Trichophyton concentricum fungal infections and skin microbiomes of Indigenous Peninsular Malaysians

Abstract

Recent outbreaks of multidrug-resistant fungi infecting human skin emphasize the importance of understanding fungal pathophysiology and spread. In efforts to address health concerns with various Indigenous Peninsular Malaysians (Orang Asli [OA]), tinea imbricata—a Trichophyton concentricum fungal skin infection—emerged as a particular concern. We investigated the etiology and transmission of tinea imbricata by culturing, testing antifungal sensitivities, and sequencing T. concentricum isolates in remote OA villages. Among regionally conserved isolates, we identified the emergence of terbinafine-resistant T. concentricum microbiologically and genomically. Investigating the skin microbiomes of 82 Indigenous OA, we found unique microbiota and lower relative abundances of bacterial commensals (Cutibacterium acnes, Staphylococcus epidermidis) among OA versus Malaysian and US urban populations, emphasizing how understudied populations provide unprecedented knowledge on host-microbiome co-evolution. These findings provide valuable insights into clinical, microbiological, and genomic features of chronic fungal skin infections, offering the potential to inform strategies to address drug resistance and effective therapy.