Serodiagnostic value of culture filtrate antigens from aspergilli with septate phialides.

Culture filtrate antigens from 6 typical isolates of Aspergillus fumigatus, 6 isolates with septate phialides, and isolates of A. fumigatus var. ellipticus, A. fishceri, A. flavus and A. niger were studied in tests with 2,100 samples of serum originating from 1,452 patients suffering from miscellaneous diseases, including 60 cases of aspergillosis, 850 samples of serum from apparently healthy blood donors and 522 sera referred to us as positive for C-reactive protein. The culture filtrate antigen prepared from a septate-phialide-strain proved to be most useful in detecting precipitating antibodies in the sera of patients suffering from aspergillosis caused by A. fumigatus. The antigen from this strain not only gave sharper and a larger number of precipitin bands than others but also proved to be an invaluable tool in the serodiagnosis of 5 to 56 (8.9%) A. fumigatus cases in which all other antigens repeatedly failed to give a positive result. The serological data also suggest that the septate-phialide strains are mutants of A. fumigatus and should not be classified as a separate species.