Pseudomonas aeruginosa quorum sensing regulatory systems (PAQS)

Pseudomonas aeruginosa quorum sensing (QS) is a sophisticated hierarchical regulatory network that enables the bacteria to coordinate gene expression in response to population density. The system is primarily composed of four interconnected pathways: the Las, Rhl, Pqs, and IQS systems, which utilize specific signaling molecules like N-acyl homoserine lactones and alkyl quinolones to synchronize group behaviors. These systems collectively regulate the production of a wide array of virulence factors, including proteases, toxins, and pigments, and are essential for the formation and structural integrity of biofilms. In human disease, the QS network is a major driver of pathogenesis in chronic infections, particularly in the lungs of cystic fibrosis patients and in healthcare-associated pneumonia. Targeting these regulatory systems, often referred to as quorum quenching, represents a promising therapeutic strategy to attenuate bacterial virulence and increase susceptibility to the host immune system and conventional antibiotics. By disrupting communication rather than directly killing the bacteria, these inhibitors may exert less selective pressure for the development of antimicrobial resistance compared to traditional bactericidal agents.

Other names

Pseudomonas aeruginosa cell-to-cell signalingLasI/LasR systemRhlI/RhlR systemPqsR/MvfR systemQuorum sensing (QS) network

Inhibition of signal molecule synthesis (synthase inhibitors), competitive antagonism of signal binding to cognate receptors (receptor antagonists), and enzymatic degradation of signaling molecules (quorum quenching).