Detection of DNA polymerase activity in Chlamydia psittaci

DNA polymerase activities of intact and disrupted suspensions of the mature infectious, extracellular elementary bodies of the meningopneumonitis strain of Chlamydia psittaci were studied. Intact elementary bodies failed to incorporate labeled thymidine triphosphate (TTP), but homogenates of the organisms did incorporate TTP into the acid insoluble fraction; the reaction continued at a linear rate for 60 min and the newly synthesized DNA hybridized exclusively with DNA derived from C. psittaci elementary bodies. Synthesized DNA sedimented in 2 fractions in alkaline sucrose gradients, one in the 50S region and the other in the 10S region, corresponding to molecular weights of 2 X 10(7) and 5 X 10(5) daltons, respectively.