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A 7-year-old boy presented with a chronic, indurated, tender left thigh swelling in association with a hypertensive emergency. He had a bilateral moderate degree of hydronephrosis and a left perinephric abscess, and MRI features of posterior reversible encephalopathy syndrome. Histopathological examination of the biopsy specimen demonstrated eosinophilic fasciitis with filamentous fungi. Basidiobolus ranarum was isolated from the culture. The fungus was also isolated from a perinephric fluid aspirate. Computerised tomography of the abdomen demonstrated features consistent with fungal invasion of the pelvic floor muscles and urinary bladder, leading to bilateral hydronephrosis. He required multiple antihypertensive drug therapy and was treated with intravenous amphotericin B, oral itraconazole and potassium iodide. Antihypertensive agents were discontinued after 2 weeks of antifungal therapy. At 6-months follow-up, the hydronephrosis had resolved completely. Perinephric abscess associated with basidiobolomycosis has not been reported previously.

Gastro-intestinal basidiobolomycosis (GIB) is a rare fungal infection caused by Basidiobolus ranarum. Treatment includes surgical resection and long-term antifungal therapy. A 2.5-year-old boy presented with a 10-day history of abdominal pain, fever and diarrhoea, and a palpable abdominal mass was detected. Resection was undertaken and histology confirmed basidiobolomycosis. Treatment with amphotericin B and itraconazole was commenced, but the infection progressed and spread to involve the intestines, liver, ribs and lung, and also the abdominal wall after 6 months, requiring four operative procedures. Because of unresponsiveness to amphotericin and itraconazole, oral potassium iodide was added which resulted in complete resolution of the infection. Potassium iodide is an essential component of the treatment of systemic B. ranarum.

We report a case of invasive retroperitoneal zygomycotic infection caused by Basidiobolus ranarum in a healthy 8-year-old boy. The youngster responded dramatically to potassium iodide. The clinical and pathological features are reviewed to highlight the problems encountered in the management of this rare infection.

The capilliconidia of Basidiobolus ranarum produce an apical droplet of extracellular material that aids in dispersal by arthropods, such as mites and termites. Electron microscopic examination ofthe ad? hesive material comprising the haptor of capilliconidia has shown it to consist of an electron-dense band di- rectly around the capilliconidial beak from which sin- uous fibrous filaments extend radially. These filaments are partially digestible with proteinase-K and measure 18-20 nm wide by 3-4 (im long. Interspersed among the filaments are double membrane-bound ovoid or? ganelles that are 0.2-0.3 fxm x 0.3-0.4 /um and which contain electron-dense granular contents. Overlying the layer of sinuous filaments is a looser layer of coarsely fibrogranular material that, in turn, is covered with an outermost layer of densely granular material. What are interpreted to be earlier stages of adhesive for? mation exhibit an almost homogeneous appearance of the haptor material. No clearly defined wall or mem? brane delimits the droplet surface. A comparison is made between this adhesive material and that reported for other fungi.

The process of endospore cleavage (sporan? giospore formation) within what were originally bal? listosporic conidia was examined with light and elec? tron microscopy in two isolates of Basidiobolus ranarum. A pathogenic isolate was obtained from skin ulcers on a frog (Davis isolate) and a nonpathogenic isolate was obtained from toad feces (Toad isolate). Electron mi? croscopy revealed that endospore formation was not the result of successive bipartitioning or progressive cleavage as previously described. Instead, the proto- plasm of the ballistosporic conidium was bisected by a wall, thus dividing the conidium into one or more sporangia within which endospores (sporangiospores) were delimited. The walls segregating the conidial cy? toplasm into sporangia were continuous with the inner layer of the original conidial wall. As spores were de- marcated, some cytoplasmic debris was left in the space between the conidial/sporangial walls and the spore walls. After a period of 16 hours of low light levels, turning on the laboratory lights stimulated the for? mation and discharge of conidia with a peak in conidial discharge 5-6 hours later.

The effects of acenaphthene on nuclear division of Basidiobolus ranarum are described and illustrated. The time required for metaphase and anaphase was significantly longer and the protoplast under...

The life cycles and relationships of a variety of minute fungi occurring on arthropod integuments are poorly known. Species of Amphoromorpha Thaxter are reported from all continents except Australia and Antarctica on arthropods and mucoralean and laboulbenialean fungi. Based upon observations of herbarium specimens and of mites and termites exposed to cultures of Basidiobolus ranarum Eidam, we conclude that species of Amphoromorpha actually may be the secondary capilliconidia of Basi? diobolus spp. Evidence was obtained from morphological similarities of attachment region on the arthropods, shape and method of internal cleavage of the conidia, and opportunity for attachment of conidia to arthropods and fungi in their habitats. Secondary capilliconidia of Basidiobolus appear to be important for dispersal to new substrates in the life cycle of these fungi.

(1956). Supplementary Developmental Stages of Basidiobolus Ranarum and Basidiobolus Haptosporus. Mycologia: Vol. 48, No. 5, pp. 655-676.

(1970). Comments on the Distribution of Basidiobolus Ranarum. Mycologia: Vol. 62, No. 3, pp. 585-587.

It was possible to cause selective damage to an area as small as 1 , in diameter within the cell of Basidiobolus ranarum with a laser microbeam without the addition of dyes. Irradiation of the cytoplasm at the tip of the cell often resulted in an arrest of cellular elongation and frequently rupture of the tip. In some cases where nuclei were irradiated during anaphase, smaller nuclei were formed which were capable of division. A single shot into the phragmoplast stopped its development. The destruction of one daughter nucleus also stopped septum formation. The nucleolus appeared to be more sensitive to laser irradiation than the adjacent nuclear sap. A chromosome bridge was observed at mitosis following the irradiation of a resting nucleus. A mutant cell with two tips resulted from the irradiation of a nucleus.