Use of atmospheric non-thermal plasma as a disinfectant for objects contaminated with methicillin-resistant Staphylococcus aureus

Background

Health care-associated infections because of methicillin-resistant strains of Staphylococcus aureus (MRSA) are increasing worldwide despite current infection control measures. Novel methods for disinfection of MRSA would be useful.

Methods

We tested the effectiveness of atmospheric, non-thermal plasma discharge at killing S aureus, including USA300 strains, and at disinfecting experimentally contaminated hospital pagers.

Results

Exposure of S aureus to plasma at different concentrations and for varying lengths of time resulted in up to a 4- to 5-log₁₀ kill on tryptic soy agar plates within 10minutes and was not toxic to epithelial cells. USA300 strains of MRSA were more resistant to plasma-based killing than other tested strains. Disinfection of hospital pagers experimentally coated with clinically relevant amounts of MRSA could be achieved in as little as 30 seconds.

Conclusion

Generation of plasma is a promising method for disinfection of objects or surfaces that warrants further study in hospital settings. The USA300 strains of S aureus may be more resistant to disinfection than other strains.

Key Words: MRSA, Staphylococcus aureus, infection control, plasma, disinfection