title: [A study on carbapenem resistance in klebsiella pneumoniae].
abstract: OBJECTIVE
  To investigate the molecular mechanisms of reduced carbapenem susceptibility in Klebsiella pneumonia.
  
  
  METHODS
  One reduced carbapenem susceptible Klebsiella pneumonia clinical isolate was investigated. Kirby-Bauer disc test was applied to determine the antibiotic susceptibility of the isolate. Modified Hodge Test and EDTA-disk synergy test were used to confirm whether this Klebsiella pneumonia strain could produce metallo-beta-lactamase. The genotype of the beta-lactamase was confirmed by PCR and DNA sequence analysis. Plasmid DNA preparations and conjugation experiment were used to determine the location of the resistant gene.
  
  
  RESULTS
  Antibacterial circle of imipenem, meropenem for Klebsiella pneumonia isolate were 16 cm and 17 cm implied that the isolated strain producing carbapenemas. Modified Hodge Test and EDTA-disk synergy test confirmed that this Klebsiella pneumonia isolate produced metallo-beta-lactamase. IMP-4 gene was amplified by PCR and confirmed with sequence analysis. A reduced carbapenem susceptibility in obtained conjugants was observed when evaluated with Kirby-Bauer disc test and conjugation experiment also revealed that blalMP-4 were carried on one plasmid with a size of approximately 73 000 bp.
  
  
  CONCLUSIONS
  Production of plasmid-mediated metallo-beta lactamase IMP-4 might lead to the reduced susceptibility of Klebsiella pneumonia spp. to carbapenems.
authors.affiliation: Department of Medical Technology, West China School of Public Health, Sichuan University, Chengdu 610041, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Guan
authors.forename: Xia
authors.initials: X
authors.lastname: Cao
authors.forename: Rui
authors.initials: R
authors.lastname: Chen
authors.forename: Tao
authors.initials: T
authors.lastname: Zhou
authors.forename: Xing-Long
authors.initials: XL
authors.lastname: Huang
authors.forename: Xin
authors.initials: X
authors.lastname: Xu
authors.forename: Xiao-Fang
authors.initials: XF
authors.lastname: Pei
mesh_terms: D015780:Carbapenems / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D006801:Humans; D007231:Infant, Newborn; D007710:Klebsiella Infections / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D011014:Pneumonia / Q000382:microbiology*; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D015780:Carbapenems; C425142:beta-lactamase IMP-4; D001618:beta-Lactamases