title: Prospective, randomised, controlled study evaluating early modification of oral microbiota following admission to the intensive care unit and oral hygiene with chlorhexidine.
abstract: Chlorhexidine (CHX) is the most commonly used oral hygiene product for the prevention of ventilator-associated pneumonia (VAP) in patients undergoing mechanical ventilation (MV). The change in dental plaque (DP) microbiota following CHX use in patients under MV has not been described previously. The aim of this study was to evaluate the incidence of pathogenic bacteria associated with VAP and the coverage of DP within the oral cavity in patients administered CHX.
  
  
  
  This was a prospective, randomised, controlled, double-blind study in patients (n=16) under MV who were mouth-rinsed with either CHX or placebo. Microbiology samples were collected from the oral mucosa (OM) and DP after admission to the ICU and on Days 3, 5, 7 and 10. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of CHX were determined.
  
  
  
  Upon admission, the occurrence of multidrug-resistant (MDR) bacteria, including carbapenem-resistant Klebsiella pneumoniae, was reported. The CHX group had a lower incidence of methicillin-resistant Staphylococcus aureus (MRSA) compared with the placebo group for the OM (RR=0.51, 95% CI 0.27-0.98; P=0.011). There was high agreement between the culture results of OM and DP (κ=0.825). VAP developed in six patients. The species identified following tracheal aspiration of VAP patients were similar to those found in the OM for four cases. The strains showed low MICs and MBCs for CHX (<0.039mg/mL).
  
  
  
  Although DP is rapidly colonised by MDR bacteria, use of 2% CHX reduced the incidence of S. aureus colonisation.
authors.affiliation: School of Medicine, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil; Division of Infectious Diseases, Universidade Federal do Paraná, Curitiba, Brazil. Electronic address: flptuon@gmail.com.
authors.forename: Felipe Francisco
authors.initials: FF
authors.lastname: Tuon
authors.affiliation: School of Medicine, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil.
authors.forename: Oleg
authors.initials: O
authors.lastname: Gavrilko
authors.affiliation: Division of Infectious and Parasitic Diseases, Hospital Universitário Evangélico de Curitiba, Curitiba, Brazil.
authors.forename: Saulo de
authors.initials: S
authors.lastname: Almeida
authors.affiliation: Division of Infectious and Parasitic Diseases, Hospital Universitário Evangélico de Curitiba, Curitiba, Brazil.
authors.forename: Eigi Ricardo
authors.initials: ER
authors.lastname: Sumi
authors.affiliation: Division of Infectious and Parasitic Diseases, Hospital Universitário Evangélico de Curitiba, Curitiba, Brazil.
authors.forename: Thiago
authors.initials: T
authors.lastname: Alberto
authors.affiliation: School of Medicine, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil.
authors.forename: Jaime Luis
authors.initials: JL
authors.lastname: Rocha
authors.affiliation: School of Medicine, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil.
authors.forename: Edvaldo Antonio
authors.initials: EA
authors.lastname: Rosa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage*; D001419:Bacteria / Q000145:classification / Q000302:isolation & purification*; D002710:Chlorhexidine / Q000008:administration & dosage*; D003773:Dental Plaque / Q000382:microbiology*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D064307:Microbiota / Q000187:drug effects*; D008875:Middle Aged; D009061:Mouth Mucosa / Q000382:microbiology; D009910:Oral Hygiene / Q000379:methods*; D010919:Placebos / Q000008:administration & dosage; D011446:Prospective Studies; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000891:Anti-Infective Agents, Local; D010919:Placebos; D002710:Chlorhexidine
keywords: Chlorhexidine; Infection; Intensive care unit; Mechanical ventilation; Microbiota; Oral hygiene