Genotyping of Candida albicans and Comparison of its Antifungal Resistance Pattern in the South Indian Region

Abstract

Recent studies have documented an increase in the incidence of antifungal resistance in newly emerging species closely related to C. albicans, and the coexistence of genotypic variants. Hence, an application of PCR-based molecular typing is crucial in identifying these fungi. Our study used molecular methods to characterize the latest genotypic subgroups of C. albicans and analysed if there was a relationship between the genotypes and the antifungal resistance pattern. The study was conducted in JSS Hospital, Mysuru, Karnataka between July 2018 and December 2020. A total of 1427 Candida species were isolated from clinical samples. Candida albicans were isolated and confirmed using Germ tube test, ID VITEK 2 and PCR (ITS primer). DNA extraction was done using the Hi-Media Yeast DNA Extraction Kit. The amplified products were analysed using Agarose gel electrophoresis (2%). Among 1427 Candida species, 282 were Candida albicans. The following resistance was exhibited to major antifungals – Caspofungin (3.5%), Amphotericin B (1.4%), flucytosine (2.8%) Fluconazole (6%) Micafungin (2.8%) Voriconazole (3.1%) and all were sensitive to miconazole. ABC genotyping showed Genotype A (450 bp) predominant (87.58%) followed by genotype B (840bp) (9.92 %) and genotype C (450bp and 840 bp) (0.2%). Genotype D and E were not observed. Our study showed the growing antifungal resistance in clinical isolates. Genotype A was predominant in South Karnataka region followed by Genotype B and C. There was no correlation between genotyping and antifungal resistance. However, a study with greater number of samples from diverse geographical locations may give more insight.

Keywords

• antifungal susceptibility
• clinical isolates
• candida albicans
• genotype a
• genotype b
• genotype c
• genotyping
• karnataka
• south indian region