TABLE 2.

Steady-state kinetic values of GIM-1 (29), IMP-1 (78), VIM-1 (41), VIM-2 (41), and SPM-1 (102) against a range of β-lactams

AntibioticGIM-1IMP-1VIM-1VIM-2SPM-1
kcat (s−1)Km (μM)kcat/Km (μM−1 s−1)kcat (s−1)Km (μM)kcat/Km (μM−1 s−1)kcat (s−1)Km (μM)kcat/Km (μM−1 s−1)kcat (s−1)Km (μM)kcat/Km (μM−1 s−1)kcat (s−1)Km (μM)kcat/Km (μM−1 s−1)
Penicilllin6.6460.143205200.62298410.03455.8491.14108382.8
Ampicillin3.3200.169502004.8379170.04117721.6
Carbenicillin4.11700.02NDaND0.02167752.2748140.09
AzlocillinNDNDND1,52512312531470.35
Piperacillin6.9690.10NDND0.721,8603,5000.5332.7720.45117592
Ticarcillin2.3570.041.17400.00154521,1170.4131.7460.69ND<0.35ND
Nitrocefin5.8120.4763272.395175.60.5340.12
Cephalothin16220.7248212.4281535.356.2441.2843411.7
Cefuroxime5.970.808370.22324427.712.1220.553748.8
Cefoxitin8.32060.04168b2261310.23240.12824
Ceftazidime18310.588440.18607940.07689980.9028460.6
Cefotaxime1.140.241.34b0.351692470.6827.5320.861691.9
Cefepime174310.04711b0.665491453.84.71840.0318181
Imipenem272870.0946391.22.01.51.39.9100.9933371
Meropenem2.7250.1150100.1213480.271.450.28632810.22
Moxalactam141,0350.018810b8.814.8800.1813970.13
AztreonamNDNDND>0.01>1,000<1 × 10−5<0.01>1,000<1 × 10−5<0.5NDNDND<0.3ND
Clavulanic acidNDNDNDND>0.1ND
TazobactamNDNDND>1,000>3.980.00395.33370.0160.630.2
  • a ND, data could not be determined.

  • b Km was obtained as the Ki value.