Scanning electron photomicrographs of
Cryptosporidium baileyi (Cryptosporidiidae)

Cryptosporidium baileyi infects the cloaca, bursa, and sometimes respiratory tract of chickens. Heavy infections may develop, but significant clinical disease is usually associated only with respiratory cryptosporidiosis. The first two photos reveal the extent of the infections. The photograph in the upper right shows a single merozoite penetrating a host cell. The photograph in the lower left provides an unusual view of the basal portion of the feeder organelle after the parasite has become dislodged from the host cell. Two type I meronts can be seen in the photograph in the lower, middle panel. The last photograph in the lower right shows a microgamete penetrating a macrogamete.