Comparative assessment of dermal Mycobiota across skin types during summer and winter periods in Cape Town, South Africa

Abstract

The human skin mycobiome represents one of the most dynamic microbial communities on the body, yet its composition across multiple skin phenotypes and opposing seasons remains inadequately documented in Southern African populations. This research conducted a comparative assessment of dermal mycobiota across five skin types - oily, dry, normal, combination, and sensitive - during summer (December to February) and winter (June to August) in Cape Town, South Africa. A cohort of 300 participants (60 per skin type) was recruited, and samples were collected from the forehead, antecubital fossa, and interscapular region using standardized swab protocols during both seasonal periods. Fungal isolation employed Sabouraud dextrose agar and dermatophyte test medium, with identification performed through morphological assessment and ITS sequencing. A total of 3,246 fungal isolates representing 26 species across 11 genera were recovered. Oily and combination skin types yielded the highest isolation rates (74.8% and 72.1% respectively), while sensitive skin produced the lowest (48.3%). Summer sampling generated 1.8-fold more isolates than winter sampling across all skin types. The Shannon diversity index ranged from 3.52 (combination skin, summer) to 1.24 (sensitive skin, winter). Candida albicans was the most prevalent species overall (18.6%), followed by Trichophyton rubrum (16.4%) and Malassezia furfur (14.9%). Statistically significant interactions between skin type and season were observed for most species (p<0.01), indicating that seasonal effects on fungal colonization are modulated by the skin's physicochemical properties. These findings provide a comprehensive multi-skin-type mycobiome baseline for the Cape Town population and have implications for seasonally tailored dermatological management.