An important focus of my research will be the study of bacterial intra- and interspecies signaling molecules. Cell-to-cell communication is used by single-cell organisms to coordinate their behavior and function in such a way that they can adapt to changing environments and possibly compete with multicellular organisms. Chemical communication amongst bacteria has been termed “quorum sensing” (QS). Examples of QS-controlled behaviors are biofilm formation, virulence factor expression, antibiotic production and bioluminescence. These processes are beneficial to a bacterial population only when they are carried out in a coordinated fashion. Quorum sensing systems exist in both gram-positive and -negative bacteria and a variety of oligopeptides and N-acyl-homoserine lactones have been identified as QS molecules. Many QS molecules have not been characterized fully, and we will attempt to clarify the role of various QS molecules in bacterial signaling (in species such as Vibrio cholerae, Salmonella typhimurium, Helicobacter pylori) through synthesis and evaluation of QS molecules and potential antagonists and we will develop methodologies to study a wide variety of newly discovered and undiscovered QS molecules.