Allergens of Epicoccum nigrum grown in different media for quality source material

Background: The Epicoccum nigrum (EN) extract used in allergy disorders exh ibits batch-to-batch variations in protein composition and allergenic poten cy. In this study, the allergens of EN grown in different media were invest igated. Methods: EN was grown in five different nutrient media as stationary cultur es at 25 degrees C for 5-23 days. The growth pattern was characterized by m easuring dry weight, protein and carbohydrate content. The antigenic and al lergenic content of EN extract was evaluated with EN-positive patients' ser a and antibodies raised in rabbit. Results: The growth of EN in Czapeck Dox medium yielded insufficient materi al, while Sabouraud's broth with yeast extract (SBY) gave maximum spore-myc elial mass and protein content. Potato dextrose broth (PDB) and potato dext rose agar (PDA) showed higher dry weight and protein in 7-9-day cultures. S DS-PAGE resolved 26, 22, and 21 protein bands in EN extracts from cultures of day-13 SBY, day-7 PDB, and day-9 PDA, respectively. IgE/IgG immunoblots showed more allergenic (25)/antigenic (25) bands in EN cultured in SBY than in the others. Specific IgE ELISA and intradermal tests showed EN extract from day-13 culture in SBY to be the most potent. Conclusions: The day-13 culture of EN in SBY was the most potent and may be selected for preparing EN extracts for diagnosis of allergy and future stu dies.