Inhibition of Growth of T-Strain Mycoplasmas by Hydroxamic Acids and by Aurothiomalate

Abstract

Sorbyl-, benzoyl-, and 3-amino-benzoyl hydroxamic acids inhibited the development of an alkaline p H by T-strain cultures grown in broth containing 0.05% urea and phenol red. The specificity of this urease inhibition was demonstrated by the inhibition, by 10 −4 m sorbyl-hydroxamic acid, of the release of 14 CO 2 from 14 C-urea by washed T-strain mycoplasmas in 4 hr of incubation. Sorbyl-, benzoyl-, and 3-amino-benzoyl hydroxamic acids at a concentration of 10 −3 m markedly inhibited the multiplication of T-strain 354 during 18 hr of incubation; this inhibition was not corrected by thymidine at a concentration of 500 μg per ml. Aurothiomalate was 20 times more inhibitory to Mycoplasma hominis DC-63 than to T-strain 354; equivalent inhibitory concentrations were 50 μg per ml for M. hominis and 1,200 μg per ml for T strains.