Rhizobium radiobacter: A Recently Recognized Cause of Bacterial Keratitis

Abstract

Purpose: To present the first reported cases of keratitis caused by Rhizobium radiobacter. Methods: A retrospective review of an observational case series from 2 institutions. Results: There were 4 cases of microbiologically proven R. radiobacter. Three of these patients were contact lens wearers. The patient in case 4 defaulted from follow-up after receipt of the culture result. Keratitis in the other cases resolved with variable clinical courses once culture-directed therapy was instituted. Conclusions: R. radiobacter is a member of the genus Rhizobium. It is a gram-negative bacillus and was previously identified as an opportunistic pathogen in nonophthalmic infections and in a few cases of endophthalmitis. To our knowledge, we have described the clinical presentation, management, and treatment outcomes of the first reported cases of keratitis caused by R. radiobacter.