Perfect State (Emmonsiella Capsulata) of the Fungus Causing Large-Form African Histoplasmosis

SUMMARY

Twenty-one cultures of Histoplasma duboisii that were isolated from African (large-form) histoplasmosis cases have been studied for their sexual state and their cross-mating ability with strains of H. capsulatum. Four interesting phenomena have been observed: 1) The H. duboisii cultures were heterothallic; 2) The sexual state of H. duboisii was identical to Emmonsiella capsulata (H. capsulatum); 3) Isolates of H. duboisii successfully mated with the reciprocal mating types of H. capsulatum and the cleistothecia and ascospores so produced were identical to those of E. capsulata; 4) The (-) type was predominant among the 21 isolates [15(-):4(+):2(?)] as is the case in H. capsulatum from human infection. These results support Ciferri's taxonomic treatment that the agent of the large-form African histoplasmosis is H. capsulatum var. duboisii.