Potential subtypes of Chlamydia psittaci based on effects of cortisone with cytochalasin B or cycloheximide

Strains of Chlamydia psittaci were differentiated as to their biological characteristics using growth in Vero cells. These host cells were chlamydial infected without centrifugation, but treated with either cortisone and cytochalasin B or cortisone and cycloheximide. The criterion was the time of 100% cytopathic effect and specific sloughing, accompanied by the maximum infectivity of C. psittaci. Possible subtypic characteristics were determined for three avian strains.