In vitro evaluation of caffeic acid derivatives as efflux pump inhibitor in Pseudomonas aeruginosa and Burkholderia pseudomallei
- Author:
Noor Zawani Zakaria
;
Norshima Abu Hasan
;
Ahmad Fahim Mohd Dani
;
Amirin Sadikun
;
Pazilah Ibrahim
;
Ezatul Ezleen Kamarulzaman
;
Suriani Mohamad
- Publication Type:Original article
- Keywords:
Gram-negative bacteria;
multidrug resistance efflux pump;
efflux pump inhibitor;
caffeic acid derivatives
- From:Malaysian Journal of Microbiology
2017;13(4):334-342
- CountryMalaysia
- Language:English
-
Abstract:
Aims: Bacterial pathogens such as Pseudomonas aeruginosa and Burkholderia pseudomallei are intrinsically resistant
to many classes of antibiotics. This is not only due to the poor permeability of their outer membrane but also because of
expression of multiple efflux pumps. A promising strategy to minimize the efflux of drugs by these pumps is the use of
efflux pump inhibitors (EPIs). In this study, the potential of caffeic acid derivatives as EPIs in P. aeruginosa and B.
pseudomallei were evaluated.
Methodology and results: The potential of caffeic acid and its derivatives, i.e. chlorogenic acid, caffeic acid phenethyl
ester (CAPE) and caffeic acid phenethyl amide (CAPA) to act as EPIs in P. aeruginosa and B. pseudomallei were
assessed using the ethidium bromide (EtBr) accumulation and minimum inhibitory concentration (MIC) validation
assays. Among the four test compounds, CAPE was found to significantly increased intracellular accumulation of EtBr in
both P. aeruginosa and B. pseudomallei. An increase of 21.4% and 16.8% in cell fluorescence, over a 5-min time frame
was observed in P. aeruginosa and B. pseudomallei respectively. Combination of CAPE with kanamycin significantly
reduced MICs of this aminoglycoside by a factor of 8-fold in P. aeruginosa and 2-fold in B. pseudomallei. Combination of
CAPE with gentamicin also led to a reduction of 4-fold MIC value of this antibiotic in B. pseudomallei.
Conclusion, significance and impact of study: The in-vitro results suggest that CAPE has the potential to act as an
EPI in P. aeruginosa and B. pseudomallei, thus improving the efficacy of aminoglycosides as antimicrobial agents.
