Submitted to: Foodborne Pathogens and Disease
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/21/2007
Publication Date: 11/27/2007
Citation: Soni, K., Jesudhasan, P., Cepeda, M., Williams, B., Hume, M., Russell, W.K., Jayaraman, A., Pillai, S.D. 2007. Proteomic analysis to identify the role of luxS/AI-2 mediated protein expression in Escherichia coli O157:H7. Foodborne Pathogens and Disease. 4:463-471. Interpretive Summary: Certain chemicals are used by bacteria to coordinate various processes including the ability to cause disease, form films, and produce light. These special chemicals are thought to stimulate communication between harmful bacteria such as some E. coli. We investigated the effect of these chemical signals on the production of proteins by E. coli. Production of some proteins were stimulated, while the production of other proteins was cut off in the presence of the chemical signals. The results are of interest to researchers investigating alternative methods to antibiotics as control strategies for bacteria and bacterial infection.
Technical Abstract: Autoinducer molecules are used by several microorganisms to control various bacterial 5 processes including virulence expression, biofilm and bioluminescence. The universal 6 autoinducer molecule AI-2 is hypothesized to mediate cell signaling in E. coli O157:H7. We investigated the role of AI-2 on the E. coli O157:H7 cellular proteins using a 2D gel 8 electrophoresis-based proteomic approach. The protein expression patterns between two 9 experimental comparisons were studied namely, a) a wild type E. coli O157:H7 and its 10 isogenic luxS mutant, and b) the luxS mutant and the luxS mutant supplemented with AI-2 11 molecules. Eleven proteins were differentially expressed between the wild type and the 12 luxS mutant strain, whereas 18 proteins were differentially expressed in the luxS mutant 13 strain when supplemented with AI-2. The tryptophan repressor binding protein (WrbA), 14 phosphoglycerate mutase (GpmA), and a putative protein YbbN were found to be 15 differentially expressed under both experimental comparisons. The FliC protein which is 16 involved in flagellar synthesis and motility was up-regulated in the wild type strain but 17 was not influenced by the addition of synthetic AI-2 molecules to the luxS mutant 18 suggesting the involvement of signaling molecules other than AI-2 on flagellar synthesis 19 and motility.