How they avoid destruction by the fungicidal mechanisms within lysosomes is unclear. Arthroconidia of C immitis inhibit phagosome-lysosome fusion and survive within normal murine peritoneal macrophages. Phagosome-lysosome fusion takes place after H capsulatum infection, but the yeast cells survive in the phagolysosome. It has been speculated that the fungus neutralizes the fungicidal components of the lysosome by a mechanism not yet elucidated. There is very little information about mechanisms of fungal pathogenicity, in contrast to what is known about molecular mechanisms of bacterial pathogenesis.
Fungal pathogenesis is complex and involves the interplay of many factors.
Studies to elucidate these mechanisms are needed because of the increasing incidence of opportunistic infections. Common themes in microbial pathogenicity. Heat shock in dimorphic fungi.