Table 1.
Characteristics of 20 M. tuberculosis strains used in the multicenter evaluation.
| Isolate number (duplicate) | Susceptibility to PZA (100 µg/ml) | pncA mutation | Other drug resistanceb |
|||
|---|---|---|---|---|---|---|
| (multiple tests) | PZA MICa | Nucleotide | Amino | |||
| Consistently | Predominately | (ug/ml) | number | acid | ||
| 1 | Susceptible | — | ≤25 | C 195 → T | Ser65Ser | CIP |
| 4 | Resistant | — | >800 | A(-11) → G | NAc | RIF, CIP |
| 7 | Susceptible | — | 50 | None | NA | None |
| 8 | Susceptible | — | ≤25 | None | NA | None |
| 11 (23) | Susceptible | — | ≤25 | None | NA | None |
| 12 (24) | — | Susceptible | 75 | None | NA | None |
| 13 (25) | — | Susceptible | 75 | None | NA | None |
| 14 | Resistant | — | >100 | T 37 → C | Phe13Leu | INH |
| 16 (26) | — | Susceptible | 75 | None | NA | FQ |
| 17 | — | Resistant | 200 | A 139 → G | Thr47Ala | INH, RIF, AMK, EMB |
| 18 | Susceptible | — | 75 | C 509 → T | Ala170Val | None |
| 19 | Inconclusive | Inconclusive | 100 | C 244 → T | His82Tyr | None |
| 20 | Susceptible | — | 75 | G 538 → A | Val180Ile | None |
| 21 (27) | Inconclusive | Inconclusive | 100 | G 82 → A | Ala28Thr | INH, RIF, EMB |
| 22 | Susceptible | — | 50 | A 110 → T | Glu37Val | None |
aNumber of tests varied by isolate. When multiple tests were performed, the value is the approximate median. bCIP: ciprofloxacin; RMP: rifampin; INH: isoniazid; AMK: amikacin; EMB: ethambutol. cRegulatory mutation.