Comparison of the hemolytic activity between C. albicans and non-albicans Candida species

The ability to produce enzymes, such as hemolysins, is an important virulence factor for the genus Candida. The objective of this study was to compare the hemolytic activity between C. albicans and non-albicans Candida species. Fifty strains of Candida species, isolated from the oral cavity of patients infected with HIV were studied. The isolates included the following species: C. albicans, C. dubliniensis, C. glabrata, C. tropicalis, C. krusei, C. parapsilosis, C. dubliniensis, C. norvegensis, C. lusitaniae, and C. guilliermondii. Hemolysin production was evaluated on Sabouraud dextrose agar containing chloramphenicol, blood, and glucose. A loop-full of pure Candida culture was spot-inoculated onto plates and incubated at 37 degrees C for 24 h in a 5% CO2 atmosphere. Hemolytic activity was defined as the formation of a translucent halo around the colonies. All C. albicans strains that were studied produced hemolysins. Among the non-albicans Candida species, 86% exhibited hemolytic activity. Only C. guilliermondii and some C. parapsilosis isolates were negative for this enzyme. In conclusion, most non-albicans Candida species had a similar ability to produce hemolysins when compared to C. albicans.