Submitted to: American Society for Microbiology Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/23/2004
Publication Date: 5/27/2004
Citation: Dyszel, J.L., Carter, H.D., Frye, J.G., Mcclelland, M., Ahmer, B.M. 2004. Identification of salmonella genes that are expressed in response to the presence of other bacterial species. American Society for Microbiology Meeting. N-294.
Technical Abstract: SdiA is a LuxR homolog in Salmonella enterica that detects and responds to N-acylhomoserine lactone (AHL) production by other species. To determine the response of S. enterica to other species, a microarray analysis has been performed. To insure maximal SdiA activation during the experiment, sdiA was expressed from a plasmid in the presence of synthetic AHL. A vector control strain was used as the negative control. Two loci already known to be activated in response to SdiA and AHL were identified in the array analysis, srgE and the rck operon, confirming that the experiment was successful. At least 16 additional genes were also identified. Chromosomal lacZY fusions are being constructed to these loci to confirm that they respond to AHL and sdiA expressed from its natural position in the chromosome. A fusion to one gene, ybbK, has been constructed and confirmed to be a new member of the SdiA regulon. This fusion becomes active in the presence of Yersinia enterocolitica but not in the presence of an isogenic yenI mutant that cannot synthesize AHL. Many of the genes identified have never been isolated in genetic screens before, consistent with the idea that they are expressed only within mixed microbial communities.