title: Direct detection of N-acylhomoserine lactones in cystic fibrosis sputum.
abstract: Pseudomonas aeruginosa and Burkholderia cepacia cause destructive lung disease in cystic fibrosis (CF) patients. Both pathogens employ 'quorum sensing', i.e. cell-to-cell communication, via diffusible N-acyl-L-homoserine lactone (AHL) signal molecules, to regulate the production of a number of virulence determinants in vitro. However, to date, evidence that quorum sensing systems are functional and play a role in vivo is lacking. This study presents the first direct evidence for the presence of AHLs in CF sputum. A total of 42 samples from 25 CF patients were analysed using lux-based Escherichia coli AHL biosensors. AHLs were detected in sputum from patients colonised by P. aeruginosa or B. cepacia but not Staphylococcus aureus. Furthermore, using liquid chromatography-mass spectrometry and thin layer chromatography, we confirmed the presence of N-hexanoylhomoserine lactone and N-(3-oxododecanoyl)homoserine lactone respectively in sputum samples from patients colonised by P. aeruginosa.
authors.affiliation: School of Pharmaceutical Sciences, University of Nottingham, University Park, NG7 2RD, UK.
authors.forename: Barry
authors.initials: B
authors.lastname: Middleton
authors.forename: Helen C
authors.initials: HC
authors.lastname: Rodgers
authors.forename: Miguel
authors.initials: M
authors.lastname: Cámara
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Knox
authors.forename: Paul
authors.initials: P
authors.lastname: Williams
authors.forename: Andrea
authors.initials: A
authors.lastname: Hardman
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000032:analysis* / Q000378:metabolism; D019121:Burkholderia Infections / Q000382:microbiology; D016956:Burkholderia cepacia / Q000302:isolation & purification / Q000378:metabolism*; D003550:Cystic Fibrosis / Q000382:microbiology*; D006801:Humans; D011552:Pseudomonas Infections / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification / Q000378:metabolism*; D015398:Signal Transduction; D013183:Sputum / Q000737:chemistry* / Q000382:microbiology
chemical_list: C088386:homoserine lactone; D015107:4-Butyrolactone