Biotyping of Chlamydia psittaci based on inclusion morphology and response to diethylaminoethyl-dextran and cycloheximide

Strains of Chlamydia psittaci from cattle, sheep, pigs, mice, guinea pigs, rabbits, cats, and parrots were subdivided based on their biological characteristics. Chlamydiae grown in the yolk sac of chicken embryos were used to infect L cell monolayers. The host cells were infected without further treatment or treated with diethylaminoethyl-dextran, cycloheximide, or both. The following criteria were used for biotyping the strains: the morphology of the inclusions and time after infection at which they appeared, the effect of chlamydial multiplication on the host cell cytoskeleton, and the change in the number of cells infected in response to diethylaminoethyl-dextran and cycloheximide. These properties were determined for 29 strains of C. psittaci. Based on the results, the strains were placed into eight biotypes.