Corona discharges with water electrospray for Escherichia coli biofilm eradication on a surface.
Low-temperature plasma (cold), a new method for the decontamination of surfaces, can be an advantageous alternative to the traditional chemical methods, autoclave or dry heat. Positive and negative corona discharges in air were tested for the eradication of 48-h Escherichia coli biofilms grown on glass slides. The biofilms were treated by cold corona discharge plasma for various exposure times. Water electrospray from the high voltage electrode was applied in some experiments. Thermostatic cultivation of the biofilm, and confocal laser scanning microscopy (CLSM) of the biofilm stained with fluorescent dyes were used for biocidal efficiency quantification. Up to 5 log10 reduction of bacterial concentration in the biofilm was measured by thermostatic cultivation after exposure to both corona discharges for 15min. This decontamination efficiency was significantly enhanced by simultaneous water electrospray through the plasma. CLSM showed that the live/dead ratio after treatment remained almost constant inside the biofilm; only cells on the top layers of the biofilm were affected. DAPI fluorescence showed that biofilm thickness was reduced by about 1/3 upon exposure to the corona discharges with electrospray for 15min. The biofilm biomass loss by about 2/3 was confirmed by crystal violet assay.
Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Mlynská dolina, 842 48 Bratislava, Slovakia; GeePs/Group of electrical engineering - Paris, UMR CNRS 8507, CentraleSupélec, Univ. Paris-Sud, Université Paris-Saclay, Sorbonne Universités, UPMC Univ. Paris 6, 3 & 11 rue Joliot-Curie, Plateau de Moulon, 91192, Gif-sur-Yvette CEDEX, France. Electronic address: sipoldovaz@gmail.com.
Zuzana
Z
Kovalova
GeePs/Group of electrical engineering - Paris, UMR CNRS 8507, CentraleSupélec, Univ. Paris-Sud, Université Paris-Saclay, Sorbonne Universités, UPMC Univ. Paris 6, 3 & 11 rue Joliot-Curie, Plateau de Moulon, 91192, Gif-sur-Yvette CEDEX, France.
Magali
M
Leroy
GeePs/Group of electrical engineering - Paris, UMR CNRS 8507, CentraleSupélec, Univ. Paris-Sud, Université Paris-Saclay, Sorbonne Universités, UPMC Univ. Paris 6, 3 & 11 rue Joliot-Curie, Plateau de Moulon, 91192, Gif-sur-Yvette CEDEX, France.
Michael J
MJ
Kirkpatrick
GeePs/Group of electrical engineering - Paris, UMR CNRS 8507, CentraleSupélec, Univ. Paris-Sud, Université Paris-Saclay, Sorbonne Universités, UPMC Univ. Paris 6, 3 & 11 rue Joliot-Curie, Plateau de Moulon, 91192, Gif-sur-Yvette CEDEX, France.
Emmanuel
E
Odic
Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Mlynská dolina, 842 48 Bratislava, Slovakia.
Zdenko
Z
Machala
D018441:Biofilms / Q000187:drug effects*; D018533:Biomass; D003666:Decontamination / Q000379:methods*; D004560:Electricity; D004566:Electrodes; D004926:Escherichia coli / Q000187:drug effects* / Q000302:isolation & purification / Q000502:physiology*; D058626:Plasma Gases / Q000494:pharmacology*; D013499:Surface Properties; D014867:Water
D058626:Plasma Gases; D014867:Water
Bacterial biofilm; Confocal microscopy; Corona discharge; Fluorescence; Non-thermal plasma; Water electrospray