Table 2. Agreement between phenotypic and genotypic drug susceptibility testing by ion semiconductor sequencing.
| Genotypic DST results | Phenotypic DST results (N) | Agreement [Kappa (95% confidence interval)] | |
|---|---|---|---|
| Resistant | Susceptible | ||
| Isoniazid* | Not estimated | ||
| Mutated (N=29) | 29 | 0 | |
| Unmutated (N=1) | 1 | 0 | |
| Rifampin | Not estimated | ||
| Mutated (N=29) | 29 | 0 | |
| Unmutated (N=1) | 1 | 0 | |
| Ethambutol | Good [0.800 (0.590–1)] | ||
| Mutated (N=18) | 15 | 3 | |
| Unmutated (N=12) | 0 | 12 | |
| Pyrazinamide | Good [0.734 (0.452–1)] | ||
| Mutated (N=8) | 6 | 2 | |
| Unmutated (N=22) | 1 | 21 | |
| Streptomycin | Good [0.769 (0.523–1)] | ||
| Mutated (N=9) | 8 | 1 | |
| Unmutated (N=21) | 2 | 19 | |
| Amikacin and Kanamycin | Not estimated | ||
| Mutated (N=0) | 0 | 0 | |
| Unmutated (N=30) | 0 | 30 | |
| Fluoroquinolones† | Good [0.783 (0.374–1)] | ||
| Mutated (N=2) | 2 | 0 | |
| Unmutated (N=28) | 1 | 27 | |
*Results of agreement are for katG mutation and phenotypic INH resistance only; †Fluoroquinolones include ofloxacin, moxifloxacin, and levofloxacin.
Abbreviation: DST, drug susceptibility testing.