Susceptibility of Staphylococcus epidermidis to Argon Cold Plasma Jet by Oxygen Admixture

Abdel-Aleam H Mohamed,Abdulrahman H Basher,Jamal Q M Almarashi,Salama A Ouf

doi:10.3390/app11083455

Abdel-Aleam H Mohamed, Abdulrahman H Basher + Show 2 more

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https://doi.org/10.3390/app11083455

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Abstract

Cold atmospheric pressure sterilization is one of the nominated and efficient techniques to prevent the spread of diseases. Reactive species such as O and OH and other radicals play a major role in the mechanism of plasma sterilization. Therefore, in this work, oxygen was mixed with different parentage from (0.2 to 1.2%) to argon to enhance the generation of the reactive species and increase the argon atmospheric pressure plasma sterilization efficacy. The emission spectra from the jet increase the radicle line intensities by increasing the percentage admixture of O2 with the argon gas to reach a maximum power at 0.8; then, it gradually decreases with a higher O2 percentage. The OH band intensity decreases with increasing the admixture of O2. The jet with different O2 percentages was tested against Gram-positive S. epidermidis, which is the causal agent of nosocomial infections. The maximum reduction in colony-forming units (CFU) was observed at 0.2% O2. No bacterial growth was observed at the later concentration applied for 8 min and the same case was detected at 0.4% O2 applied to 16 min.

Highlights

S. epidermidis ranks first among the causative agents of nosocomial infections
The generated reactive species (OH, NO, O) from the non-thermal Atmospheric pressure plasma jets (APPJs) can be enhanced by mixing the input gas with other gases
The current–voltage waveform in case of mixing oxygen is presenting the same effect of increasing the current peaks per each half cycle, and this effect could be due to the increase in the residual charge carriers from the privies pulse owing to oxygen electron affinity [20]

Summary

Introduction

S. epidermidis ranks first among the causative agents of nosocomial infections. Staphylococci are common bacterial colonizers of the skin and mucous membranes of humans and other mammals. S. epidermidis represents the most common source of infections on medical devices [1]. One of the efficient sterilization techniques is cold atmospheric pressure plasma sterilization [2,3]. Several techniques have been used to overcome the restrictions to generate non-thermal plasma at atmospheric pressure such as using Dielectric-barrier discharges (DBD) [4], pulsed power source [5], segmented cathode [6], and the micro-hollow cathode system [7]. The method by which the non-thermal atmospheric pressure plasma (APP) is generated will depend on the plasma properties required such as volume of the generated plasma, gas temperature, electron density and temperature, and homogeneity of the plasma. It is believed that a combination of the different techniques can be used to fulfill the requirement for generating non-thermal plasma with a high rate of reactive species generation and large-scale plasma

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