隐孢子虫卵囊攻击免疫抑制小鼠的剂量反应关系研究

Dose-response relationship after challenging of the immunosuppressed

目的求出小鼠尤其是免疫抑制小鼠感染隐孢子虫的ID5、ID50、ID95,为水质原虫卫生标准的制定提供依据。方法用地塞米松饮水喂饲小鼠建立免疫抑制模型,并对攻击剂量和感染率做线性回归分析,计算相应的ID5、ID50、ID95。结果免疫抑制组小鼠的胸腺指数、脾脏指数、血清IgG、IgM含量与相应的非免疫抑制组小鼠比较,均具有统计学差异(P<0.05);免疫抑制组小鼠感染隐孢子虫的ID5、ID50、ID95分别是4、44、445个卵囊,而非免疫抑制小鼠分别是12、360、10580个。免疫抑制条件下,小鼠感染隐孢子虫ID5、ID50、ID95的剂量降低。结论地塞米松使小鼠免疫功能受到抑制后,小鼠对隐孢子虫的易感性增加,制定水质原虫卫生标准时对免疫抑制群体应予以高度重视。

To calculate the ID5, ID50 and ID95 of mice, particularly the immunosuppressed mice after challenging with Cryptosporidium oocysts to provide a hygienic standard for the protozoa-infected water, dexamethasome (DEX) was fed to mice through drinking water to establish an immuno-suppressed animal model, and the mice were challenged with different doses of Cryptosporidium oocysts. Line regression analysis was made between challenging doses and rate of infection, and the corresponding ID5 ID50 and ID95 were calculated respectively. It was found that the weight indexes of spleen and thymus and the serum leve of IgG and IgM in the immuno-suppressed mice were to be lower than those of the immuno-competent mice, the ID5, ID50 and ID95 values of the infected mice were 4, 44 and 445 oocycts respectively, and those of the in-non-immunosuppressed mice were 12, 360 and 10580 respectively. It is concluded that the susceptibility of mice to Cryptospordium infection increases under immunosuppressed status, and this condition should be considered in case of shaping the standard for drinking water.