TABLE 3.
Changes in drug susceptibility testing within 12 months after treatmenta
| Tigecycline group (n = 28) | ||||||
|---|---|---|---|---|---|---|
| Drug | Before treatment (n = 27) |
After treatment (n = 20) |
||||
| Susceptible | Intermediate | Resistant | Susceptible | Intermediate | Resistant | |
| Amikacin | 26 (96) | 1 (4) | 0 (0) | 17 (85) | 2 (10) | 1b (5) |
| (≤16 μg/mL) | (32 μg/mL) | (≥64 μg/mL) | (≤16 μg/mL) | (32 μg/mL) | (≥64 μg/mL) | |
| Cefoxitin | 9 (33) | 18 (67) | 0 (0) | 4 (20) | 16 (80) | 0 (0) |
| (≤16 μg/mL) | (32 to 64 μg/mL) | (≥128 μg/mL) | (≤16 μg/mL) | (32 to 64 μg/mL) | (≥128 μg/mL) | |
| Imipenem | 17 (63) | 10 (37) | 0 (0) | 9 (45) | 11 (55) | 0 (0) |
| (≤4 μg/mL) | (8 to 16 μg/mL) | (≥32 μg/mL) | (≤4 μg/mL) | (8 to 16 μg/mL) | (≥32 μg/mL) | |
| Clarithromycin | 1 (4) | 0 (0) | 26c (96) | 0 (0) | 0 (0) | 20c (100) |
| (≤2 μg/mL) | (4 μg/mL) | (≥8 μg/mL) | (≤2 μg/mL) | (4 μg/mL) | (≥8 μg/mL) | |
| Nontigecycline group (n = 36) | ||||||
| Drug | Before treatment (n = 35) |
After treatment (n = 33) |
||||
| Susceptible | Intermediate | Resistant | Susceptible | Intermediate | Resistant | |
| Amikacin | 27 (77) | 8 (23) | 0 (0) | 289 (85) | 5 (15) | 0 (0) |
| (≤16 μg/mL) | (32 μg/mL) | (≥64 μg/mL) | (≤16 μg/mL) | (32 μg/mL) | (≥64 μg/mL) | |
| Cefoxitin | 9 (26) | 25 (71) | 1 (3) | 4 (12) | 29 (88) | 0 (0) |
| (≤16 μg/mL) | (32 to 64 μg/mL) | (≥128 μg/mL) | (≤16 μg/mL) | (32 to 64 μg/mL) | (≥128 μg/mL) | |
| Imipenem | 13 (37) | 20 (57) | 2 (6) | 14 (42) | 19 (58) | 0 (0) |
| (≤4 μg/mL) | (8 to 16 μg/mL) | (≥32 μg/mL) | (≤4 μg/mL) | (8 to 16 μg/mL) | (≥32 μg/mL) | |
| Clarithromycin | 4 (11) | 0 (0) | 31d (89) | 2 (6) | 0 (0) | 31d (94) |
| (≤2 μg/mL) | (4 μg/mL) | (≥8 μg/mL) | (≤2 μg/mL) | (4 μg/mL) | (≥8 μg/mL) | |
Data are presented as number (percentage) or median (interquartile range).
In the tigecycline group, one patient with cavitary nodular bronchiectatic disease was treated with multiple intravenous agents (amikacin, imipenem, tigecycline) and oral agents (azithromycin, clofazimine, and linezolid). However, the patient acquired resistance to amikacin after 8 months of treatment.
Before treatment, 25 patients showed inducible resistance to clarithromycin, and 1 patient showed acquired resistance to clarithromycin, but after treatment, 18 patients showed inducible resistance to clarithromycin and 2 patients showed acquired resistance to clarithromycin.
Before treatment, 30 patients showed inducible resistance to clarithromycin and 1 patient showed acquired resistance to clarithromycin, but after treatment, 25 patients showed inducible resistance to clarithromycin and 6 patients showed acquired resistance to clarithromycin.