TABLE 3.
Antibiotic resistance of all M. abscessus isolatesa
| Isolate group (n) | Antibiotic | No. of isolates/MIC (mg/ml) of: |
No. (%) resistant isolatesb | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0.06 | 0.125 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | |||
| Resistant (69) | Clarithromycin before induction | 7 | 11 | 13 | 10 | 9 | 19 | 28 (40.6) | ||||||
| Clarithromycin after induction | 1 | 68 | 68 (98.6) | |||||||||||
| Amikacin | 2 | 13 | 35 | 10 | 8 | 1 | 1 (1.4) | |||||||
| Linezolid | 1 | 3 | 2 | 10 | 20 | 33 | 33 (47.8) | |||||||
| Moxifloxacin | 1 | 3 | 65 | 68 (98.6) | ||||||||||
| Doxycycline | 1 | 68 | 68 (98.6) | |||||||||||
| Imipenem | 3 | 14 | 52 | 66 (95.7) | ||||||||||
| Tobramycin | 9 | 22 | 38 | 60 (87.0) | ||||||||||
| Cefoxitin | 3 | 23 | 43 | 43 (62.3) | ||||||||||
| Sulfonamides | 2 | 7 | 22 | 22 | 16 | 38 (55.1) | ||||||||
| Tigecycline | 4 | 10 | 30 | 16 | 9 | ND | ||||||||
| Sensitive (31) | Clarithromycin before induction | 2 | 9 | 4 | 8 | 3 | 3 | 3 | 6 (19.4) | |||||
| Clarithromycin after induction | 7 | 4 | 7 | 4 | 1 | 4 | 4 | 8 (25.8) | ||||||
| Amikacin | 2 | 3 | 15 | 9 | 1 | 1 | 1 (3.2) | |||||||
| Linezolid | 1 | 7 | 10 | 13 | 13 (42.0) | |||||||||
| Moxifloxacin | 1 | 2 | 28 | 30 (96.8) | ||||||||||
| Doxycycline | 1 | 30 | 31 (100) | |||||||||||
| Imipenem | 1 | 4 | 26 | 30 (96.8) | ||||||||||
| Tobramycin | 1 | 9 | 21 | 30 (96.8) | ||||||||||
| Cefoxitin | 2 | 7 | 22 | 22 (71.0) | ||||||||||
| Sulfonamides | 1 | 5 | 7 | 10 | 8 | 18 (58.1) | ||||||||
| Tigecycline | 2 | 6 | 10 | 7 | 6 | ND | ||||||||
a
The erm(41) sequevar-dependent resistance of 100 M. abscessus isolates to the antibiotics indicated was determined by the microdilution method. The incubation time was 3 days (before) and 14 days (after) induction for CLA and 3 days for the other antibiotics listed.
b
Resistant isolates were distinguished according to the breakpoint provided by NCCLS document M24-A2. ND, no data. Tigecycline has no recommended breakpoint.