Vaccinia virus directed RNA and protein synthesis in the presence of rifampicin

The effects of rifampicin, an inhibitor of bacterial DNA transcription, on the formation of infectious vaccinia virus and viral particles, RNA and proteins were studied under single step growth conditions. Although virion formation was inhibited by more than 99%, the synthesis of early and late viral directed RNA species, as characterized by their sedimentation properties, was unaffected. Rifampicin did not prevent the synthesis of early and late viral proteins identified by immunodiffusion, disc gel electrophoresis and disc gel immunoelectrophoresis. The drug also did not inhibit the in-vitro activity of the virion associated RNA polymerase.