Isolation of Rhizopus microsporus varietasmicrosporus from urine in patient with renal mucormycosis

V. Adamkova, E. Bendova

Author address: 

Prague, CZ


Isolated renal mucormycosis is an uncommon kidney infection affecting usually immunocompromised patients. Primary renal mucormycosis is a rare infection that occasionally causes acute illness with sepsis. We report a unique case of isolation fungus Rhizopus microsporus var. microsporus from urine in patient with renal mucormycosis in the microbiological literature. A 37-year-old man with diabetes mellitus, with gastric resection and with defect of calprotectin metabolism was admitted with a five-day history of scrotal pain and weight loss. The preliminary diagnosis was sepsis at orchiepididimitis. Urine and blood culture were negative. Necrotic and nephrotic syndrome developed during hospitalization. Renal biopsy showed membranoproliferative glomerulonephritis; renal insufficiency developed; CT demonstrated an enlarged left kidney. The urine specimen was opaque with fluff. Fluff was examinated in 20% KOH preparations by direct microscopy and revealed numerous nonseptate hyphae. Culture grew moulds on Sabouraud agar. This mould grew as a floccose aerial mycelium which was brown to grey in surface coloration; it did not grow at 50°C. Microscopically, the colonies were composed of broad hyphae with stolons which bore rhizoids and fascicles of unbranched sporangiophores. Our identification was Rhizopus sp. The species identification was confirmed by M. vanova as Rhizopus microsporus, var. microsporus. Rhizopusmicrosporus was repeatedly isolated from urine. Treatment was changed to amphotericin B lipid complex. A simple nephrectomy was performed. Examination of the enlarged kidney showed presence of identical mould. Postoperatively the patient was continued on systemic amphotericin B, he started to urinate. He died of heart failure 3 months after nephrectomy. Renal mucormycosis is usually not clinically suspected and are diagnosed only through surgical, pathological or postmortem examinations. Identification of the genus and species requires culture of tissue and assessment of the morphology of the fungal growth. They usually become nonviable when their walls are damaged by tissue homogenization. The availability of lipid formulation of amphotericin B within the past few years has provided an attractive alternative for the management of zygomycosis. The mortality rate of primary renal mucormycosis is high, with an overall survival rate of only 36%.

abstract No: 


Full conference title: 

16th European Congress of Clinical Microbiology and Infectious Diseases
    • ECCMID 16th (2006)