Treatment of Candida Albicans and Trichophyton Rubrum with Several Antimicrobial Agents Using a Fungal Nail Model

Background: Onychomycosis is a nail infection that can be caused by dermatophyte fungi including Candida albicans and Trichophyton rubrum. Onychomycosis can cause nail discolouration, nail thickening and separation from the nail bed, as well as complications such as cellulitis and ulceration. Whilst oral antifungal agents are available, topical agents are beneficial to patients on multiple medications to avoid drug-drug interactions and have reduced side effects.

Purpose: The aim of this study was to evaluate several antimicrobial agents for efficacy against T. rubrum and C. albicans. Antifungal efficacy was evaluated against T. rubrum and C. albicans by an agar diffusion method.

Methods: SDA was inoculated with each strain and poured into a petri dish. Antimicrobial agents were placed into wells created in the agar and plates were incubated at 30C overnight. The following day the zone of inhibition was measured (ZOI). The permeability of efficacious agents through keratin was determined using a fungal nail model. Nail fragments were put in contact with inoculated SDA and treatment was applied routinely. At the end of treatment, nails were qualitatively and quantitatively evaluated for antifungal activity.

Results: A ZOI could be determined for some antimicrobial agents against both strains. Additionally, following testing in the fungal nail model reduced fungal colonisation could be observed visually. Serial dilution and plating of samples showed reduced fungal cell density in comparison to untreated controls.

Conclusion: Antifungal activity and the ability to permeate nails was demonstrated by some antimicrobial agents in this study, suggesting potential for treatment of onychomycosis.