Inhibition of growth of T-strain mycoplasmas by hydroxamic acids and by aurothiomalate.

Sorbyl-, benzoyl-, and 3-amino-benzoyl hydroxamic acids inhibited the development of an alkaline pH 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 mug per ml. Aurothiomalate was 20 times more inhibitory to Mycoplasma hominis DC-63 than to T-strain 354; equivalent inhibitory concentrations were 50 mug per ml for M. hominis and 1,200 mug per ml for T strains.