Related Experiment Video
Updated: May 2, 2026

Anti-virulent Disruption of Pathogenic Biofilms using Engineered Quorum-quenching Lactonases
Published on: January 1, 2016
Quorum Sensing Inhibition and Virulence Factor Attenuation in Pseudomonas aeruginosa by Camphor
Farah Khader Al-Helo1, Nasser El-Banna1, Haitham Qaralleh2
1Department of Medical Laboratory Analysis, Faculty of Science, Al-Balqa Applied University, Al-Salt, Jordan.
Objectives:
This study aimed to assess the inhibitory effects of camphor on quorum sensing (QS), virulence factors, and biofilm formation in Pseudomonas aeruginosa, a multidrug-resistant pathogen.
Methods:
P. aeruginosa was treated with sub-inhibitory concentrations of camphor (500, 250, and 125 µg/mL). Assays evaluated biofilm formation, surface hydrophobicity, swarming motility, cell aggregation, and exopolysaccharide (EPS) production. Inhibition of virulence factors-pyocyanin, rhamnolipid, protease, and chitinase-was also assessed. RT-PCR was used to quantify expression of QS-related genes (LasR, LasI, RhlR, and RhlI).
Results:
The minimum biofilm inhibitory concentration (MBIC50) ranged between 125 and 63 µg/mL. Camphor significantly reduced biofilm formation and virulence factor production at all tested concentrations. It also decreased EPS synthesis, swarming motility, hydrophobicity, and cell aggregation. Camphor suppressed acyl homoserine lactone (AHL) production and downregulated QS genes, reducing LasR and LasI expression by 5-fold and 4.6-fold, and RhlR and RhlI by 1.8-fold and 1.5-fold, respectively.
Conclusion:
Camphor demonstrates strong antibiofilm, antivirulence, and anti-QS activities against P. aeruginosa at concentrations as low as 125 µg/mL. These results suggest camphor is a promising candidate for alternative treatment strategies, warranting further investigation of its mechanisms and clinical safety.
More Related Videos
11:31Establishment of a High-throughput Setup for Screening Small Molecules That Modulate c-di-GMP Signaling in Pseudomonas aeruginosa
Published on: June 30, 2016
07:13Quantification of Violacein in Chromobacterium violaceum and Its Inhibition by Bioactive Compounds
Published on: August 8, 2025
Related Concept Videos
Bacterial Signaling
GPCRs Regulate Adenylyl Cylase Activity
Gene Regulation in Microbial Communities: Quorum Sensing