Quorum sensing in Escherichia coli and Salmonella.
Quorum sensing in Escherichia coli and Salmonella has been an elusive topic for a long time. However, in the past 8 years, several research groups have demonstrated that these bacteria use several quorum-sensing systems, such as: the luxS/AI-2, AI-3/epinephrine/norepinephrine, indole, and the LuxR homolog SdiA to achieve intercellular signaling. The majority of these signaling systems are involved in interspecies communication, and the AI-3/epinephrine/norepinephrine signaling system is also involved in interkingdom communication. Both E. coli and Salmonella reside in the human intestine, which is the largest and most complex environment in the mammalian host. The observation that these bacteria evolved quorum-sensing systems primarily involved in interspecies communication may constitute an adaptation to this environment. The gastrointestinal tract harbors a high density and diversity of bacterial cells, with the majority of the flora residing in the colon (10(11)-10(12) bacterial cells/ml). Given the enormous number and diversity of bacteria inhabiting the gastrointestinal environment, it should not be surprising that the members of this community communicate amongst themselves and with the host itself to coordinate a variety of adaptive processes.
Department of Microbiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9048, USA.
Matthew
M
Walters
Vanessa
V
Sperandio
D001426:Bacterial Proteins / Q000502:physiology; D013437:Carbon-Sulfur Lyases; D002450:Cell Communication; D004926:Escherichia coli / Q000502:physiology*; D019453:Escherichia coli O157 / Q000472:pathogenicity; D006714:Homoserine / Q000031:analogs & derivatives / Q000502:physiology; D006801:Humans; D007211:Indoles / Q000378:metabolism; D007783:Lactones; D012475:Salmonella / Q000502:physiology*; D015534:Trans-Activators / Q000502:physiology
D001426:Bacterial Proteins; D007211:Indoles; D007783:Lactones; C091088:N-octanoylhomoserine lactone; C097686:SdiA protein, bacteria; D015534:Trans-Activators; D006714:Homoserine; C030374:indole; D013437:Carbon-Sulfur Lyases; C117753:LuxS protein, Bacteria