title: Novel intercellular communication system in Escherichia coli that confers antibiotic resistance between physically separated populations.
abstract: OBJECTIVE
  To determine whether intercellular signalling can occur between physically separated populations of Escherichia coli.
  
  
  RESULTS
  Intercellular signalling between physically discrete populations of E. coli BL21 was analysed in bi-partite Petri dishes. Transfer of a growth-promoting signal resulted in induction of resistance to the antibiotic ampicillin. Optimal expression of the signal occurred when the signalling population was established as a bacterial lawn for 24 h. This represented an entry into the stationary phase of growth, as indicated by the expression profile of the RNA polymerase subunit sigma38 (sigmaS; sigma S). The growth-promoting effect was also observed when E. coli DH5alpha (luxS-) was used as the signalling population. Preventing passage of air between the two populations resulted in a complete cessation of the growth-promoting effect.
  
  
  CONCLUSIONS
  A growth-promoting signal occurs between physically separated cultures of E. coli. The exact nature of the signal remains to be determined but does not involve the production of autoinducer-2 from the luxS gene. Signal transmission is likely to involve airborne transfer of a signal species.
  
  
  CONCLUSIONS
  Intercellular signalling systems exist in bacteria that enable antibiotic resistance to be conferred between physically separated populations.
authors: BioPhysics Research Group, QinetiQ ltd., Winfrith Technology Centre, Dorchester, UK. rdheal@QinetiQ.com
authors: R D
authors: RD
authors: Heal
authors: A T
authors: AT
authors: Parsons
mesh_terms: D000388:Air; D000668:Ampicillin Resistance / Q000502:physiology*; D001426:Bacterial Proteins / Q000502:physiology; D001431:Bacteriological Techniques; D013437:Carbon-Sulfur Lyases; D004926:Escherichia coli / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D013437:Carbon-Sulfur Lyases; C117753:LuxS protein, Bacteria