TABLE 2.
Kinetic parameters of CTX-M-10
| Antibiotic | Relative hydrolysis ratea (%) | Relative Vmax (%) | Km (μM) | Relative Vmax/Km ratio | IC50 (μM) |
|---|---|---|---|---|---|
| Penicillin G | 100 | 100 | 34 | 100 | |
| Cephaloridine | 167 | 200 | 96 | 71 | |
| Cefuroxime | 95 | 100 | 38 | 88 | |
| Cefotaxime | 81 | 50 | 28 | 61 | |
| Ceftazidime | NHb | NDc | ND | ND | |
| Cefepime | 5 | ND | ND | ND | |
| Clavulanic acid | 0.006 | ||||
| Tazobactam | 0.0009 | ||||
| Sulbactam | 0.32 |
a
Hydrolysis rates (micromoles per minute per microliter) were determined using a 100 μM concentration of each substrate; relative values were determined by considering the penicillin G rate to be 100.
b
NH, no hydrolysis detected.
c
ND, not done.