Lives in the intestines of many amphibians i.e. frogs, toads, salamanders, often in their feces as well as decaying fruits and soil
Tropical and subtropical but expanding into US
Conidiobolus more common in India, Asia, and Saudi Arabia
Clinical Manifestations
Basidiobolus
A single enlarging, painless and firm swelling in soft tissues on extremities e.g. buttocks, thighs, perineum, trunk
As the infection progresses, they will start to develop burning sensation over the area
There may be evidence of a diffuse bluish discoloration over the swollen area
Conidiobolus
Chronic rhinofacial zygomycosis: painless swelling of the rhinofacial region that causes substantial disfigurement. The infection itself starts at the nose and invades into the subcutaneous tissue and develops into large masses. The masses eventually get so big that they block the nasal passages causing discharge, chronic sinusitis or complete nasal passage obstruction. Described as “facial elephantiasis”.
It does not disseminate as it is not angioinvasive.
Mainly infects adults males, disease often occurs after having inhaled the spores into the nasal cavities or through trauma
Diagnosis
Needs tissue and culture for diagnosis
Culture
On KOH-Calcofluor, shows broad, thin-walled and pauci-septate or aseptate fungus
Rapid-growing in culture
Microscopically looks similar to Mucoromycotina, with wide, pauci-septate hyaline mold form
Conidiobolus can have “beaked” shape on spores, with a spore that has secondary spores attached to it
Basidiobolus also has spores with a beak.
Biopsy
Strong eosinophilic reaction in tissue histopathology.
