Breaking down bacterial communication: a review of quorum quenching agents

Background Bacterial cells communicate via small extracellular molecules that facilitate gene expression which is dependent on cell density and this mechanism is known as Quorum Sensing (QS). At low cell density, these bacteria show a single cellular type of behavior but once they reach the threshold level they alter to a multicellular type and hence a QS is established by the transfer of signalling molecules called autoinducers. Quorum sensing inhibitors (QSI) are those that hinder the quorum sensing pathway. Main body of the abstract The emergence of antimicrobial resistance has become a threat to mankind with quorum sensing being one of the mechanisms responsible for this resistance. Hence Quorum Quenching can be considered to interrupt bacterial communication. This review focuses on the effects of different synthetic and natural quorum-sensing inhibitors on different organisms and how it affects their gene regulation. Conclusion Different natural and synthetic agents can quench quorum sensing by various mechanistic pathways. The various quorum-sensing inhibitors against both Gram-positive and Gram-negative bacteria provide a wider scope to prevent emerging antimicrobial resistance.