Plasma-activated water for the decontamination of textiles: A proof-of-concept study using Escherichia coli and Staphylococcus aureus

Pathogen transmission via healthcare textiles is a severe threat contributing to hospital-acquired infections. This study proposes the use of plasma-activated water (PAW) for textile decontamination as an alternative to hightemperature treatments and the use of potentially harmful chemicals, which can remain in the wastewater. PAW was generated by treating deionized water using a commercial atmospheric plasma system and was used at 37 degrees C. A 100 % cotton coat served as a healthcare textile model, from which samples were cut, inoculated with Escherichia coli or Staphylococcus aureus and treated by immersion in PAW, deionized water (negative control) and ethanol 70 % v/v (positive control) with different immersion times (up to 30 min) and stirring rates (0, 250, and 500 rpm). Antimicrobial efficacy increased with treatment time and stirring rate. For both bacteria types, exposure to PAW for 15 min at 500 rpm resulted in sterility (six log10 reduction) and no bacteria growth in the wastewater. Following the recommendation of ISO 11135, the treatment time was increased to 1 h to achieve Sterility Assurance Level of 10-6 and the antimicrobial activity was compared to autoclaving. An endpoint test revealed sterilization with both treatments. Notably, PAW-treated samples showed no cytotoxicity towards human cells. Furthermore, repeated one-hour PAW cycles did not affect the chemical and mechanical properties of the textile. PAW treatment is a promising way to decontaminate textiles to combat pathogen transmission in healthcare facilities, with the advantage of avoiding the handling of chemical agents and their presence in the wastewater.