中文摘要：

为比较微小隐孢子虫不同亚型对小鼠的感染性,分别从河南和宁夏的犊牛体内获得两株微小隐孢子虫,利用分子方法进行基因亚型鉴定后,分别感染提前免疫抑制的3～6周的BALB/c小鼠,对感染前后小鼠粪样进行显微观察和PCR检测。结果显示,2个微小隐孢子虫分离株的亚型分别为ⅡdA19G1和ⅡdA15G2R1;2个亚型均可感染BALB/c小鼠,其中ⅡdA15G2R1感染小鼠后2d和3d可在显微镜下观察到卵囊,而感染ⅡdA19G1的小鼠在任何时间均未在显微镜下观察到卵囊;PCR检测发现2个亚型的小鼠排卵囊周期分别为18d和20d。该研究结果为微小隐孢子虫感染小鼠模型的建立提供一定理论依据。

英文摘要：

To study the infectivity of differentⅡ d subgenotypes of Cryptosporidium parvumin mice,two isolates of C.parvum were obtained from calves in Henan province and Ningxia Hui Autonomous Region.After subgenotype identification using molecular technology,3-6weeks old BALB/c mice were taken orally with dexamethasone and then infected with oocysts of the two isolates.The feces from mice were examined using the Sheater＇s sugar flotation and nested-PCR techniques.The results showed that the two isolates were C.parvumsubgenotypes ofⅡdA19G1and ⅡdA15G2R1,respectively,and both of two subgenotypes can infect BALB/c mice.By microscopic examination,oocysts were detected in feces of mice infected with the subgenotype ⅡdA15G2R1at post-infection 2day（2dpi）and 3dpi,but no oocyst was found in mice with subgenotypeⅡdA19G1in whole study.However,nested-PCR examination showed successive 18 days and 20 days of oocyst excretion for mice infected with two isolates,respectively.The present study provided a theoretical basis for the establishment of the mice infection model with C.parvum.