Identification of N-acylhomoserine lactones in mucopurulent respiratory secretions from cystic fibrosis patients

Authors

  • Catherine E. Chambers,

    1. Department of Microbiology and Infectious Diseases, University of Calgary Health Sciences Centre, Calgary, Alta., Canada T2N 4N1
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      C.E.C. and M.B.V. contributed equally to this work.

  • Michelle B. Visser,

    1. Department of Microbiology and Infectious Diseases, University of Calgary Health Sciences Centre, Calgary, Alta., Canada T2N 4N1
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      C.E.C. and M.B.V. contributed equally to this work.

  • Ute Schwab,

    1. Department of Food Science, Cornell University, Ithaca, NY 14853, USA
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  • Pamela A. Sokol

    Corresponding author
    1. Department of Microbiology and Infectious Diseases, University of Calgary Health Sciences Centre, Calgary, Alta., Canada T2N 4N1
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  • Edited by C.W. Penn

*Corresponding author. Tel.: +1 403 220 6037; fax: +1 403 270 2772, E-mail address: psokol@ucalgary.ca

Abstract

Pseudomonas aeruginosa and species of the Burkholderia cepacia complex are the primary bacterial pathogens contributing to lung disease in patients with cystic fibrosis. Quorum sensing systems using N-acyl homoserine lactone (AHL) signal molecules are involved in the regulation of a number of virulence factors in these species. Extracts of mucopurulent respiratory secretions from 13 cystic fibrosis patients infected with P. aeruginosa and/or strains of the B. cepacia complex were fractionated using reverse-phase fast pressure liquid chromatography and analyzed for the presence of AHLs using a traI–luxCDABE-based reporter that responds to AHLs with acyl chains ranging between 4 and 12 carbons. Using this assay system, a broad range of AHLs were detected and identified despite being present at low concentrations in limited sample volumes. N-(3-oxo-dodecanoyl)-l-homoserine lactone, N-(3-oxo-decanoyl)-l-homoserine lactone and N-octanoyl-l-homoserine lactone (OHL) were the AHLs most frequently identified. OHL and N-decanoyl-l-homoserine lactone were detected in nanomolar concentrations compared to picomolar amounts of the 3-oxo-derivatives of the AHLs identified.

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