TABLE 4.
MICs of β-lactams in the presence of a fixed concentration of 5 μg/ml tazobactam
| Drug | MIC50 (μg/ml)a |
MIC90 (μg/ml)a |
Ratio rangeb (%) |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|
| − | + | − | + | 0.031 | 0.062 | 0.125 | 0.25 | 0.5 | 1 | |
| Amoxicillin | 128 | 32 | 256 | 128 | 0 (0.0) | 1 (0.8) | 20 (16.5) | 74 (61.2) | 19 (15.7) | 7 (5.8) |
| Imipenem | 32 | 16 | 128 | 64 | 0 (0.0) | 0 (0.0) | 1 (0.8) | 4 (3.3) | 19 (15.7) | 97 (80.2) |
| Meropenem | 16 | 8 | 32 | 16 | 0 (0.0) | 0 (0.0) | 0 (0.0) | 22 (18.2) | 83 (68.6) | 16 (13.2) |
| Biapenem | 8 | 4 | 32 | 16 | 0 (0.0) | 1 (0.8) | 5 (4.1) | 31 (25.6) | 55 (45.5) | 29 (24.0) |
a
−, Medium supplemented without tazobactam; +, medium supplemented with tazobactam.
b
Ratio represents the MIC value with tazobactam divided by MIC value without tazobactam.