Diagnostic possibilities of serology in diseases caused by members of the genus Candida berkhout.

Up to now, the diagnosis of candidiases has been an intriguing problem chiefly because the detection of Candida in the sick organism is no conclusive evidence of its etiological involvement. The endeavour to use serological methods in the diagnosis has not been successful and their use has so far practically been limited to taxonomic studies. In an effort to find a serological approach to the diagnosis, we found the agarimmunodiffusion assay of Ouchterlony to be the most promising method and used it in our own modification. The first stage of the work was to select and prepare the most suitable type of antigen for this reaction (described in the present paper). Sixteen antigen types classifiable into four groups were prepared: simple water-extracted antigens, alcohol-extracted antigens, antigens obtained on disrupting cells by repeated freezing and thawing, and antigens prepared by boiling cultures. Cultures for antigen preparation were grown on Salvin's medium or on liquid Sabourad's medium and the antigens obtained were either used in their native form or dialysed. Serological tests with hyperimmune rabbit sera prepared by our own schedule were done repeatedly. By far the best were simple water-extracted antigens, nondialysed, from cultures grown on Sabouraud's medium. They reacted the most sensitively, gave high antibody detection rates and assessable precipitin reactions and showed high species specificity. Tests with positive human sera fully confirmed these findings; in fact, species specificity was even somewhat higher here.