Clinical Features, Antibiotic Susceptibility Profile, and Outcomes of Infectious Keratitis Caused by Stenotrophomonas maltophilia

Abstract

Purpose Stenotrophomonas maltophilia, an uncommon cause of infectious keratitis, is difficult to treat due to its resistance to multiple antibiotics. The purpose of this study is to describe the clinical features, antibiotic susceptibility profile, and outcomes of S. maltophilia keratitis. Methods A retrospective review of records from 1987–2014 identified 26 eyes of 26 patients who were treated at the Bascom Palmer Eye Institute for a S. maltophilia corneal ulcer. Clinical data was analyzed as to predisposing factors, clinical presentation, antibiotic susceptibility, treatment selection and clinical outcomes. Results Median age at presentation was 64.9 years (range, 16.0 – 97.7). Twelve patients were using topical corticosteroids, 8 patients had a history of penetrating keratoplasty and 9 were contact lens wearers. All patients received topical antibiotics, two required a therapeutic penetrating keratoplasty, and one was enucleated. At presentation, 57.7% (15/26) of the patients had visual acuity 20/400 or worse. At the final visit only 30.4% (7/23) of the patients had visual acuity worse than 20/400, while 65.2% (15/23) of the patients were at 20/100 or better. Almost all isolates (25/26, 96.2%) were susceptible to fluoroquinolones and 77.3% (17/22) of them to polymyxin B/trimethoprim. Only 33.3% (5/15) of the tested isolates were susceptible to aminoglycosides and 58.3% (7/12) to cephalosporins. Conclusion Infectious keratitis due to S. maltophilia presents a treatment challenge due to its resistance to aminoglycosides and cephalosporins, which are typically used for empiric broad-spectrum gram-negative coverage as fortified solutions. Fluoroquinolones and polymyxin B/trimethoprim should be considered instead in cases of S. maltophilia infection.

Comparative activity of antimicrobials againstPseudomonas aeruginosa,Achromobacter xylosoxidansandStenotrophomonas maltophiliakeratitis isolates

“…Yet, the actual clinical efficacy of trimethoprim-sulfamethoxazole against S. maltophilia as well as against A. xylosoxidans may be limited as its inhibitory quotient was low (0.70 and 0.92, respectively, table 2). In a retrospective review of the medical records of patients treated for S. maltophilia keratitis in our institute during a 30-year period, we found that this pathogen showed as high as 92% susceptibility rate to fluoroquinolones, represented by ciprofloxacin 21. However, in the current report susceptibility rate to ciprofloxacin was as low as 13.3%.…”

Electroactive Smart Polymers for Biomedical Applications

“…For instance, bone implants are always associated with risks of bacterial infection that leads to implant failure or, in critical cases, amputation or death of the patient [144,145]. In contact with the eye lens this process causes serious eye infections [146]. Other examples of fouling formation are in catheter-associated urinary tract infections [147,148], and dental implants cause periodontal diseases and gingivitis [144].…”

Current understanding and therapeutic management of contact lens associated sterile corneal infiltrates and microbial keratitis

“…87 Similarly, these bacteria are found in contact lens cases of patients with CIEs. [88][89][90][91][92][93][94][95][96] Although rare, these bacteria have been reported as causes of MK in contact lens wearers. 89,90,[95][96][97][98] Achromobacter xylosoxidans is known to be resistant to multiple antibiotics including aminoglycosides, most cephalosporins and have varying sensitivity to fluoroquinolones.…”

“…[88][89][90][91][92][93][94][95][96] Although rare, these bacteria have been reported as causes of MK in contact lens wearers. 89,90,[95][96][97][98] Achromobacter xylosoxidans is known to be resistant to multiple antibiotics including aminoglycosides, most cephalosporins and have varying sensitivity to fluoroquinolones. 89,90 Strains from both Stenotrophomonas maltophilia and Delftia acidovorans can be multidrug resistant.…”

“…94 Other studies from the US and Taiwan both reported Stenotrophomonas maltophilia keratitis to remain mostly susceptible to fluoroquinolones. 95,96 However, only 33.3% were noted to be susceptible to aminoglycosides and cephalosporins in the US, which led to the poor outcome when these were prescribed as the initial empirical treatment. 95 Hence, it is important for practitioners to consider alternative causes for cases of bacterial keratitis that are not responding to the conventional initial empirical therapies, as discussed in the earlier paragraphs.…”