Pathogenicity of Wangiella Dermatitidis

Wangiella dermatitidis is a polymorphic dematiaceous human pathogen causing phaeohyphomycosis.2,5,12 The dark pigmentation associated with the majority of the dematiaceous fungi causing chromoblastomycosis and phaeohyphomycosis results from cell wall melanin which is synthesized via pentaketide metabolism and is termed DHN melanin.6–8,16 Wangiella dermatitidis is strongly neurotropic in natural infection in man and in experimental infections in mice.2,5 Cryptococcus neoformans is similarly neurotropic and also produces melanin. However the pigment is DOPA melanin and is derived by a different pathway from that of DHN melanin. DOPA melanin has been shown to be closely associated with virulence in Cryptococcus neoformans.9–11 DHN melanin has been shown to play an important role in pathogenesis of selected phytopathogens.4,6,16 Thus, it is logical to consider the role of DHN melanin in the pathogenesis of W. dermatitidis infections in mammals. This was investigated with the use of spontaneous and UV-derived melanin deficient mutants of W. dermatitidis as well as two wild type strains.