title: Effects of minimal exposures to atmospheric pressure plasma on the activity of Salmonella Typhimurium: Deactivation of bacterial motility and suppression of host-cell invasion.
abstract: Atmospheric pressure plasma (APP) has been shown effective in sterilization by reducing the number of viable microbes during surface cleaning, food processing, or human tissue treatment. For safe conduct, the majority of previous research focused on complete abolition of microbes, which may require severe treatments. Our aim is to investigate the minimal treatment conditions necessary for effective inactivation of bacteria in such a manner that the APP treated bacteria would not be able to harm the host cells. For this, we ought to identify the objective criteria to make the bacteria dysfunctional. We choose the motile properties and the host-cell invasion capability as two measures to quantify the pathogenic state of bacteria. In this paper, we investigated how the APP treatment in a minimal dosage affects the activity of Salmonella Typhimurium. At 100 W and 15 kHz for 20 s, the APP treatment effectively suppressed active "run and tumble" type motility and induced formation of abnormally long structures. With 20 s exposure, the bacterial cells failed to cause pyroptosis in the host cells with >90% survival after 12 h of co-incubation. Our results suggest novel measures to evaluate the functional pathogenic state for identifying safe APP treatment conditions.
authors.affiliation: Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea.
authors.forename: Jin-Sung
authors.initials: JS
authors.lastname: Park
authors.affiliation: Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea.
authors.forename: Kijung
authors.initials: K
authors.lastname: Kim
authors.affiliation: Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea.
authors.forename: Je-Hyun
authors.initials: JH
authors.lastname: Han
authors.affiliation: Department of Biomedical Engineering, Hanyang University, Seoul 04763, Republic of Korea.
authors.forename: Bomi
authors.initials: B
authors.lastname: Gweon
authors.affiliation: Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea.
authors.forename: Ung Hyun
authors.initials: UH
authors.lastname: Ko
authors.affiliation: National Fusion Research Institute, Plasma Technology Research Center, Gunsan 54004, Republic of Korea.
authors.forename: Suk Jae
authors.initials: SJ
authors.lastname: Yoo
authors.affiliation: Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea.
authors.forename: Wonho
authors.initials: W
authors.lastname: Choe
authors.affiliation: Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea. Electronic address: j_shin@kaist.ac.kr.
authors.forename: Jennifer H
authors.initials: JH
authors.lastname: Shin
mesh_terms: D001274:Atmospheric Pressure; D045744:Cell Line, Tumor / Q000382:microbiology; D049109:Cell Proliferation; D002470:Cell Survival; D004203:Disinfection / Q000379:methods*; D005511:Food Handling; D006801:Humans; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D009584:Nitrogen / Q000737:chemistry; D010641:Phenotype; D058626:Plasma Gases / Q000737:chemistry*; D012486:Salmonella typhimurium / Q000166:cytology* / Q000472:pathogenicity; D014774:Virulence
chemical_list: D058626:Plasma Gases; D009584:Nitrogen
keywords: Atmospheric pressure plasma (APP); Bacterial elongation; Brownian motion; Host-cell invasion; Run-and-tumble; Salmonella Typhimurium (S. Typhimurium)