title: Determining the resistance of carbapenem-resistant Klebsiella pneumoniae to common disinfectants and elucidating the underlying resistance mechanisms.
abstract: BACKGROUND
  Carbapenem-resistant Klebsiella pneumoniae (CRKP) infection is a serious problem in hospitals worldwide, posing a particular risk to immunocompromised patients. Elimination strategies may prevent these drug-resistant bacteria from spreading within hospital environments. Here, the susceptibility of patient-derived CRKP strains to common chemical disinfectants and possible correlations between the presence of drug-resistance genes and increased resistance to disinfectants were investigated.
  
  
  METHODS
  The minimum inhibitory (MIC) and the minimum bactericidal concentrations (MBC) of common chemical disinfectants against each CRKP strain were determined using agar dilution; K. pneumoniae ATCC700603 served as a standard. The presence of the drug-resistance genes qacΔE, qacA, acrA and qacE was determined using PCR.
  
  
  RESULTS
  A total of 27 clinically isolated CRKP strains collected in our hospital from 2011 to 2013 exhibited sensitivity to the following common chemical disinfectants in decreasing order of sensitivity: 75% ethyl alcohol > 2% glutaraldehyde > "84" disinfectant > 0.2% benzalkonium bromide > 2% iodine tincture > 1% iodophor > 0.1% chlorhexidine acetate. Of the 27 strains, 59, 41, 19 and 15% contained qacΔE, qacA, acrA and qacE resistance genes; 15% carried acrA, qacΔE and qacA, and 26% carried both qacA and qacΔE. Comparative analysis indicated that drug-resistance genes were correlated with higher MIC values.
  
  
  CONCLUSIONS
  These pan-resistant pathogenic CRKP strains contained various drug-resistance genes and exhibited relatively high resistance to ethyl alcohol, chlorhexidine acetate and iodophor. Monitoring the drug-resistance rates of CRKP strains displaying disinfectant resistance may facilitate appropriate and effective sterilisation and thus preventing the spread of these pan-resistant strains.
authors.forename: Wei
authors.initials: W
authors.lastname: Guo
authors.forename: Kai
authors.initials: K
authors.lastname: Shan
authors.forename: Bin
authors.initials: B
authors.lastname: Xu
authors.forename: Jianguo
authors.initials: J
authors.lastname: Li
mesh_terms: D000900:Anti-Bacterial Agents; D016470:Bacteremia / Q000382:microbiology; D015780:Carbapenems / Q000627:therapeutic use*; D003428:Cross Infection / Q000382:microbiology* / Q000517:prevention & control; D004202:Disinfectants; D024881:Drug Resistance, Bacterial / Q000187:drug effects*; D006761:Hospitals; D006801:Humans; D016867:Immunocompromised Host / Q000276:immunology*; D007710:Klebsiella Infections / Q000188:drug therapy / Q000382:microbiology* / Q000401:mortality; D007711:Klebsiella pneumoniae / Q000187:drug effects*; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; D004202:Disinfectants
keywords: Carbapenem,; Disinfectant; Klebsiella pneumonia ,; Resistant,