中文摘要：

目的探究VEG株弓形虫卵囊对中国昆明小鼠的致病性。方法分别选择〈1个,100个~108个的VEG株弓形虫卵囊灌胃昆明小鼠,采用MAT、H＆E和IHC方法研究小鼠对弓形虫的感染情况,并分析小鼠感染率,生存率及其大脑内的弓形虫包囊数量。结果≥10~2个VEG株弓形虫卵囊可引起小鼠100%感染,最低致死剂量为10~2个卵囊,100%致死剂量为108个卵囊,急性期死亡时间为7DPI~14DPI,弓形虫的成囊率是32.14%（9/28）,包囊数量为9~857个/只小鼠大脑,感染小鼠生存率为67.44%（29/43）,最长存活时间≥390DPI。结论 VEG株弓形虫卵囊对昆明小鼠的毒力中等,包囊形成率较高。

英文摘要：

To explore the pathogenicity of VEG strain Toxoplasma gondii oocysts on China Kunming mice,T.gondii oocysts of 1 and 102-108 were chosen to feed the mice orally.And the modified agglutination test（MAT）,HE and IHC were used to check the infection of mice.The infection rate,the survival rate of mice,and number of cysts in brain were analyzed.Results showed that 100% of the mice fed with ≥10~2 oocysts were infected,the minimum lethal dose was 10~2 oocysts and the 100% lethal dose was 108 oocysts.The time of death in acute infection was 7DPI to 14 DPI.T.gondii cysts formation rate was 32.14%（9/28）,and the number of cysts was 9 to 857 per mouse.The survival rate of infected mice was 67.44%（29/43）,and the longest survival time was more than 390 DPI.Accordingly,the virulence of T.gondii VEG strain is medium,and has a higher cysts formation rate.