TABLE 1.
Cumulative frequency distributions of nafithromycin MIC results against 4,739 bacterial isolates (all regions combined)
| Organism or phenotype (MIC)c | No. of isolates | No. of isolates (cumulative %) with nafithromycin MIC (μg/ml) |
MIC50 (μg/ml) | MIC90 (μg/ml) | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ≤0.002 | 0.004 | 0.008 | 0.015 | 0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | >a | ||||
| S. aureus | 716 | 1 (0.1) | 39 (5.6) | 562 (84.1) | 27 (87.8) | 3 (88.3) | 2 (88.5) | 0 (88.5) | 2 (88.8) | 80 (100.0) | 0.06 | >2 | ||||||
| MSSA | 468 | 28 (6.0) | 409 (93.4) | 20 (97.6) | 1 (97.9) | 2 (98.3) | 0 (98.3) | 2 (98.7) | 6 (100.0) | 0.06 | 0.06 | |||||||
| MRSA | 248 | 1 (0.4) | 11 (4.8) | 153 (66.5) | 7 (69.4) | 2 (70.2) | 0 (70.2) | 0 (70.2) | 0 (70.2) | 74 (100.0) | 0.06 | >2 | ||||||
| TelithromycinS (≤1 μg/ml) | 633 | 1 (0.2) | 39 (6.3) | 562 (95.1) | 27 (99.4) | 3 (99.8) | 1 (100.0) | 0.06 | 0.06 | |||||||||
| TelithromycinI (2 μg/ml) | 3 | 1 (33.3) | 0 (33.3) | 0 (33.3) | 2 (100.0) | >2 | ||||||||||||
| TelithromycinR (≥4 μg/ml) | 80 | 2 (2.5) | 78 (100.0) | >2 | >2 | |||||||||||||
| ERYr (≥1 μg/ml), CLIs (≤0.5 μg/ml), D test−b | 85 | 3 (3.5) | 74 (90.6) | 8 (100.0) | 0.06 | 0.06 | ||||||||||||
| ERYr (≥1 μg/ml), CLIs (≤0.5 μg/ml), D test+b | 110 | 11 (10.0) | 93 (94.5) | 4 (98.2) | 0 (98.2) | 1 (99.1) | 0 (99.1) | 0 (99.1) | 1 (100.0) | 0.06 | 0.06 | |||||||
| CLINS (≥1 μg/ml) | 85 | 1 (1.2) | 2 (3.5) | 1 (4.7) | 0 (4.7) | 2 (7.1) | 79 (100.0) | >2 | >2 | |||||||||
| ERYs (≤0.5 μg/ml), CLIs (≤0.5 μg/ml) | 436 | 1 (0.2) | 25 (6.0) | 395 (96.6) | 14 (99.8) | 1 (100.0) | 0.06 | 0.06 | ||||||||||
| S. pneumoniae | 1,911 | 1 (0.1) | 20 (1.1) | 396 (21.8) | 1014 (74.9) | 224 (86.6) | 162 (95.1) | 88 (99.7) | 6 (100.0) | 0.015 | 0.06 | |||||||
| PENs (≤2 μg/ml) | 1,762 | 1 (0.1) | 20 (1.2) | 392 (23.4) | 994 (79.9) | 200 (91.2) | 127 (98.4) | 25 (99.8) | 3 (100.0) | 0.015 | 0.03 | |||||||
| PENi (4 μg/ml) | 133 | 4 (3.0) | 18 (16.5) | 21 (32.3) | 29 (54.1) | 59 (98.5) | 2 (100.0) | 0.06 | 0.12 | |||||||||
| PENr (≥8 μg/ml) | 16 | 2 (12.5) | 3 (31.2) | 6 (68.8) | 4 (93.8) | 1 (100.0) | 0.06 | 0.12 | ||||||||||
| ERYs (≤0.25 μg/ml), CLIs (≤0.25 μg/ml) | 1,173 | 19 (1.6) | 371 (33.2) | 765 (98.5) | 14 (99.7) | 3 (99.9) | 1 (100.0) | 0.015 | 0.015 | |||||||||
| ERYr (≥0.5 μg/ml), CLIs (≤0.25 μg/ml) | 344 | 1 (0.3) | 1 (0.6) | 11 (3.8) | 121 (39.0) | 114 (72.1) | 88 (97.7) | 8 (100.0) | 0.03 | 0.06 | ||||||||
| ERYr (≥0.5 μg/ml), CLIr (≥0.5 μg/ml) | 394 | 14 (3.6) | 128 (36.0) | 96 (60.4) | 71 (78.4) | 79 (98.5) | 6 (100.0) | 0.03 | 0.12 | |||||||||
| TelithromycinS (≤0.25 μg/ml) | 1,707 | 1 (0.1) | 20 (1.2) | 396 (24.4) | 1014 (83.8) | 209 (96.1) | 64 (99.8) | 3 (100.0) | 0.015 | 0.03 | ||||||||
| TelithromycinNS (≥0.5 μg/ml) | 204 | 15 (7.4) | 98 (55.4) | 85 (97.1) | 6 (100.0) | 0.06 | 0.12 | |||||||||||
| S. pyogenes | 606 | 46 (7.6) | 513 (92.2) | 22 (95.9) | 10 (97.5) | 6 (98.5) | 2 (98.8) | 7 (100.0) | 0.015 | 0.015 | ||||||||
| ERYs (≤0.25 μg/ml), CLIs (≤0.25 μg/ml) | 542 | 42 (7.7) | 483 (96.9) | 16 (99.8) | 1 (100.0) | 0.015 | 0.015 | |||||||||||
| ERYr (≥0.5 μg/ml), CLIs (≤0.25 μg/ml) | 33 | 3 (9.1) | 18 (63.6) | 4 (75.8) | 7 (97.0) | 1 (100.0) | 0.015 | 0.06 | ||||||||||
| ERYr (≥0.5 μg/ml), CLIr (≥0.5 μg/ml) | 31 | 1 (3.2) | 12 (41.9) | 2 (48.4) | 2 (54.8) | 5 (71.0) | 2 (77.4) | 7 (100.0) | 0.06 | 0.5 | ||||||||
| H. influenzae | 1002 | 2 (0.2) | 2 (0.4) | 6 (1.0) | 42 (5.2) | 428 (47.9) | 455 (93.3) | 56 (98.9) | 5 (99.4) | 6 (100.0) | 4 | 4 | ||||||
| β-Lactamase positive | 210 | 5 (2.4) | 90 (45.2) | 99 (92.4) | 14 (99.0) | 1 (99.5) | 1 (100.0) | 4 | 4 | |||||||||
| β-Lactamase negative | 792 | 2 (0.3) | 2 (0.5) | 6 (1.3) | 37 (5.9) | 338 (48.6) | 356 (93.6) | 42 (98.9) | 4 (99.4) | 5 (100.0) | 4 | 4 | ||||||
| M. catarrhalis | 504 | 1 (0.2) | 6 (1.4) | 1 (1.6) | 6 (2.8) | 58 (14.3) | 265 (66.9) | 159 (98.4) | 8 (100.0) | 0.12 | 0.25 | |||||||
a
The MIC was greater than the highest concentration tested, which was 16 μg/ml for H. influenzae and 2 μg/ml for all other organisms.
b
The D test was performed by broth microdilution as described in CLSI document M100-S26 (20).
c
Abbreviations: MSSA, methicillin-susceptible S. aureus; MRSA, methicillin-resistant S. aureus; s, susceptible; i, intermediate; r, resistant; ERY, erythromycin; CLI, clindamycin; PEN, penicillin; ns, nonsusceptible.