Modulation of Pseudomonas fluorescens Biofilm and Quorum Sensing Pathways by Natural and Synthetic Inhibitors

Overview

Antibiotic-resistant Pseudomonas aeruginosa is responsible for an estimated 559,000 deaths annually worldwide, and for immunocompromised patients like myself, it is a leading cause of mortality. It survives with quorum sensing and uses biofilms to shield from antimicrobial penetration. Alternative strategies that restore antibiotic efficacy without accelerating resistance development are crucial. Recent studies have identified quorum-sensing inhibitors as a promising synergistic approach. In my research, Pseudomonas fluorescens was chosen as a BSL-1 organism with QS and biofilm regulatory pathways similar to P. aeruginosa. This study investigated whether selected QSIs could suppress biofilm formation and enhance antibiotic susceptibility under sublethal kanamycin stress. Kanamycin was selected as the sublethal/lethal antibiotic because it is clinically used for Pseudomonas treatments. Biofilm biomass was quantified using crystal-violet staining with absorbance-based assays across pure growth controls, solvent controls, antibiotic-only treatments, QSI-only treatments, and combined QSI–antibiotic conditions. QSIs significantly reduced biofilm formation compared to antibiotic-only treatments, with quercetin producing the greatest antibiotic efficacy, followed by cinnamaldehyde, curcumin, green tea extract, and allicin. This indicates that natural QS inhibition can restore bacterial susceptibility to antibiotics. From my research, natural QSIs could be integrated into advanced wound dressings to locally modulate bacterial communication at infection sites. I aim to test my engineered hydrogel model to carry quercetin with kanamycin for targeted disruption of biofilm architecture. This would use dual-action nanoparticle systems that combine QSIs with immune-modulating agents to penetrate biofilm matrices. Over time, this strategy would lead to safer, longer-lasting treatments that manage infections by controlling bacterial behavior.

Competition history

• CSEF 2026 Medicine & Physiology (Junior Division) · Entry J-15-02

Related projects

Closest projects by meaning, across every fair and year in the corpus.

Browse more like this

• All Biomedical and Health Sciences projects
• CSEF Biomedical and Health Sciences projects
• Every CSEF 2026 project