title: Dissemination of SHV-12 and CTX-M-type extended-spectrum beta-lactamases among clinical isolates of Escherichia coli and Klebsiella pneumoniae and emergence of GES-3 in Korea.
abstract: OBJECTIVE
  To assess the prevalence and genotypes of Ambler class A extended-spectrum beta-lactamases (ESBLs) in Korea.
  
  
  METHODS
  Clinical isolates of Escherichia coli and Klebsiella pneumoniae collected from 12 Korean hospitals during February-July 2003 were evaluated. Antimicrobial susceptibilities were determined by disc diffusion and agar dilution methods, and the putative ESBL-producing strains were tested by the double-disc synergy method. Detection of genes encoding class A beta-lactamases was performed by PCR amplification, and the PCR products were subjected to direct sequencing.
  
  
  RESULTS
  The double-disc synergy test showed positive results in 9.3% (23/246) of E. coli and 23.0% (55/239) of K. pneumoniae isolates. The most prevalent types of Ambler class A ESBLs in E. coli isolates were CTX-M-15 (n = 4) and CTX-M-3 (n = 3), and those in K. pneumoniae isolates were SHV-12 (n = 30) and CTX-M-3 (n = 13). Two isolates produced both SHV-12 and GES-3, simultaneously.
  
  
  CONCLUSIONS
  CTX-M-type and/or SHV-12 ESBL-producing E. coli and K. pneumoniae isolates are spreading, and a GES-type ESBL has emerged in Korea.
authors.affiliation: Department of Laboratory Medicine, Keimyung University College of Medicine, Daegu.
authors.forename: Nam Hee
authors.initials: NH
authors.lastname: Ryoo
authors.forename: Eui-Chong
authors.initials: EC
authors.lastname: Kim
authors.forename: Seong Geun
authors.initials: SG
authors.lastname: Hong
authors.forename: Yeon Joon
authors.initials: YJ
authors.lastname: Park
authors.forename: Kyungwon
authors.initials: K
authors.lastname: Lee
authors.forename: Il Kwon
authors.initials: IK
authors.lastname: Bae
authors.forename: Eun Hyang
authors.initials: EH
authors.lastname: Song
authors.forename: Seok Hoon
authors.initials: SH
authors.lastname: Jeong
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology*; D006761:Hospitals; D006801:Humans; D007710:Klebsiella Infections / Q000453:epidemiology / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D007723:Korea / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; C456080:beta-lactamase CTX-M-14; C473109:beta-lactamase CTX-M-15; C417271:beta-lactamase CTX-M-3; C107198:beta-lactamase SHV-12; D001618:beta-Lactamases; C487649:beta-lactamase GES-3, Klebsiella pneumoniae