TABLE 3.

Spectrum of mutations in the RRDR locus of rifampin-resistant isolates of three M. smegmatis strains

Mutations detected% of M. smegmatis isolates with indicated mutations (no. with mutations/total)a
WT (hyg)bung::kancpMVnarK2ungd
A→G, T→C43 (18/42)14 (4/28)72 (34/47)
C→T, G→A45 (19/42)86 (24/28)21 (10/47)
C→G, G→C5 (2/42)None2 (1/47)
C→A, G→T5 (2/42)NoneNone
A→C, T→G2 (1/42)None4 (2/47)
  • a Bacterial cultures (five replicates for each strain) were subjected to hypoxia and, at the end of the 10-day incubation, plated on medium containing rifampin. The RRDR loci from the rifampin-resistant colonies were sequenced. Values in parentheses are the number of isolates with the indicated mutations/the total number with mutations in the RRDR locus.

  • b A total of 50 samples were sequenced for mutations in the RRDR, of which 8 samples did not have mutations.

  • c A total of 45 samples were sequenced for mutations in the RRDR, of which 17 samples did not have mutations.

  • d A total of 63 samples were sequenced for mutations in the RRDR, of which 16 samples did not have mutations.