title: Efficacy of different carrier gases for barrier discharge plasma generation compared to chlorhexidine on the survival of Pseudomonas aeruginosa embedded in biofilm in vitro.
abstract: Because of its antimicrobial properties, nonthermal plasma could serve as an alternative to chemical antisepsis in wound treatment. Therefore, this study investigated the inactivation of biofilm-embedded Pseudomonas aeruginosa SG81 by a surface barrier-discharged (SBD) plasma for 30, 60, 150 and 300 s. In order to optimize the efficacy of the plasma, different carrier gases (argon, argon admixed with 1% oxygen, and argon with increased humidity up to approx. 80%) were tested and compared against 0.1% chlorhexidine digluconate (CHG) exposure for 600 s. The antimicrobial efficacy was determined by calculating the difference between the numbers of colony-forming units (CFU) of treated and untreated biofilms. Living bacteria were distinguished from dead by fluorescent staining and confocal laser scanning microscopy. Both SBD plasmas and CHG showed significant antimicrobial effects compared to the untreated control. However, plasma treatment led to a higher antimicrobial reduction (argon plasma 4.9 log10 CFU/cm(2), argon with admixed oxygen 3 log10 CFU/cm(2), and with increased gas humidity 2.7 log10 CFU/cm(2) after 300 s) compared to CHG. In conclusion, SBD plasma is suitable as an alternative to CHG for inactivation of Pseudomonas aeruginosa embedded in biofilm. Further development of SBD plasma sources and research on the role of carrier gases and humidity may allow their clinical application for wound management in the future.
authors.affiliation: Institute for Hygiene and Environmental Medicine, University of Greifswald, Greifswald, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Matthes
authors.forename: N-O
authors.initials: NO
authors.lastname: Hübner
authors.forename: C
authors.initials: C
authors.lastname: Bender
authors.forename: I
authors.initials: I
authors.lastname: Koban
authors.forename: S
authors.initials: S
authors.lastname: Horn
authors.forename: S
authors.initials: S
authors.lastname: Bekeschus
authors.forename: K-D
authors.initials: KD
authors.lastname: Weltmann
authors.forename: T
authors.initials: T
authors.lastname: Kocher
authors.forename: A
authors.initials: A
authors.lastname: Kramer
authors.forename: O
authors.initials: O
authors.lastname: Assadian
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D001128:Argon / Q000737:chemistry; D018441:Biofilms / Q000187:drug effects*; D002710:Chlorhexidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D015169:Colony Count, Microbial; D005453:Fluorescence; D006813:Humidity; D018613:Microscopy, Confocal; D010100:Oxygen / Q000737:chemistry; D058626:Plasma Gases / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D013997:Time Factors
chemical_list: D000890:Anti-Infective Agents; D058626:Plasma Gases; D001128:Argon; C010882:chlorhexidine gluconate; D002710:Chlorhexidine; D010100:Oxygen