Mycobacterium ulcerans (M. ulcerans) is a slow-growing mycobacterium that classically infects the skin and subcutaneous tissues, giving rise to indolent nonulcerated (nodules, plaques) and ulcerated lesions. After tuberculosis and leprosy, Buruli ulcer is the third most common mycobacteriosis of humans. M. ulcerans grows optimally on routine mycobacteriologic media at 33°C and elaborates a necrotizing immunosuppressive cytotoxin (mycolactone). Large ulcers almost certainly caused by M. ulcerans were first observed by Cook in Uganda in 1897; however, the etiologic agent was not isolated and characterized until 1948 in Australia by MacCallum and associates.
Lesions of M. ulcerans disease have several synonyms (e.g. Bairnsdale or Searle's ulcer). The name Buruli is probably most appropriate for historic reasons, as it is a county of Uganda where important foci of the disease were studied.