الملخص

In this study, 63 oral swabs were collected . Thirty six yeast isolates were obtained (57.14%) grown on sabouraud dextrose agar medium (SDA). Symbols were given to isolates from RA1 to RA36 in order to differentiate them. The isolates were identified by growth on HiCrome Candida differential agar M1297A and identification by Vitek 2 Compact system. The identification results showed 5 species of the isolated yeasts belonging to the genus Candida, 29 isolates belonging to the species C. albicans (80.55%) and one species from C. famata, C. glabrata, C. kefyr and C. lusitaniae (2.77% for each species). Moreover one isolate was obtained from each of the following yeasts: Saccharomyces serevisiae, Malassezia furfur and Rhodotorula glutinis (2.77% for each one). This study included the evaluation of two virulence factors for all C. albicans isolates , phospholipase enzyme production on egg yolk agar and hemolytic activity on sugar-enriched sheep blood agar. . Phospholipase production test showed differences in phospholipase production among the isolates , twenty three isolates (79.31%) were producers and precipitation zone (Opaque zone) was observed around the grown colonies with different Pz values and the isolate RA13 exhibited highest activity (Pz value = 0.53). The results showed also that all isolates were producers of hemolysin with different hemolytic indexes (Hi). Isolate RA7 represented the highest one in activity (Hi = 2.16). Hemolysis of all isolates involved beta hemolysis.