Propagation of Cryptosporidium baileyi in the chicken embryonated SPF eggs

Cryptosporidium baileyi is one of the pathogen protozoa which is specific for poultry. C. baileyi is able to infect، grow and reproduce in epithelial cells of respiratory، gastrointestinal and urinary tracts of chickens. This parasite has been isolated from Iran poultry industry. The aim of this study was to propagate the parasite in the chicken embryonating SPF eggs. Oocysts were maintained by passage through chicks. Faeces containing excreted oocysts were mixed with 2. 5% potassium dichromate (w/v) and stored at 4°C. Oocysts of C. baileyi were purified and cleaned by modification of Sheater’s sugar flotation method and using 1% sodium hypochlorite solution. The oocysts were washed with PBS and appropriate antibiotics were added. Ten day- old embryonating SPF eggs were inoculated via allantoic cavity with 1x 105 oocysts or equivalent oocysts exposed by excystation fluid. The eggs inoculated by samples were incubated 7 days at 37 ºC and candled once a day. The results showed that both inoculated samples were able to grow and propagate in chorio allantoic membrane and release the oocysts in allantoic fluid. Inoculation of 1x105 oocysts caused releasing of 1x106 oocysts in the allantoic fluid of one egg. Upon the results the propagation of C. baileyi in the chicken embryonating SPF eggs can be used in research works. This method can be used for limited propagation of the parasite using the intact oocysts as inoculated samples in embryonating eggs of chickens or even other birds..