Role Of Azole Resistance Gene Expression In Aspergillus Fumigatus Associated Fungal Keratitis.
Published 2025 - 43rd Congress of the ESCRS
Reference: FP23.06 | Type: Free paper | DOI: 10.82333/9thy-7793
Authors: Matthew Rauen* 1 , Hillery Joiner 1 , Robyn Kohler 1 , Sara O'Connor 2
1Anterior Segment Surgery,Wolfe Eye Clinic,West Des Moines, Iowa,United States, 2O'Connor Consulting Services,Charleston, West Virginia,United States
Purpose
To study the effect of voriconazole on selected azole resistance gene expression in Aspergillus fumigatus associated fungal keratitis.
Setting
Tertiary eye care center of eastern India
Methods
Culture positive Aspergillus keratitis were selected for this study. Antifungal susceptibility and MICs were recorded against voriconazole. Three doses of below MICs (1mg, 0.5mg, 0.25mg and 0.12mg) were applied on Aspergillus fumigatus and sub cultured. In every subculture azole resistance gene expression (Cyp51, L98H, T289A, Y121F) were studied. After 8th generation the same fungal species was sub cultured again without any azole exposure. In every batch gene expression was measured.
Results
Initially invivo no azole resistance found with the selective fungi. From 7th generation all suboptimal doses of voriconazole showed the expression of azole resistance genes (Ct value range 18-32 in qPCR). This gene expression came back to normal pattern from 5th generation in higher doses when azole exposure stopped but slight azole resistance gene expressions still found for lower suboptimal doses (0.25mg & 0.12mg) where no azole was added invitro upto 7th generation (Ct value range 28-30 in qPCR) .
Conclusions
Continuous exposure of suboptimal doses of azole can give rise the azole resistance. In community azole resistance among Aspergillus is uncommon. Before giving azole in fungal keratitis as treatment Screening of azole resistance is an important approach to initiate antifungal medications.