Quorum sensing regulatory system (QS) (QS)

The quorum sensing regulatory system is a sophisticated bacterial communication mechanism that allows populations to coordinate gene expression based on cell density (Miller & Bassler, 2001, Annual Review of Microbiology). Bacteria produce, release, and detect chemical signaling molecules called autoinducers; when the concentration of these molecules reaches a threshold, the population collectively alters its behavior (Rutherford & Bassler, 2012, Cold Spring Harbor Perspectives in Medicine). This system is a critical regulator of virulence factors, biofilm formation, and antibiotic resistance in many pathogenic bacteria, such as Pseudomonas aeruginosa and Staphylococcus aureus (Defoirdt, 2018, Trends in Microbiology). As a therapeutic target, the quorum sensing system offers an anti-virulence approach, aiming to disarm pathogens rather than killing them directly, which may reduce the selective pressure for antibiotic resistance (Hentzer et al., 2003, EMBO Journal). Drugs targeting this system, known as quorum sensing inhibitors or quorum-quenching agents, work by inhibiting signal synthesis, degrading signaling molecules, or blocking receptor binding (LaSarre & Federle, 2013, Microbiology and Molecular Biology Reviews). While promising for treating chronic and multidrug-resistant infections, challenges include ensuring specificity to pathogens to avoid disrupting the host microbiome and achieving sufficient penetration into complex biofilms (Whiteley et al., 2017, Nature).

Other names

Bacterial cell-to-cell communicationQuorum signalingAutoinduction systemBacterial pheromone systemDensity-dependent gene regulation

Inhibition of autoinducer synthesis (synthase inhibitors), enzymatic degradation of signaling molecules (quorum quenching), and competitive antagonism of quorum sensing receptors (LuxR-type or histidine kinases) to prevent the activation of virulence-related genes.