A new TEM-derived extended-spectrum beta-lactamase (TEM-91) with an R164C substitution at the omega-loop confers ceftazidime resistance

Antimicrob Agents Chemother. 2003 Sep;47(9):2981-3. doi: 10.1128/AAC.47.9.2981-2983.2003.

Abstract

A new plasmid-mediated TEM-derived extended-spectrum beta-lactamase, TEM-91, was identified in a ceftazidime-resistant (MIC, >128 microg per ml) Escherichia coli strain isolated in 1996 in Japan. TEM-91 has three amino acid substitutions, R164C, M184T, and E240K, compared with TEM-1 penicillinase. The isoelectric point (pI), K(m), and k(cat) of TEM-91 for ceftazidime were 5.7, 179 microM, and 29.0 s(-1), respectively. The K(i) of clavulanic acid for ceftazidime hydrolysis was 30.3 nM.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Substitution
  • Anti-Bacterial Agents / metabolism
  • Anti-Bacterial Agents / pharmacology
  • Ceftazidime / pharmacology*
  • Cephalosporin Resistance / genetics*
  • Cephalosporins / pharmacology*
  • Chromatography, High Pressure Liquid
  • DNA, Bacterial / analysis
  • DNA, Bacterial / genetics
  • Drug Combinations
  • Enzyme Inhibitors / pharmacology
  • Escherichia coli / enzymology
  • Escherichia coli / genetics
  • Escherichia coli Infections / microbiology
  • Escherichia coli Infections / urine
  • Escherichia coli Proteins / antagonists & inhibitors
  • Escherichia coli Proteins / genetics*
  • Escherichia coli Proteins / metabolism*
  • Humans
  • Kinetics
  • Molecular Sequence Data
  • Point Mutation / genetics
  • beta-Lactamase Inhibitors
  • beta-Lactamases / genetics*
  • beta-Lactamases / metabolism*

Substances

  • Anti-Bacterial Agents
  • Cephalosporins
  • DNA, Bacterial
  • Drug Combinations
  • Enzyme Inhibitors
  • Escherichia coli Proteins
  • beta-Lactamase Inhibitors
  • Ceftazidime
  • beta-Lactamases
  • TEM-91 beta-lactamase, E coli

Associated data

  • GENBANK/AB049569