Cytotoxicity of Fusobacterium ulcerans.

A new species of Fusobacterium, F. ulcerans, was isolated from 46 tropical ulcers. All the isolates had shown identical soluble cell protein patterns on polyacrylamide gel electrophoresis although there were two morphological types with slightly different biochemical properties. A representative strain of each of the two groups was selected for in- vitro cytotoxicity testing on a range of tissue-culture cell lines. Both strains of F. ulcerans induced a marked cytotoxic effect on Vero and Int-407 cells. This effect may contribute to the pathogenesis of tropical ulcers.