N-Acylhomoserine-lactone-mediated communication between Pseudomonas aeruginosa and Burkholderia cepacia in mixed biofilms

• Published in: Microbiology (Society for General Microbiology) 2001-12, Vol.147 (12), p.3249-3262
• Main Authors: Riedel, Kathrin, Hentzer, Morten, Geisenberger, Otto, Huber, Birgit, Steidle, Anette, Wu, Hong, Hoiby, Niels, Givskov, Michael, Molin, Soren, Eberl, Leo
• Format: Article
• Language: English
• Subjects: Animals; Bacteriology; Biofilms - growth & development; Biological and medical sciences; Burkholderia cepacia; Burkholderia cepacia - physiology; Burkholderia Infections - metabolism; Endopeptidases - biosynthesis; Fundamental and applied biological sciences. Psychology; Genes, Reporter; Green Fluorescent Proteins; Homoserine - analogs & derivatives; Luminescent Proteins; Lung Diseases - microbiology; Mice; Microbiology; Motility, taxis; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Pheromones - pharmacology; Pseudomonas aeruginosa; Pseudomonas aeruginosa - physiology; Pseudomonas Infections - metabolism; quorum sensing; Signal Transduction
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/00221287-147-12-3249

Department of Microbiology, TUM, Am Hochanger 4, D-85350 Freising, Germany 1 Department of Microbiology, DTU, Building 301, DK-2800 Lyngby, Denmark 2 Department of Clinical Microbiology, University Hospital Copenhagen Ø, DK-2100, Denmark 3 Author for correspondence: Leo Eberl. Tel: [phone]. Fax: [phone]. e-mail: eberl{at}mikro.biologie.tu-muenchen.de Pseudomonas aeruginosa and Burkholderia cepacia are capable of forming mixed biofilms in the lungs of cystic fibrosis patients. Both bacteria employ quorum-sensing systems, which rely on N -acylhomoserine lactone (AHL) signal molecules, to co-ordinate expression of virulence factors with the formation of biofilms. As both bacteria utilize the same class of signal molecules the authors investigated whether communication between the species occurs. To address this issue, novel Gfp-based biosensors for non-destructive, in situ detection of AHLs were constructed and characterized. These sensors were used to visualize AHL-mediated communication in mixed biofilms, which were cultivated either in artificial flow chambers or in alginate beads in mouse lung tissue. In both model systems B. cepacia was capable of perceiving the AHL signals produced by P. aeruginosa , while the latter strain did not respond to the molecules produced by B. cepacia . Measurements of extracellular proteolytic activities of defined quorum-sensing mutants grown in media complemented with AHL extracts prepared from culture supernatants of various wild-type and mutant strains supported the view of unidirectional signalling between the two strains. Keywords: quorum sensing, cross-talk, intergeneric communication, cystic fibrosis Abbreviations: AHL, N -acylhomoserine lactone; C4-, C6-, C8-, C10- and C-12-HSL, N -butanoyl, N -hexanoyl-, N -octanoyl, N -decanoyl- and N -dodecanoyl-L-homoserine lactone; 3-oxo-C10, 3-oxo-C12 and 3-oxo-C14-HSL, N -(3-oxodecanoyl)-, N -(3-oxododecanoyl)- and N -(3-oxotetradecanoyl)-L-homoserine lactone; CF, cystic fibrosis; CSLM, confocal scanning laser microscopy; DsRed, red fluorescent protein; Gfp, green fluorescent protein; QS, quorum sensing