TABLE 1.
MIC distributions for meropenem alone and combined with QPX7728 at various concentrations against 598 carbapenem-resistant strains of Enterobacteralesa
| Treatment | % of strains inhibited at MIC (μg/ml) of: |
MIC50 (μg/ml) | MIC90 (μg/ml) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ≤0.06 | 0.125 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | >64 | |||
| MER alone | 0.5 | 0.5 | 0.5 | 1.2 | 2.7 | 5.5 | 13.2 | 26.3 | 43.5 | 56.5 | 70.7 | 100 | 32 | >64 |
| MER with QPX at concn of: | ||||||||||||||
| 1 μg/ml | 30.9 | 37.8 | 45.7 | 53.3 | 61.5 | 68.6 | 73.2 | 77.8 | 82.3 | 86.8 | 91.0 | 99.8 | 05 | 64 |
| 2 μg/ml | 39.3 | 52.7 | 64.0 | 72.4 | 77.4 | 81.6 | 84.6 | 87.5 | 90.1 | 93.5 | 96.3 | 100 | 0.125 | 16 |
| 4 μg/ml | 51.5 | 66.7 | 76.8 | 83.3 | 86.3 | 89.8 | 93.6 | 96.5 | 97.8 | 98.5 | 99.5 | 100 | ≤0.06 | 4 |
| 8 μg/ml | 66.4 | 76.4 | 86.6 | 92.0 | 95.7 | 98.0 | 99.0 | 99.3 | 99.7 | 100 | 100 | 100 | ≤0.06 | 0.5 |
| 16 μg/ml | 84.3 | 91.1 | 95.0 | 97.8 | 99.5 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | ≤0.06 | 0.125 |
a
The panel consisted of 324 strains producing serine carbapenemases from class A (n = 285; 274 KPC, 8 SME, and 3 NMC-A) and class D (n = 39), 224 strains producing metallo-beta-lactamases (151 NDM, 53 VIM, and 20 IMP), and 50 strains that did not carry any known carbapenemases but had a meropenem (MER) MIC of ≥4 μg/ml (non-carbapenemase-producing CRE). QPX, QPX7728.