Spontaneous and experimental infections of Xenopus laevis with Chlamydia psittaci.

Chlamydial infection was suspected when widespread pyogranulomatous inflammation and large basophilic intracytoplasmic inclusion bodies were evident histopathologically in African clawed frogs (Xenopus laevis) dying of a spontaneous disease of high morbidity and mortality. Organism morphology was determined by electron microscopy of infected hepatic sinusoidal lining cells, and it was characteristic of the unique developmental cycle of a chlamydial agent. Isolation and speciation of the organism was achieved in a McCoy cell culture system. The infected cells were inoculated into disease-free frogs reproducing the disease.