Figure 1. Simplified schematic representation of virulence regulatory systems based on detection of signal molecules in animal pathogenic bacteria.

These include (left) quorum sensing based on acylhomoserine lactones (AHL) and (right) quorum sensing in vibrios and catecholamine stress hormone sensing. For each type of system, examples of natural ligands, receptor inhibitors, and other inhibiting agents are shown. Dioxazaborocane is an inhibitor of AI-2 sensing in V. harveyi and LED209 is an inhibitor of catecholamine sensing in E. coli. The signal transduction inhibitors are inhibitors of quorum sensing signal transduction in vibrios.