Can disc diffusion susceptibility tests assess the antimicrobial activity of engineered nanoparticles?

Journal article (2018)

Authors

A. Kourmouli ChemE/Materials for Energy Conversion and Storage - AS , University of the Aegean
M. Valenti ChemE/Materials for Energy Conversion and Storage - AS
E. van Rijn Kavli institute of nanoscience Delft, RID/KEWO/Stralingsbeschermingseenheid
H.J.E. Beaumont BN/Bertus Beaumont Lab - AS , Kavli institute of nanoscience Delft
Olga Ioanna Kalantzi University of the Aegean
A. Schmidt-Ott ChemE/Materials for Energy Conversion and Storage - AS
G. Biskos Energy and Industry , The Cyprus Institute, Atmospheric Remote Sensing - CEG
Research Group
ChemE/Materials for Energy Conversion and Storage (AS) (TU Delft)
Copyright: © 2018 A. Kourmouli, M. Valenti, E. van Rijn, H.J.E. Beaumont, Olga Ioanna Kalantzi, A. Schmidt-Ott, G. Biskos
DOI: https://doi.org/10.1007/s11051-018-4152-3
More Info
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Published Date

2018

Language

English

Faculty

Applied Sciences

Department

ChemE/Chemical Engineering

Research Group

ChemE/Materials for Energy Conversion and Storage

Abstract

The use of disc diffusion susceptibility tests to determine the antibacterial activity of engineered nanoparticles (ENPs) is questionable because their low diffusivity practically prevents them from penetrating through the culture media. In this study, we investigate the ability of such a test, namely the Kirby-Bauer disc diffusion test, to determine the antimicrobial activity of Au and Ag ENPs having diameters from 10 to 40 nm on Escherichia coli cultures. As anticipated, the tests did not show any antibacterial effects of Au nanoparticles (NPs) as a result of their negligible diffusivity through the culture media. Ag NPs on the other hand exhibited a strong antimicrobial activity that was independent of their size. Considering that Ag, in contrast to Au, dissolves upon oxidation and dilution in aqueous solutions, the apparent antibacterial behavior of Ag NPs is attributed to the ions they release. The Kirby-Bauer method, and other similar tests, can therefore be employed to probe the antimicrobial activity of ENPs related to their ability to release ions rather than to their unique size-dependent properties. [Figure not available: see fulltext.].