Quorum sensing in Escherichia coli and Salmonella typhimurium. Author M Surette, Bonnie Bassler Publication Year 1998 Type Journal Article Abstract Escherichia coli and Salmonella typhimurium strains grown in Luria-Bertani medium containing glucose secrete a small soluble heat labile organic molecule that is involved in intercellular communication. The factor is not produced when the strains are grown in Luria-Bertani medium in the absence of glucose. Maximal secretion of the substance occurs in midexponential phase, and the extracellular activity is degraded as the glucose is depleted from the medium or by the onset of stationary phase. Destruction of the signaling molecule in stationary phase indicates that, in contrast to other quorum-sensing systems, quorum sensing in E. coli and S. typhimurium is critical for regulating behavior in the prestationary phase of growth. Our results further suggest that the signaling factor produced by E. coli and S. typhimurium is used to communicate both the cell density and the metabolic potential of the environment. Several laboratory and clinical strains of E. coli and S. typhimurium were screened for production of the signaling molecule, and most strains make it under conditions similar to those shown here for E. coli AB1157 and S. typhimurium LT2. However, we also show that E. coli strain DH5alpha does not make the soluble factor, indicating that this highly domesticated strain has lost the gene(s) or biosynthetic machinery necessary to produce the signaling substance. Implications for the involvement of quorum sensing in pathogenesis are discussed. Keywords Escherichia coli, Signal Transduction, Cell Communication, Salmonella typhimurium, Biosensing Techniques, Biological Assay, Cell Count Journal Proc Natl Acad Sci U S A Volume 95 Issue 12 Pages 7046-50 Date Published 1998 Jun 09 ISSN Number 0027-8424 DOI 10.1073/pnas.95.12.7046 Alternate Journal Proc Natl Acad Sci U S A PMCID PMC22733 PMID 9618536 PubMedPubMed CentralGoogle ScholarBibTeXEndNote X3 XML