Beauveria bassiana keratitis in bullous keratopathy: antifungal sensitivity testing and management

Abstract

Purpose: Beauveria bassiana is a ubiquitous fungus available as an insecticide. In humans, it has limited virulence; to our knowledge, only 3 cases of invasive disease and 10 cases of keratitis have been documented.

Methods and results: We report the first case of B bassiana keratitis in a patient with aphakic bullous keratopathy. The fungal keratitis proved to be highly resistant to topical clotrimazole. Molecular identification was based on DNA sequence analysis. The minimal inhibitory concentrations (MIC) obtained were 2 µg/mL for voriconazole, 0.250 µg/mL for posaconazole, and >128 µg/mL for fluconazole; amphotericin B MIC was >16 µg/mL. In the absence of clinical improvement, a penetrating keratoplasty (PK) was performed. The patient was discharged on topical and systemic voriconazole and prednisolone 40 mg PO/day. The eye remained calm with a transparent cornea and clear anterior chamber.

Conclusions: B bassiana keratitis is extremely rare, with only a few cases reported. Its risk factors are unknown. We report the first case in a patient with aphakic bullous keratopathy, which proved highly resistant to antifungal therapy (antifungal susceptibility results are presented). A PK was necessary for clinical improvement. A review of the literature is performed in an effort to define therapeutic strategies.