Quorum Quenching Potential of the Indigenous Kalimantan Fern Stenochlaena palustris Against Pseudomonas aeruginosa

Background and Objective: Plant-derived compounds that disrupt bacterial quorum sensing (QS) provide alternatives to combat antibiotic resistance. This quorum quenching (QQ) strategy reduces virulence without inhibiting growth, thus minimizing resistance. Kelakai (Stenochlaena palustris (Burm.) Bedd.), an endemic Kalimantan plant traditionally used by the Dayak people, was evaluated for QQ activity against Pseudomonas aeruginosa. Materials and Methods: Ethanolic extract of S. palustris leaves was prepared by maceration with 96% ethanol. The extract was tested for inhibition of P. aeruginosa motility, pyocyanin production and LasA activity. Antibiofilm effects were assessed using the microtiter plate method, EPS quantified, chemical profiling performed by Liquid Chromatography-High-Resolution Mass Spectrometry (LC-HRMS) and acute toxicity evaluated in Rasbora lateristriata embryos. The results from three independent trials were analyzed in SPSS using one-way ANOVA followed by Dunn's test, with significance set at p