Tazobactam is a potent inactivator of selected inhibitor-resistant class A beta-lactamases

FEMS Microbiol Lett. 1997 Mar 1;148(1):59-62. doi: 10.1111/j.1574-6968.1997.tb10267.x.


The beta-lactam beta-lactamase inhibitor combinations (ampicillin/clavulanate, ampicillin/sulbactam, ticarcillin/clavulanate and piperacillin/tazobactam) were tested against selected inhibitor-resistant class A beta-lactamases of the TEM and OHIO-1 varieties. Minimum inhibitor concentrations (MIC) revealed that the Escherichia coli DH5 alpha transconjugate strains that possessed the OHIO-1 beta-lactamase, Met69Ile mutant of the OHIO-1 beta-lactamase, TEM-30 (Arg244Ser) and TEM-31 (Arg244Cys) beta-lactamase were most susceptible to piperacillin and piperacillin/tazobactam. Kinetic experiments with each beta-lactamase demonstrated that tazobactam was 10-25-fold more potent than clavulanate or sulbactam against TEM-30 and TEM-31 beta-lactamase. Tazobactam was also as effective as clavulanate against the Met69Ile mutant of the OHIO-1 beta-lactamase. Among the clinically available beta-lactams and beta-lactamase inhibitors, piperacillin/tazobactam appears to be the most potent combination against selected inhibitor-resistant strains of TEM and OHIO-1 beta-lactamase.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Ampicillin / pharmacology
  • Ampicillin Resistance / physiology*
  • Anti-Bacterial Agents / pharmacology
  • Clavulanic Acid / pharmacology
  • Enzyme Inhibitors / metabolism*
  • Enzyme Inhibitors / pharmacology
  • Escherichia coli / drug effects
  • Escherichia coli / enzymology*
  • Kinetics
  • Penicillanic Acid / analogs & derivatives*
  • Penicillanic Acid / metabolism
  • Penicillanic Acid / pharmacology
  • Penicillins / pharmacology
  • Piperacillin / pharmacology
  • Tazobactam
  • beta-Lactamase Inhibitors*


  • Anti-Bacterial Agents
  • Enzyme Inhibitors
  • Penicillins
  • beta-Lactamase Inhibitors
  • Clavulanic Acid
  • Ampicillin
  • Penicillanic Acid
  • Tazobactam
  • Piperacillin