TABLE 1.

Kinetic parameters of SPM-1 with a range of β-lactam antibiotics in comparison with those of other metallo-β-lactamases

AntibioticSPM-1IMP-1VIM-1VIM-2
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)
Benzylpenicillin108 ± 438 ± 12.83205200.62298410.03456491.14
Ampicillin117 ± 272 ± 31.69502004.8379170.04 b b b
Carbenicillin74 ± 4814 ± 290.09 a a 0.02167752.2 b b b
Azlocillin53 ± 2147 ± 170.35 b b b 1,52512312 b b b
Piperacillin117 ± 659 ± 52 a a 0.721,8603,5000.5333720.45
Ticarcillin a <0.35 a 1.17400.00154521,1170.4132460.69
Nitrocefin0.53 ± 0.014 ± 10.1263272.395175.6 b b b
Cephaloridine14 ± 118 ± 30.853222.43133010 b b b
Cephalothin43 ± 24 ± 111.748212.4281535.357441.28
Cefuroxime37 ± 34 ± 18.88370.22324427.712220.55
Ceftazidime28 ± 246 ± 20.68440.18607940.07689980.90
Cefotaxime16 ± 0.59 ± 11.91.34c0.351692470.6828320.86
Cefoxitin8 ± 0.52 ± 14168c2261310.23240.12
Cefepime18 ± 118 ± 31711c0.665491453.851840.03
Imipenem33 ± 237 ± 4146391.22.01.51.310100.99
Meropenem63 ± 3281 ± 270.2250100.1213480.271.050.28
Moxalactam13 ± 197 ± 100.138810c8.8 b b b 15800.18
Aztreonam a <0.3 a >0.01>1,000<0.0001<0.01>1,000<0.0001<0.5 a a
Clavulanic acid a <0.1 a b b b b b b b b b
Tazobactam0.6 ± 0.53 ± 10.2>1,000>3.980.00395.33370.016 b b b
  • a Data could not be determined.

  • b No data were available.

  • c Km, was obtained as the Ki value.