Natural products show diverse mechanisms of action against Clostridium difficile
Document Type
Journal Article
Publication Title
Journal of Applied Microbiology
ISSN
1365-2672
Volume
126
Issue
2
First Page
468
Last Page
479
PubMed ID
30412324
Publisher
Blackwell Publishing Ltd
School
School of Medical and Health Sciences
RAS ID
29588
Abstract
AIMS: To investigate the mechanisms of action of natural products with bactericidal (cinnamon root powder, peppermint oil, trans-cinnamaldehyde, menthol and zingerone) or bacteriostatic (fresh garlic bulb extract, garlic clove powder, Leptospermum honey and allicin) activity against two Clostridium difficile strains.
METHODS AND RESULTS: Bactericidal products significantly reduced intracellular ATP after 1 h (P ≤ 0·01), quantified using the BacTiter-Glo reagent, and damaged the cell membrane, shown by the leakage of both 260-nm-absorbing materials and protein, and the uptake of propidium iodide. Bacteriolysis was not observed, determined by measuring optical density of treated cell suspensions at 620-nm. The effect of three bacteriostatic products on protein synthesis was quantified using an Escherichia coli S30 extract system, with Leptospermum honey (16% w/v) showing significant inhibition (P < 0·01). Lastly, no products showed elevated minimum inhibitory concentrations against antimicrobial-resistant C. difficile, determined by broth microdilution.
CONCLUSIONS: Cytoplasmic membrane damage was identified as a mechanism of action that may contribute to the activity of several natural products against C. difficile.
SIGNIFICANCE AND IMPACT OF THE STUDY: This study describes the possible mechanisms of action of natural products against C. difficile, yet the efficacy in vivo to be determined.
DOI
10.1111/jam.14152
Access Rights
subscription content
Comments
Roshan, N., Riley, T. V., Knight, D. R., Steer, J. H., & Hammer, K. A. (2019). Natural products show diverse mechanisms of action against clostridium difficile. Journal of Applied Microbiology, 126(2), 468-479. Available here