Direct-Contact and Contact-free Treatment of a DBD-like Non-thermal Atmospheric Pressure Plasma Jet on Pseudomonas aeruginosa

Abstract

In this study, a Dielectric Barrier Discharge (DBD)-like non-thermal atmospheric pressure plasma jet (NTAPPJ) was exposed to the Pseudomonas aeruginosa planktonic bacteria. The P. aeruginosa bacteria were treated by the NTAPPJs in both Ar and He at the non-contact distance (contact-free) and the contact distance (direct-contact). The contact of the NTAPPJs with the bacteria has generated spark discharges in both filamentary mode and diffuse mode. The antibacterial efficacy of the Ar and He NTAPPJs for various treatment times (60, 120, 180, and 300 sec) were investigated by treatment on the bacteria without contact and with contact in both filamentary mode and diffuse mode. The NTAPPJs in both Ar and He caused ero­sion on the agar surface when treated in direct-contact with the bacteria in the filamentary mode, while the NTAPPJs in Ar in the diffuse mode produced the greatest antibacterial efficacy without damage.