ASPERGILLUS DIFFERENTIATION MEDIUM BASE

Aspergilli are hyaline moulds that commonly cause opportunistic infections in humans. Allergic bronchopulmonary disease is a manifestation of hypersensitivity to fungal spores or products, a common manifestation of Aspergillus species (particularly A. flavus). Aspergillus Differentiation Medium Base formulated by Pitt et al is a modification of the medium formulated by Bothast and Fennel. Aspergillus flavus develops intense yellow orange colour at the base of the colonies, which is a differential characteristic of this species. This pigmentation helps in differentiating A. flavus from other Aspergillus species. Assante et al showed that the orange yellow coloration was due to the reaction of ferric ions (from ferric ammonium citrate) with aspergillic acid or neoaspergillic acid forming a colored complex.