Analysis of ribosomes from viomycin-sensitive and -resistant strains of Mycobacterium smegmatis.

Viomycin-resistant strains were isolated from Mycobacterium smegmatis . Ribosomes were isolated and tested for drug resistance in subcellular systems containing poly(U) as messenger ribonucleic acid. Resistance to viomycin in these strains was due to altered ribosomes. Further analysis showed that viomycin resistance of two mutants with low level resistance (20 μg/ml) was due to altered 30 S ribosomal subunits. Another mutant that was highly resistant to viomycin (1 mg/ml), however, had altered 50 S ribosomal subunits.