Cold atmospheric pressure plasmas exhibit antimicrobial properties against critical bacteria and yeast species

Objective: Cold atmospheric pressure plasmas (CAPPs) have been used to sterilise implant materials and other thermally unstable medical products and to modify chemical surfaces. This study investigates the antimicrobial effect of the gas and input power used to generate CAPPs on microorganisms causing skin infections, such as Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and Malassezia pachydermatis. Method: Microorganisms were cultivated on Mueller Hinton 2 (MH2) agar plates. CAPP treatment was performed using the Plasma BLASTER MEF. To investigate the antimicrobial effects the following CAPP parameters were varied: the gas used, input power, as well as number of treatments and treatment time. Results: The antimicrobial efficacy of the CAPPs was found to increase with increasing input power and treatment time (or cycles). Furthermore the plasma generated from nitrogen is more effective than from air. Conclusion: The study showed that CAPPs demonstrate strong bactericidal and fungicidal properties in vitro. The selective application of CAPPs for the treatment of wound infections may offer a promising supplementary tool alongside current therapies.