Revisiting old friends: Developments in understanding Histoplasma capsulatum pathogenesis.

Histoplasma capsulatum is a dimorphic pathogenic fungus and causative agent of histoplasmosis, which is a respiratory and systemic infection that is particularly severe in immunocompromised hosts and represents the fungal homolog of tuberculosis. In highly endemic regions, the majority of individuals have been infected and carry the organism in a persistent latent form that is a danger for reactivation if host defenses are suppressed. H. capsulatum has been a model organism for intracellular pathogenesis and fungal morphogenesis for decades. New genomic information and application of approaches for molecular genetic manipulation are shedding new light on virulence mechanisms.