Clinical Outcomes of Methicillin Resistant Staph Aureus (MRSA) Corneal Infections Resistant to Fourth Generation Fluoroquinolones

Abstract

Purpose: : To describe the incidence and clinical consequences of MRSA corneal infections with in vitro resistance to 4^th generation fluoroquinolones at a hospital–based multispecialty group practice.

Methods: : Retrospective case series of five consecutive MRSA corneal infections, four of which presented on therapy with fluoroquinolones.

Results: : All five cases were culture positive for MRSA and represented 13% of corneal culture specimens obtained during the same period. All of the MRSA–positive cultures were resistant to fluoroquinolones. The average patient age was 84.6 years with three of the patients being female. Four of five cases presented with corneal perforation. These four were on concurrent or recent topical corticosteroid therapy, with two requiring emergent tectonic surgery.

Conclusions: : The incidence of MRSA corneal infections are increasing similar to non–ophthalmic MRSA infections. MRSA are usually resistant to 4^th generation fluoroquinolones, which have become increasingly popular antibiotic in the practice of Ophthalmology. This case series reports on the severe consequences of MRSA corneal infections with in vitro resistance to 4^th generation fluoroquinolones, with concurrent corticosteroid use portending a poor prognosis. Ophthalmologists should be aware of the increasing problem with MRSA corneal infections, and the widespread resistance to the new 4^th generation fluoroquinolones.

Keywords: keratitis • bacterial disease • microbial pathogenesis: clinical studies