Imaging of the Staphylococcus aureus Inactivation Process Induced by a Multigas Plasma Jet

Abstract

To identify mechanisms underlying the bacterial inactivation process by atmospheric nonthermal plasma using a unique plasma jet that can generate various gas plasmas, Staphylococcus aureus were irradiated with carbon dioxide plasma, which produces a large amount of singlet oxygens, and nitrogen plasma, which produces a large amount of OH radicals. And damaged areas of plasma-treated bacteria were observed by field emission scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. As a result, bacteria were damaged by both gas plasmas, but the site of damage differed according to gas species. Therefore, it suggests that singlet oxygen generated by carbon dioxide plasma or other reactive species caused by singlet oxygen contributes to the damage of internal structures of bacteria through the cell wall and membrane, and OH radicals generated by nitrogen plasma or other reactive species derived from OH radicals contribute to damage of the cell wall and membrane.

Comparative Proteomic and Morphological Change Analyses of Staphylococcus aureus During Resuscitation From Prolonged Freezing

“…Several dark granules were seen to be in combination with nucleic acid material. This combination could promote the accumulation of cell components within a short time, which would accelerate cell growth and multiplication ( Nilsson et al, 2002 ; Takamatsu et al, 2016 ). Moreover, fewer cells exhibit a gap between the cytoplasmic membrane and the cell wall.…”

Investigation of blood coagulation effect of nonthermal multigas plasma jet in vitro and in vivo

“…The multi-gas plasma jet source [19][20][21][22] has a columnar like a pen and is connected to an AC power supply (Plasma Concept Tokyo, Inc., Tokyo, Japan) of 16 kHz and 9kV and a gas cylinder Plasma is The experiments were performed as follows. Blood with anticoagulants in a volume of 10 µL, was set on an adjustable platform and the multi-gas plasma jet was fixed at mm from the jet hole to sample.…”

Role and Mechanism of Cold Plasma in Inactivating Alicyclobacillus acidoterrestris in Apple Juice

“…However, which one plays the most important role is still controversial, and it differs with the reactor type, gas type, etc. Recent studies have shown results that regard 1 O 2 as having the most important role in inactivating Staphylococcus aureus [ 13 , 15 ], bacteriophage T4 [ 16 ], yeast [ 12 ], and virus [ 14 ]. Such studies suggest that as long as researchers detect singlet oxygen, they will find that singlet oxygen plays the most important role.…”

“…Typically, ROS and RNS are regarded as the primary causes of bacteria inactivation, which could attack bacteria and cause cell wall damage by electroporation and lipid oxidation, leading to DNA damage and protein modulation [ 11 ]. In recent years, more and more research has reported that •OH, 1 O 2 , •O 2 − , and ONOOH, but especially 1 O 2 , play important roles [ 12 , 13 , 14 , 15 , 16 ]. Our previous study using surface discharge plasma has also reported that •OH, 1 O 2 , and •O 2 − play important roles in inactivating A. spiroides and Escherichia coli [ 17 , 18 ].…”