title: Comparison of real time diagnostic chemistries to detect Pseudomonas aeruginosa in respiratory samples from cystic fibrosis patients.
abstract: BACKGROUND
  Early eradication therapy is key to keeping the airways Pseudomonas aeruginosa infection-free and rapid identification is essential.
  
  
  METHODS
  We used rapid DNA extraction and qPCR assays to detect bacterial, P. aeruginosa and strain-specific targets in samples using two qPCR chemistries. Using 459 respiratory samples from adult and children CF patients, we compared two qPCR methods to culture-based methods in terms of sensitivity and time to result.
  
  
  RESULTS
  For adult samples, there was 100% concordance between methods. There was no clear pattern in fluctuations in P. aeruginosa number during exacerbation. In child samples, qPCR methods identified additional P. aeruginosa positive samples. The time-to-result was reduced by over 24h and copy number and colony forming unit could differ dramatically in some samples.
  
  
  CONCLUSIONS
  If adopted, these methods could significantly improve early P. aeruginosa detection in diagnostic laboratories and therefore play a pivotal role in prolonging infection-free airways in CF patients.
authors.affiliation: NIHR Biomedical Research Centre in Microbial Disease, Royal Liverpool Hospital, Prescott Rd, Liverpool L7 8XP, UK; Institute of Infection and Global Health, University of Liverpool, Ronald Ross Building, West Derby St, Liverpool L69 7BE, UK. Electronic address: j.fothergill@liv.ac.uk.
authors.forename: J L
authors.initials: JL
authors.lastname: Fothergill
authors.forename: M J
authors.initials: MJ
authors.lastname: Ledson
authors.forename: M J
authors.initials: MJ
authors.lastname: Walshaw
authors.forename: P S
authors.initials: PS
authors.lastname: McNamara
authors.forename: K W
authors.initials: KW
authors.lastname: Southern
authors.forename: C
authors.initials: C
authors.lastname: Winstanley
mesh_terms: D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D003550:Cystic Fibrosis / Q000382:microbiology*; D004269:DNA, Bacterial / Q000032:analysis; D060740:Disease Eradication; D018450:Disease Progression; D006801:Humans; D011552:Pseudomonas Infections / Q000175:diagnosis*; D011550:Pseudomonas aeruginosa; D060888:Real-Time Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology
chemical_list: D004269:DNA, Bacterial
keywords: Chronic infection; Cystic fibrosis; Diagnostic testing; Early colonisation; Pseudomonas aeruginosa; qPCR