Mycolactones and Mycobacterium ulcerans disease

Context: Mycobacterium ulcerans causes devastating necrotic lesions in affected individuals. The disease, commonly called Buruli ulcer, is increasing in prevalance in western African countries. Treatment is mainly surgical; no clinical trials have been done to support the use of antimycobacterial drugs. A secreted polyketide toxin, mycolactone, is responsible for the tissue damage; its chemical structure has been elucidated. Starting point: Although the main treatment is surgical, many patients with Buruli ulcer present late because of unusual beliefs about the disease and its treatment. Isabelle Aujoulat and colleagues recently showed, in a study in southern Bénin, Africa (Trop Med Int Health 2003; 8: 750-59), that although the ulcer is well recognised, the cause is often seen as environmental or because of witchcraft. In addition, treatment is thought to be destructive, costly, and ineffective. Where next? Antimycobacterial drug regimens that hold promise based on animal and preliminary human studies will soon be tested in large well-designed controlled clinical trials. Information gleaned from the genomic sequence of M ulcerans could be used to design more effective vaccines, or new drug targets (eg, that knock out the enzymes of M ulcerans that synthesise mycolactone species).