The infectious aetiology of tropical ulcer--a study of the role of anaerobic bacteria.

We have cultured anaerobic bacteria from patients with tropical ulcers. Fusobacteria were isolated most frequently. Anaerobes were always present, together with aerobes or facultative anaerobes, particularly in early phase ulcers, suggesting that the combination of organisms is important in the pathogenesis of the disease. Spirochaetes were identified in material examined by light and electron microscopy, but were not cultured.