title: Evaluation of bactericidal effects of low-temperature nitrogen gas plasma towards application to short-time sterilization.
abstract: To develop a novel low-temperature plasma sterilizer using pure N(2)  gas as a plasma source, we evaluated bactericidal ability of a prototype apparatus provided by NGK Insulators. After determination of the sterilizing conditions without the cold spots, the D value of the BI of Geobacillus stearothermophilus endospores on the filter paper was determined as 1.9 min. However, the inactivation efficiency of BI carrying the same endospores on SUS varied to some extent, suggesting that the bactericidal effect might vary by materials of sterilized instruments. Staphylococcus aureus and Escherichia coli were also exposed to the N(2)  gas plasma and confirmed to be inactivated within 30 min. Through the evaluation of bactericidal efficiency in a sterilization bag, we concluded that the UV photons in the plasma and the high-voltage pulse to generate the gas plasma were not concerned with the bactericidal effect of the N(2)  gas plasma. Bactericidal effect might be exhibited by activated nitrogen atoms or molecular radicals.
authors.affiliation: Department of Medical Technology, Nagoya University School of Health Sciences, Nagoya, Aichi 461-8673, Japan.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Kawamura
authors.forename: Ayaka
authors.initials: A
authors.lastname: Sakuma
authors.forename: Yuka
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Tomoko
authors.initials: T
authors.lastname: Oguri
authors.forename: Natsumi
authors.initials: N
authors.lastname: Sato
authors.forename: Nobuo
authors.initials: N
authors.lastname: Kido
mesh_terms: D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development; D003080:Cold Temperature; D005740:Gases / Q000633:toxicity*; D050296:Microbial Viability / Q000187:drug effects; D009584:Nitrogen / Q000633:toxicity*; D013171:Spores, Bacterial / Q000187:drug effects / Q000254:growth & development; D013242:Sterilization / Q000379:methods*
chemical_list: D005740:Gases; D009584:Nitrogen