Efficacy of Plasma ONE apparatus for disinfection of S. aureus, P. aeruginosa and E. coli bacteria from the solid surface

Cold atmospheric plasma (CAP) is a cocktail of charged particles with high antibacterial potency. In this study, we evaluated CAP efficacy generated by Plasma ONE, a mobile medical device against common chronic wound pathogens. Two sets of working saline suspensions, i.e. 10(5) and 10(3) CFU/ml of each reference strain E. coli, P. aeruginosa and S. aureus, were inoculated on Mueller-Hinton media plates and exposed to CAP for 30, 60, 120, 300 s and incubated for 24 h. The radiating nozzle surface was 3.4 cm. Plasma efficacy evaluation was based on the diameter of attained inactivation area and bacterial decontamination rate within. Plasma ONE device showed high capacity against S. aureus in all time intervals and exposure yielded a gradual time-dependent CFU reduction starting with 99.6% after 30 s in the 10(5) plates. Comparison between mean area diameters of S. aureus and E. coli of 30 and 120 s indicated a significant area increase (p < 0.05). In contrast, P. aeruginosa appeared more resistant to a longer exposure and the inactivation area was hardly extended following the longest exposure. In both Gram-negative bacteria, CFU reduction plateaued at 30 s in 10(3) petri dishes, while in 10(5) groups more than 120-s interval was insufficient for attaining full decontamination; however, treatment for 300 s led to complete eradication. Plasma ONE is effective against most commonly isolated pathogens from wounds, but its further validation requires data concerning efficacy in eradicating biofilms.