A case of Beauveria bassiana keratitis confirmed by internal transcribed spacer and LSU rDNA D1–D2 sequencing

Abstract

We describe a case of fungal keratitis due to Beauveria bassiana in a farmer with Fuchs' dystrophy, treated with amphotericin B. Surgery with penetrating keratoplasty was necessary to resolve the lesions. Susceptibility testing and molecular sequencing permitted the identification and treatment of this rare aetiological agent of invasive fungal disease.

Filamentous fungal infections of the cornea: a global overview of epidemiology and drug sensitivity

“…The generally applied strategy of sequence‐based molecular identification is the amplification of a fragment from a specific locus by polymerase chain reaction (PCR), followed by sequence determination and analysis of the resulting sequence with a nucleotide–nucleotide BLAST (Basic Local Alignment Search Tool) search in the nucleotide sequence collection of the National Center for Biotechnology Information (NCBI). The application of this approach resulted in the diagnosis of several keratitis cases caused by uncommon filamentous fungal agents, many of them previously unreported from corneal infections (Table ) . These included Lagenidium and Pythium species from the Oomycota division, a series of species from the Botryosphaeriales , Capnodiales , Diaporthales , Eurotiales , Glomerellales , Hypocreales , Microascales , Pleosporales , Sordariales and Xilariales orders of the Ascomycota division, as well as Schizophyllum commune from Basidiomycota .…”

Fungal Keratitis Due to Beauveria bassiana in a Contact Lenses Wearer and Review of Published Reports

“…As in the case reported, antifungal therapy requires adjunct debridement surgery to treat the lesions [1,6,10]. However, topical and systemic antifungal therapy has been reported to be effective in some cases, especially if it includes natamycin [7] and azoles (voriconazole, itraconazole) [8].…”

“…On the microscope, they present septate hyphae, short spherical conidia and long, zig-zag-arranged, curved conidiogenous cells distributed in whorls [13]. However, generally, the species can only be identified using molecular biology techniques [1]. In all reports reviewed, microbiological diagnosis was performed by culture methods, using macroscopic and microscopic characteristics of fungus colonies for species identification and also in six most recent reports the diagnosis was confirmed by molecular techniques.…”

“…It primarily affects agriculture workers and risk factors include allergic conjunctivitis, previous eye surgery, previous treatment with corticosteroids and wide-spectrum antimicrobial agents and using contact lenses [1]. In 40-60 % of cases, fungal infection occurs secondary to corneal trauma involving organic material (vegetal or animal), which is usually the only predisposing factor.…”

“…Since it is an entomopathogenic fungus, it is used as insecticide and rarely causes infections in humans [3]. B. bassiana has been isolated in opportunistic lung and tissue infections in immunocompromised patients [3][4][5] and in a few patients with torpid keratitis secondary to eye surgery, ocular trauma or the use of contact lenses [1,[6][7][8]. We report the case of a patient with keratitis due to B. bassiana diagnosed by microbiological analysis of corneal scrape, which responded to topical and systemic treatment with antifungal agents plus debridement surgery.…”