Armaghane Danesh Bimonthly Journal (Mar 2022)
Evaluation of Drug Susceptibility of Aspergillus Species Isolated from Patients with Otomycosis in Vitro
Abstract
Background & aim: Atomycosis is an acute, subacute and chronic fungal infection of the external auditory canal. The most common known fungi that cause atomycosis are Aspergillus and Candida species. Incidence and report of resistance to antifungal drugs in Aspergillus and Candida fungi with increasing long-term use of antifungal drugs, access to standard diagnostic allergy tests has increased. Therefore, the aim of the present study was to determine and evaluate the drug susceptibility of Aspergillus species isolated from patients with otomycosis referred to Shahid Mofatteh Clinic in Yasuj in laboratory conditions. Methods: In the present experimental study conducted in 2018, 160 clinical isolates of Aspergillus, including 60 strains of Aspergillus flavus, 53 strains of Aspergillus tubingensis, 43 strains of Aspergillus niger, 3 strains of Aspergillus treus and 1 isolated strain of Aspergillus fumigaranus, with otomycosis was cultured on PDA medium and drug susceptibility for amphotericin B, itraconazole, vriconazole and clotrimazole was determined according to CLSI M38A2 instructions. Based on this, using microdilution broth method, different drug dilutions were prepared and added to standard fungal suspensions. The collected data were analyzed using Excel 2016 software. Results: MIC50 and MIC90 of amphotericin B, itraconazole, vriconazole and clotrimazole for Aspergillus flavus strains (1 and 2, 0.0156 and 0.025, 0.125 and 0.25, 0.25 and 1, respectively), Aspergillus niger (2 and 4, 0.025 and 0.25, 0.125 and 0.25, 0.5 and 1) and Aspergillus tubinogenesis (2 and 4, 0.125 and 0.5, 0.25 and 0.25, 1 and 1) micrograms per milliliter. All strains of Aspergillus were sensitive to itraconazole and vriconazole. Conclusion: The laboratory data obtained from the present study indicated that itraconazole had the best antifungal effect against Aspergillus strains, followed by vriconazole, clotrimazole and amphotericin, respectively. Itraconazole and vriconazole appeared to be suitable drugs in the treatment of infections associated with Aspergillus species isolated from atomycosis.
