title: Contribution of the production of quormones to some phenotypic characteristics of Pseudomonas aeruginosa clinical strains.
abstract: The contribution of quorum sensing in some phenotypic and pathogenic characteristics of Pseudomonas aeruginosa was studied. The production of acylhomoserine lactones (AHL) by planktonic cultures of eight clinical and reference strains of P. aeruginosa was evaluated using two biosensors. The adhesion of the bacteria on a surface (Biofilm Ring Test ®, BFRT), their capacity to develop a biofilm (crystal violet staining method, CVSM), their sensitivity to tobramycin and their secretion of proteases or of rhamnolipids were also measured. The production and the release of AHL widely varied among the eight strains. An analysis of the extracts by TLC showed that 3-oxo-C8-HSL, 3-oxo-C10-HSL and 3-oxo-C12-HSL were released by the five strains producing the highest amount of Cn≥6-HSL. The genes lasI and lasR involved in the synthesis and response to 3-oxo-C12-HSL were detected in the genomes of all strains. Two clinical strains had deletions in the lasR gene leading to truncation of the protein. One subpopulation of the PAO1 strain had a major deletion (98 bp) of the lasR gene. Strains with significant mutations of lasR secreted the lowest amount of AHL, probably due to deficiencies in the self-induction and amplification of the synthesis of the lactone. These strains formed a biofilm with low biomass. C4-HSL production also differed among the strains and was correlated with rhamnolipid production and biofilm formation. Whereas the production of AHL varied among P. aeruginosa strains, few correlations were observed with their phenotypic properties except with their ability to form a biofilm.
authors.affiliation: Laboratoire de Chimie biologique et médicale et de Microbiologie pharmaceutique, Faculté de Pharmacie, Université libre de Bruxelles, Brussels, Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Nagant
authors.affiliation: Laboratoire de Chimie biologique et médicale et de Microbiologie pharmaceutique, Faculté de Pharmacie, Université libre de Bruxelles, Brussels, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Seil
authors.affiliation: Laboratoire de Chimie biologique et médicale et de Microbiologie pharmaceutique, Faculté de Pharmacie, Université libre de Bruxelles, Brussels, Belgium.
authors.forename: A
authors.initials: A
authors.lastname: Nachtergael
authors.affiliation: Laboratoire de Chimie biologique et médicale et de Microbiologie pharmaceutique, Faculté de Pharmacie, Université libre de Bruxelles, Brussels, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: Dulanto
authors.affiliation: Laboratoire de Chimie biologique et médicale et de Microbiologie pharmaceutique, Faculté de Pharmacie, Université libre de Bruxelles, Brussels, Belgium.
authors.forename: J P
authors.initials: JP
authors.lastname: Dehaye
mesh_terms: D054742:Acyl-Butyrolactones / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development; D015374:Biosensing Techniques; D024881:Drug Resistance, Bacterial; D006017:Glycolipids / Q000235:genetics / Q000378:metabolism; D006801:Humans; D010447:Peptide Hydrolases / Q000378:metabolism; D010641:Phenotype; D011550:Pseudomonas aeruginosa / Q000145:classification* / Q000187:drug effects / Q000472:pathogenicity / Q000502:physiology*; D053038:Quorum Sensing / Q000502:physiology*; D012137:Respiratory System / Q000382:microbiology; D015398:Signal Transduction; D013183:Sputum / Q000382:microbiology; D014031:Tobramycin / Q000494:pharmacology
chemical_list: D054742:Acyl-Butyrolactones; D000900:Anti-Bacterial Agents; D006017:Glycolipids; C418382:rhamnolipid; D010447:Peptide Hydrolases; D014031:Tobramycin