Weitzman, McGough, Rinaldi & Della-Latta, 1996

Macroscopic morphology

Colonies on potato dextrose agar at 25°C are effuse (flat) and mostly remaining white due to failure to sporulate. Growth occurs up to 45 °C on this medium. Colonies on Czapek agar are grayish-white, diffuse, thin, floccose, and measure approximately 8 cm in 4 days at 30°C. Optimum growth occurs at 30°C, with very restricted growth up to 45 °C [2202], [531], [2399].

Microscopic morphology

On potato dextrose agar hyphae are hyaline, broad (5-15 µm), ribbon-like, irregularly branched, and aseptate to sparsely septate. Numerous chlamydoconidia of various sizes are produced. Fruiting structures are lacking. On Czapek agar sporangiophores (100-460 µm in length by 5-15 µm in width) occur on stolons, are brown, often septate, and are produced singly, in pairs, or are aggregated in groups of up to 10 from a nest of rhizoids (usually simple, rarely branched, hyaline or light brown, and occasionally septate). Sporangia are gray-brown (up to 80 µm in diameter). Columellae are subglobose to somewhat conical, hyaline to light tan. Sporangiospores are subglobose to oval, faintly striated in water, angular, oval, and distinctly striated when dry (5.8-6.8 x 4.8-5.8 µm) [2202], [531], [104], [2399].

Special notes

Rhizopus schipperae, like Apophysomyces elegans and Saksenaea vasiformis, fails to produce diagnostic structures on routine media such as potato dextrose agar or Sabouraud dextrose agar. The organism was first reported and described in bronchial wash and lung specimens in a patient with multiple myeloma [2399]. It was subsequently reported as an agent of disseminated zygomycosis in a patient with heatstroke [104].

FTL* in vitro susceptibility data


None available
* Fungus Testing Laboratory unpublished data (NCCLS M38-A)