Alterations in the Ocular Surface Fungal Microbiome in Fungal Keratitis Patients

Area of Science:

• Ophthalmology
• Microbiology
• Genomics

Background:

• Keratitis is an inflammatory eye disease with a significant global impact, potentially leading to blindness.
• Microbial infections, including fungal pathogens, are a primary cause of keratitis.
• Understanding the ocular surface microbiome is crucial for diagnosing and managing fungal keratitis.

Purpose of the Study:

• To compare the fungal microbiome of the ocular surface in healthy individuals versus those with fungal keratitis.
• To identify alterations in fungal diversity and abundance associated with fungal keratitis.
• To establish the first report of fungal microbiome dysbiosis in conjunctival swabs and corneal scrapings from fungal keratitis patients.

Main Methods:

• Fungal DNA was extracted from conjunctival swabs (healthy and keratitis) and corneal scrapings (keratitis).
• The ITS2 region was amplified and sequenced using Illumina MiSeq (2x250 bp paired-end).
• Bioinformatic analyses included Alpha diversity, phylum/genera level comparisons, and heat mapping to assess microbiome structure.

Main Results:

• Fungal microbiomes from individuals with fungal keratitis showed significant dysbiosis compared to healthy controls.
• Alterations in fungal diversity and abundance were observed in both conjunctival swabs and corneal scrapings of keratitis patients.
• A core ocular microbiome comprising 11 genera was identified across most eyes.

Conclusions:

• Fungal keratitis is associated with dysbiosis of the ocular surface fungal microbiome.
• This study provides the first evidence of fungal microbiome dysbiosis in both conjunctival swabs and corneal scrapings in fungal keratitis.
• Identifying these microbial shifts may offer new diagnostic or therapeutic targets for fungal keratitis.