Emerging Dermatophytes

Dermatophytes are fungi that are adapted to colonize and degrade keratin, leading to infection of the skin, nails and hair. Dermatophytes comprise species belonging to the Trichophyton, Epidermophyton, Microsporum, and Nannizzia genera, among others, with Trichophyton rubrum and Trichophyton interdigitale currently recognized as the most common globally. Over the past decade there has been an increase in reporting of terbinafine resistant dermatophytes, including T. rubrum, T. interdigitale, and now the emergence and global expansion of a newly designated species, Trichophyton indotineae, which is associated with severe recalcitrant infections. In addition, one genotype of T. mentagrophytes (genotype VII) is emerging with transmission predominantly via sexual activity. In this presentation, I will discuss the current state of diagnostics, epidemiology, resistance and treatment.

Originally published on September 2, 2025

Lecture Presenter

Sarah Kidd, BMedSc(Hons) PhD FASM FECMM Associate Professor (Adjunct), School of Biological Sciences University of Adelaide Head of Unit, National Mycology Reference Centre, MID SA Pathology

Dr. Sarah Kidd is the Head of the National Mycology Reference Centre at SA Pathology, in Adelaide, Australia, and an adjunct associate professor in the School of Biological Sciences, University of Adelaide. She completed her PhD in medical mycology at the University of Sydney, before undertaking postdoctoral research at the University of British Columbia, Vancouver, Canada, and then at Monash University, Melbourne, Australia. Dr. Kidd is a fellow of the European Confederation of Medical Mycology (FECMM) and of the Australian Society for Microbiology (FASM). She coordinates the Royal College of Pathologists of Australasia Mycology Quality Assurance Program, convenes a biennial mycology masterclass in Australia, and manages the Mycology Online website. Her research interests include the epidemiology, antifungal susceptibilities, and nomenclature of clinically important fungi.

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Objectives

After this presentation, participants will be able to:

• Discuss the utility of currently available laboratory methods for the identification of emerging dermatophytes
• Discuss the predominant cause of the global expansion of Trichophyton indotineae
• Describe common antifungal resistance patterns associated with T. indotineae and mechanisms of resistance
• Discuss the management of patients with emerging dermatophyte infections

Sponsored by:

University of Utah School of Medicine, Department of Pathology, and ARUP Laboratories