Rapid identification of Candida albicans by filamentation on serum and serum substitutes.

Abstract

It was noted by Hill and Gebhardt (1956), as well as by Young (1958), that Candida albicans will begin to form mycelia within 60 minutes after subcutaneous injection into mice. Hill and Gebhardt demonstrated that this phenomenon occurs only with C. albicans and C. stellatoidea, while other Candida species fail to form mycelia and are rapidly destroyed in the tissues. Johnson (1954) observed that C. albicans forms mycelia on human serum but does not mention the time interval of beginning filamentation. We noted that C. albicans spores produce short germ-tubes within 90 minutes on human serum at 37 to 42 C. This occurred on pooled and individual, hemolyzed and nonhemolyzed, and inactivated sera and on fresh as well as on deep-frozen stored material. Of other Candida species, only C. stellatoidea, whose species status is doubtful, produced these characteristic short germtubes. C. tropicalis showed long mycelia, carried over with the inoculum