Evaluation of Virulence Factors of Candida Species Isolated from Superficial Versus Systemic Candidiasis
Background: Various virulence factors are contributing to the colonization and pathogenicity of Candida during both superficial and systemic infections Objectives: The current study was conducted to investigate production of extracellular hydrolytic enzymes, hemolysis and biofilm formation among Candida species isolated from superficial versus systemic candidiasis and to compare the production of these virulence factors among albicans and non albicans Candida species, in addition to comparing hemolysis and hydrolytic enzymes production under aerobic and anaerobic conditions. Methodology: A total of 51 Candida strains isolated from vulvovaginal candidiasis and 44 strains isolated from systemic candidiasis were included in the study. Germ tube test and Hi Crom Candida Differential Agar medium were used for species identification of the isolates. The Candida isolates were tested for expression of hemolytic activity, phospholipase, proteinase and esterase production under aerobic and anaerobic conditions, in addition to their ability of biofilm formation. Results: In both groups, 55 isolates were identified as Candida albicans (C. albicans) while 44 isolates were identified as non albicans species. Hemolytic activity and biofilm formation were significantly higher among the systemic Candida isolates than superficial isolates, while expression of proteinase activity was significantly higher among superficial isolates. Expression of phospholipase and esterase was significantly higher among C. albicans isolates than non albicans isolates. Expression of proteinase and esterase activities was significantly better under aerobic conditions than under anaerobic conditions. Conclusions: Hemolytic activity and bioflm formation were more evident among the systemic isolates while proteinase production appears to be more evident among the vaginal isolates. Phospholipase production is almost an exclusive characteristic feature of C. albicans, while C. albicans is the leading species in terms of esterase production. Aerobic conditions favor expression of proteinase and esterase activities.