Biofilm disruption by citronellol and geraniol against clinical uropathogenic Pseudomonas aeruginosa: an integrated in vitro and in silico investigation.

BACKGROUND

Antimicrobial resistance (AMR) by Pseudomonas aeruginosa, within urinary tract and nosocomial infections, involves biofilm formation and quorum sensing (QS) constituting a major clinical challenge.

METHODS

The chemical composition of Pelargonium graveolens essential oil (EO) was determined by gas chromatography-mass spectrometry (GC-MS). Antibacterial activity of the EO and its major constituents, citronellol and geraniol, was evaluated against clinical and reference P. aeruginosa strains using disk diffusion and broth microdilution assays. Antibiofilm activity was assessed at concentrations ranging from 2×MIC to sub-MIC levels. Interference with quorum-sensing-associated phenotypes was investigated using Chromobacterium violaceum CV12472 and CV026 biosensor strains. Swarming and swimming motility assays were performed. Molecular docking and ADMET analyses were conducted to explore potential target interactions and pharmacokinetic properties.

RESULTS

Citronellol (34.29%) and geraniol (18.62%) were the predominant constituents of the EO. Antibacterial activity yielded inhibition zones of 10-14 mm and MIC values ranging from 1% to 0.031% (v/v), with geraniol showing the lowest MIC (0.031%). The EO, citronellol, and geraniol inhibited biofilm formation, reaching 87.28% inhibition at 2×MIC while retaining activity at sub-MIC concentrations. All treatments reduced violacein production in C. violaceum biosensors and inhibited bacterial motility, with maximum reductions of 82.6% (swarming) and 74.3% (swimming). Geraniol generally exhibited the strongest activity. Docking analysis revealed binding affinities of - 6.08 and - 5.83 kcal/mol for citronellol and geraniol, respectively.

CONCLUSION

P. graveolens EO, citronellol, and geraniol exhibited promising anti-virulence properties against multidrug-resistant uropathogenic P. aeruginosa, supporting their potential as complementary agents for controlling biofilm- and motility-associated infections.