Table 5.
Susceptibility of Mycobacterium kansasii to antimicrobial agents determined by the broth dilution method
| Grouping/species | M. Kansasii (n = 31) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Antimicrobial agent | Broth dilution ranges (μg/ml) | MIC50 | MIC90 | Susceptible | Intermediate | Resistant | S (%) | I (%) | R (%) |
| Antimicrobial agents and susceptibility breakpoints (MICs) for testing M. kansasiia | |||||||||
| First line | |||||||||
| Clarithromycin | 0.06‒64 | 0.25 | 0.5 | ≤ 8 | 16 | ≥ 32 | 100 | 0 | 0 |
| Rifampicin | 0.12‒8 | 0.5 | 0.5 | ≤ 1 | - | ≥ 2 | 93.55 | - | 6.45 |
| Second line | |||||||||
| Amikacin | 1‒64 | 2 | 8 | ≤ 16 | 32 | ≥ 64 | 96.77 | 3.23 | 0 |
| Ciprofloxacin | 0.12‒16 | 2 | 4 | ≤ 1 | 2 | ≥ 4 | 32.26 | 41.93 | 25.81 |
| Doxycycline | 0.12‒16 | 8 | 16 | ≤ 1 | 2‒4 | ≥ 8 | 9.68 | 12.90 | 77.42 |
| Linezolid | 1‒64 | 2 | 4 | ≤ 8 | 16 | ≥ 32 | 96.77 | 0 | 3.23 |
| Moxifloxacin | 0.12‒8 | ≤ 0.12 | 0.25 | ≤ 1 | 2 | ≥ 4 | 96.77 | 3.23 | 0 |
| Rifabutin | 0.25‒8 | ≤ 0.25 | 0.5 | ≤ 2 | - | ≥ 4 | 96.77 | 0 | 3.23 |
| TMP‒SMX | 0.12/2.38‒8/152 | 4/76 | > 8/152 | ≤ 2/38 | - | ≥ 4/76 | 48.39 | - | 51.61 |
TMP‒SMX trimethoprim-sulfamethoxazole, CLSI Clinical and Laboratory Standards Institute
aCLSI M24, 3rd ed. 2018 (2)