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Updated: Aug 16, 2026
Candida albicans Biofilm Development on Medically-relevant Foreign Bodies in a Mouse Subcutaneous Model Followed by Bioluminescence Imaging
Published on: January 27, 2015
Contact lens-induced infection--a new model of Candida albicans keratitis
D M O'Day1, W S Head, R D Robinson
1Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
Purpose:
A model of experimental keratomycosis was established that mimics human disease in which the only fungi present are those that are actively growing within the cornea.
Methods:
Dutch-belted rabbits received a subconjunctival injection of triamcinolone acetonide to one eye. One day later the epithelium was removed from the central cornea and a standardized inoculum of Candida albicans blastoconidia was placed on the corneal surface and covered with a contact lens. The lids were closed with a lateral tarsorrhaphy. After 24 hours, the lid sutures and contact lens were removed. Five days later the animals were killed, and their corneas were subjected to separate isolate recovery and histology studies. A group of similarly infected rabbits without corticosteroid injection served as controls.
Results:
Both groups developed invasive corneal disease. Although isolate recovery was not significantly different from corticosteroid-treated rabbits compared with controls, fungal biomass was increased. Hyphal invasion was limited to the anterior cornea in control eyes, but penetrated deep stroma in most of the corticosteroid-treated rabbits.
Conclusions:
Invasive corneal disease can be established with a surface inoculum. Corticosteroid administration increased corneal penetration of hyphae. Quantitative isolate recovery is not a reliable measure of the fungal load within the cornea.
Insights
This study developed an experimental keratomycosis model in rabbits. Corticosteroids increased fungal hyphae penetration into the deep cornea, indicating enhanced invasive disease.
Area of Science:
- Ophthalmology
- Mycology
- Infectious Diseases
Background:
- Experimental models are crucial for understanding corneal fungal infections (keratomycosis).
- Investigating the role of corticosteroids in modulating the host-pathogen interaction in keratomycosis is essential.
Purpose of the Study:
- To establish an experimental keratomycosis model in rabbits that accurately mimics human disease.
- To evaluate the impact of corticosteroid administration on the progression and severity of experimental keratomycosis.
Main Methods:
- A rabbit model of keratomycosis was created using Candida albicans.
- Subconjunctival corticosteroid injection (triamcinolone acetonide) was administered to one eye.
- Corneal fungal invasion and fungal load were assessed via histology and isolate recovery.
Main Results:
- Both corticosteroid-treated and control rabbits developed invasive corneal disease.
- Corticosteroid administration led to increased fungal biomass and deeper stromal penetration of hyphae.
- Quantitative fungal isolate recovery did not significantly differ between groups, suggesting limitations in measuring fungal load.
Conclusions:
- A surface inoculum can effectively establish invasive keratomycosis in an experimental model.
- Corticosteroids exacerbate keratomycosis by promoting deeper corneal invasion of fungal hyphae.
- Quantitative isolate recovery is an unreliable metric for assessing fungal burden in experimental keratomycosis.
