Rapid bactericidal effect of cinnamon bark essential oil against Pseudomonas aeruginosa

Elcocks, Ellena; Spencer‐Phillips, Peter; Adukwu, Emmanuel

Abstract

AIMS:
This study aimed to identify the most effective antimicrobial from a selection of essential oils and investigate its bactericidal properties against Ps. aeruginosa.

METHODS AND RESULTS:
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.

CONCLUSION:
Cinnamon bark essential oil is a broad-spectrum antimicrobial capable of rapid killing at low concentrations.

SIGNIFICANCE AND IMPACT OF STUDY:
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.

• Journal Article Type: Article
• Acceptance Date: Nov 28, 2019
• Online Publication Date: Dec 17, 2019
• Publication Date: Apr 1, 2020
• Deposit Date: Dec 17, 2019
• Publicly Available Date: Dec 18, 2020
• Journal: Journal of Applied Microbiology
• Print ISSN: 1364-5072
• Electronic ISSN: 1365-2672
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 128
• Issue: 4
• Pages: 1025-1037
• DOI: https://doi.org/10.1111/jam.14538
• Keywords: Biotechnology; Applied Microbiology and Biotechnology; General Medicine
• Public URL: https://uwe-repository.worktribe.com/output/4773669