Sterilization of Escherichia coli and MRSA using microwave-induced argon plasma at atmospheric pressure

The use of microwave plasma for sterilization is a relatively new method. The advantages of this method include relatively low temperature, time-saving and nontoxicity compared to the known techniques, such as dry heat, steam autoclave and ethylene oxide (EtO) gas. The aim of this study was to investigate the sterilization effects on Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA) using self-designed, low-cost and reliable, 2.45 GHz, wave guide-based applicator to generate microwave plasma at atmospheric pressure. The results of this study confirmed that the sterilization effect of microwave-induced argon plasma at atmospheric pressure was caused by free radicals and UV light generated during the plasma treatment and the etching process. The microwave plasma system used in this study required much less exposure time than the previous study on bacterial strains of E. coli and MRSA, because of the high plasma density, the large number of free radicals, and the strong UV intensity.