TABLE 2.
Spectrum of rpoB mutations in spontaneous Rif-resistant mutants derived from M. tuberculosis mutant strains lacking dinB1 and/or dinB2
| Base change | Codon mutation | Substitution | Frequency of mutation (%)a |
|||
|---|---|---|---|---|---|---|
| H37Rv | dinB1::hyg mutant | ΔdinB2 mutant | ΔdinB1::hyg ΔdinB2 mutant | |||
| C→T | TCG→TTG | Ser531→Leu | 69.6 | 82.6 | 56.5 | 50 |
| A→G | CAC→CGC | His526→Arg | 21.7 | 8.7 | 17.4 | 20.8 |
| C→G | CAC→GAC | His526→Asp | 8.7 | 0 | 0 | 0 |
| C→T | CAC→TAC | His526→Tyr | 0 | 8.7 | 21.7 | 25 |
| A→C | CAC→CCC | His526→Pro | 0 | 0 | 0 | 4.2 |
| C→G | TCG→TGG | Ser522→Trp | 0 | 0 | 4.4 | 0 |
a
Twenty-three independent Rif-resistant mutants were analyzed for H37Rv and the dinB1::hyg and ΔdinB2 mutants, and 24 mutants were analyzed for the ΔdinB1::hyg ΔdinB2 mutant.