Inhibition of Biofilms by Non-Thermal Plasma Treated Novel Solutions

Abstract

Biofilms act as a reservoir of infection, and periodically release cells in vicinity that are capable of developing new biofilm colonies and disseminate infection. Many chronic bacterial infections are serious that are associated with biofilms and have high morbidity and mortality, partly due to their higher resistance to antimicrobial agents, and partly due to lack of strong biocides which can efficiently treat and inhibit biofilm formation. We recently demonstrated that nonequilibrium non-thermal dielectric-barrier discharge plasma (Plasma) can also be applied to control pathogens via applying treated-liquids, and these liquids acquire broad-spectrum antimicrobial properties. In present studies we demonstrated a range of plasma-activated simple chemical solutions which significantly inhibited biofilm formation by multidrug-resistant bacterial pathogens. Plasma-activated methionine solution exhibited strong inhibitory activity against the biofilms of car-bapenem-resistant <i>Acinetobacter baumannii</i>, methicillin-resistant <i>Staphylococcus aureus</i>, metal-lo-β-lactamase (NDM1)-positive <i>Klebsiella pneumoniae</i>, and <i>Enterococcus faecalis</i>, and prevented the formation of biofilms by about 70% as compared to untreated controls in single exposure. In addition to inhibition of biofilm formation, a complete inactivation of biofilm-embedded bacterial cells was observed in less than 30 minute’s exposure to candidate plasma-activated methionine solution. These findings suggest that plasma-activated solutions have a potential to prevent biofilm formation, and as biofilm inhibitor.