In Situ Monitoring of the Antibacterial Activity of a Copper–Silver Alloy Using Confocal Laser Scanning Microscopy and pH Microsensors
Abstract 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 proto...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2019-11-01
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| Series: | Global Challenges |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/gch2.201900044 |
| _version_ | 1831539812618731520 |
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| author | Nicole Ciacotich Kasper Nørskov Kragh Mads Lichtenberg Jens Edward Tesdorpf Thomas Bjarnsholt Lone Gram |
| author_facet | Nicole Ciacotich Kasper Nørskov Kragh Mads Lichtenberg Jens Edward Tesdorpf Thomas Bjarnsholt Lone Gram |
| author_sort | Nicole Ciacotich |
| collection | DOAJ |
| description | Abstract 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. |
| first_indexed | 2024-12-16T23:47:48Z |
| format | Article |
| id | doaj.art-a27b7320adfb49718f70ade650ffe1c0 |
| institution | Directory Open Access Journal |
| issn | 2056-6646 |
| language | English |
| last_indexed | 2024-12-16T23:47:48Z |
| publishDate | 2019-11-01 |
| publisher | Wiley |
| record_format | Article |
| series | Global Challenges |
| spelling | doaj.art-a27b7320adfb49718f70ade650ffe1c02022-12-21T22:11:25ZengWileyGlobal Challenges2056-66462019-11-01311n/an/a10.1002/gch2.201900044In Situ Monitoring of the Antibacterial Activity of a Copper–Silver Alloy Using Confocal Laser Scanning Microscopy and pH MicrosensorsNicole Ciacotich0Kasper Nørskov Kragh1Mads Lichtenberg2Jens Edward Tesdorpf3Thomas Bjarnsholt4Lone Gram5Elplatek A/S Bybjergvej 7 DK‐3060 Espergærde DenmarkDepartment of Immunology and Microbiology Costerton Biofilm Center Faculty of Health and Medical Sciences University of Copenhagen Blegdamsvej 3B DK‐2200 Copenhagen N DenmarkDepartment of Immunology and Microbiology Costerton Biofilm Center Faculty of Health and Medical Sciences University of Copenhagen Blegdamsvej 3B DK‐2200 Copenhagen N DenmarkDepartment of Biotechnology and Biomedicine Technical University of Denmark Søltofts Plads Bldg. 221 DK‐2800 Kgs Lyngby DenmarkDepartment of Clinical Microbiology Rigshospitalet Juliane Maries vej 22 2100 Copenhagen Ø DenmarkDepartment of Biotechnology and Biomedicine Technical University of Denmark Søltofts Plads Bldg. 221 DK‐2800 Kgs Lyngby DenmarkAbstract 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.https://doi.org/10.1002/gch2.201900044antibacterial activitybacterial biofilmsconfocal laser scanning microscopycopper–silver alloyelectroplating |
| spellingShingle | Nicole Ciacotich Kasper Nørskov Kragh Mads Lichtenberg Jens Edward Tesdorpf Thomas Bjarnsholt Lone Gram In Situ Monitoring of the Antibacterial Activity of a Copper–Silver Alloy Using Confocal Laser Scanning Microscopy and pH Microsensors Global Challenges antibacterial activity bacterial biofilms confocal laser scanning microscopy copper–silver alloy electroplating |
| 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 | antibacterial activity bacterial biofilms confocal laser scanning microscopy copper–silver alloy electroplating |
| url | https://doi.org/10.1002/gch2.201900044 |
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