Abstract: Objective To establish encephalitozoonosis model of FMMU albino guinea-pig. Method FMMU albino guinea-pigs were divided into 2 groups: immunosuppressed group, non-immunosuppressed control group. Encephalitozoon cuniculi were isolated and purified from diseased rabbit, guinea-pigs were infected by intragas trie administration of E. cuniculi, and hydrocortisone was administered by intramuscular injection. E. cuniculi in faeces，clinical manifestations, and histopathologic changes in major organs were observed, the ultrastructure of E. cuniculi was observed by electron microscope(EM). Result E. cuniculi were detected from hydrocortisone-immunosuppressed guinea-pigs at day 3 post infection, one day earlier than that of non-immunosuppressed ones, and all immunosuppressed guinea-pigs were detected with E. cuniculi at day 6, ahead of control group 2 days. Minority of guinea-pigs in control group showed loss of appetite and emaciation, others were asymptomatic. Emaciation and ascites could be seen in immunosuppressed guinea-pigs, and 5 of which had neurological and urinary symptoms such as wryneck, convulsion, oliguria and painful urination at day 35 post infection. Mortality rate was 25% at day 40 post infection in immunosuppressed group. Under light microscope there were focal lymphoepithelioid granuloma in internal organ, such as brain, kidney and liver. EM observation showed that E. cuniculi spore has a trilaminar wall, the interior polar tube was arranged into 6 coils. Conclusion E. cunicul infection model of immunosuppressed FMMU albino guinea-pig was established successfully and could be used as acute Encephalitozoonosis animal model for human and other animals.

Key words: Encephalitozoon cuniculi, FMMU albino guinea-pig, Immunosuppression, Encephalitozoonosis