Table 2.
Susceptibility of RGM to antimicrobial agents determined by the broth dilution method
| Grouping/species | RGM (n = 128) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Antimicrobial agent | Broth dilution ranges (μg/ml) | MIC50 | MIC90 | Susceptible | Intermediate | Resistant | S (%) | I (%) | R (%) | ||
| Antimicrobial agents and susceptibility breakpoints (MICs) for testing rapidly growing mycobacteriaa | |||||||||||
| Amikacin | 1‒64 | 8 | 16 | ≤ 16 | 32 | ≥ 64 | 93.75 | 1.56 | 4.69 | ||
| Clarithromycin (3D) | 0.06‒16 | 0.12 | 8 | ≤ 2 | 4 | ≥ 8 | 85.04 | 0 | 14.96 | ||
| Clarithromycin (14D) | 8 | > 16 | 44.09 | 2.36 | 53.5 | ||||||
| Imipenem | 2‒64 | > 64 | > 64 | ≤ 4 | 8‒16 | ≥ 32 | 0 | 3.15 | 96.85 | ||
| Linezolid | 1‒32 | 16 | > 32 | ≤ 8 | 16 | ≥ 32 | 33.07 | 32.28 | 34.6 | ||
| Cefoxitin | 4‒128 | 64 | 128 | ≤ 16 | 32‒64 | ≥ 128 | 6.30 | 74.8 | 18.90 | ||
| Tobramycin | 1‒16 | 8 | > 16 | ≤ 2 | 4 | ≥ 8 | 13.39 | 12.60 | 74.02 | ||
| Doxycycline | 0.12‒16 | > 16 | > 16 | ≤ 1 | 2‒4 | ≥ 8 | 4.72 | 0 | 95.28 | ||
| Moxifloxacin | 0.25‒8 | 8 | > 8 | ≤ 1 | 2 | ≥ 4 | 7.81 | 1.56 | 90.63 | ||
| Ciprofloxacin | 0.12‒4 | > 4 | > 4 | ≤ 1 | 2 | ≥ 4 | 11.02 | 0.79 | 88.19 | ||
| Tigecycline | 0.015‒4 | 1 | 2 | - | - | - | - | - | - | ||
| TMP‒SMX | 0.25/4.75‒8/152 | > 8/152 | > 8/152 | ≤ 2/38 | - | ≥ 4/76 | 4.72 | - | 95.28 | ||
NTM nontuberculous mycobacteria, RGM rapid growing mycobacteria, SGM slow growing mycobacteria, TMP‒SMX trimethoprim-sulfamethoxazole
aCLSI M24, 3rd ed. 2018 (2)