Rhizopus nigricans

Rhizopus nigricans is a fungus commonly known as bread mold and is the most common species of Rhizopus. It is found on spoiled food, in soils, and even in children's sandboxes. The genus contains some 50 species and bread mold is sometimes confused with species of Mucor or other species of Rhizopus like Rhizopus oryzae. Dispersed in hot dry weather, the spores contain allergenic proteins with 31 distinct allergens, which can produce respiratory and nasal symptoms in concentration (e.g. chronic cough, shortness of breath, chest tightness, chronic phlegm, snuffle, and allergic rhinitis). Food-handling workers are particularly at risk if they are allergic to mold.