The contribution of mycetoma grains to suboptimal disease management

A defining feature of mycetoma is the presence of grains, which are dense, compact structures composed of the causative bacterial or fungal microorganisms. These grains define clinical resistance to treatment, and the likelihood of chronicity. Understanding the molecular mechanisms underlying grain development are critical for enhancing treatment efficacy; however, important questions remain about the underlying genetic, biochemical, and structural pathways. In this Review, we discuss what is known about mycetoma grain formation, with a focus on Madurella mycetomatis, and the need for multi-disciplinary approaches to aid their clinical management and treatment.