A rare case of keratitis due to co-infection with Plectosphaerella cucumerina and Acanthamoeba T5 genotype

Abstract

Aims: This report summarizes clinical findings, diagnosis, management, and long term outcomes of a recalcitrant Plectosphaerella and Acanthamoeba keratitis. Methods and materials: An otherwise healthy male patient presented with a corneal infiltrate with predominantly fungal characteristics, but atypical in terms of progression. The infiltrate remained undiagnosed even after several scrapings, and aqueous tap cultures. Since conventional therapy with antifungals and intrastromal voriconazole injections was ineffective, a therapeutic keratoplasty was done. Results: The excised corneal button was cultured; molecular identification of the Acanthamoeba and fungus isolates revealed the rare T5 genotype and the even rarer Plectosphaerella cucumerina. Judicious use of antifungals and anti-amoebic drops in the post-operative period, combined with gradual introduction of steroids resulted in favourable visual outcome. Conclusions: The T5 is the second most frequent environmental Acanthamoeba, but rarely isolated clinically. Plectosphaerella keratitis has been reported only 4 times in the literature. Neither of these have been previously reported from India.

Keywords

• Keratitis
• Acanthamoeba
• Plectosphaerella
• Co-infection
• Genotype T5