Stenotrophomonas maltophilia: A clinical perspective

Stenotrophomonas maltophilia, formerly known as Xanthomonas maltophilia or Pseudomonas maltophilia, has increasingly become an important nosocomial pathogen. This organism is the most common-found pseudomonad after P aeruginosa, S. maltophilia has a predisposition for immunocompromised patients, particularly those suffering from HIV, cancer, and cystic fibrosis. S. maltophilia has shown an alarming trend toward increasing antimicrobial resistance. Risk factors such as the presence of a central line, broad spectrum antimicrobial therapy, and prolonged hospitalization contribute to the prevalence of this bacteria. In the absence of controlled comparative clinical trials, current antimicrobial recommendations for S. maltophilia infections are based on retrospective clinical reviews, case reports, and laboratory susceptibility studies. The literature suggests that trimethoprim/sulfamethoxazole is the drag of choice, with moxalactam and ticarcillin/clavulanic acid as additional alternatives. Several infection control methods and preventional measures have been suggested to reduce colonization frequency. Such efforts include inservice education, an increase in awareness to and practice of appropriate handwashing and glove use, and utilization of high level disinfectants on all surfaces between patients' contact of these materials. The purpose of this communication is to summarize the microbiology and epidemiology of S. maltophilia and discuss the pathogenicity and therapeutic options for infections caused by this pathogen.