Candida albicans  Genotyping and Relationship of Virulence Factors with Fluconazole Tolerance in Infected Pediatric Patients

PURPOSE: Candida albicans of different genotypes is a common cause of fungal infection in pediatric setting. This cross sectional study was designed to investigate ABC genotypes and the relationship between virulence factors and fluconazole tolerance among C. albicans isolates from infected pediatric patients. MATERIALS AND METHODS: C. albicans isolates were identified by germ tube test and ABC typing using PCR. Antifungal susceptibility testing was done according to Clinical Laboratory Standard Institution recommendations. Testing for proteinase and phospholiase production were done using bovine serum albumin agar and egg yolk agar, respectively. All isolates were tested for biofilm formation. Fluconazole tolerance was detected by reading the fluconazole susceptibility testing after 48 hours. Candida albicans isoltes were considered as fluconazole tolerant if they exhibited a susceptible minimum inhibatory concentration (MIC) after 24 hours of incubation and a resistant MIC following 48 hours of incubation. RESULTS: A total of 88 C. albicans isolates were collected. Genotype A was the most prevalent (46 isolates, 52.3%). Biofilm formation, proteinase and phospholipase enzymes activity were detected in 76.1% 77.3% and 65.9% of the C. albicans isolates, respectively. Fluconazole resistance was found in 36.4% of the isolated C. albicans. Fluconazole tolerance was detected in 29 isolates (33%). Fluconazole tolerance has significant positive correlation with proteinase production and biofilm formation. CONCLUSION: Genotype A was the most prevalent genotype. Biofilm and hydrolytic enzymes production are important Candida albicans virulence determinants in pediatric infections. Fluconazole tolerance has significant positive correlation with biofilm formation and proteinase production in C. albicans. More studies are recommended to investigate the molecular relationship between fluconazole tolerance and C. albicans virulence determinants. Also, to identify the effect of fluconazole tolerance on the clinical outcome of virulent Candida albicans infections.