FIG. 3.

Effect of salicylate on induction of resistance to PAS and EMB. The susceptibilities of M. tuberculosis H37Ra to PAS (1 μg/ml) and EMB (4 μg/ml) were determined on 7H11 plates. Triplicate dilutions (10⁻¹, 10⁻², and 10⁻³) of the H37Ra liquid culture with or without 0.5 mM salicylate were plated onto 7H11 agar plates with or without 0.2 mM salicylate, which were then incubated at 37°C for 3 weeks. The activities of PAS and EMB were reduced in the presence of salicylate.