Variation of a 470 000 daltons antigen complex and catalase antigen in clinical isolates of Aspergillus fumigatus.

Antigens in ruptured mycelium of 18 Aspergillus strains including 14 clinical isolates of A. fumigatus were studied by immunoelectrophoresis. One antigenic component of molecular weight 470 000 previously characterized by hydrophobic interaction chromatography and gel filtration and a second component with catalase activity were detected in all A. fumigatus isolates but in varying quantities. The 470 000 antigen complex cross-reacted with antigens in A. flavus and A. nidulans but not in A. niger or A. terreus. A. fumigatus catalase antigen cross-reacted with catalase in A. flavus, A. nidulans and A. terreus, but not in A. niger. One A. fumigatus isolate produced two catalase antigens showing a reaction of partial identity. A. flavus also produced two catalase antigens, one of which was species-specific.