Molecular Detection of (ERG11 and CDR1) Genes and Evaluation of Alternative Therapeutic Agents against Candida Species Isolated from Otomycosis Patients

Abstract

Objectives: Antifungal resistance among Candida species has become a major clinical challenge worldwide, particularly in patients with recurrent or progressive otomycosis. This growing problem highlights the need to explore new therapeutic strategies and alternative treatment options.
Aim: Detection of resistance genes in Candida species isolated from otomycosis patients in Basra Governorate hospitals and evaluation of some alternative treatments for antifungal-resistant isolates.
Method: A total of 114 ear swab samples were collected from patients diagnosed with otomycosis. Candida isolates were identified using conventional phenotypic methods and confirmed by sequencing of the ITS1-5.8S-ITS2 region. Antifungal susceptibility testing was performed using the VITEK® 2 Compact System, while the antifungal activity of selected non-specific antiseptic agents was evaluated by the agar well diffusion method. The CDR1 and ERG11 resistance genes were detected by conventional PCR to determine their prevalence among the isolates.
Results: Females were more affected (54.38%) than males (45.61%), with the highest infection rate observed in the 31-40 years age group (20.2%). Four nonspecific topical antifungal agents for the ear, 7.5% povidone iodine, 3% hydrogen peroxide, 2% acetic acid and 70% isopropyl alcohol showed the strongest inhibitory activity against Candida species isolates, The VITEK® 2 system evaluated variable susceptibility profiles among the isolates. Molecular identification revealed that Candida albicans (36.8%) was the most prevalent species, followed by Candida parapsilosis (26.3%), Candida glabrata (14.0%), and Candida tropicalis (12.4%), while Candida krusei showed the lowest prevalence (10.5%). PCR amplification revealed that the prevalence of the CDR1 and ERG11 resistance genes among the Candida species was 67.5% and 75.4%, respectively.
Conclusions: A high prevalence of the CDR1 and ERG11 resistance genes was observed among Candida species isolated from otomycosis patients. The evaluated topical antiseptic agents exhibited promising antifungal activity and may serve as effective alternative therapies, contributing to yeast growth control and reducing the risk of antifungal resistance development.