幼年大鼠隐孢子虫感染模型的建立

Animal Model of Cryptosporidial Infection in Yong Rats

目的：建立大鼠隐孢子虫（CPS）感染模型。方法：采用地塞米松2mg／kg·d灌喂大鼠，第8无灌胃接种人源型隐孢子虫卵囊（CSO）。结果：大鼠在接种后第3天起粪便CSO计数明显增加，第6天达高峰，此后维持在较高水平。动物无腹泻症状。病理切片发现小肠粘膜表面有虫体定植，肠绒毛出现病变。结论：用地塞米松免疫抑制大鼠，然后接种CSO，建立CPS感染模型成功。

To establish an animal model of CPS infection. METHOD: Two-month-old female Sprague-Dawley rats were fed with dexamethasone (DEX) 2mg/kg·d during the whole experiment. On d8,they were inoculated with Cryptosporidium paroum oocysts (CSO,isolated from infected children)5×106 per rat p. o. to form the infection model. RESULTS: The density of CSO shed with stool began to increase on d3 after infection,remained at high level from d6 through d35 when the animals were killed. Diarrhea was not seen in any of the rats. Light and electron microscopies showed the parasites were localized on the epithelium of small intestine. There was atrophy,and sometimes fusion of villi, and widening and deepening of crypts. CONCLUSION: The animal model of CPS infection can be established in DEX immunosuppressed young rats by oral inoculation with CSO of human origin.