Stenotrophomonas maltophilia ocular infections

Objectives: To determine if the number of ocular infections associated with Stenotrophomonas maltophilia is increasing, to identify predisposing factors, and to evaluate antimicrobial susceptibility. Methods: Retrospective review of ocular microbiology laboratory records from January 1, 1972, through December 31, 1995. Results: Stenotrophomonas maltophilia was recovered from 15 cases of ocular infection, at a rate of one in every 1339 ocular specimens in the 1970s, one in 413 in the 1980s, and one in 363 in the 1990s through 1995. The organism was the predominant isolate in five cases and was part of a polybacterial infection in the remaining 10 cases. Eight of the 15 cases had bacterial keratitis, including one with infectious crystal-line keratopathy. Of the remaining seven infections, S maltophilia was recovered from two cases of acute conjunctivitis, two infected scleral buckles (one with orbital cellulitis), two cases of infantile dacryocystitis, and one case of preseptal cellulitis. Ocular isolates of S maltophilia were resistant to the aminoglycosides and most p-lactams, and showed variable susceptibility to the fluoroquinolones. Conclusions: Stenotrophomonas maltophilia is emerging as an important opportunistic ocular pathogen. Most infections by this organism occur in patients with ocular compromise, and the characteristically resistant antibiogram of S maltophilia limits the therapeutic options.