Inactivation Kinetics Study of an Atmospheric-Pressure Cold-Plasma Jet Against Pathogenic Microorganisms

Inactivation kinetics of a nanosecond-pulsed plasma jet against a panel of common pathogenic microorganisms was studied to assist the design and development of nonthermal plasma-based treatment schemes for pathogenic infection control. We evaluated the effectiveness of our cold-plasma in vitro against microbes with varying cell wall and membrane characteristics: the Gram-positive organisms Staphylococcus aureus and Staphylococcus epidermidis, the Gram-negative organisms Pseudomonas aeruginosa and Escherichia coli, and the yeast Candida albicans. We found that all of the organisms tested in this paper were rendered nonculturable (>;99.99%) by the end of the short plasma treatment times ranging from 30 to 180 s. Our results indicate that the pathogenic bacteria and yeast tested in this paper can be effectively rendered noncultivable within seconds using the He/(1%)O₂ cold plasma, and that susceptibility to plasma may vary depending on the cell wall and membrane characteristics of the organisms in addition to the other resistant mechanisms of individual strain.