CTX-M and SHV-12 beta-lactamases are the most common extended-spectrum enzymes in clinical isolates of Escherichia coli and Klebsiella pneumoniae collected from 3 university hospitals within Korea

FEMS Microbiol Lett. 2005 Apr 1;245(1):93-8. doi: 10.1016/j.femsle.2005.02.029.


Among the 443 clinical isolates of Escherichia coli and Klebsiella spp. collected between June and November 2003 from 3 university hospitals in Korea, 62 isolates were confirmed as extended-spectrum beta-lactamase (ESBL)- or plasmid-mediated AmpC beta-lactamase-producers by double disk synergy test, PCR and sequencing for beta-lactamase genes. The most frequently identified ESBL gene among E. coli and K. pneumoniae isolates was bla(SHV-12) and bla(CTX-M) (bla(CTX-M-9), bla(CTX-M-14), bla(CTX-M-3), and bla(CTX-M-15)). Four kinds of plasmid-mediated AmpC beta-lactamases, ACT-1, CMY-1, CMY-2, and DHA-1, were detected. ESBL production was associated with high levels of resistance to tetracycline, sulfisoxazole, streptomycin, kanamycin, gentamicin and tobramycin when compared to non-ESBL producing isolates. Conclusively, this study suggests that the CTX-M beta-lactamases are prevalent and various kinds of plasmid-mediated AmpC enzymes are distributed in clinical isolates of E. coli and Klebsiella spp. in Korea.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / metabolism
  • Drug Resistance, Multiple, Bacterial
  • Escherichia coli / drug effects
  • Escherichia coli / enzymology*
  • Escherichia coli / isolation & purification
  • Escherichia coli Infections / epidemiology
  • Escherichia coli Infections / microbiology
  • Hospitals, University*
  • Humans
  • Klebsiella Infections / epidemiology
  • Klebsiella Infections / microbiology
  • Klebsiella pneumoniae / drug effects
  • Klebsiella pneumoniae / enzymology*
  • Korea / epidemiology
  • Microbial Sensitivity Tests
  • Plasmids
  • beta-Lactam Resistance
  • beta-Lactamases / metabolism*


  • Anti-Bacterial Agents
  • Bacterial Proteins
  • beta-lactamase SHV-12
  • AmpC beta-lactamases
  • beta-Lactamases