title: Vitamin C Pretreatment Enhances the Antibacterial Effect of Cold Atmospheric Plasma.
abstract: Bacterial biofilms are three-dimensional structures containing bacterial cells enveloped in a protective polymeric matrix, which renders them highly resistant to antibiotics and the human immune system. Therefore, the capacity to make biofilms is considered as a major virulence factor for pathogenic bacteria. Cold Atmospheric Plasma (CAP) is known to be quite efficient in eradicating planktonic bacteria, but its effectiveness against biofilms has not been thoroughly investigated. The goal of this study was to evaluate the effect of exposure of CAP against mature biofilm for different time intervals and to evaluate the effect of combined treatment with vitamin C. We demonstrate that CAP is not very effective against 48 h mature bacterial biofilms of several common opportunistic pathogens:Staphylococcus epidermidis, Escherichia coli, andPseudomonas aeruginosa. However, if bacterial biofilms are pre-treated with vitamin C for 15 min before exposure to CAP, a significantly stronger bactericidal effect can be obtained. Vitamin C pretreatment enhances the bactericidal effect of cold plasma by reducing the viability from 10 to 2% inE. colibiofilm, 50 to 11% inP. aeruginosa, and 61 to 18% inS. epidermidisbiofilm. Since it is not feasible to use extended CAP treatments in medical practice, we argue that the pre-treatment of infectious lesions with vitamin C prior to CAP exposure can be a viable route for efficient eradication of bacterial biofilms in many different applications.
authors.affiliation: Department of Physics, Chalmers University of Technology Göteborg, Sweden.
authors.forename: Saga
authors.initials: S
authors.lastname: Helgadóttir
authors.affiliation: Systems and Synthetic Biology Division, Department of Biology and Biological Engineering, Chalmers University of Technology Gothenburg, Sweden.
authors.forename: Santosh
authors.initials: S
authors.lastname: Pandit
authors.affiliation: Systems and Synthetic Biology Division, Department of Biology and Biological Engineering, Chalmers University of Technology Gothenburg, Sweden.
authors.forename: Venkata R S S
authors.initials: VR
authors.lastname: Mokkapati
authors.affiliation: Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology Gothenburg, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Westerlund
authors.affiliation: Department of Physics, Chalmers University of Technology Göteborg, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Apell
authors.affiliation: Systems and Synthetic Biology Division, Department of Biology and Biological Engineering, Chalmers University of TechnologyGothenburg, Sweden; Novo Nordisk Foundation Center for Biosustainability, Technical University of DenmarkLyngby, Denmark.
authors.forename: Ivan
authors.initials: I
authors.lastname: Mijakovic
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000378:metabolism*; D001274:Atmospheric Pressure; D018441:Biofilms / Q000187:drug effects*; D004926:Escherichia coli / Q000187:drug effects*; D050296:Microbial Viability / Q000187:drug effects; D058626:Plasma Gases / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D013212:Staphylococcus epidermidis / Q000187:drug effects*; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D058626:Plasma Gases; D001205:Ascorbic Acid
keywords: antibacterial; biofilm; cold plasma; resistance; vitamin C