Disseminated zygomycosis due to Rhizopus schipperae after heatstroke

Abstract

A 21-year-old woman suffered heatstroke and developed diarrhea while trekking across south Texas. The heatstroke was complicated by seizures, rhabdomyolysis, pneumonia, renal failure, and disseminated intravascular coagulation. The patient's stool and blood cultures grew Campylobacter jejuni. The patient subsequently developed paranasal and gastrointestinal zygomycosis and required surgical debridement and a prolonged course of amphotericin B. The zygomycete cultured was Rhizopus schipperae. This is only the second isolate of R. schipperae that has been described. R. schipperae is characterized by the production of clusters of up to 10 sporangiophores arising from simple but well-developed rhizoids. These asexual reproductive propagules are produced on Czapek Dox agar but are absent on routine mycology media, where only chlamydospores are observed. Despite multiorgan failure, bacteremia, and disseminated zygomycosis, the patient survived and had a good neurological outcome. Heatstroke has not been previously described as a risk factor for the development of disseminated zygomycosis.

FIG. 1

(A) Necrotic lesion on nasal ala prior to surgery. (B) Appearance of patient 1 month after surgery. (C) Branching, nonseptate hyphae of R. schipperae in nasal mucosa. Hematoxylin-eosin stain. Magnification, ×613. (D) Hyphae of R. schipperae in intestinal mucosa. Gomori methenamine-silver stain. Magnification ×613. (E) Thick- and thin-walled chlamydospores of R. schipperae on PDA. Magnification, ×613. Lactophenol cotton blue mount. (F) Cluster of sporangiophores of R. schipperae on CDA. The arrow shows a septate rhizoid. Magnification, ×213. Lactophenol cotton blue mount.

FIG. 2

Cluster of sporangiophores of R. schipperae on CDA. Magnification, ×306. Lactophenol cotton blue mount.

FIG. 3

Rhizoids and sporangiospores of R. schipperae on CDA. Magnification, ×306. Lactophenol cotton blue mount.

FIG. 4

Columella of R. schipperae on CDA. Magnification, ×213. Lactophenol cotton blue mount.

FIG. 5

Columella and striated sporangiospores of R. schipperae on CDA. Magnification, ×613. Lactophenol cotton blue mount.

FIG. 6

Crystals on hyphae of R. schipperae on PDA. Magnification, ×613. Lactophenol cotton blue mount.