title: The significance of distal bronchial samples with commensals in ventilator-associated pneumonia: colonizer or pathogen?
abstract: OBJECTIVE
  To investigate the role of oropharyngeal and cutaneous commensal microorganisms (OCCs) as a cause of ventilator-associated pneumonia (VAP).
  
  
  METHODS
  Retrospective analysis of the medical and microbiological records.
  
  
  METHODS
  One medical-surgical ICU.
  
  
  METHODS
  All VAP episodes recorded during a 10-year period were reviewed. All patients with suspected VAP underwent bronchoscopy with protected-specimen brush (PSB) sampling and BAL before any change in antibiotic therapy was made. OCC-VAP was defined as VAP with significant growth in quantitative cultures (PSB yielded > or = 10(3) cfu/mL and/or BAL yielded > or = 10(4) cfu/mL) of OCCs only. Three experts reviewed the episodes. Exposed patients (ie, those with OCC-VAP) and unexposed patients (ie, patients without VAP) matched on condition severity at ICU admission and mechanical ventilation duration were compared.
  
  
  RESULTS
  Twenty-nine episodes in 28 patients with > or = 10(4) cfu/mL OCCs in BAL fluid and/or > or = 10(3) cfu/mL OCCs in PSB specimens were found. All patients in these episodes had new radiologic lung infiltrates, with 26 episodes involving purulent tracheal aspirates, 23 episodes involving temperatures > or = 38.5 degrees C, and 18 episodes involving > or = 11,000 leukocytes/ microL. The main OCCs found were non-beta-hemolytic Streptococcus spp (n = 12), Neisseria spp (n = 7), and coagulase-negative Staphylococcus spp (n = 6). Other possible reasons for fever and the presence of new chest infiltrates were found in 20 and 17 patients, respectively. Histologic evidence of pneumonia was found in 2 of the 10 patients who died. The three experts agreed on the diagnosis for 23 patients. In the OCC-VAP group only, the mean (+/- SD) logistic organ dysfunction (LOD) scores increased significantly (LOD score, 2 +/- 4; p = 0.008) during the 3 days before bronchoscopy, and ICU stay duration was longer than in the unexposed group. The exposed/unexposed study found no difference in mortality.
  
  
  CONCLUSIONS
  OCCs may behave like classic nosocomial pathogens in critically ill patients.
authors.affiliation: Réanimation polyvalente, Hôpital Saint-Joseph, 46 rue Henri Huchard, 75018 Paris, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Lambotte
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Timsit
authors.forename: Maïté
authors.initials: M
authors.lastname: Garrouste-Orgeas
authors.forename: Benoit
authors.initials: B
authors.lastname: Misset
authors.forename: Adel
authors.initials: A
authors.lastname: Benali
authors.forename: Jean
authors.initials: J
authors.lastname: Carlet
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001980:Bronchi / Q000382:microbiology; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D001999:Bronchoscopy; D003422:Critical Care / Q000379:methods; D003428:Cross Infection / Q000453:epidemiology / Q000209:etiology / Q000382:microbiology*; D004866:Equipment Contamination; D005260:Female; D005500:Follow-Up Studies; D006090:Gram-Negative Bacteria / Q000302:isolation & purification*; D006094:Gram-Positive Bacteria / Q000302:isolation & purification*; D006801:Humans; D015994:Incidence; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000209:etiology / Q000382:microbiology*; D011336:Probability; D012121:Respiration, Artificial / Q000009:adverse effects* / Q000295:instrumentation; D012189:Retrospective Studies; D012307:Risk Factors; D017678:Sex Distribution