title: Bacterial biofilms and increased bacterial counts are associated with airway stenosis.
abstract: OBJECTIVE
  Most airway stenoses are acquired secondary to the use of prolonged endotracheal intubation. Antibiotics have been shown to decrease local inflammation and granulation tissue formation in the trachea. However, antibiotic therapy is not 100% effective in preventing or treating granulation tissue formation. Development of bacterial biofilms may explain this finding. This study evaluates the difference between tracheal stenotic segments and normal trachea in terms of (1) presence of bacterial biofilms, (2) quantitative bacterial counts, and (3) inflammatory markers.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Tertiary care academic medical center.
  
  
  METHODS
  A total of 12 patients were included in the study. Tissue from stenotic segments from 6 patients with airway stenosis undergoing open airway procedures were compared with tracheal tissue from 6 patients without airway stenosis undergoing tracheostomy.
  
  
  METHODS
  Scanning electron microscopy for biofilm detection, quantitative polymerase chain reaction for quantitative analysis of bacterial count, and immunohistochemistry were performed for inflammatory markers transforming growth factor β1 (TGF-β1) and SMAD3.
  
  
  RESULTS
  Compared with the patients without airway stenosis, patients in the airway stenosis group showed presence of bacterial biofilms, a significantly higher expression of 16S rRNA gene copies per microgram of tissue (187.5 vs 7.33, P = .01), and higher expression of TGF-β1 (91% vs 8%, P < .001) and SMAD3 (83.5% vs 17.8%, P < .001).
  
  
  CONCLUSIONS
  Bacterial biofilms, increased bacterial counts, and higher expression of TGF-β1 and SMAD3 are associated with airway stenosis.
authors: Pediatric Otolaryngology-Head and Neck Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
authors: Kashif
authors: K
authors: Mazhar
authors: Manjula
authors: M
authors: Gunawardana
authors: Paul
authors: P
authors: Webster
authors: Christian
authors: C
authors: Hochstim
authors: Jeffery
authors: J
authors: Koempel
authors: Niels
authors: N
authors: Kokot
authors: Uttam
authors: U
authors: Sinha
authors: Dale
authors: D
authors: Rice
authors: Marc
authors: M
authors: Baum
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058491:Bacterial Load; D018441:Biofilms; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D008297:Male; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012307:Risk Factors; D051900:Smad3 Protein / Q000378:metabolism; D014132:Trachea / Q000382:microbiology; D014135:Tracheal Stenosis / Q000382:microbiology*; D053773:Transforming Growth Factor beta1 / Q000378:metabolism
chemical_list: C497790:SMAD3 protein, human; D051900:Smad3 Protein; D053773:Transforming Growth Factor beta1
keywords: airway stenosis; bacterial biofilm; bacterial counts