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In Situ Monitoring of the Antibacterial Activity of a Copper–Silver Alloy Using Confocal Laser Scanning Microscopy and pH Microsensors

The antibacterial efficacy of a copper–silver alloy coating under conditions resembling build up of dry surface bacterial biofilms is successfully demonstrated according to US EPA test methods with a ≥99.9% reduction of test organisms over a 24 h period. A tailor‐made confocal imaging protocol is de...

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Autores principales: Ciacotich, Nicole, Kragh, Kasper Nørskov, Lichtenberg, Mads, Tesdorpf, Jens Edward, Bjarnsholt, Thomas, Gram, Lone
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6827527/
https://www.ncbi.nlm.nih.gov/pubmed/31692989
http://dx.doi.org/10.1002/gch2.201900044
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author Ciacotich, Nicole
Kragh, Kasper Nørskov
Lichtenberg, Mads
Tesdorpf, Jens Edward
Bjarnsholt, Thomas
Gram, Lone
author_facet Ciacotich, Nicole
Kragh, Kasper Nørskov
Lichtenberg, Mads
Tesdorpf, Jens Edward
Bjarnsholt, Thomas
Gram, Lone
author_sort Ciacotich, Nicole
collection PubMed
description The antibacterial efficacy of a copper–silver alloy coating under conditions resembling build up of dry surface bacterial biofilms is successfully demonstrated according to US EPA test methods with a ≥99.9% reduction of test organisms over a 24 h period. A tailor‐made confocal imaging protocol is designed to visualize in situ the killing of bacterial biofilms at the copper–silver alloy surface and monitor the kinetics for 100 min. The copper–silver alloy coating eradicates a biofilm of Gram‐positive bacteria within 5 min while a biofilm of Gram‐negative bacteria are killed more slowly. In situ pH monitoring indicates a 2‐log units increase at the interface between the metallic surface and bacterial biofilm; however, the viability of the bacteria is not directly affected by this raise (pH 8.0–9.5) when tested in buffer. The OH(−) production, as a result of the interaction between the electrochemically active surface and the bacterial biofilm under environmental conditions, is thus one aspect of the contact‐mediated killing of the copper–silver alloy coating and not the direct cause of the observed antibacterial efficacy. The combination of oxidation of bacterial cells, release of copper ions, and local pH raise characterizes the antibacterial activity of the copper–silver alloy‐coated dry surface.
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spelling pubmed-68275272019-11-05 In Situ Monitoring of the Antibacterial Activity of a Copper–Silver Alloy Using Confocal Laser Scanning Microscopy and pH Microsensors Ciacotich, Nicole Kragh, Kasper Nørskov Lichtenberg, Mads Tesdorpf, Jens Edward Bjarnsholt, Thomas Gram, Lone Glob Chall Full Papers The antibacterial efficacy of a copper–silver alloy coating under conditions resembling build up of dry surface bacterial biofilms is successfully demonstrated according to US EPA test methods with a ≥99.9% reduction of test organisms over a 24 h period. A tailor‐made confocal imaging protocol is designed to visualize in situ the killing of bacterial biofilms at the copper–silver alloy surface and monitor the kinetics for 100 min. The copper–silver alloy coating eradicates a biofilm of Gram‐positive bacteria within 5 min while a biofilm of Gram‐negative bacteria are killed more slowly. In situ pH monitoring indicates a 2‐log units increase at the interface between the metallic surface and bacterial biofilm; however, the viability of the bacteria is not directly affected by this raise (pH 8.0–9.5) when tested in buffer. The OH(−) production, as a result of the interaction between the electrochemically active surface and the bacterial biofilm under environmental conditions, is thus one aspect of the contact‐mediated killing of the copper–silver alloy coating and not the direct cause of the observed antibacterial efficacy. The combination of oxidation of bacterial cells, release of copper ions, and local pH raise characterizes the antibacterial activity of the copper–silver alloy‐coated dry surface. John Wiley and Sons Inc. 2019-07-15 /pmc/articles/PMC6827527/ /pubmed/31692989 http://dx.doi.org/10.1002/gch2.201900044 Text en © 2019 The Authors. Published by WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Full Papers
Ciacotich, Nicole
Kragh, Kasper Nørskov
Lichtenberg, Mads
Tesdorpf, Jens Edward
Bjarnsholt, Thomas
Gram, Lone
In Situ Monitoring of the Antibacterial Activity of a Copper–Silver Alloy Using Confocal Laser Scanning Microscopy and pH Microsensors
title In Situ Monitoring of the Antibacterial Activity of a Copper–Silver Alloy Using Confocal Laser Scanning Microscopy and pH Microsensors
title_full In Situ Monitoring of the Antibacterial Activity of a Copper–Silver Alloy Using Confocal Laser Scanning Microscopy and pH Microsensors
title_fullStr In Situ Monitoring of the Antibacterial Activity of a Copper–Silver Alloy Using Confocal Laser Scanning Microscopy and pH Microsensors
title_full_unstemmed In Situ Monitoring of the Antibacterial Activity of a Copper–Silver Alloy Using Confocal Laser Scanning Microscopy and pH Microsensors
title_short In Situ Monitoring of the Antibacterial Activity of a Copper–Silver Alloy Using Confocal Laser Scanning Microscopy and pH Microsensors
title_sort in situ monitoring of the antibacterial activity of a copper–silver alloy using confocal laser scanning microscopy and ph microsensors
topic Full Papers
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6827527/
https://www.ncbi.nlm.nih.gov/pubmed/31692989
http://dx.doi.org/10.1002/gch2.201900044
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