title: An investigation of the bactericidal activity of chlorhexidine digluconateagainst multidrug-resistant hospital isolates.
abstract: OBJECTIVE
  Hospital infections are among the most prominent medical problems around the world. Using proper biocides in an appropriate way is critically important in overcoming this problem. Several reports have suggested that microorganisms may develop resistance or reduce their susceptibility to biocides, similar to the case with antibiotics. In this study we aimed to determine the antimicrobial activity of chlorhexidine digluconate against clinical isolates.
  
  
  METHODS
  The susceptibility of 120 hospital isolated strains of 7 bacterial genera against chlorhexidine digluconate was determined by agar dilution test, using minimum inhibitory concentration (MIC) values and the EN 1040 Basic Bactericidal Activity Test to determine the bactericidal activity. According to MIC values, Pseudomonas aeruginosa and Stenotrophomonas maltophilia were found to be less susceptible to chlorhexidine digluconate.
  
  
  RESULTS
  Quantitative suspension test results showed that 4% chlorhexidine digluconate was effective against antibiotic resistant and susceptible bacteria after 5 min of contact time and can be safely used in our hospital. However, concentrations below 4% chlorhexidine digluconate caused a decrease in bactericidal activity, especially for Staphylococcus aureus and P. aeruginosa.
  
  
  CONCLUSIONS
  It is crucial to use biocides at appropriate concentrations and to perform surveillance studies to trace resistance or low susceptibility patterns of S. aureus, P. aeruginosa, and other hospital isolates.
authors: Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Hacettepe University, Sıhhiye, Ankara, Turkey.
authors: Melike
authors: M
authors: Ekizoğlu
authors: Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Hacettepe University, Sıhhiye, Ankara, Turkey.
authors: Meral
authors: M
authors: Sağiroğlu
authors: Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Hacettepe University, Sıhhiye, Ankara, Turkey.
authors: Ekrem
authors: E
authors: Kiliç
authors: Department of Medical Microbiology, Faculty of Medicine, Hacettepe University, Sıhhiye, Ankara, Turkey.
authors: Ayşe Gülşen
authors: AG
authors: Hasçelik
mesh_terms: D002710:Chlorhexidine; D004202:Disinfectants; D024901:Drug Resistance, Multiple, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa; D013211:Staphylococcus aureus
chemical_list: D004202:Disinfectants; D002710:Chlorhexidine
keywords: Biocides; EN 1040; chlorhexidine digluconate; quantitative suspension test; resistance