Stenotrophomonas (Xanthomonas) maltophilia urinary tract infection: A disease that is usually severe and complicated

Background: Stenotrophomonas (Xanthomonas) maltophilia has emerged as a causative agent of serious nosocomial infections. However, well-documented eases of urinary tract infection with this organism have rarely been reported. Methods: Review of the medical records of patients admitted to a large cancer center with cultures yielding S maltophilia from urinary sources during a 15-month period. Results: All urinary tract infections were serious: 13 were complicated and two were acute uncomplicated pyelonephritis. The urinary tracts of 13 other patients were colonized with S maltophilia. Most of the colonized and infected patients were hospitalized with genitourinary malignancy, underwent urinary catheterization, and were receiving antibiotics inactive against S maltophilia. Neutropenia and urinary structural abnormalities were significantly associated with infection. The clinical course of infection was usually severe: fever (100%), sepsis disorder (47%), neutrophilia (70% of patients without neutropenia), bacteremia (13%), and death (7%). Still, response to treatment was prompt. Conclusions: Stenotrophomonas maltophilia urinary tract infection is usually associated with a severe clinical course. Risk factors for urinary colonization by this organism include hospitalization, urinary catheterization, and administration of inactive antibiotics. Risk factors for urinary tract infection include neutropenia and urinary structural abnormalities. In the presence of these risk factors, treatment for S maltophilia should be considered in patients with urinary colonization by the organism or in those with nosocomial urinary tract infection caused by an unknown pathogen and that is unresponsive to therapy with the antibiotics that are used to treat the common uropathogens.