Film-forming agents as potential barriers to fungal skin infections

Superficial fungal infections are one of the most common causes of human disease caused by dermatophytes or yeasts. Dermatophyte infections are caused by fungi that can digest keratin, infecting the keratinised tissues e.g. skin, hair and nails. It has a higher prevalence than the other superficial mycoses, and its incidence has increased continuously over the last few decades, probably because of the change in lifestyle and frequent usage of antibiotics. Therefore, the aim of the project is to develop a physical barrier that can prevent the early stages of infection to the skin, to avoid development of antifungal resistance and cross-contamination.

We developed an ex vivo model using porcine skin to study the potential of film-forming agents in prevention and treatment of dermatophytosis caused by Trichophyton rubrum. We used cell viability assays, confocal and electron microscopy to study the effects of film-forming agents on T. rubrum, followed by using QTOF-LCMS and NMR to analyse the carbohydrates binding and chelation to study its mechanism of action.

A cationic polymer used in pharmaceutical and cosmetic products inhibited growth of T. rubrum on porcine skin. Viability assays indicated that the polymer has a fungistatic activity and microscopy imaging indicated it formed a coating on top of T. rubrum. The QTOF-LCMS and NMR indicated the polymer inhibits fungal growth by removing the carbohydrate content and chelation.

The present study suggests this cationic polymer has considerable antifungal activity against Trichophyton rubrum by preventing the supply of nutrients to the fungi.