title: Subinhibitory concentrations of the cationic antimicrobial peptide colistin induce the pseudomonas quinolone signal in Pseudomonas aeruginosa.
abstract: Colistin is an important cationic antimicrobial peptide (CAMP) in the fight against Pseudomonas aeruginosa infection in cystic fibrosis (CF) lungs. The effects of subinhibitory concentrations of colistin on gene expression in P. aeruginosa were investigated by transcriptome and functional genomic approaches. Analysis revealed altered expression of 30 genes representing a variety of pathways associated with virulence and bacterial colonization in chronic infection. These included response to osmotic stress, motility, and biofilm formation, as well as genes associated with LPS modification and quorum sensing (QS). Most striking was the upregulation of Pseudomonas quinolone signal (PQS) biosynthesis genes, including pqsH, pqsB and pqsE, and the phenazine biosynthesis operon. Induction of this central component of the QS network following exposure to subinhibitory concentrations of colistin may represent a switch to a more robust population, with increased fitness in the competitive environment of the CF lung.
authors.affiliation: BIOMERIT Research Centre, Department of Microbiology, University College Cork, Ireland.
authors.forename: Joanne
authors.initials: J
authors.lastname: Cummins
authors.affiliation: BIOMERIT Research Centre, Department of Microbiology, University College Cork, Ireland.
authors.forename: F Jerry
authors.initials: FJ
authors.lastname: Reen
authors.affiliation: BIOMERIT Research Centre, Department of Microbiology, University College Cork, Ireland.
authors.forename: Christine
authors.initials: C
authors.lastname: Baysse
authors.affiliation: BIOMERIT Research Centre, Department of Microbiology, University College Cork, Ireland.
authors.forename: Marlies J
authors.initials: MJ
authors.lastname: Mooij
authors.affiliation: BIOMERIT Research Centre, Department of Microbiology, University College Cork, Ireland.
authors.forename: Fergal
authors.initials: F
authors.lastname: O'Gara
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D003091:Colistin / Q000008:administration & dosage*; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D005798:Genes, Bacterial; D006801:Humans; D006912:Hydroxyquinolines / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000378:metabolism; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D011710:Pyocyanine / Q000096:biosynthesis; D015363:Quinolones / Q000378:metabolism*; D053038:Quorum Sensing; D015533:Transcriptional Activation
chemical_list: C407944:2-heptyl-3-hydroxy-4-quinolone; D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D006912:Hydroxyquinolines; D015363:Quinolones; C049991:MY 12-62c; D011710:Pyocyanine; D003091:Colistin