title: Patterns and density of early tracheal colonization in intensive care unit patients.
abstract: OBJECTIVE
  The study aimed to describe the patterns and density of early tracheal colonization among intubated patients and to correlate colonization status with levels of antimicrobial peptides and inflammatory cytokines.
  
  
  METHODS
  The was a prospective cohort study.
  
  
  METHODS
  The study was conducted in medical and cardiovascular intensive care units of a tertiary referral hospital.
  
  
  METHODS
  Seventy-four adult patients admitted between March 2003 and May 2006 were recruited for the study.
  
  
  METHODS
  Tracheal aspirates were collected daily for the first 4 days of intubation using standardized, sterile technique and sent for quantitative culture and cytokines, lactoferrin and lysozyme measurements.
  
  
  RESULTS
  The mean acute physiology and chronic health evaluation (APACHE II) score in this cohort was 24 +/- 7. Proportion of subjects colonized by any microorganism increased over the first 4 days of intubation (47%, 60%, 70%, 70%, P = .08), but density of colonization for bacteria or yeast did not change significantly. No known risk factors predicted tracheal colonization on day 1 of intubation. Several patterns of colonization were observed (persistent, transient, new colonization, and clearance of initial colonization).The most common organisms cultured were Candida albicans and coagulase-negative Staphylococcus. Levels of cytokines, lactoferrin, or lysozyme did not change over time and were not correlated with tracheal colonization status. Four subjects (6%) had ventilator-associated pneumonia.
  
  
  CONCLUSIONS
  The density of tracheal colonization did not change significantly over the first 4 days of intubation in medical intensive care unit patients. There was no correlation between tracheal colonization and the levels of antimicrobial peptides or cytokines. Several different patterns of colonization may have to be considered while planning interventions to reduce airway colonization.
authors.affiliation: Department of Medicine, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA. ashley-small@uiowa.edu
authors.forename: Lakshmi
authors.initials: L
authors.lastname: Durairaj
authors.forename: Zeinab
authors.initials: Z
authors.lastname: Mohamad
authors.forename: Janice L
authors.initials: JL
authors.lastname: Launspach
authors.forename: Alix
authors.initials: A
authors.lastname: Ashare
authors.forename: James Y
authors.initials: JY
authors.lastname: Choi
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Rajagopal
authors.forename: Gary V
authors.initials: GV
authors.lastname: Doern
authors.forename: Joseph
authors.initials: J
authors.lastname: Zabner
mesh_terms: D018806:APACHE; D000328:Adult; D002177:Candidiasis / Q000382:microbiology; D016022:Case-Control Studies; D015169:Colony Count, Microbial; D003428:Cross Infection / Q000175:diagnosis / Q000382:microbiology*; D016207:Cytokines / Q000032:analysis; D005260:Female; D006801:Humans; D007249:Inflammation; D007362:Intensive Care Units; D007442:Intubation, Intratracheal / Q000009:adverse effects*; D007781:Lactoferrin / Q000032:analysis; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009113:Muramidase / Q000032:analysis; D053717:Pneumonia, Ventilator-Associated / Q000209:etiology; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000009:adverse effects*; D020545:Respiratory Mucosa / Q000378:metabolism / Q000382:microbiology*; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000382:microbiology; D018709:Statistics, Nonparametric; D013396:Suction; D013997:Time Factors; D014132:Trachea / Q000378:metabolism / Q000382:microbiology*
chemical_list: D016207:Cytokines; D009113:Muramidase; D007781:Lactoferrin