Quorum quenching pathoblockers from bacteria: an alternative approach for bacterial infection management.

Antibiotic resistance in bacterial pathogens has reached a crisis stage and has led to fears of a “post-antibiotic era”. To combat this, current approach focuses on indirect attack on bacteria by disrupting their communication system, quorum sensing (QS). This system comprises small diffusible signalling molecules activating expression of myriad genes that control an array of functions, including biofilm formation, production of virulence factors and development of antibiotic resistance. Gram-positive bacteria utilise peptide derivatives of these signalling molecules, whereas Gram-negative bacteria employ fatty acid derivatives. Majority of bacteria utilise both types to regulate expression of target gene. Recent research has prioritised identifying several compounds from diverse sources that can hinder the signalling systems responsible for bacterial virulence and pathogenicity. QS inhibitor (QSI) should target the signalling circuit and have no effect on other bacterial systems. Major mechanisms involved in QS inhibition include inhibition of signal molecule synthesis, inactivation/enzymatic degradation of signal molecules, interference with signal receptor, and blocking signal transduction cascades. QSI thus decreases/completely inhibits production of virulence factors. Bacterial products as QSI constitute a promising approach in developing anti-virulence therapies, providing a new avenue for combating bacterial infections parallelly improving effectiveness of traditional antibiotics. Exploring a diverse array of bacterial products like secondary metabolites, cell-free extracts, bacteriocins, biosurfactants, and enzymes as QSIs are gaining prominence due to their selectivity, reduced propensity to induce resistance, and capacity to target multiple pathogens. This review comprehends reported research outcomes from this domain in the recent past and highlights the need of future clinical/translational studies.