Exploring the impact of parthenolide as anti-quorum sensing and anti-biofilm agent against Pseudomonas aeruginosa.

AIMS: Pseudomonas aeruginosa is a well-known pathogen responsible for various infections due to its capability to develop biofilm and various virulent phenotypes that are regulated by quorum sensing. Pathogenesis of the bacteria may be halted by interfering with the signaling molecules and the quorum sensing receptors. Therefore, the present study explores the potential of parthenolide, a sesquiterpene lactone of feverfew plant, as a promising candidate against P. aeruginosa PAO1 associated virulence factors and biofilm.

MAIN METHODS: Effect of parthenolide on virulence and biofilm formation of P. aeruginosa was studied using standard protocols. Mechanism of action was studied using Real-time PCR as well as molecular docking studies.

KEY FINDINGS: Significant decrease in virulence factors and biofilm formation was observed when treated with the sub-MIC concentration (1 mM) of parthenolide. Gene expression studies showed the down-regulation of autoinducer synthase (lasI, rhlI) as well as their receptors (lasR and rhlR) with remarked repression of lasR by 57% compared to the control. Biofilm-associated fluorescent microscopic studies after staining with FITC-ConA and propidium iodide showed reduced extracellular polymeric substance (EPS) production and killing of bacterial cells after treatment with parthenolide.

SIGNIFICANCE: The study is important as it reports for the first time the potential of parthenolide as an anti-quorum and anti-biofilm agent. This study will be helpful in designing of new quorum sensing inhibitors that help in the eradication of infections and can be given in combination with the antibiotics.