Simplified diagnostic susceptibility testing of mycobacteria against thiacetazone, hydroxylamine, p-nitrobenzoic acid and picric acid.

In order to simplify diagnostic susceptibility testing of mycobacteria against thiacetazone, hydroxylamine, p-nitrobenzoic acid and picric acid, we modified the standard procedure by using Middlebrook 7H11 agar in a single quadrant petri dish. This plate can be inoculated and read in parallel with routine susceptibility tests done by the proportion method. We present results of 449 consecutive routine strains tested with our method.