Multifaceted quorum-sensing inhibiting activity of 3-(Benzo[d][1,3]dioxol-4-yl)oxazolidin-2-one mitigates <i>Pseudomonas aeruginosa</i> virulence

As antibiotic resistance escalates into a global health crisis, novel therapeutic approaches against infectious diseases are in urgent need. <i>Pseudomonas aeruginosa</i>, an adaptable opportunistic pathogen, poses substantial challenges in treating a range of infections. The quorum-sensing (QS) system plays a pivotal role in orchestrating the production of a large set of virulence factors in a cell density-dependent manner, and the anti-virulence strategy targeting QS may show huge potential. Here, we present a comprehensive investigation into the potential of the synthesized compound 3-(benzo[d][1,3]dioxol-4-yl)oxazolidin-2-one (OZDO, C₁₀H₉NO₄) as a QS inhibitor to curb the virulence of <i>P. aeruginosa</i>. By employing an integrated approach encompassing <i>in silico</i> screening, <i>in vitro</i> and <i>in vivo</i> functional identification, we elucidated the multifaceted effects of OZDO. Molecular docking predicted that OZDO interfered with three core regulatory proteins of <i>P. aeruginosa</i> QS system. Notably, OZDO exhibited significant inhibition on the production of pyocyanin, rhamnolipid and extracellular proteases, biofilm formation, and cell motilities of <i>P. aeruginosa</i>. Transcriptomic analysis and quantitative real-time PCR displayed the down-regulation of QS-controlled genes in OZDO-treated PAO1, reaffirming the QS-inhibition activity of OZDO. <i>In vivo</i> assessments using a <i>Caenorhabditis elegans</i>-infection model demonstrated OZDO mitigated <i>P. aeruginosa</i> pathogenicity, particularly against the hypervirulent strain PA14. Moreover, OZDO in combination with polymyxin B and aztreonam presented a promising avenue for innovative anti-infective therapy. Our study sheds light on the multifaceted potential of OZDO as an anti-virulence agent and its significance in combating <i>P. aeruginosa</i>-associated infections.