Antimicrobial efects of airborne acoustic ultrasound and plasma activated water from cold and thermal plasma systems on bioflms

Abstract

Bacterial bioflms are difcult to inactivate due to their high antimicrobial resistance. Therefore, new approaches are required for more efective bacterial bioflm inactivation. Airborne acoustic ultrasound improves bactericidal or bacteriostatic activity which is safe and environmentally friendly. While, plasma activated water (PAW) is attracting increasing attention due to its strong antimicrobial properties. This study determined efcacy of combined airborne acoustic ultrasound and plasma activated water from both cold and thermal plasma systems in inactivating Escherichia coli K12 bioflms. The application of airborne acoustic ultrasound (15 min) alone was signifcantly more efective in reducing E. coli counts in 48 and 72 h bioflms compared to 30 min treatment with PAW. The efect of airborne acoustic ultrasound was more pronounced when used in combination with PAW. Airborne acoustic ultrasound treatment for 15 min of the E. coli bioflm followed by treatment with PAW signifcantly reduced the bacterial count by 2.2—2.62 Log10 CFU/mL when compared to control bioflm treated with distilled water. This study demonstrates that the synergistic efects of airborne acoustic ultrasound and PAW for enhanced antimicrobial efects. These technologies have the potential to prevent and control bioflm formation in food and bio-medical applications.