Antibacterial effect of plant volatiles against Pseudomonas aeruginosa assessed by using broth microdilution volatilization method

Abstract

Plant-derived compounds (carvacrol, cinnamaldehyde, eugenol, 8-hydroxyquinline, thymol, and thymoquinone) were assessed for their in vitro growth-inhibitory effect against Pseudomonas aeruginosa. For this purpose, the broth microdilution volatilization method evaluating antibacterial activity simultaneously in liquid and vapour phase was used. This recently developed screening method is performed in 96-well microtiter plates, it combines principles of standard broth microdilution assay with disc volatilization test. The results showed 8-hydroxyquinoline and thymol as the most effective antibacterial agents with the lowest minimum inhibitory concentration 256 μg/mL for both compounds.