Xanthomonas maltophilia endophthalmitis after cataract surgery.

Xanthomonas maltophilia, previously known as Pseudomonas maltophilia and Stenotrophomonas maltophilia, is a gram-negative motile bacillus that can be isolated from human, animal, and environmental sources. It may cause potentially lifethreatening opportunistic systemic infections. Most isolates demonstrate multidrug resistance, making it a highly virulent organism. Postoperative endophthalmitis caused by X maltophilia is rare. To date, only 2 case reports have been published. We describe 4 additional patients with postoperative X maltophilia endophthalmitis treated between January 1, 1996, and March 31, 1999, at the Bascom Palmer Eye Institute, Miami, Fla (Table 1). Report of Cases. Case 1. An 80year-old woman was evaluated for increasing pain and decreased vision in the left eye, 2 weeks after uneventful clear-corneal phacoemulsification and posterior chamber intraocular lens (IOL) insertion. Her medical history was unremarkable. Visual acuity in the affected eye was hand movements. Clinical findings included a 5% hypopyon and marked vitritis. Vitreous tap was performed through the pars plana, and the patient was given intravitreal injections of ceftazidime, 2.25 mg; vancomycin hydrochloride, 1.0 mg; and dexamethasone sodium phosphate, 0.4 mg. On the first day after the initial treatment, a combined regimen was started with topical fortified ceftazidime, vancomycin, and 1% prednisolone acetate, every hour, and 1% atropine sulfate, 3 times daily. No systemic antibiotic therapy was used. Gram stain of the vitreous aspirate revealed many neutrophils, but no organisms were identified. Three days later, X maltophilia was isolated from the culture that was resistant to ceftazidime but sensitive to amikacin sulfate (Table 2). However, her clinical condition continued to improve, with resolution of the hypopyon; visual acuity returned to 20/50 OS. A small amount of retained lens cortex was noted at the 6-o’clock position. Gradual tapering of topical medications was begun. Three weeks after the initial treatment, she returned with visual acuity in the left eye of light perception and recurrent hypopyon. Vitreous tap was performed and intravitreal injections of amikacin sulfate, 0.4 mg, and dexamethasone sodium phosphate, 0.4 mg, were given. Cultures of the vitreous aspirate were again positive for X maltophilia. During the next 48 hours, she developed worsening intraocular inflammation; the visual acuity remained light perception. Pars plana vitrectomy was performed and intravitreal injections of amikacin sulfate, 0.4