Immunodiffusion test for diagnosing basidiobolomycosis

An immunodiffusion test was developed for the diagnosis of basidiobolomycosis. When culture filtrate antigen (CFA) from Basidiobolus ranarum was reacted against two human patient and two rabbit antisera, 2 precipitin bands, inner (N) and outer (Y), were revealed for both patient and rabbit antisera. A line of identity was also observed between precipitin bands obtained with patient and rabbit sera. When CFA from B. ranarum (B CFA) was reacted against rabbit sera which contained antibody to Conidiobolus coronatus and Pythium insidiosum, 1 precipitin band corresponding to inner band (N) was observed. This finding showed that B. ranarum, C. coronatus and P. insidiosum shared at least one common antigen. After B CFA was absorbed with Pythium rabbit antiserum, the inner precipitin line that occurred between B CFA and rabbit antisera of Pythium and Conidiobolus disappeared. However, with Basidiobolus rabbit antiserum, the result did not change. The antigens which could be demonstrated by inner (N) and outer (Y) precipitin bands were heat stable at 56 ° C for 30 min. The titer of the antibodies specific to these antigens decreased as the lesions subsided. When B. ranarum CFA was reacted against sera from 20 apparently normal persons, 20 diabetes mellitus patients, 5 aspergillosis patients, 2 candidosis patients and 3 pythiosis patients, no precipitin band was found. B. ranarum CFA was also treated with each rabbit antiserum specific to Candida albicans, Malassezia furfur and Aspergillus fumigatus. No precipitin bands occurred with any of these antisera. Thus, this test was found to be practical, sensitive and specific, and can be used to monitor patients infected with Basidiobolus ranarum.     

Histological and ultrastructural features of gastrointestinal basidiobolomycosis

Basidiobolus ranarum is a fungus found in the dung of amphibians, reptiles, and insectivorous bats. Its structural elements include both hyphae and zygospores. Patients with B. ranarum infection may present with subcutaneous, gastrointestinal, or systemic lesions. Here we report a case of gastrointesinal badidiomycosis in a 13-year-old male child who presented with acute abdomen. Exploration revealed a mass in the ascending colon. On histology, transmural granulomatous inflammation composed of abundant eosinophils, lymphocytes, histiocytes and giant cells was seen. Histochemical stains revealed broad, non-septate, hyphae-like structures surrounded by an eosinophilic sheath. On an ultrastructural level, fungal hyphae, spores, and macrophage-laden crystalloids were observed. The diagnosis of gastrointestinal basidiobolomycosis was established and the patient received antifungal treatment. This paper reviews the relevant literature regarding basidiomycosis, and discusses its diverse clinicopathological features, as well as distinguishing it from other diseases.