INHIBITION OF THE GROWTH OF AGENTS OF THE PSITTACOSIS GROUP BYd-CYCLOSERINE AND ITS SPECIFIC REVERSAL BYd-ALANINE

Abstract

D-Cycloserine inhibited multiplication of four members of the psittacosis group in chick embryo yolk sac. D-Alanine reversed each inhibition. In infections with the agent of mouse pneumonitis, the most sensitive member of the psittacosis group tested, (D-alanine) competitively antagonized the growth inhibition produced by D-cycloserine. Of a number of other potential reversing agents, only DL-alanyl-DL-alanine reversed the effect of D-cycloserine on mouse pneumonitis agent. The significance of the susceptibility of the psittacosis group to D-cycloserine is discussed in light of the known mode of action of this antibiotic on bacteria.