Rapid Bactericidal Effect Of Cinnamon Bark Essential Oil Against Pseudomonas Aeruginosa.

This study aimed to identify the most effective antimicrobial from a selection of essential oils and investigate its bactericidal properties against Ps. aeruginosa.The disc diffusion assay and minimal inhibitory/bactericidal concentration tests were used to identify antimicrobial potential. Several oils exhibited antimicrobial effects at concentrations as low as 0·03% (v/v). Significantly, cinnamon (Cinnamomum zeylanicum) bark oil exhibited broad spectrum activity against Gram-negative and Gram-positive bacteria and showed bacteriostatic and bactericidal effects against Ps. aeruginosa PAO1 at 0·125% (v/v) and all other tested organisms, including known multidrug resistant species. Time-kill assays and metabolic activity tests showed cinnamon oil to exhibit rapid killing, with bactericidal activity observed in ≤ 6 min at ≥ 0·5% (v/v). Furthermore, scanning electron microscopy and a membrane permeability assay indicated damage to membrane integrity, loss of turgor and cell collapse.Cinnamon bark essential oil is a broad-spectrum antimicrobial capable of rapid killing at low concentrations.This study provides a sound basis for further investigation of the potential of cinnamon bark essential oil as an alternative to conventional antimicrobial products due to its fast acting bactericidal properties at low concentrations.