# Listeria monocytogenes Endophthalmitis—Good Outcome With Rapid Diagnosis Using MALDI-TOF and Treatment With Benzylpenicillin and Trimethoprim–Sulfamethoxazole

## TL;DR

A case of Listeria monocytogenes endophthalmitis was rapidly diagnosed and successfully treated with a combination of antibiotics, preserving most vision.

## Contribution

Demonstrates the effectiveness of dual antibiotic therapy and rapid MALDI-TOF diagnosis in treating Listeria endophthalmitis.

## Key findings

- Rapid diagnosis via MALDI-TOF led to timely treatment initiation.
- Combination therapy with benzylpenicillin and trimethoprim–sulfamethoxazole preserved visual acuity.
- Endogenous seeding from gastrointestinal infection was confirmed as the source.

## Abstract

Purpose: Describe a case of rapidly diagnosed Listeria monocytogenes endophthalmitis, with a clearly established route of endogenous seeding, treated with dual antibiotics, with outcomes better than many reported.

Observations: A 79-year-old male developed Listeria monocytogenes endophthalmitis after a gastrointestinal infection with an associated bacteraemia. Rapid microbiologic diagnosis was obtained via matrix assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF). The case was managed with 3 weeks of benzylpenicillin and 6 weeks of trimethoprim–sulfamethoxazole. Visual acuity in the affected eye was preserved with a mild to moderate residual deficit.

Conclusion: Clinicians should be aware of the potential for Listeria monocytogenes endophthalmitis associated with preceding gastrointestinal symptoms. Better outcomes are associated with rapid diagnosis, and the use of dual antimicrobial therapy should be considered.