Factors Related to the Growth of Psittacosis Agent (Strain 6BG). VI. Host Cell Purine Nucleotide Pyrophosphorylases. ∗

Summary

The 6BC strain of psittacosis agent is sensitive to the growth inhibitory effects of 2, 6 diaminopurine (DP) and 8-aza-guanine (AZA) when infecting normal L cells. However, when L-cell mutants resistant to the analogs are derived and are infected with the psittacosis agent, its growth is not effectively inhibited by addition of DP to infected cultures of DP resistant cells. In contrast, addition of AZA to infected cultures of AZA resistant cells is as effective in inhibition of growth of psittacosis agent as it is when placed on infected, normal L-cells. The implications regarding the dependence of this agent on the metabolic functions of the host cell are discussed and the usefulness of this technic for investigation of the specific cellular enzymatic dependence of intracellular parasites is considered.