title: [Genotype of extended-spectrum beta-lactamases produced by antibiotic-resistant Escherichia coli and Klebsiella pneumoniae in surgical intensive care unit].
abstract: OBJECTIVE
  To describe the antibiotic resistant mode of extended-spectrum beta-lactamases(ESBLs) producing Escherichia coli (E. coli.) and Klebsiella pneumoniae (KPn) in surgical intensive care unit(SICU), and to implore the molecular epidemiology of ESBLs coding genes of these strains.
  
  
  METHODS
  The minimal inhibitory concentrations (MICs) at antibiotics were examined by agar dilution method. The ESBLs coding genes were amplified by TEM, SHV and CTX-M specific primers. Amplicons of such genes with conjugates' plasmids as templates were sequenced.
  
  
  RESULTS
  In vitro susceptibility tests of ESBLs producing strains showed a high level of resistance to most of the beta-lactam biotics, especially cefotaxime. 93.5% of these ESBLs positive strains contained CTX-M group genes,and 38.7% of the strains contained SHV genes. By sequencing, some genotype were determined: TEM-1, CTX-M-1,3,14,22.
  
  
  CONCLUSIONS
  ESBLs producing strains were resistant to most of the beta-lactam biotics. The most prevalent ESBLs genotype of ESBLs produced by E coli and KPn in SICU was CTX-M subgroup. The most probable reason might be the extensive use of cefotaxime.
authors.affiliation: Department of General Surgery, Peking University First Hospital, Beijing 100034, China.
authors.forename: Peng-yuan
authors.initials: PY
authors.lastname: Wang
authors.forename: Yu-cun
authors.initials: YC
authors.lastname: Liu
authors.forename: Min
authors.initials: M
authors.lastname: Zhao
authors.forename: Li-ying
authors.initials: LY
authors.lastname: Sun
authors.forename: Wen-yi
authors.initials: W
authors.lastname: Luo
authors.forename: Hong-qiao
authors.initials: HQ
authors.lastname: Gao
authors.forename: Yuan-lian
authors.initials: YL
authors.lastname: Wan
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002439:Cefotaxime / Q000494:pharmacology; D018550:Cephalosporin Resistance / Q000235:genetics; D002681:China / Q000453:epidemiology; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology; D006801:Humans; D007362:Intensive Care Units; D007710:Klebsiella Infections / Q000453:epidemiology / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D001618:beta-Lactamases / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases; D002439:Cefotaxime