Table 3.

Inhibition profiles of CTX-M-4 wild-type and S237A mutant β-lactamases

β-LactamaseaIC50(μM) of inhibitorb
ClavulanateSulbactamTazobactam
CTX-M-41.0140.10
S237A mutant2.5170.12
  • a Two hundred fifty units of β-lactamase was used.

  • b IC50s were the mean values of three measurements not differing by more than 10%.