title: Contact-free cold atmospheric plasma treatment of Deinococcus radiodurans.
abstract: In this study we investigated the sensitivity of Deinococcus radiodurans to contact-free cold atmospheric plasma treatment as part of a project to establish new efficient procedures for disinfection of inanimate surfaces. The Gram-positive D. radiodurans is one of the most resistant microorganisms worldwide. Stationary phases of D. radiodurans were exposed to cold atmospheric plasma for different time intervals or to ultraviolet C (UVC) radiation at dose rates of 0.001-0.0656 J cm⁻², respectively. A methicillin-resistant Staphylococcus aureus strain (MRSA) served as control for Gram-positive bacteria. The surface microdischarge plasma technology was used for generation of cold atmospheric plasma. A plasma discharge was ignited using ambient air. Surprisingly, D. radiodurans was sensitive to the cold atmospheric plasma treatment in the same range as the MRSA strain. Survival of both bacteria decreased with increasing plasma exposure times up to 6 log₁₀ cycles (>99.999 %) within 20 s of plasma treatment. In contrast, UVC radiation of both bacteria demonstrated that D. radiodurans was more resistant to UVC treatment than MRSA. Cold atmospheric plasma seems to be a promising tool for industrial and clinical purposes where time-saving is a critical point to achieve efficient disinfection of inanimate surfaces and where protection from corrosive materials is needed.
authors.affiliation: Department of Dermatology, Regensburg University Hospital, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany. tim.maisch@klinik.uni-regensburg.de
authors.forename: Tim
authors.initials: T
authors.lastname: Maisch
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Shimizu
authors.forename: Anindita
authors.initials: A
authors.lastname: Mitra
authors.forename: Julia
authors.initials: J
authors.lastname: Heinlin
authors.forename: Sigrid
authors.initials: S
authors.lastname: Karrer
authors.forename: Yang-Fang
authors.initials: YF
authors.lastname: Li
authors.forename: Gregor
authors.initials: G
authors.lastname: Morfill
authors.forename: Julia L
authors.initials: JL
authors.lastname: Zimmermann
mesh_terms: D034301:Deinococcus / Q000166:cytology / Q000187:drug effects* / Q000528:radiation effects; D004203:Disinfection / Q000379:methods*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000166:cytology / Q000187:drug effects / Q000528:radiation effects; D050296:Microbial Viability / Q000187:drug effects / Q000528:radiation effects; D058626:Plasma Gases / Q000494:pharmacology*; D014466:Ultraviolet Rays
chemical_list: D058626:Plasma Gases