Dual-action host-guest chemistry suppresses virulence in Pseudomonas aeruginosa

This study describes the influence of selected synthetic macrocycle on the gene expression in Pseudomonas aeruginosa PAO1. In this work, we propose two distinct functionalities responsible for a dual mechanism of action. We identified a water-soluble pillararene whose inner cavity tightly binds to specific homoserine lactones (HSLs) thereby interfering with interbacterial signalling, leading to effective synchronized suppression of exotoxins and biofilms in P. aeruginosa. An additional concerted mechanism of action is suggested that involves the cationic functional side groups on the pillararene that disrupt both the bacterial outer membrane and biofilms, to increase the penetration and efficacy of intracellular antibiotics. Overall design: Bacterial cells were grown with (P5A samples) or without (Ctrl samples) the addition of 2.5 mM pillararene for 24 h.