Rapid bactericidal effect of cinnamon bark essential oil againstPseudomonas aeruginosa

Abstract

Aims This study aimed to identify the most effective antimicrobial agent from a selection of essential oils (EO) and investigate its bactericidal properties against Pseudomonas 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 EO exhibited a broad‐spectrum activity against Gram‐negative and Gram‐positive bacteria and showed bacteriostatic and bactericidal effects against P. 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 EO is a broad‐spectrum antimicrobial agent capable of rapid killing at low concentrations. Significance and Impact of the Study This study provides a sound basis for further investigation of the potential of cinnamon bark EO as an alternative to conventional antimicrobial products due to its fast‐acting bactericidal properties at low concentrations.

Optimization of ohmic heating assisted hydrodistillation of cinnamon and bay leaf essential oil

“…As a control, methanol did not present any antibacterial activities against all tested strains. Similar results for CEO were reported by Elcocks et al (2020). CEO has a strong antimicrobial activity due to cinnamaldehyde (Masghati & Ghoreishi, 2018; Ribeiro‐Santos et al, 2017).…”

It’s Not Easy Being Green: A Narrative Review on the Microbiology, Virulence and Therapeutic Prospects of Multidrug-Resistant Pseudomonas aeruginosa

“…Additionally, it is questionable how long the new agents can manage the worsening resistance situation [146,157,[249][250][251][252][253][254]. With the daunting increase in antimicrobial resistance rates in all types of bacteria, one of the main aims of antimicrobial research is the exploration for new approaches past conventional antibiotics, such as bacteriophages, antimicrobial peptides with diverse structures and mechanisms of action, virulence inhibitors, siderophores, compounds from natural origins (like essential oils), and other adjuvants (e.g., efflux pump inhibitors, monoclonal antibodies) (Table 3) [118,[255][256][257][258][259][260][261][262][263][264][265][266][267][268][269][270]. It is possible that in the next couple of decades, these agents will play a major role in the management of serious bacterial infections caused by P. aeruginosa and other pathogens of critical importance.…”

In vitro antifungal activity of Cinnamomum zeylanicum bark and leaf essential oils against Candida albicans and Candida auris

“…The potential of cinnamon EO as an antifungal agent is also evident with the inhibitory and fungicidal action against C. albicans and C. auris at low concentrations of both leaf and bark oils. Both EOs were shown to be fast-acting antimicrobials against Pseudomonas aeruginosa in a recent study by Elcocks et al (2020), and with such promising action against two troublesome pathogenic Candida species, there is a clear need to explore this EO further as a treatment option for candidiasis infections. In summary, the findings reported here demonstrate for the first time the potential of both bark and leaf CEOs to exert antifungal activity against C. auris, which is a newly found Candida spp., along with C. albicans.…”