Genetic and biochemical characterization of GES-5, an extended-spectrum class A beta-lactamase from Klebsiella pneumoniae

Diagn Microbiol Infect Dis. 2007 Aug;58(4):465-8. doi: 10.1016/j.diagmicrobio.2007.02.013. Epub 2007 Apr 27.


The present study was conducted to characterize a new class 1 integron containing the blaGES-5 gene cassette in Klebsiella pneumoniae clinical isolate CHAK36 and measure the kinetic parameters of GES-5 beta-lactamase. Long-range polymerase chain reactions (PCRs) and sequence analysis were performed to identify and analyze the blaGES-5 gene cassette-containing integrons. Kinetic parameters were determined from purified GES-5. Sequencing of the 6190-bp PCR amplicon from K. pneumoniae CHAK36 isolate revealed the new structure of class 1 integron. The integron has 3 unique gene cassettes (blaGES-5-aac(6')-IIa-blaOXA-17/orf4), but the 59-base element of the blaOXA-17 gene cassette was interrupted by a putative transposase gene, orf4. The kinetic parameters of GES-5 showed its broad-spectrum activity against most beta-lactams, including benzylpenicillin, cefaloridine, cefotaxime, and imipenem. This work shows that the blaGES-5 gene was located on a new class 1 integron as a gene cassette. Our kinetic characterizations show that GES-5 was more active against impenem than GES-2 and GES-4.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cloning, Molecular
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / genetics
  • Female
  • Humans
  • Integrons
  • Kinetics
  • Klebsiella Infections / microbiology
  • Klebsiella pneumoniae / drug effects*
  • Klebsiella pneumoniae / genetics*
  • Klebsiella pneumoniae / isolation & purification
  • Microbial Sensitivity Tests
  • Molecular Sequence Data
  • Sequence Analysis, DNA
  • Sputum / microbiology
  • beta-Lactam Resistance / genetics*
  • beta-Lactamases / chemistry
  • beta-Lactamases / genetics*
  • beta-Lactamases / isolation & purification
  • beta-Lactamases / metabolism
  • beta-Lactams / pharmacology


  • DNA, Bacterial
  • beta-Lactams
  • beta-Lactamases

Associated data

  • GENBANK/DQ902344