Natural Quorum Sensing Inhibitors - Small Molecules, Big Messages

Due to the increasing emergence of antibiotic resistant bacterial strains within the past few decades, bacterial infections in general - and hospital-borne infections, in particular - have become increasingly difficult to fight. It is therefore crucial to find new strategies to fight pathogenic bacteria. Targeted inhibition of quorum sensing (QS) presents a promising alternative. QS is a cell density-dependent signaling pathway used for intra- and interspecies coordination of gene expression. In many bacteria, pathogenic phenotypes, as well as the expression of virulence factors, are under the control of QS regulons. A closer look at natural quorum sensing inhibitors may be helpful to identify potent compounds that can be used as alternatives to antibiotics. Moreover, it will also provide insight into the interactions between species that compete for the same habitat and resources. This review aims to summarize our current knowledge concerning natural QS inhibitors, as a starting point for the design and synthesis of new therapeutics to treat or prevent bacterial infections.