A Tear-Based Approach for Rapid Identification of Bacterial Pathogens in Corneal Ulcers Using Nanopore Sequencing

Area of Science:

• Ophthalmology
• Microbiology
• Genomics

Background:

• Corneal ulcers are serious eye infections often requiring prompt diagnosis.
• Traditional methods for identifying bacterial pathogens, like corneal scraping and culture, can be invasive and time-consuming.

Purpose of the Study:

• To assess the efficacy of portable next-generation sequencing (NGS) directly on tear samples for identifying bacterial pathogens in corneal ulcers.

Main Methods:

• Prospective observational study involving tear sample collection using Schirmer strips from ulcerated and contralateral eyes.
• Polymerase chain reaction (PCR) amplification of the 16S rRNA gene from tear samples.
• Nanopore sequencing for bacterial species identification and taxonomic classification.

Main Results:

• Bacterial DNA was identified in 8 of 10 tear samples using the NGS method.
• Nanopore sequencing accurately identified causative bacteria in culture-confirmed cases and detected pathogens in ulcers without bacterial growth on culture.
• Tear sequencing successfully identified bacterial species in cases where corneal cultures were not feasible.

Conclusions:

• PCR amplification of 16S rRNA from tears followed by Nanopore sequencing is an effective, non-invasive diagnostic method for bacterial corneal ulcers.
• This tear-based approach provides non-inferior results compared to traditional culture methods.
• The method improves diagnostic timing and accuracy, enabling earlier targeted antimicrobial therapy and potentially better patient outcomes.