title: Microarray analysis of Pseudomonas aeruginosa quorum-sensing regulons: effects of growth phase and environment.
abstract: Bacterial communication via quorum sensing (QS) has been reported to be important in the production of virulence factors, antibiotic sensitivity, and biofilm development. Two QS systems, known as the las and rhl systems, have been identified previously in the opportunistic pathogen Pseudomonas aeruginosa. High-density oligonucleotide microarrays for the P. aeruginosa PAO1 genome were used to investigate global gene expression patterns modulated by QS regulons. In the initial experiments we focused on identifying las and/or rhl QS-regulated genes using a QS signal generation-deficient mutant (PAO-JP2) that was cultured with and without added exogenous autoinducers [N-(3-oxododecanoyl) homoserine lactone and N-butyryl homoserine lactone]. Conservatively, 616 genes showed statistically significant differential expression (P </= 0.05) in response to the exogenous autoinducers and were classified as QS regulated. A total of 244 genes were identified as being QS regulated at the mid-logarithmic phase, and 450 genes were identified as being QS regulated at the early stationary phase. Most of the previously reported QS-promoted genes were confirmed, and a large number of additional QS-promoted genes were identified. Importantly, 222 genes were identified as being QS repressed. Environmental factors, such as medium composition and oxygen availability, eliminated detection of transcripts of many genes that were identified as being QS regulated.
authors.affiliation: Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, New York 14642, USA.
authors.forename: Victoria E
authors.initials: VE
authors.lastname: Wagner
authors.forename: Daniel
authors.initials: D
authors.lastname: Bushnell
authors.forename: Luciano
authors.initials: L
authors.lastname: Passador
authors.forename: Andrew I
authors.initials: AI
authors.lastname: Brooks
authors.forename: Barbara H
authors.initials: BH
authors.lastname: Iglewski
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002455:Cell Division / Q000235:genetics; D003470:Culture Media; D015964:Gene Expression Regulation, Bacterial; D018398:Homeodomain Proteins / Q000235:genetics; D006714:Homoserine / Q000031:analogs & derivatives / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D011550:Pseudomonas aeruginosa / Q000502:physiology*; D018085:Regulon / Q000235:genetics*; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D018398:Homeodomain Proteins; C109860:N-(3-oxododecanoyl)homoserine lactone; C092312:N-butyrylhomoserine lactone; D006714:Homoserine; D015107:4-Butyrolactone