Stenotrophomonas maltophilia keratitis and scleritis

Stenotrophomonas maltophilia is a seldom-reported pathogen in ocular infections. The report describes six cases of Stenotrophomonas maltophilia (S. maltophilia) keratitis and scleritis. To our knowledge, this is the foremost report of S. maltophilia scleritis.

Laboratory reports of patients diagnosed with S. maltophilia ocular infections were collected from the ophthalmic department of Chang-Gung memorial hospital from January 1, 2000, through December 31, 2003. On evaluation of risk factors, isolates, antibiotic sensitivities, and response to the treatment ensued.

Of the 6 reported cases, 5 related bacterial keratitis and 2 scleritis. (One case reported S. maltophilia keratitis and secondary scleritis.) The primary risk factor in such cases is ocular surgery. The organism cultured was the single isolate in three cases (50%). The susceptibility test showed that 50%, 83%, and 100% of the isolates were sensitive to ceftazidime, a combination of trimethoprim and sulfamethoxazole, and ciprofloxacin respectively.

Ocular surface compromise such as penetrating keratoplasty was a primary risk factor of S. maltophilia keratitis in our study. The results of isolates and the antibiotic sensitivities were different from previously published results. Our cases responded well to antibiotic therapy and antibiotic therapy combined with conjunctival autografting. One case of S. maltophilia keratitis and secondary scleritis had a poor prognosis, arguably associated with a co-infection of Mycobacteria chelonae.