Rhizopus schipperae

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].

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].

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].

None available

* Fungus Testing Laboratory unpublished data (NCCLS M38-A)

PubMed

GenBank

Several sporangiophores arising as a group

References

104. Anstead, G. M., D. A. Sutton, E. H. Thompson, I. Weitzman, R. A. Otto, and S. K. Ahuja. 1999. Disseminated zygomycosis due to Rhizopus schipperae after heatstroke. J Clin Microbiol. 37:2656-2662.

531. de Hoog, G. S., J. Guarro, J. Gene, and M. J. Figueras. 2000. Atlas of Clinical Fungi, 2nd ed, vol. 1. Centraalbureau voor Schimmelcultures, Utrecht, The Netherlands.

2202. Sutton, D. A., A. W. Fothergill, and M. G. Rinaldi (ed.). 1998. Guide to Clinically Significant Fungi, 1st ed. Williams & Wilkins, Baltimore.

2399. Weitzman, I., D. A. McGough, M. G. Rinaldi, and P. Della-Latta. 1996. Rhizopus schipperae, sp. nov., a new agent of zygomycosis. Mycotaxon. 69:217-225.