Abstract
Abstract: :
Purpose: To establish a murine model of corneal candidiasis that permits molecular evaluation of pathogenic mechanisms of ocular fungal infection. Methods: Immunocompetent and immunosuppressed adult NIH Swiss and BALB/c mice were inoculated with 102 to 106 colony forming units (cfu) of Candida albicans following corneal scarification. Mock-inoculated animals served as controls. Mice were scored daily for corneal involvement. At various time-points post-inoculated eyes were enucleated and examined histologically, or analyzed for infectious organisms by microbial culturing and fungal DNA by PCR. Results: Ocular involvement was observed to be dose-dependent with 104 cfu or more being required to initiate a measurable infection, and with a consistent infection being achieved using greater than or equal to 106 cfu. Immunosuppression with either methyprednisolone or cyclophosphamide increased the susceptibility of the animals. Organisms and infiltration were histologically evident within ocular tissue, infectious organisms were recovered by culture, and candidal DNA was detectable by PCR. Conclusions: Although mice are innately resistant to Candida infection following corneal inoculation, moderate to severe keratomycosis can be established in the immunocompromised mice by the route of corneal scarification. Our findings support the potential use of mice as a model system for fungal infections of the eye.
Keywords: 316 animal model • 414 fungal disease • 469 microbial pathogenesis: experimental studies