Table 3.
Genotypic resistance of 43 phenotypic MDR strains to first-line anti-TB drugs
| Drug | Resistance phenotype (No. of strains) | Resistance genotype | MIC (µg/mL) | Total | ||
|---|---|---|---|---|---|---|
| Gene | Mutations | No. of strains | ||||
| RFP | Resistant (43) | rpoB | S450L | 23 | 16 | 42/43 |
| D435V | 3 | 16 | ||||
| D435G | 1 | 16 | ||||
| Q450L | 1 | 2 | ||||
| L452P | 1 | 2 | ||||
| H445Y | 4 | 16 | ||||
| Q432P | 1 | 16 | ||||
| H445Q\S450W | 1 | 16 | ||||
| L430R\H445Y | 1 | 16 | ||||
| D435Y\P454L | 1 | 1 | ||||
| L430R\D435N | 1 | 1 | ||||
| N437D\L452P | 1 | 16 | ||||
| L430P\S431G | 1 | 16 | ||||
| A286V\S450L | 1 | 0.12 | ||||
| L430R\D435G | 1 | 8 | ||||
| RFB | Resistant (32) | rpoB | S450L | 23 | 2,4,8,16 | 31/32 |
| Q450L | 1 | 2 | ||||
| L452P | 1 | 1 | ||||
| H445Y | 3 | 2,16 | ||||
| H445Q\S450W | 1 | 2 | ||||
| L430R\H445Y | 1 | 4 | ||||
| N437D\L452P | 1 | 1 | ||||
| Susceptible (11) | rpoB | D435G | 1 | 0.5 | 11/11 | |
| D435V | 3 | 0.25 | ||||
| S450L | 2 | 0.12, 0.25 | ||||
| Q432P | 1 | 0.12 | ||||
| D435Y\P454L | 1 | 0.12 | ||||
| L430R\D435N | 1 | 0.25 | ||||
| A286V\S450L | 1 | 0.12 | ||||
| L430R\D435G | 1 | 0.12 | ||||
| INH | Resistant (43) | katG | S315T | 37 | 1, 2, 4 | 37/43 |
| EMB | Resistant (14) | embB | Q497R | 1 | 32 | 13/14 |
| G406A | 1 | 8 | ||||
| M306V | 6 | 8 | ||||
| M306L | 3 | 8 | ||||
| E405D | 1 | 8 | ||||
| Q497K | 1 | 8 | ||||
| Susceptible (29) | embB | G406A | 1 | 4 | 8/29 | |
| M306V | 2 | 4 | ||||
| M306L | 4 | 2, 4 | ||||
| embA | C 12 T | 1 | 4 | |||
| Sm | Resistant ( 34) | rpsL | K43R | 20 | 8, 32 | 31/34 |
| K88R | 5 | 8, 16, 32 | ||||
| rrs | A514C | 2 | 8,32 | |||
| C517T | 1 | 32 | ||||
| rpsl/rrs | K43T/A514C | 2 | 32 | |||
| rpsl/rrs | K43R/A1401G | 1 | 32 | |||
| Susceptible (9) | rrs | A514C | 1 | 2 | 1/9 | |