Role of ERG3 mutation and expression in azole resistant Candida albicans isolated from vulvovaginal candidiasis patients

TL;DR

The study found that azole-resistant Candida albicans isolates have lower ERG3 gene expression and synonymous mutations.

Contribution

The study identifies synonymous mutations and reduced ERG3 expression in azole-resistant Candida albicans isolates.

Findings

Six synonymous mutations in the ERG3 gene were found in azole-resistant isolates.

ERG3 mRNA expression was significantly lower in azole-resistant Candida albicans strains.

High resistance rates to multiple azoles were observed among Candida albicans isolates.

Abstract

The study aimed to investigate mutations and mRNA expression of the ERG3 gene in resistant Candida albicans isolates.

This cross-sectional study was conducted from October 2018 to June 2019. High vaginal swab samples were collected from Hayatabad Medical Complex and transported to Khyber Medical University. Samples were inoculated on different media and identified by 20C AUX strips. Antifungal susceptibility was determined using the disc diffusion and broth microdilution methods. The ERG3 gene was amplified and sequenced to find amino acid polymorphisms. Real-time PCR was performed to study level of ERG3 expression.

A total of seventy-three (n=73) Candida albicans out of 369 samples were isolated. Among the isolates 49.3%, 54.8%, 53.4%, 47.9%, 30.1% were resistant to fluconazole, Clotrimazole, Miconazole, Voriconazole and Itraconazole, respectively. Sanger sequencing of ERG3 gene of isolates revealed six synonymous mutations. Expression level of mRNA of ERG3 gene in azoles sensitive stains (3.72±2.22) was higher than those in the resistant Candida albican strains (1.74±0.96).

This study revealed synonymous mutations and low expression of ERG3 gene in azole-resistant C. albican.

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