) and above 1-year-old cattle(3.8%)(P<0.01).The infection rate of Cryptosporidium in winter was higher than that in summer,however,no significant difference was found(P>0.05).PCR-RFLP analysis suggested that seven Cryptosporidium isolates all belonged to Cryptosporidium andersoni.The results indicated that the C.andersoni was the predominant species of Cryptosporidium in dairy cattle in Guangxi.The infection rate of Cryptosporidium in dairy cattle was similar to that in Henan,Jiangsu,Anhui,and Jilin provinces.