Fungal keratitis caused by Coniochaeta mutabilis-A case report

Jadesola Oremosu; Lawson Ung; James Chodosh; Connie Cañete-Gibas; Nathan P Wiederhold; Emma C Davies; Paulo J M Bispo

doi:10.1016/j.mycmed.2023.101384

Fungal keratitis caused by Coniochaeta mutabilis-A case report

J Mycol Med. 2023 May;33(2):101384. doi: 10.1016/j.mycmed.2023.101384. Epub 2023 Mar 29.

Authors

Jadesola Oremosu¹, Lawson Ung², James Chodosh³, Connie Cañete-Gibas⁴, Nathan P Wiederhold⁴, Emma C Davies⁵, Paulo J M Bispo⁶

Affiliations

¹ Tulane University School of Medicine, New Orleans, LA, USA; Summer Scholars Program, Department of Ophthalmology, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, USA.
² Department of Ophthalmology, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, USA; Infectious Disease Institute, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, USA; Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA, USA.
³ Department of Ophthalmology and Visual Sciences, University of New Mexico School of Medicine, Albuquerque, NM, USA.
⁴ Fungus Testing Laboratory, University of Texas Health Science Center, San Antonio, TX, USA.
⁵ Department of Ophthalmology, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, USA. Electronic address: emma_davies@meei.harvard.edu.
⁶ Department of Ophthalmology, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, USA; Infectious Disease Institute, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, USA. Electronic address: paulo_bispo@meei.harvard.edu.

PMID: 37012189
DOI: 10.1016/j.mycmed.2023.101384

Abstract

We present a rare case of recalcitrant fungal keratitis caused by Coniochaeta mutabilis, successfully managed with a course of oral, topical, intrastromal, and intracameral antifungals. A 57-year-old male on their fourth week of treatment for presumed left herpes simplex keratitis presented to clinic with severe left-sided foreign body sensation after gardening in his yard. On examination, a white corneal plaque was observed at 8 o'clock, shown to be a dense collection of fungal hyphae on confocal microscopy. Corneal cultures revealed yeast-like cells, initially identified as Kabatiella zeae by matching 100% identity with K. zeae strains CBS 767.71 and CBS 265.32 in BLASTn search using the internal transcribed spacer (ITS) sequence. Treated for over four months with topical amphotericin B and oral voriconazole without improvement, recourse to intrastromal and intracameral amphotericin B injections, coupled with the application of cyanoacrylate glue to the lesion and a bandage contact lens, led to eventual resolution. The patient subsequently underwent cataract surgery, achieving a BCVA of 20/20 in the eye. Surprisingly, upon further sequence analyses of combined ITS and large subunit ribosomal ribonucleic acid (LSU) and investigation of the K. zeae German strain CBS 767.71, the organism was revealed to be Coniochaeta mutabilis (formerly Lecythospora mutabilis). This means that the correct name for CBS 767.71 and CBS 265.32 is C. mutabilis and should be corrected in the GenBank record to avoid misleading identification in the future. This case also underscores the urgent unmet need for improved molecular diagnostic modalities in the care of corneal infections.

Keywords: Coniochaeta mutabilis; Fungal keratitis; Intrastromal injections; Kabatiella zeae; Lecythospora mutabilis.

Publication types

Case Reports

MeSH terms

Amphotericin B / therapeutic use
Antifungal Agents / therapeutic use
Corneal Ulcer*
Eye Infections, Fungal* / diagnosis
Eye Infections, Fungal* / drug therapy
Eye Infections, Fungal* / microbiology
Humans
Keratitis* / diagnosis
Keratitis* / drug therapy
Keratitis* / microbiology
Male
Middle Aged
Voriconazole / therapeutic use

Substances

Amphotericin B
Antifungal Agents
Voriconazole

Supplementary concepts

Coniochaeta mutabilis