Phase-dependent differential in vitro and ex vivo susceptibility of Aspergillus flavus and Fusarium keratoplasticum to azole antifungals

Fungal keratitis (FK) is an invasive infection of the cornea primarily associated with Aspergillus and Fusarium species. FK is treated empirically with a limited selection of topical antifungals with varying levels of success. Though clinical infections are typically characterized by a dense network of mature mycelium, traditional models used to test antifungal susceptibility of FK isolates exclusively evaluate susceptibility in fungal cultures derived from asexual spores known as conidia. The purpose of this study was to characterize differences in fungal response when topical antifungal treatment is initiated at progressive phases of fungal development. We compared efficacy of voriconazole and luliconazole against in vitro cultures of A. flavus and F. keratoplasticum at 0, 24, and 48 h of fungal development. Data from this assay is included here, reported as end-point absorbance values. A porcine cadaver corneal model was used to compare antifungal efficacy of voriconazole and luliconazole in ex vivo tissue cultures of A. flavus and F. keratoplasticum at 0, 24, and 48 h of fungal development. Data from this assay may be found here, reported as pixel counts of the determined area.

Methods
In vitro absorbance: Absorbance at 490 nm was measured following assay conclusion (Sunrise Microplate Reader, Tecan Group Ltd, Switzerland). A sample size of three wells (n=3) was included for each fungal/drug combination. Raw absorbance per well is reported. 

Ex vivo corneal coverage: Corneas were photographed following assay conclusion (Nikon D200, AF-S FX Micro NIKKOR 105mm 1:2.8G ED Lens). Images were analyzed using ImageJ software to outline the total area/cornea and the affected area/cornea in pixels. Raw total and affected areas/cornea are reported alongside the proportion of affected to total area.