Sir,

Acute-onset postoperative endophthalmitis occurring 2–7 days after surgery is often caused by Staphylococcus epidermidis, Staphylococcus aureus, and Gram-negative bacilli.1 Alcaligenes faecalis, a Gram-negative rod, has been reported as a cause of bacterial keratitis, but there has been no documented report of postcataract surgery of endophthalmitis caused by A. faecalis.

Phacoemulsification via scleral tunnel with posterior chamber intraocular lens was performed in the left eye of a 53-year-old lady. No sutures were put. The surgery was uneventful. On the first postoperative day, the patient had a visual acuity of 6/18. The ocular media was clear and fundus was normal. Slit-lamp examination revealed a 1+ flare and cells. On the second postoperative day, the patient complained of sudden pain and drop in vision. Examination revealed edematous lids and exudates in the pupillary plane covering the intraocular lens. A 4+ flare and cells were present (Figure 1a). There was a 2 mm hypopyon and no red reflex. Vision had reduced to light perception. An ultrasonography B-scan of the left eye revealed echogenic vitreous and a diagnosis of postoperative endophthalmitis was made. Vitreous and aqueous aspirates were sent for Gram's stain, KOH study, and bacterial and fungal culture/sensitivity. Intravitreal and intracameral injections of vancomycin (1 mg/0.1 ml) and amikacin (400 μg/0.1 ml) were given simultaneously. Intravenous ciprofloxacin 200 mg 12 hourly was also started. Gram's and KOH were negative, but bacterial culture of both aqueous and vitreous aspirates revealed A. faecalis, sensitive to chloramphenicol, tetracycline, cefotaxime, amikacin, and ciprofloxacin. Cefotaxime eye drops (5% concentrated) and 2% fortified amikacin eye drops in addition to 1% prednisolone acetate eyedrops were started. The patient improved symptomatically as well as clinically (Figure 1b). The second set of cultures taken from the vitreous was found to be negative. With negative cultures and reduction in vitreous exudates by ultrasonography, the patient was started on oral prednisolone 60 mg daily. At the end of 2 months the eye was quiet (Figure 1c). Posterior capsule opacification was noted. Visual acuity did not improve beyond hand movements. Fundus examination after Nd:YAG capsulotomy (Figure 1d) revealed consecutive optic atrophy and macular infarction.

Figure 1
figure 1

(a) The left eye shows edematous lids, congestion, and exudates in the anterior chamber on second postoperative day. (b) The eye on the eighth postoperative day after intravitreal injection showing reduction of exudates. (c) The eye with posterior capsule opacification at the end of second month. (d) The eye after Nd:Yag opening.

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Organisms of the Alcaligenes genus are a group of nonfermenting Gram-negative bacilli found in soil and water. Most isolates of A. faecalis from blood or respiratory secretions are related to the contamination of hospital equipment or fluids with the organism, with resulting human colonization or infection.2 It has also been recovered from corneal ulcers, ear discharges, wound drainage, and faeces.3, 4 Identification of Alcaligenes species is made by oxidase-positive, indole-negative, and urease-negative organisms with flat, spreading edges on blood-agar plates.5 A. faecalis has been associated with infections in immunocompromised patients, but our patient's medical history was unremarkable. The pathogenic role and virulence of this organism is not clear. The virulence has been attributed to various factors including histamine sensitizing factor, adherence and cytotoxicity, and exocellular ‘o’ antigen. Although most of the studies conducted were based on susceptibility of avian and mammalian cells to the above factors, the same can hold true for humans.6

The patient developed endophthalmitis on the second day after surgery. A. faecalis endophthalmitis developing on the fourth day following penetrating keratoplasty was reported.7 An epidemiological search for the organism revealed the conjunctival sac as the source of infection. The organism must have gained entry into the eye as surface fluid refluxes through the wound during surgery. Another explanation could be the intraocular lens getting contaminated as it touches the ocular surface. There was good anatomic outcome and good response to intravitreal and intravenous antibiotics. Perhaps a better visual outcome could have been possible if the macula and optic nerve events did not take place. However, no conclusion can be drawn regarding its virulence based on this case report.