Cold atmospheric plasma for surface disinfection: a promising weapon against deleterious meticillin-resistant Staphylococcus aureus biofilms

Abstract

Bacteria are becoming increasingly resistant to classical antimicrobial agents, so new approaches need to be explored. To assess the potential of cold atmospheric plasma for the management of meticillin-resistant Staphylococcus aureus (MRSA). The 24, 48, and 72h resistant and susceptible S.aureus biofilms were exposed to 60, 120, and 180s treatment with plasma. Increasing the treatment time results in higher cell reduction for both susceptible and resistant strains of S.aureus (P < 0.05). Up to log10 reduction factor of 5.24cfu/cm2 can be achieved in 180s of plasma treatment. Furthermore, plasma can substantially alter the cell's metabolisms and impact cell membrane integrity. However, it has not been shown that plasma can reduce biofilm biomass in the case of 24h and 48h biofilms, although the 72h biofilm was more susceptible, and its biomass was decreased (P < 0.05). The accumulation of intrabacterial reactive oxygen species was also observed, which confirms the plasma's induction of oxidative stress. Finally, it was shown that continuous plasma exposure of bacterial cells does not cause resistance to plasma, nor is resistance developed to cefoxitin. Cold atmospheric plasma is a good candidate for S.aureus and MRSA biofilm treatment and may therefore be of value in the bacterial resistance crisis.