Contact-Free Inactivation of Trichophyton Rubrum and Microsporum Canis by Cold Atmospheric Plasma Treatment

Abstract

Aim: Cold atmospheric plasma (CAP) has already proven efficient at disinfection of microorganisms including biofilms. The objective of the present study is to assess the efficacy of CAP against the dermatophytes Trichophyton rubrum and Microsporum canis in vitro. Materials & methods:T. rubrum and M. canis were exposed to CAP for different treatment times and time intervals in vitro. Treatment with ciclopirox olamine or UVC radiation (0.120 J/cm²) served as controls. CAP was generated by the surface microdischarge technology. Fungal colony growth was measured upon CAP treatment. Results: Repeated daily CAP treatments of 10 min demonstrated an inhibition of growth during the treatment period of 9 days. Single CAP treatment sessions for 5, 8 and 10 min, as well as treatments for 5 or 8 min daily, resulted in less fungal growth inhibition. UVC radiation treatment failed, but not ciclopirox olamine. Conclusion: CAP shows promising potential for future application in the treatment of dermatophyte infections.

Keywords:

• CAP
• cold atmospheric plasmas
• dermatophytes
• disinfection
• plasma medicine

Author contributions

Conceived and designed the experiments: J Heinlin, T Maisch, JL Zimmermann, T Shimizu, T Holzmann, M Simon, J Heider, M Landthaler, G Morfill and S Karrer. Performed the experiments: J Heinlin, T Maisch and J Heider. Analyzed the data: J Heinlin and T Maisch. Contributed reagents/materials/analysis tools: J Heinlin, T Maisch, G Karrer and G Morfill. Wrote the paper: J Heinlin, T Maisch, JL Zimmermann, T Shimizu and S Karrer. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.

Financial & competing interests disclosure

T Maisch was supported by a grant (M.TT.A.EXT00002) of the Max–Planck Institute for Extraterrestrial Physics, Garching b. München, Germany. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations.

Additional information

Funding

T Maisch was supported by a grant (M.TT.A.EXT00002) of the Max–Planck Institute for Extraterrestrial Physics, Garching b. München, Germany. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.