saeedeh balabandi

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 &

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.

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.

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.

Candida albicans as an opportunistic fungal pathogen in human causes candidiasis. The widespread use of azoles has led to the increase of azole resistance in Candida albicans isolates. Mutation in the ERG11 gene is one of several azole resistance reasons in Candida albicans. The aim of this study was to find ERG11 gene mutations in fluconazole resistant isolates in Rasht.
Candida albicans isolates were identified by standard identification methods such as germ tubes. The fluconazole resistance and susceptibility of the isolates was evaluated by Disc diffusion and MIC methods. For mutation determining, ERG11 gene was amplified by PCR and then sequenced in clinical isolates.
From 23 isolates of Candida albicans, 20 isolates were fluconazole resistant. The MIC of fluconazole in these isolates was determined between 128 to 2048µg/ml. Also, sequencing analysis showed that 10 fluconazole resistant isolates had two missense mutations (D116E and E266D) in ERG11 gene.
In this study, resistance to high concentration of fluconazole shows that different mechanisms simultaneously implicated in developing azoles resistance in the isolates. Association of ERG11 gene mutation and deregulation of other genes can be led to resistance to high fluconazole concentration in this study.