Cold plasma for bacterial inactivation

Non thermal plasmas had been used for many years for different applications. Plasma is a cocktail of reactive oxygen species, negative species, radicals etc. This mixture has a positive effect also in killing bacteria. This fact is highly important in applications like disinfection of burned wounds where large skin areas need to be cleaned before the treatment. In this work we studied in vitro the effects of cold plasma treatment in inactivation of bacteria. The inactivation mechanism was investigated using two types of bacteria: Gram Positive and Gram Negative. Bacteria were cultured in logarithmic concentrations in Petri dishes. Three types of plasmas were applied on the bacteria for different time points. After treatment, the plates were incubated overnight. The colonies formed were counted next day For the treatment, a cold atmospheric plasma needle (13.56 MHz micro-jet) was used. We analyzed the influence of cold plasma treatment in killing the bacteria. Three types of gases were used in our investigation. Under high doses bacteria suffered a damage which leaded in a decrease in the number of colonies.