TABLE 1.
Detection of isoniazid resistance in clinical isolates by the G-MTBDR and the G-MTBDRplus assays compared with sequencing data
| Assay | Gene | No. (%) of isolates carrying:a
|
||
|---|---|---|---|---|
| Wild-type gene | Isoniazid-resistant gene | Indeterminate genec | ||
| GT-MTBDRb | katG | 55 (31.8) | 117 (67.6) | 1 (0.6) |
| GT-MTBDRplus | katG | 55 (31.8) | 117 (67.6) | 1 (0.6) |
| inhA | 153 (88.4) | 20 (11.6) | 0 (0.0) | |
| Sequence analysis | katG | 55 (31.8) | 117 (67.6) | 1 (0.6) |
| inhA | 153 (88.4) | 20 (11.6) | 0 (0.0) | |
a
The isolates tested (n = 173) were previously determined to be isoniazid resistant by drug susceptibility testing.
b
The GT-MTBDR assay did not target the inhA gene.
c
In one isolate, the katG gene was not detected by either the GT-MTBDR or GT-MTBDRplus assay, which sequence analysis confirmed as being due to several mutations in the same gene.