title: Identification of a quorum-sensing signal molecule in the facultative intracellular pathogen Brucella melitensis.
abstract: Brucella melitensis is a gram-negative alpha2-proteobacterium responsible for abortion in goats and for Malta fever in humans. This facultative intracellular pathogen invades and survives within both professional and nonprofessional phagocytes. A dichloromethane extract of spent culture supernatant from B. melitensis induces bioluminescence in an Escherichia coli acyl-homoserine lactone (acyl-HSL) biosensor strain based upon the activity of the LasR protein of Pseudomonas aeruginosa. HPLC fractionation of the extract, followed by mass spectrometry, identified the major active molecule as N-dodecanoylhomoserine lactone (C12-HSL). This is the first report of the production of an acyl-HSL by an intracellular pathogen. The addition of synthetic C12-HSL to an early log phase culture of either B. melitensis or Brucella suis 1330 reduces the transcription of the virB operon, which contains virulence genes known to be required for intracellular survival. This mimics events seen during the stationary phase of growth and suggests that quorum sensing may play a role in the control of virulence in Brucella.
authors: Unité de Recherche en Biologie Moléculaire (URBM), Laboratoire d'Immunologie et Microbiologie, Facultés Universitaires Notre-Dame de la Paix, 5000 Namur, Belgium. Bernard.Taminiau@fundp.ac.be
authors: Bernard
authors: B
authors: Taminiau
authors: Mavis
authors: M
authors: Daykin
authors: Simon
authors: S
authors: Swift
authors: Maria-Laura
authors: ML
authors: Boschiroli
authors: Anne
authors: A
authors: Tibor
authors: Pascal
authors: P
authors: Lestrate
authors: Xavier
authors: X
authors: De Bolle
authors: David
authors: D
authors: O'Callaghan
authors: Paul
authors: P
authors: Williams
authors: Jean-Jacques
authors: JJ
authors: Letesson
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D017347:Brucella melitensis / Q000254:growth & development / Q000378:metabolism*; D003470:Culture Media; D007424:Intracellular Fluid; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D037521:Virulence Factors
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D014157:Transcription Factors; D037521:Virulence Factors; C088386:homoserine lactone; D015107:4-Butyrolactone