Phagocytosis of medically important yeasts by polymorphonuclear leukocytes

Phagocytosis is a critical function of polymorphonuclear leukocytes in the control of mycotic infections. By using a modified fluorescence quenching assay to distinguish between attached and ingested organisms, we determined the percent phagocytosis of several medically important yeasts. The percentages of phagocytosis of serum-opsonized Candida albicans, Candida tropicalis, Candida parapsilosis, and Torulopsis glabrata were all comparable at 37 degrees C. By comparison, there was significantly less phagocytosis of Cryptococcus neoformans and Trichosporon beigelii isolates (P < 0.001). Thus, phagocytosis of C. albicans by polymorphonuclear leukocytes is comparable to that of species other than C. albicans but is significantly greater than that of the basidiomycetous yeasts T. beigelii and C. neoformans.