Diagnosis of Fusarium keratitis in an animal model using the polymerase chain reaction
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, Connecticut, USA
- Peter Gloor, MD, Department of Ophthalmology and Visual Science, Yale University School of Medicine, PO Box 208061, New Haven, CT 06520–8061, USA.
- Accepted 29 September 1997
Abstract
AIMS/BACKGROUND The purpose of this study was apply the polymerase chain reaction (PCR) to develop a sensitive, specific, and rapid test to diagnose Fusarium keratitis.Fusarium is the most common cause of fungal corneal infection in some parts of the world. It is often difficult to establish that a keratitis is due to fungal infection.
METHODS Fusarium solanikeratitis was induced in three eyes of three rabbits by injection of a suspension of the fungus into the anterior corneal stroma. In one rabbit the contralateral eye served as a control. From four to 28 days after inoculation, the corneas were scraped for culture, then scraped and swabbed for PCR analysis. The PCR was performed with primers directed against a portion of the Fusarium cutinase gene, and the presence or absence of this amplified target sequence was determined by agarose gel.
RESULTS The amplified DNA sequence was detected in 25 of 28 samples from the corneas infected with Fusarium, for a sensitivity of 89%. Only three of the 14 samples from these eyes with Fusarium keratitis were positive by culture, for a sensitivity of 21%. Seven of eight control samples were negative by the PCR based test, for a specificity of 88%.
CONCLUSION This PCR based test holds promise of being an effective method of diagnosing Fusarium keratitis as well as Fusarium infections at other sites.
Footnotes
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↵Current address: Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, FL 33101, USA.
