TABLE 3.
MICs of β-lactams for H. alvei 1 clinical isolate, in vitro-obtained ceftazidime-resistant mutant H. alvei 1 DER, E. coli DH10B harboring recombinant plasmid pDEL-1, and the E. coli DH10B reference strain
| β-Lactam(s)a | MIC (μg/ml)
|
|||
|---|---|---|---|---|
| H. alvei 1 | H. alvei 1 DER | E. coli DH10B(pDEL-1)b | E. coli DH10B | |
| Amoxicillin | 256 | 512 | 128 | 2 |
| Amoxicillin + CLA | 128 | 512 | 128 | 2 |
| Amoxicillin + TZB | 128 | 512 | 128 | 2 |
| Ticarcillin | 4 | 128 | 8 | 2 |
| Piperacillin | 4 | 128 | 8 | 1 |
| Cephalothin | >512 | >512 | >512 | 4 |
| Cephalothin + CLA | >512 | >512 | >512 | 2 |
| Cephalothin + TZB | >512 | >512 | >512 | 2 |
| Cefamandole | 64 | >512 | 128 | 1 |
| Cefoxitin | 8 | 64 | 8 | 8 |
| Cefotaxime | 0.25 | 128 | 2 | 0.06 |
| Ceftriaxone | 1 | 64 | 4 | <0.06 |
| Ceftazidime | 2 | >512 | 32 | 0.12 |
| Ceftazidime + CLA | 8 | >512 | 32 | 0.12 |
| Ceftazidime + TZB | 8 | >512 | 32 | 0.12 |
| Cefepime | 0.12 | 4 | 0.12 | 0.03 |
| Cefpirome | 0.5 | 16 | 2 | 0.03 |
| Cefpirome + CLA | 2 | 16 | 2 | 0.03 |
| Cefpirome + TZB | 4 | 16 | 2 | 0.03 |
| Imipenem | 0.5 | 0.5 | 0.12 | 0.06 |
| Aztreonam | 1 | 16 | 0.5 | 0.12 |
a
CLA, clavulanic acid at a fixed concentration of 2 μg/ml; TZB, tazobactam at a fixed concentration of 4 μg/ml.
b
E. coli DH10B(pDEL-1) expressed cephalosporinase ACC-2 from H. alvei 1.