Table 3.
The resistance rates of 77 slowly growing mycobacteria isolates against eight antibiotics using the broth microdilution method.
| SGM species | Antibiotics | Antibiotics breakpoints |
MIC50 | MIC90 | Susceptibility profile |
||||
|---|---|---|---|---|---|---|---|---|---|
| Susceptible | Intermediate | Resistant | S (%) | I (%) | R (%) | ||||
|
M. kansasii (n = 46) |
RIF | ≤ 1 | - | ≥ 2 | 1.0 | 16.0 | 26 (56.5) | 0 (0.0) | 20 (43.5) |
| MXF | ≤ 1 | 2 | ≥ 4 | 0.25 | 4.0 | 30 (65.2) | 10 (21.7) | 6 (13.0) | |
| CLR | ≤ 8 | 16 | ≥ 32 | 16.0 | ≥ 32 | 18 (39.1) | 20 (43.5) | 8 (17.4) | |
| EMB | ≤ 2 | 4 | ≥ 8 | 4.0 | 16.0 | 24 (52.1) | 8 (17.4) | 14 (30.4) | |
| AMK | ≤ 16 | 32 | ≥ 64 | 1.0 | 4.0 | 46 (100) | 0 (0.0) | 0 (0.0) | |
| LZD | ≤ 8 | 16 | ≥ 32 | ≥ 32 | ≥ 32 | 1 (2.2) | 4 (8.6) | 41 (89.1) | |
| INH | ≤ 0.5 | - | ≥1 | ≥ 32 | ≥ 32 | 1 (2.2) | 0 (0.0) | 45 (97.8) | |
| CFZ | - | - | ≥1 | ≥ 64 | ≥ 64 | 12 (26.0) | 0 (0.0) | 34 (73.9) | |
|
M. simiae (n = 21) |
RIF | ≤ 1 | - | ≥ 2 | ≥ 16 | ≥ 16 | 0 (0.0) | 0 (0.0) | 21 (100) |
| MXF | ≤ 1 | 2 | ≥ 4 | 2.0 | 16.0 | 6 (28.5) | 5 (23.8) | 10 (47.6) | |
| CLR | ≤ 8 | 16 | ≥ 32 | 16.0 | ≥ 32 | 4 (19.0) | 12 (57.1) | 5 (23.8) | |
| EMB | ≤ 2 | 4 | ≥ 8 | 16.0 | 16.0 | 10 (47.6) | 0 (0.0) | 11 (52.4) | |
| AMK | ≤ 16 | 32 | ≥ 64 | 1.0 | 4.0 | 19 (90.4) | 0 (0.0) | 2 (9.5) | |
| LZD | ≤ 8 | 16 | ≥ 32 | ≥ 32 | ≥ 32 | 0 (0.0) | 0 (0.0) | 21 (100) | |
| INH | ≤ 0.5 | - | ≥1 | ≥ 32 | ≥ 32 | 0 (0.0) | 0 (0.0) | 21 (100) | |
| CFZ | - | - | ≥ 1 | ≥ 64 | ≥ 64 | 0 (0.0) | 0 (0.0) | 21 (100) | |
|
MAC (n = 10) |
RIF | ≤ 1 | - | ≥ 2 | 4.0 | 16.0 | 0 (0.0) | 0 (0.0) | 10 (100) |
| MXF | ≤ 1 | 2 | ≥ 4 | ≤ 0.25 | 2.0 | 7 (70.0) | 2 (20.0) | 1 (10.0) | |
| CLR | ≤ 8 | 16 | ≥ 32 | 8.0 | 16.0 | 7 (70.0) | 2 (20.0) | 1 (10.0) | |
| EMB | ≤ 2 | 4 | ≥ 8 | 2.0 | 8.0 | 6 (60.0) | 1 (10.0) | 3 (30.0) | |
| AMK | ≤ 16 | 32 | ≥ 64 | ≤ 0.5 | 4 | 10 (100) | 0 (0.0) | 0 (0.0) | |
| LZD | ≤ 8 | 16 | ≥ 32 | ≥ 32 | ≥ 32 | 0 (0.0) | 0 (0.0) | 10 (100) | |
| INH | ≤ 0.5 | - | ≥ 1 | ≥ 32 | ≥ 32 | 0 (0.0) | 0 (0.0) | 10 (100) | |
| CFZ | - | - | ≥ 1 | 16.0 | ≥ 64 | 3 (30) | 0 (0.0) | 7 (70) | |
|
Total resistant n (%) |
RIF | MXF | CLR | EMB | AMK | LZD | CFZ | INH | |
| 51 (66.2) | 17 (22.1) | 14 (18.2) | 26 (33.8) | 2 (2.6) | 76 (98.7) | 68 (88.3) | 58 (75.3) | ||
S: susceptible; I: intermediate; R: resistant; RIF: rifampin; MXF: moxifloxacin; CLR: clarithromycin; EMB: ethambutol; AMK: amikacin; LZD: linezolid; CFZ: clofazimine; INH: isoniazid.