Non-thermal plasma-mediated inactivation of biofilms formed by imipenem-resistant Klebsiella pneumoniae: a non-antibiotic approach

Bacteria often form complex communities known as biofilms—hydrated extracellular polymeric matrices that protect sessile cells. Non-thermal plasma (NTP) is emerging as a potential strategy for biofilm disruption due to the oxidative damage caused by reactive oxygen and nitrogen species (RONS). In this study, the antimicrobial activity of an argon-based atmospheric pressure NTP jet was evaluated against imipenem-resistant Klebsiella pneumoniae biofilms in vitro. Plasma exposure times ranged from 0 to 120 s. A 15-s treatment reduced bacterial growth by 72% (p < 0.0001), with complete inhibition observed reach 100% at 60–120 s. Biofilm degradation reached 42% at 15 s and 100% at 60 s. Scanning electron microscopy revealed significant morphological damage, including cell deformation and shrinkage. These findings highlight NTP’s potential as an effective, non-antibiotic method for combating multidrug-resistant K. pneumoniae infections.