title: Bactericidal effects of non-thermal argon plasma in vitro, in biofilms and in the animal model of infected wounds.
abstract: Non-thermal (low-temperature) physical plasma is under intensive study as an alternative approach to control superficial wound and skin infections when the effectiveness of chemical agents is weak due to natural pathogen or biofilm resistance. The purpose of this study was to test the individual susceptibility of pathogenic bacteria to non-thermal argon plasma and to measure the effectiveness of plasma treatments against bacteria in biofilms and on wound surfaces. Overall, Gram-negative bacteria were more susceptible to plasma treatment than Gram-positive bacteria. For the Gram-negative bacteria Pseudomonas aeruginosa, Burkholderia cenocepacia and Escherichia coli, there were no survivors among the initial 10(5) c.f.u. after a 5 min plasma treatment. The susceptibility of Gram-positive bacteria was species- and strain-specific. Streptococcus pyogenes was the most resistant with 17 % survival of the initial 10(5) c.f.u. after a 5 min plasma treatment. Staphylococcus aureus had a strain-dependent resistance with 0 and 10 % survival from 10(5) c.f.u. of the Sa 78 and ATCC 6538 strains, respectively. Staphylococcus epidermidis and Enterococcus faecium had medium resistance. Non-ionized argon gas was not bactericidal. Biofilms partly protected bacteria, with the efficiency of protection dependent on biofilm thickness. Bacteria in deeper biofilm layers survived better after the plasma treatment. A rat model of a superficial slash wound infected with P. aeruginosa and the plasma-sensitive Staphylococcus aureus strain Sa 78 was used to assess the efficiency of argon plasma treatment. A 10 min treatment significantly reduced bacterial loads on the wound surface. A 5-day course of daily plasma treatments eliminated P. aeruginosa from the plasma-treated animals 2 days earlier than from the control ones. A statistically significant increase in the rate of wound closure was observed in plasma-treated animals after the third day of the course. Wound healing in plasma-treated animals slowed down after the course had been completed. Overall, the results show considerable potential for non-thermal argon plasma in eliminating pathogenic bacteria from biofilms and wound surfaces.
authors.affiliation: Gamaleya Research Institute of Epidemiology and Microbiology, Russian Academy of Medical Sciences, Moscow, Russia.
authors.forename: Svetlana A
authors.initials: SA
authors.lastname: Ermolaeva
authors.affiliation: Gamaleya Research Institute of Epidemiology and Microbiology, Russian Academy of Medical Sciences, Moscow, Russia.
authors.forename: Alexander F
authors.initials: AF
authors.lastname: Varfolomeev
authors.affiliation: Gamaleya Research Institute of Epidemiology and Microbiology, Russian Academy of Medical Sciences, Moscow, Russia.
authors.forename: Marina Yu
authors.initials: MY
authors.lastname: Chernukha
authors.affiliation: Gamaleya Research Institute of Epidemiology and Microbiology, Russian Academy of Medical Sciences, Moscow, Russia.
authors.forename: Dmitry S
authors.initials: DS
authors.lastname: Yurov
authors.affiliation: Joint Institute of High Temperatures, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Mikhail M
authors.initials: MM
authors.lastname: Vasiliev
authors.affiliation: Gamaleya Research Institute of Epidemiology and Microbiology, Russian Academy of Medical Sciences, Moscow, Russia.
authors.forename: Anastasya A
authors.initials: AA
authors.lastname: Kaminskaya
authors.affiliation: Lomonosov Moscow State University, Moscow, Russia.
authors.forename: Mikhail M
authors.initials: MM
authors.lastname: Moisenovich
authors.affiliation: Gamaleya Research Institute of Epidemiology and Microbiology, Russian Academy of Medical Sciences, Moscow, Russia.
authors.forename: Julia M
authors.initials: JM
authors.lastname: Romanova
authors.affiliation: Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Pushchino, Russia.
authors.forename: Arcady N
authors.initials: AN
authors.lastname: Murashev
authors.affiliation: Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia.
authors.forename: Irina I
authors.initials: II
authors.lastname: Selezneva
authors.affiliation: Max Planck Institute for Extraterrestrial Physics, Munich, Germany.
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Shimizu
authors.affiliation: Gamaleya Research Institute of Epidemiology and Microbiology, Russian Academy of Medical Sciences, Moscow, Russia.
authors.forename: Elena V
authors.initials: EV
authors.lastname: Sysolyatina
authors.affiliation: Gamaleya Research Institute of Epidemiology and Microbiology, Russian Academy of Medical Sciences, Moscow, Russia.
authors.forename: Igor A
authors.initials: IA
authors.lastname: Shaginyan
authors.affiliation: Joint Institute of High Temperatures, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Oleg F
authors.initials: OF
authors.lastname: Petrov
authors.affiliation: Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia.
authors.forename: Evgeny I
authors.initials: EI
authors.lastname: Mayevsky
authors.affiliation: Joint Institute of High Temperatures, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Vladimir E
authors.initials: VE
authors.lastname: Fortov
authors.affiliation: Max Planck Institute for Extraterrestrial Physics, Munich, Germany.
authors.forename: Gregor E
authors.initials: GE
authors.lastname: Morfill
authors.affiliation: Gamaleya Research Institute of Epidemiology and Microbiology, Russian Academy of Medical Sciences, Moscow, Russia.
authors.forename: Boris S
authors.initials: BS
authors.lastname: Naroditsky
authors.affiliation: Gamaleya Research Institute of Epidemiology and Microbiology, Russian Academy of Medical Sciences, Moscow, Russia.
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Gintsburg
mesh_terms: D000818:Animals; D000891:Anti-Infective Agents, Local / Q000494:pharmacology* / Q000627:therapeutic use*; D000985:Antisepsis / Q000379:methods; D001128:Argon / Q000494:pharmacology* / Q000627:therapeutic use*; D001424:Bacterial Infections / Q000188:drug therapy / Q000382:microbiology; D018441:Biofilms / Q000187:drug effects; D015169:Colony Count, Microbial; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D008297:Male; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects*; D023421:Models, Animal; D058626:Plasma Gases / Q000494:pharmacology* / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014946:Wound Infection / Q000188:drug therapy / Q000382:microbiology
chemical_list: D000891:Anti-Infective Agents, Local; D058626:Plasma Gases; D001128:Argon