Table 4. In vitro antimicrobial susceptibilities of Mycobacterium avium-intracellulare complex (MAC).
| Antimicrobial | All*(%) |
M. avium (4) |
M. intracellulare (23) |
M. kansasii (3) |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MIC† (μg/mL) |
Susceptibility‡ [n, (%)] | MIC† (μg/mL) |
Susceptibility‡ [n, (%)] | MIC† (μg/mL) |
Susceptibility‡ [n, (%)] | ||||||||
| Range | MIC50 | MIC90 | Range | MIC50 | MIC90 | Range | MIC50 | MIC90 | |||||
| Slow growth mycobacterium (n = 30) | |||||||||||||
| Amikacin | NI | 1 to >64 | 32 | >64 | NI | 16 to >64 | 32 | >64 | NI | 8 to >64 | 32 | >64 | 2 (66.7) |
| Clarithromycin | 86.7 | 1 to >16 | 4 | >16 | 2 (50.0) | 1 to 64 | 2 | 4 | 22 (95.7) | 1 to >16 | 2 | >16 | 2 (66.7) |
| Linezolid | 3.3 | 32 to >64 | 64 | >64 | 0 | 16 to >64 | 32 | 64 | 0 | 16 to 64 | 32 | 64 | 1 (33.3) |
| Moxifloxacin | 0 | 2 to 64 | 8 | 64 | 0 | 2 to 16 | 8 | 16 | 0 | 2 to 16 | 8 | 16 | 0 |
| Ethambutol | NI | 2 to 8 | 4 | 8 | NI | 4 to >16 | 16 | >16 | NI | 4 to 16 | 8 | 16 | 1 (33.3) |
| Isoniazid | NI | 2 to 8 | 4 | 8 | NI | 2 to >8 | 4 | >8 | NI | 2 to >8 | 4 | >8 | NI |
| Rifampin | NI | 2 to 8 | 4 | 8 | NI | 2 to >8 | 4 | 8 | NI | 1 to 4 | 1 | 4 | 2 (66.7) |
| Antimicrobial | All*(%) | M. abscessus s.s.(5) | M. massiliense(4) | M. bolletii(1) | |||||||||
| MIC† (μg/mL) | Susceptibility‡ [n, (%)] | MIC† (μg/mL) | Susceptibility‡ [n, (%)] | MIC† (μg/mL) | Susceptibility‡ [n, (%)] | ||||||||
| Range | MIC50 | MIC90 | Range | MIC50 | MIC90 | Range | MIC50 | MIC90 | |||||
| Rapid growth mycobacterium (n = 10) | |||||||||||||
| Amikacin | 100 | 4 to 8 | 8 | 8 | 5 (100.0) | 4 to 16 | 4 | 16 | 4 (100.0) | 4 | 4 | 4 | 1 (100.0) |
| Clarithromycin | 60 | 2 to 4 | 4 | 4 | 2 (40.0) | 0.5 to 1 | 1 | 1 | 4 (100.0) | 4 | 4 | 4 | 0 |
| Linezolid | 10 | 32 to >32 | 32 | >32 | 0 | 8 to >32 | >32 | >32 | 1 (25.0) | >32 | >32 | >32 | 0 |
| Cefoxitin | 0 | 128 to >128 | >128 | >128 | 0 | 64 to >128 | >128 | >128 | 0 | 128 | 128 | 128 | 0 |
| Moxifloxacin | 0 | >8 | >8 | >8 | 0 | >8 | >8 | >8 | 0 | >8 | >8 | >8 | 0 |
| Ciprofloxacin | 0 | >4 | >4 | >4 | 0 | >4 | >4 | >4 | 0 | >4 | >4 | >4 | 0 |
| Doxycycline | 0 | >16 | >16 | >16 | 0 | >16 | >16 | >16 | 0 | >16 | >16 | >16 | 0 |
| Tobramycin | 0 | 4 to >16 | 16 | >16 | 0 | 16 to >16 | >16 | >16 | 0 | >16 | >16 | >16 | 0 |
| Imipenem | 0 | 32 to >64 | >64 | >64 | 0 | 64 to >64 | >64 | >64 | 0 | >64 | >64 | >64 | 0 |
Mycobacterium kansasii and Mycobacterium abscessus complex isolates obtained from rheumatoid arthritis patients. (n = 40).
*All: antimicrobial susceptibilities of slow growth mycobacterium (MAC and M. kansasii) and rapid growth mycobacterium (M. abscessus complex), respectively.
†MIC, minimum inhibitory concentration; MIC50/90, MIC at which 50% and 90%, respectively, of the tested isolates did not show any visible growth.
‡The susceptibilities based on Clinical and Laboratory Standards Institute (CLSI) criteria. NI, No interpretation.