(described by Zimmerman in 1902)
Genus: Khuskia (teleomorph)
Description and Natural Habitats
Nigrospora is a filamentous dematiaceous fungus widely distributed in soil, decaying plants, and seeds. It is a common laboratory contaminant. Although it has been isolated from a few clinical samples, its pathogenicity in man remains uncertain [531, 1295, 2144, 2202].
Nigrospora sphaerica is the best-known species of the genus Nigrospora.
See the summary of synonyms and teleomorph-anamorph relations for Nigrospora spp.
Pathogenicity and Clinical Significance
Nigrospora has been isolated from cutaneous lesions of a leukemic patient and from a case with keratitis. However, its pathogenic role as a causative agent is not well-known [1847, 2218].
Nigrospora grows rapidly and produces woolly colonies on potato dextrose agar at 25°C. The colonies mature within 4 days. Color of the colony is white initially and then becomes gray with black areas and turns to black eventually from both front and reverse. Sporulation may take more than 3 weeks for some isolates [531, 1295, 2144, 2202].
Septate hyaline hyphae, hyaline or slightly pigmented conidiophores, and conidia are visualized. The conidiogenous cells on the conidiophores are inflated, swollen, and ampulliform in shape. They bear a single conidium (14-20 µm in diameter) at their apex. Conidia are black, solitary, unicellular, slightly flattened horizontally, and have a thin equatorial germ slit [531, 1295, 2144, 2202].
Nigrospora is differentiated from Humicola by its very black conidia that originate from hyaline, inflated conidiophores.
No special precautions other than general laboratory precautions are required.
No data are available.