Elucidation of the mechanisms of action of Bacteriophage K/nano-emulsion formulations against S. aureus via measurement of particle size and zeta potential


In earlier work we have demonstrated the effect that nano-emulsions have on bacterial growth, and most importantly the enhanced bacteriophage infectivity against Staphylococcus aureus in planktonic culture when phage are carried in nano-emulsions. However, the mechanisms of enhancement of the bacteriophage killing effect are not specifically understood. This work focuses on the investigation of the possible interactions between emulsion droplets and bacterial cells, between emulsion droplets and bacteriophages, and finally interactions between all three components: nano-emulsion droplets, bacteria, and bacteriophages. The first approach consists of simple calculations to determine the spatial distribution of the components, based on measurements of particle size. It was found that nano-emulsion droplets are much more numerous than bacteria or bacteriophage, and due to their size and surface area they must be covering the surface of both cells and bacteriophage particles. Stabilisation of bacteriophages due to electrostatic forces and interaction with nano-emulsion droplets is suspected, since bacteriophages may be protected against inactivation due to 'charge shielding'. Zeta potential was measured for the individual components in the system, and for all of them combined. It was concluded that the presence of nano-emulsions could be reducing electrostatic repulsion between bacterial cells and bacteriophage, both of which are very negatively 'charged'. Moreover, nano-emulsions lead to more favourable interaction between bacteriophages and bacteria, enhancing the anti-microbial or killing effect. These findings are relevant since the physicochemical properties of nano-emulsions (i.e. particle size distribution and zeta potential) are key in determining the efficacy of the formulation against infection in the context of responsive burn wound dressings-which is the main target for this work.

Publication DOI: https://doi.org/10.1016/j.colsurfb.2015.11.030
Divisions: College of Health & Life Sciences
College of Health & Life Sciences > School of Biosciences > Cell & Tissue Biomedical Research
Funding Information: The authors thank AmpliPhi Biosciences for their collaboration and technical assistance. The authors also thank the Engineering and Physical Sciences Research Council (EPSRC) for a Healthcare Partnership award (EP/I027602/1).
Additional Information: © 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Uncontrolled Keywords: Anti-microbial formulations,Bacteriophage K,Electrostatic interactions,Enhanced phage infectivity,Nano-emulsions,S. aureus infections,Wound dressings,Zeta potential,Biotechnology,Surfaces and Interfaces,Physical and Theoretical Chemistry,Colloid and Surface Chemistry
Publication ISSN: 1873-4367
Last Modified: 03 Jun 2024 07:33
Date Deposited: 27 Jun 2018 10:40
Full Text Link:
Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Article
Published Date: 2016-03-01
Published Online Date: 2015-12-01
Accepted Date: 2015-11-12
Authors: Perez Esteban, Patricia (ORCID Profile 0000-0001-7084-1065)
Jenkins, A. Toby A.
Arnot, Tom C.



Version: Published Version

License: Creative Commons Attribution

| Preview

Export / Share Citation


Additional statistics for this record