Allergenic variability of different strains of Candida albicans

The allergenic variation of six Candida albicans strains was studied by immunoblotting with pooled sera from 20 C. albicans-RAST-positive subjects. The presence of a 46-kilodalton (kD) protein, the major allergen, and a 29-kD protein, an intermediate allergen, was shown in crude extracts from disrupted cells (six strains). There was a significant variation in the content of the major C. albicans allergen (46 kD) between the different strains. Surface extracts of all six C. albicans strains contained mannan. Immunoblotting of cell wall extracts of intact C. albicans (agar plate) of different age revealed the strongest IgE binding in cultures incubated for 36-50 h. Due to the varying proportions of allergens demonstrated in the different strains of C. albicans, the starting source material for extract production should be a pool of individual strains, which all should be analysed prior to pooling. Special attention should be paid to the selection of C. albicans strains, and a parameter such as the breakability of the strain should be considered.