MUTATION IN HOTSPOT REGIONS OF THE ERG11 GENE AND FLUCONAZOLE RESISTANCE IN CLINICAL ISOLATES OF CANDIDA ALBICANS IN RASHT CITY

Nowadays, the common use of azoles has led to increased resistance to azole
among Candida albicans strains. Amino acid substitutions in azole target enzyme, ERG11p, is attributed
to azole resistance in some clinical strains of Candida albicans. The aim of this study was to evaluate
ERG11 gene mutations in fluconazole-resistant isolates of Candida albicans in Rasht.
Materials & Methods: In this study, the clinical specimens were isolated from the vaginal mucosa of 50
women. Candida albicans isolates were identified using standard identification methods such as germ
tubes production and culture in CHROMagar media. Resistance and susceptibility of isolates to
fluconazole were investigated through disc diffusion and broth micro-dilution methods. The mutations
in the ERG11 gene were determined in clinical isolates using PCR-sequencing method.
Results: In this study, 20 clinical isolates of Candida albicans were resistant to fluconazole. The highest
MIC of fluconazole was determined at 2048 µg/ml. Also, in eight fluconazole-resistant isolates by PCR-
sequencing, two missense mutations (V437I and V488I) were found in the ERG11 gene.
Conclusion: It seems that having several mutations in the ERG11 gene is a reason for high MIC in
resistant isolates of Candida albicans in this study. However, investigating other mechanisms of azole
resistance is recommended in Candida albicans isolates.