TABLE 1.
β-Lactam resistance levels conferred by CMY-30 and CMY-2 in an isogenic background
| β-Lactam | MIC (μg/ml) for blaCMY-carrying E. coli MC4100 clone:
|
||
|---|---|---|---|
| pAC-cmy30 (CMY-30) | pAC-cmy2 (CMY-2) | pACYC184 (−) | |
| Amoxicillin | >512 | >512 | 4 |
| Amoxicillin + clavulanic acida | >512 | >512 | 4 |
| Ticarcillin | >512 | >512 | 2 |
| Ticarcillin + clavulanic acida | >512 | >512 | 1 |
| Piperacillin | 64 | 128 | 0.5 |
| Piperacillin + tazobactamb | 16 | 16 | 0.5 |
| Cephalothin | >512 | >512 | 2 |
| Cefaclor | >512 | >512 | 2 |
| Cefoxitin | >512 | >512 | 2 |
| Cefuroxime | >512 | >512 | 1 |
| Cefotaxime | 256 | 16 | 0.12 |
| Ceftazidime | >512 | 128 | 0.25 |
| Aztreonam | 128 | 16 | 0.12 |
| Cefepime | 0.25 | 0.25 | 0.06 |
| Imipenem | 0.25 | 0.25 | 0.12 |
a
Clavulanic acid at a fixed concentration of 2 μg/ml.
b
Tazobactam at a fixed concentration of 4 μg/ml.