In vitro antimicrobial activity of Cymbopogon flexuosus against Staphylococcus aureus and Acinetobacter baumannii

Green, Nikki; Adukwu, Emmanuel

Abstract

Staphylococcus aureus (S. aureus) and Acinetobacter baumannii (A. baumannii) are both significant
nosocomial pathogens that have become increasingly resistant to conventional antimicrobial
therapies. There is a need for alternative therapies to combat this issue and recent literature has
shown that essential oils can be effective.
This study investigated the antimicrobial effect of Cymbopogon flexuosus (lemongrass) against the
mentioned pathogens, using the disc diffusion assay and broth microdilution method to determine
the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) as well
as growth kinetics using the optical density method.
The results of the disc diffusion assays showed that lemongrass was effective against both
organisms, though less so against A. baumannii, likely due to the intrinsically resistant nature of
Gram-negative bacteria. The broth microdilution method showed the low concentrations of
lemongrass could inhibit and kill each organism, 0.06% (v/v) and 0.13% (v/v) for S. aureus and 0.13%
(v/v) and 0.25% (v/v) for A. baumannii respectively. These findings were corroborated by the 96-
hour optical density growth kinetics, which identified the same MIC and MBC and the broth
microdilution method. This suggests that the optical density growth kinetic method of determining
MIC and MBC could, if not replace, the corroborate results from the more commonly used methods

• Presentation Conference Type: Poster
• Conference Name: ECM Forum Summer Conference 2018
• Start Date: Jun 14, 2018
• End Date: Nov 15, 2019
• Deposit Date: Aug 12, 2021
• Keywords: Acinetobacter baumannii, Essential oil, Antibiotics
• Public URL: https://uwe-repository.worktribe.com/output/4749808
• Publisher URL: https://microbiologysociety.org/uploads/assets/uploaded/b42b59ec-e996-4c35-a6fcf5bdc50a7cbf.pdf