Endophthalmitis Induced by Chryseomonas indologen

Bacterial endophthalmitis is a rare ocular disease that often has a poor visual outcome. The investigators for the Endophthalmitis Vitrectomy Study have developed guidelines for treatment of patients with endophthalmitis in addition to reporting prognostic indicators. Although visual acuity at the time of evaluation was the best predictor of final visual outcome, microbiological factors seem to play an important predictive role.¹ Patients with endophthalmitis related to gram-negative organisms fared considerably worse compared with cases associated with gram-positive organisms.

We report a case of gram-negative endophthalmitis following cataract surgery induced by Chryseomonas indologen. To our knowledge, this description represents the first reported case of endophthalmitis caused by this organism.

A healthy 92-year-old white man underwent phacoemulsification of a cataract of the left eye, during which a dehiscence of the posterior capsule and posterior displacement of lens material occurred. An anterior vitrectomy was performed and a posterior chamber intraocular lens was placed in the ciliary sulcus. During rotation of the implant, it subluxed into the vitreous cavity. An anterior chamber intraocular lens was then inserted.

Though the patient experienced persistent intense pain and redness of the left eye that began the night of the surgery, he did not return for follow-up examination until 7 days later, when he was referred to the University of British Columbia Eye Care Center, Vancouver.

Examination disclosed a visual acuity of 20/30 OD and hand motions OS. The intraocular pressures were 20 mm Hg OD and 45 mm Hg OS. Slitlamp examination disclosed a markedly edematous left cornea with cells (4+) and flare in the anterior chamber with extensive fibrin and a layered hypopyon (Figure 1). Fundus examination revealed only a hazy red reflex.

The patient underwent an immediate anterior chamber and vitreous aspiration followed by an intravitreal injection of 1 mg of vancomycin (1 mg/0.1 mL), 2 mg of ceftazidime (2 mg/0.1 mL), and 1 mg of dexamethasone (1 mg/0.1 mL). Therapy was begun with acetazolamide, 250 mg once daily; 1% prednisolone acetate once daily; 0.5% timolol maleate twice daily; and ciprofloxacin drops hourly. Six hours later, the pain had largely subsided. The clinical appearance remained unchanged except for a reduction of the intraocular pressure to 25 mm Hg OS.

The vitreous specimen revealed gram-negative rods and polymorphonuclear cells (2+). The aqueous specimen contained polymorphonuclear cells (1+) but no organisms. Microbiological cultures subsequently grew Cindologen from both specimens.

One month later, the visual acuity had improved to 20/200 OS. The fibrin in the anterior chamber had largely resolved. The peripheral retina was visible but the presence of vitreous debris obscured a clear view of the macular region. No retinal necrosis was present. Ten weeks after the antibiotic injection, the visual acuity was 20/70 OS. Mild persistent corneal edema was noted. Results of a fundus examination were unremarkable.

Chryseomonas indologen is an aerobic motile gram-negative rod with a distinct yellow-orange pigment seen most commonly in petroleum-contaminated soils.²Chryseomonas is one of a few bacteria species that is capable of utilizing hydrocarbons as its sole source of carbon and energy. This group of organisms rarely causes systemic infections, and such cases are often related to the introduction of indwelling lines or prostheses.³ It morphologically resembles Pseudomonas species and was originally categorized in that genus. The 2 organisms are phylogenetically similar and share select common RNA sequences.⁴

While Pseudomonas infection is virulent and often devastating, Chryseomonas infection tends to take a more indolent course with less extensive inflammation and necrosis. To our knowledge, this is the first reported case of endophthalmitis caused by this rare organism. Of particular interest is the fact that our patient went untreated for 7 days but still recovered useful vision.

Corresponding author: Tom S. Chang, MD, FRCSC, Department of Ophthalmology, University of British Columbia, 2550 Willow St, Vancouver, BC, Canada V5Z 3N9.