Sensitivity to capreomycin and prothionamide in strains of Mycobacterium, Nocardia, Rhodococcus, and related taxa for taxonomical purposes.

Sensitivity to capreomycin and to prothionamide was analysed for 150 strains belonging to the genera Mycobacterium, Nocardia, Rhodococcus, and related taxa. The analyses showed, e.g., that strains of Mycobacterium chelonei and Nocardia brasiliensis were more resistant to capreomycin than the other strains tested and that M. farcinogenes differed from M. senegalense concerning sensitivity to this drug. The analysis showed, furthermore, that strains of Mycobacterium differ from those of Nocardia, Rhodococcus, “Mycobacterium album”, and “Gordona aurantiaca” in being more sensitive to prothionamide than these organisms. Strains designated N. amarae were more sensitive to both drugs than were the other tested strains of Nocardia, which indicates that N. amarae diverges from the other species of this genus.