The Potential Use of a Cold Atmospheric Plasma Jet for Decontamination of Hospital Surfaces. A Pilot Study

Hospital surfaces are a source of potential infection due to contamination by microorganisms such as bacteria and viruses. Bacterial biofilms are of particular importance, due to their persistence in the hospital environment. Cold atmospheric pressure plasma (CAPP) is a novel potential method of hospital surface decontamination. In this study, we aimed to show the potential use of a CAPP jet for hospital decontamination. Bacterial biofilms were grown on common hospital surface materials and treated with an air-driven CAPP jet. Viable bacteria in treated biofilms were measured. Confocal microscopy and staining were used to gather images of CAPP-treated biofilms. The effect of CAPP inactivation was also assessed alongside the use of a detergent. CAPP inactivated clinically relevant bacteria both in planktonic and biofilm structures. A 90 s CAPP treatment led to an average of 82% decrease in Escherichia coli (E. coli) and 70% decrease in methicillin-resistant Staphylococcus aureus (MRSA) biofilm viability grown on polysterene. Confocal microscopy was used to confirm CAPP-induced inactivation of bacterial cells within mature growth on glass. CAPP treatment was also compared to treatment with detergent commonly used in hospitals. It was found that biofilm inactivation was greatest when treated with both detergent and CAPP. When in combination with detergent, viability of E. coli and MRSA biofilms grown on polysterene were decreased by 97% and 94%, respectively. A CAPP jet was shown to inactivate biofilms on hospital surfaces, particularly when used alongside detergent. This may suggest a role for CAPP in hospital decontamination.