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2026 OMIG Abstract

Metagenomic Deep Sequencing Reveals a Balanced Distribution of Fungal and Bacterial Pathogens in Infectious Keratitis in Guatemala

Mario R. Papa¹, Santiago Y. Melgar¹, Mariano Y. Melgar¹, Kelly Ngo², Danny Yu², Thomas Abraham², YuHeng Liu², Armin Hinterwirth², Thuy Doan^2,3, and Gerami D. Seitzman^2,3 for the capriCORN Study Group

¹Visualiza Eye Care System, Guatemala City, Guatemala; ²Francis I. Proctor Foundation, San Francisco, California; ³Department of Ophthalmology, University of California, San Francisco, San Francsico, California

Purpose: Little is known about the microbial etiologies of infectious keratitis in Guatemala, a country with one of the highest rates of blindness in Latin America. We sought to characterize the microbial etiologies of infectious keratitis using metagenomic deep sequencing (MDS).

Methods: Patients with presumed infectious keratitis presenting to a tertiary referral center in Guatemala between January 2023 and March 2025 were prospectively enrolled. Corneal specimens underwent conventional microbiologic testing, when available, and MDS. Demographic, clinical, and microbiologic findings were summarized descriptively.

Results: Forty-eight patients were enrolled. Conventional microbiologic testing (smear and/or culture) was performed in 16/48 (33%) patients, with 10/16 (63%) yielding positive results. MDS was performed on all specimens, and at least one presumed pathogen was identified in 39/48 (81%). Among MDS-positive cases, fungi were identified in 19/39 (49%), bacteria in 17/39 (44%), and viruses in 4/39 (10%). No parasitic pathogens were detected. Fusarium spp. accounted for 18/20 (90%) of the fungal organisms detected. In contrast, bacterial keratitis was associated with a broader range of organisms, with Pseudomonas aeruginosa representing the most frequently identified bacterial pathogen (6/19 [32%]). Polymicrobial infections were identified in 4/48 (8%) patients.

Conclusions: MDS enabled an unbiased characterization of infectious keratitis pathogens in Guatemala and demonstrated a high pathogen detection rate. The balanced distribution of fungal and bacterial pathogens highlights the importance of regional pathogen surveillance to guide empiric antimicrobial therapy.