Raper & Thom, 1944

Macroscopic morphology

Colonies on potato dextrose agar at 25°C are buff to ochraceous to dull brown, plane or irregularly furrowed, mostly floccose, uneven in texture, and often have a granular appearance due to the production of small aggregates of Hülle cells which may initially resemble sclerotia. The reverse is dark yellow to reddish brown, and a faint mushroom odor may be present. Growth rate is moderate to rapid. Conidial heads are pale blue-green, however their production in some strains may be so minimal that this color pigmentation may not be evident.

Microscopic morphology

Hyphae are septate and hyaline. Conidial heads are radiate. Conidiophores are thin walled, smooth, pale brown and described by Raper & Fennell as measuring 350-500 µm long, however the Fungus Testing Laboratory has seen an isolate with very long conidiophores measuring up to over 1 mm. Vesicles are elliptical, 12-18 µm in diameter, and biseriate, with almost the entire surface being covered. Conidia are globose, pale green, delicately roughened, and measure 3.5-5.5 µm. Hülle cells are numerous in freshly isolated strains, occur in colorless clusters, and may be subglobse to ovoid to quite elongate, measuring 12 to 30 µm long [1875].

Special notes

This species was reported as the etiologic agent of disseminated disease in a cardiac transplant recipient[711]. They reported that the isolate appeared susceptible to amphotericin B and itraconazole with 24 hour MICs of <0.14 and 0.07 µg/ml, respectively. Fluconazole appeared resistant with an MIC of >80 µg/ml. This species has been placed in both the Aspergillus versicolor [1875] and Aspergillus ustus [1243] groups.

FTL* in vitro susceptibility data

None available