Acinetobacter baumannii Deactivation by Means of DBD-Based Helium Plasma Jet

Panagiotis Svarnas,Petros Koutsoukos,Kristaq Gazeli,Evangelos Anastassiou,Anastasia Spiliopoulou

doi:10.3390/plasma2020008

Panagiotis Svarnas, Petros Koutsoukos + Show 3 more

Open Access

https://doi.org/10.3390/plasma2020008

Copy DOI

Abstract

Acinetobacter baumannii is a typically short, almost round, rod-shaped (coccobacillus) Gram-negative bacterium. It can be an opportunistic pathogen in humans, affecting people with compromised immune systems, and it is becoming increasingly important as a hospital-associated (nosocomial) infection. It has also been isolated from environmental soil and water samples. In this work, unlike conventional medical methods like antibiotics, the influence of atmospheric-pressure cold plasma on this bacterium is evaluated by means of a colony count technique and scanning electron microscopy. The plasma used here refers to streamers axially propagating into a helium channel penetrating the atmospheric air. The plasma is probed with high resolution optical emission spectroscopy and copious reactive species are unveiled under low-temperature conditions. Based on the experimental results, post-treatment (delayed) biochemical effects on Acinetobacter baumannii and morphological modifications appear dominant, leading to complete deactivation of this bacterium.

Highlights

Atmospheric-pressure plasma jets (APPJs) are novel micro-discharges, which allow for the effective formation of user-friendly non-thermal plasmas under ambient-air conditions
The present plasma jet has a profound effect on the A. baumannii population which is drastically decreased mainly in the post-treatment time
Under the conditions of the present work, A. baumannii may efficiently be deactivated by atmospheric-pressure cold plasma produced in the form of “guided streamers” which propagate within helium channeling into atmospheric air

Summary

Introduction

Atmospheric-pressure plasma jets (APPJs) are novel micro-discharges, which allow for the effective formation of user-friendly non-thermal plasmas under ambient-air conditions. They are mainly produced by means of Dielectric-Barrier Discharge (DBD) reactors of different electrode configurations and dielectric materials [1]. These devices are electrically driven mostly by sinusoidal and pulsed high voltage power supplies of audio frequencies [1,2]. The use of the dielectric barrier placed between the electrodes and the short duration of the applied voltage (in the case of pulsed power supply) limit the discharge current. The discharge comprises a DBD region, a displacement along the dielectric tube and a penetration into the atmospheric air at distances up to a few centimeters [4,5,6]

Methods

Results

Conclusion