ABSTRACT
We report a case of Serratia ficaria endophthalmitis in a 73-year-old man. The patient's ocular history included a chemical burn, glaucoma, and corneal transplantation. S. ficaria is part of the fig tree ecosystem and is rarely isolated from clinical specimens. When it has been previously implicated as an agent of disease, the patients have been treated successfully and there have been no complications. In our patient, however, the infection resulted in the loss of the infected eye. This case illustrates that S. ficaria infection in a compromised patient can have serious consequences.
CASE REPORT
A 73-year-old man had visited the Flinders Eye Centre for 2 years. He was in good general health but had an extensive ocular history. He suffered chemical burns to the eyes as a young man, and since then his vision had never been better than hand movements. At age 40, his left retina detached and the eye was removed. Ten years later, glaucoma developed in his remaining eye and was controlled by timolol drops, oral acetazolamide, and surgery. By age 71, the integrity of the ocular surface had deteriorated and his cornea threatened to perforate. A limbal stem cell allograft and a tectonic lamellar graft were performed. Within 18 months, however, his cornea had become vascularized and opaque and his vision had diminished to light perception. A penetrating corneal graft was performed with the hope that navigational vision would be restored. Chloramphenicol (0.5%) and prednisolone phosphate (0.5%) drops were given postoperatively, four times a day. Five days after surgery, the graft was found to be edematous although there were no signs of infection. However, 2 days later, the patient developed purulent endophthalmitis with associated pain, conjunctival discharge, raised intraocular pressure, and graft opacity. There was no perception of light. The eye was eviscerated, and the material was sent to the pathology service at Flinders Medical Centre for culturing.
Pure growth of an enterobacterium occurred on all bacterial media. It was identified as Serratia ficaria based on the following criteria: a strong smell resembling bean sprouts, motility, acid production in the slant and butt of a tube of triple sugar iron agar, fermentation on glucose oxidation-fermentation medium, weak lactose fermentation on MacConkey agar, and fitting API 20E (Biomérieux, Marcy l'Etoile, France) profile 0207773. The isolate was susceptible to amikacin, ceftriaxone, chloramphenicol, ciprofloxacin, gentamicin, meropenem, norfloxacin, and tetracycline and resistant to ampicillin, amoxicillin-clavulanate potassium (Augmentin), cefotaxime, cephalothin, and trimethoprim (on Kirby-Bauer disks). To confirm the identification, the isolate was sent (with clinical details only) to the pathology services at the Royal North Shore Hospital in Sydney, Australia, and St. Vincent's Hospital in Melbourne, Australia. Both laboratories identified the organism as S. ficaria.
S. ficaria is a gram-negative rod present in the fig-fig wasp biological cycle (5). It has been reported for a small number of clinical specimens. Some of the patients had purulent infections (1, 7), while others had no evidence of bacterial disease (2, 4). Only one person had had recent contact with figs (4). S. ficaria was the sole organism isolated in three cases of gallbladder empyema (1) and one case of septicemia (3) and was presumed to be the etiologic agent. The ages of the patients (59, 70, 81, and 83 years) and the presence of other medical conditions suggested that the organism is an opportunistic pathogen in compromised individuals. Since the patients were treated successfully and there were no complications, S. ficaria is considered to have low pathogenicity. Although our case of endophthalmitis in a compromised eye had serious consequences, the level of morbidity was more likely related to the site of the infection than to the virulence of the strain.
Our patient loves figs. He grew up on a property with a fig tree, had fig trees at each of his homes until the age of 71, and has had figs in his apartment ever since. We suspect that S. ficaria had become an established part of his flora, since the infection occurred in midwinter, when fresh figs are not available and the fig wasp is inactive (1). We considered investigating this possibility but decided not to further trouble the unfortunate patient.
The sudden onset of the infection 7 days after surgery suggests that the organism did not gain access to the eye in the surgical theater but rather invaded later. The route of infection is not known. It is possible that the organism entered the eye from the blood; the permeability of the blood-aqueous barrier is increased for several weeks following penetrating keratoplasty (6). Alternatively, the organism may have crossed the surgical wound. It would have had to survive a high concentration of chloramphenicol but would have been aided by the corticosteroid and compromised recipient tissue.
The climate of South Australia is similar to that of California, and fig trees are common. However, S. ficaria has been isolated only once at our hospital, that single instance being the case above. The largest pathology service in South Australia, the Institute of Medical and Veterinary Science, has no record of isolating the organism (R. Pratt, personal communication). The laboratories contacted in Sydney and Melbourne, also in temperate climatic zones, have not encountered another isolate. Infection due to S. ficaria seems to be a genuinely rare occurrence.
FOOTNOTES
- Received 9 January 2002.
- Accepted 13 January 2002.
- American Society for Microbiology
