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Cold Atmospheric-Pressure Plasma Caused Protein Damage in Methicillin-Resistant Staphylococcus aureus Cells in
1State Key Laboratory of Electrical Insulation and Power Equipment, Center for Plasma Biomedicine, Xi'an Jiaotong University, Xi'an 710049, China.
Abstract:
Biofilms formed by multidrug-resistant bacteria are a major cause of hospital-acquired infections. Cold atmospheric-pressure plasma (CAP) is attractive for sterilization, especially to disrupt biofilms formed by multidrug-resistant bacteria. However, the underlying molecular mechanism is not clear. In this study, CAP effectively reduced the living cells in the biofilms formed by methicillin-resistant Staphylococcus aureus, and 6 min treatment with CAP reduced the S. aureus cells in biofilms by 3.5 log10. The treatment with CAP caused the polymerization of SaFtsZ and SaClpP proteins in the S. aureus cells of the biofilms. In vitro analysis demonstrated that recombinant SaFtsZ lost its self-assembly capability, and recombinant SaClpP lost its peptidase activity after 2 min of treatment with CAP. Mass spectrometry showed oxidative modifications of a cluster of peaks differing by 16 Da, 31 Da, 32 Da, 47 Da, 48 Da, 62 Da, and 78 Da, induced by reactive species of CAP. It is speculated that the oxidative damage to proteins in S. aureus cells was induced by CAP, which contributed to the reduction of biofilms. This study elucidates the biological effect of CAP on the proteins in bacterial cells of biofilms and provides a basis for the application of CAP in the disinfection of biofilms.
Insights
Cold atmospheric-pressure plasma (CAP) effectively eradicates multidrug-resistant bacterial biofilms by damaging key proteins. This research clarifies CAP
Area of Science:
- Biomedical Engineering
- Microbiology
- Plasma Physics
Background:
- Biofilms from multidrug-resistant bacteria are a significant cause of hospital-acquired infections.
- Cold atmospheric-pressure plasma (CAP) shows promise for sterilization, particularly for disrupting bacterial biofilms.
- The precise molecular mechanisms by which CAP affects bacterial biofilms remain unclear.
Purpose of the Study:
- To investigate the molecular mechanisms underlying the efficacy of CAP in reducing biofilms formed by methicillin-resistant Staphylococcus aureus (MRSA).
- To elucidate the impact of CAP treatment on essential proteins within MRSA cells in biofilms.
Main Methods:
- Treatment of MRSA biofilms with CAP.
- Analysis of bacterial cell reduction using quantitative methods.
- Investigation of protein polymerization and activity changes (SaFtsZ, SaClpP) using in vitro assays.
- Mass spectrometry to identify oxidative modifications on proteins.
Main Results:
- CAP treatment significantly reduced viable MRSA cells in biofilms, achieving a 3.5 log10 reduction after 6 minutes.
- CAP induced polymerization of SaFtsZ and SaClpP proteins within MRSA cells.
- In vitro studies showed CAP treatment inactivated recombinant SaFtsZ and SaClpP.
- Mass spectrometry identified oxidative modifications on proteins, suggesting CAP-induced reactive species damage.
Conclusions:
- CAP effectively disrupts MRSA biofilms by causing oxidative damage to essential bacterial proteins.
- The study clarifies the molecular mechanisms of CAP's antimicrobial action against biofilms.
- Findings support the potential application of CAP for biofilm disinfection in healthcare settings.
