Table 2.
Hydrolytic efficiencies of representative carbapenemase variants against various β-lactam substrates
| β-Lactamase | Hydrolytic efficiency (kcat/Km) (s−1 μM−1)a against: |
Reference | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Imipenem | Meropenem | Ceftazidime | Cefotaxime | Aztreonam | Cefoxitin | Cephalothin | Penicillin G | ||
| KPC-2 | 0.29 | 0.27 | ND | 0.10 | 0.08 | 0.002 | 0.84 | 1.90 | 271 |
| KPC-3 | 1.90 | 1.40 | 0.03 | 0.50 | ND | 0.50 | 3.50 | ND | 4 |
| VIM-1 | 0.13 | 0.26 | 0.08 | 0.68 | — | 0.20 | 5.10 | 0.04 | 93 |
| VIM-2 | 3.80 | 2.50 | 0.05 | 5.80 | — | 1.20 | 11.8 | 4.0 | 74 |
| VIM-4 | 23.0 | 0.90 | ND | ND | — | ND | 36.0 | 3.10 | 137 |
| VIM-5 | 0.29 | 0.05 | 0.001 | 0.09 | — | ND | ND | 0.26 | 95 |
| VIM-19 | 6.0 | 2.0 | 0.02 | 30.0 | — | 0.50 | ND | 5.0 | 227 |
| VIM-27 | 0.26 | ND | ND | 0.82 | — | 0.03 | 8.30 | ND | 198 |
| IMP-1 | 1.20 | 0.12 | 0.18 | 0.35 | — | 2.0 | 2.40 | 0.62 | 136 |
| IMP-4 | 0.35 | 0.18 | 0.07 | 0.14 | — | ND | 0.43 | 0.08 | 51 |
| NDM-1 | 0.21 | 0.25 | 0.03 | 0.58 | — | 0.02 | 0.40 | 0.68 | 273 |
| NDM-4 | 0.46 | 0.31 | 0.06 | 1.20 | — | — | 0.50 | ND | 189 |
| OXA-48 | 0.14 | <0.001 | 0.001 | 0.05 | — | ND | 0.15 | 6.10 | 217 |
a
ND, not determined; —, no hydrolysis detected.