Rare fungal keratitis caused by plant pathogens: report of two cases and review of the literature.

Abstract

Macrophomina phaseolina and Colletotrichum fructicola are notable plant pathogens, yet cases of keratitis from these fungi are rarely reported. Limited awareness of this keratitis etiology among ophthalmic professionals reduces the likelihood of accurate diagnosis and timely treatment. This report aims to improve the understanding of these rare infections in eye care. We present two cases of keratitis: one caused by M. phaseolina and another by C. fructicola, both of whom experienced a complicated treatment course. Traditional fungal exams yielded negative results, which limited disease identification and focused therapy. To determine the cause, we used metagenomic next-generation sequencing (mNGS) on clinical samples obtained from corneal scrapings. The mNGS report was received during therapy and quickly identified the pathogen. Based on this, we looked for treatment regimens for this kind of infection in previous literature, altered and implemented appropriate antifungal drug therapy, and the patient's condition improved. We review the literature from 1970 to 2025 on M. phaseolina and Colletotrichum spp. keratitis. We identified 10 cases of M. phaseolina keratitis from four studies and 72 cases of Colletotrichum spp. keratitis, including five of C. fructicola, in 43 articles. Misdiagnosis was common due to limited clinical and microbiologic suspicion. The rise of infections by rare pathogens highlights diagnostic challenges. Traditional methods often delay accurate diagnosis, while mNGS enables rapid identification of pathogen, crucial for effective treatment and vision preservation.