title: Noninvasive Staphylococcus aureus biofilm determination in chronic rhinosinusitis by detecting the exopolysaccharide matrix component poly-N-acetylglucosamine.
abstract: BACKGROUND
  The role that bacterial biofilms might play in recalcitrant forms of chronic rhinosinusitis (CRS) is increasingly being recognized. However, the detection of bacteria existing in this form, using standard culture, is limited by their unique metabolically inactive properties. All current biofilm diagnostic modalities require invasive mucosal biopsies, which limit their use to the operating theatre.
  
  
  METHODS
  Twenty CRS patients and 5 controls were enrolled in a prospective study to assess the feasibility of noninvasively diagnosing S. aureus biofilms by detecting the biofilm matrix polysaccharide poly-N-acetylglucosamine (PNAG). An immunofluorescence protocol was developed for PNAG detection and compared with both standard microbiological cultures and fluorescence in situ hybridization (FISH).
  
  
  RESULTS
  Thirteen of 20 CRS patients had evidence of S. aureus biofilm formation using FISH. Of these, 12 had detectable PNAG. Interestingly none of the S. aureus FISH-negative patients were PNAG-positive despite the presence of coagulase-negative Staphylococci biofilms, some of which may exhibit PNAG in their pathogenic forms. The development of a noninvasive S. aureus biofilm diagnostic test provides a reliable means to identify a high-risk group of CRS patients who harbor S. aureus biofilms. The ability to be used outside of the perioperative period to assess surgical efficacy, guide management, and evaluate new treatment modalities provides a significant advance in this field of research and clinical practice.
  
  
  CONCLUSIONS
  This study has confirmed the feasibility of noninvasive detection of S. aureus biofilms with a simple test that produces results comparable to the more invasive methods that are currently relied upon.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Discipline of Surgery, University of Adelaide and Flinders University, Adelaide, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Foreman
authors.forename: Josh
authors.initials: J
authors.lastname: Jervis-Bardy
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Boase
authors.forename: Lorwai
authors.initials: L
authors.lastname: Tan
authors.forename: Peter-John
authors.initials: PJ
authors.lastname: Wormald
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000581:Amidohydrolases / Q000302:isolation & purification*; D018441:Biofilms / Q000254:growth & development*; D016022:Case-Control Studies; D002908:Chronic Disease; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012220:Rhinitis / Q000382:microbiology*; D012852:Sinusitis / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000302:isolation & purification / Q000502:physiology*
chemical_list: D000581:Amidohydrolases; C497363:poly-N-acetylglucosamine deacetylase