Postvitrectomy endophthalmitis caused by Morganella morganii: a case report and literature review

Abstract

Background: Postvitrectomy endophthalmitis is a rare and serious complication following vitreoretinal surgeries. Morganella morganii, an emerging gram-negative, facultative anaerobic rod, is related to severe nosocomial infections in various organs and thus has gained importance in recent decades. Morganella morganii infection following intraocular surgery is rarely reported. Case presentation: We report an immunocompetent patient with Morganella morganii-related endophthalmitis after vitrectomy for retinal detachment who presented with hand motion visual acuity, hypopyon and a unique retrolental exudative membrane. Initially, the patient was unresponsive to empirical intravitreal ceftazidime and vancomycin but recovered with vision preservation (20/63) after surgical removal of the membrane and silicone oil tamponade. Conclusions: Morganella morganii intraocular infection is often devastating, likely due to its high multidrug-resistance rate via intrinsic ß-lactamase production, multiple acquired traits related to additional genetic mechanisms, and fimbrial adhesion, urease production, and type III secretion system-associated biofilm formation. The above characteristics of M. morganii may lead to an inadequate response to empirical intravitreal antibiotics, and early surgical intervention should be considered.