Posters

Contemporary bacterial keratitis caused by Stenotrophomonas maltophilia in two patients with different settings and outcomes

Poster Details

First Author: C.Colliga SPAIN

Co Author(s):    A. Escalona   B. Garcia-Valcarcel   D. Da Saude   M. Ruiz del Tiempo   R. Yela   L. Ibares     

Abstract Details

Purpose:

To study the epidemiology, risk factors, pathogenicity, management and prognosis of bacterial keratitis caused by Stenotrophomonas maltophilia, an aerobic, nonfermentative, Gram negative bacterium. It is considered to be an infrequent cause of keratitis in humans and it is usually difficult to treat due to its natural and acquired multiple antibiotic resistances. Initially named Pseudomonas maltophilia and Xantomonas maltophilia, S. maltophilia are ubiquitous in water, soil and plants and it has been described as a nosocomial pathogen in immunocompromised patients and frequently colonise medical devices, such as catheters and endoscopes.

Setting:

Unit of Cornea, Ophthalmology Department, Hospital Gregorio Marañon, Madrid (Spain)

Methods:

We present two cases of Stenotrophomonas corneal infection, diagnosed within a short period of time. The first case is a 63-year old woman with terminal stage glaucoma of the right eye. She underwent previous combined trabeculoplasty and cataract surgery, herpetic infection with progressive corneal edema treated with lubricant drops, topical dexamethasone, antiedema and therapeutic contact lens. The second case is a 68 year old male with diabetes mellitus, Sjögren syndrome and chronic renal failure who underwent a first tectonic keratoplasty due to a a perforated corneal ulcer secondary to chronic use of topical NSAIDs to treat macular edema.

Results:

First patient developed a corneal ulcer with poor response to usual treatment. Cultures were taken, growing S. maltophilia resistant to almost all antibiotics, susceptible to trimetroprim /sulfamethoxazole, colistin, tetracyclin, ciprofloxacin, achieving complete resolution in 3 weeks of treatment with topical ciprofloxacin and colistin. Second patient developed infection over persistent epithelial defect with progressive corneal melting and cultures positive for similar Stenotrophomonas clinically resistant to topical and intravenous in vitro-susceptible colistin, ciprofloxacin and oral trimetroprim/sulfamethoxazole. Thus, a secondary keratoplasty was needed. Patient was treated with topical antibiotics, and oral trimetroprim /sulfamethoxazole plus cacicol and parenteral immunoglobulins achieving resolution with cataract development

Conclusions:

Stenotrophomonas maltophilia is an emerging cause of bacterial keratitis, important to take into account, specially in the setting of immunocompromised patients or medical device carriers. Another important aspect to consider is the common inefficacy of empirical antibiotic treatment due to the special profile of antibiotic susceptibilities and resistances. Microbiological culture and directed antibiotic treatment are necessary to achieve a better clinical outcome, although this is not always possible due to their aggressive behavior.

Financial Disclosure:

None