Stenotrophomonas maltophilia in Lower Respiratory Tract Infections.

BACKGROUND Stenotrophomonas maltophilia infection is gaining importance as an important cause of nosocomial pneumonia due to its characteristic inherent resistance to many broad- spectrum antibiotics. In this study we evaluated the demographic, clinical and microbiological profile of patients with lower respiratory tract infection due to Stenotrophomonas maltophilia. MATERIALS AND METHODS A retrospective analysis of 33 patients diagnosed with Stenotrophomonas maltophilia lower respiratory tract infections during a period of two years from 2012 - 2013 was done. RESULTS The predominant predisposing factor observed was mechanical ventilation in 17(51.5%) cases. Fluoroquinolones were the most effective antibiotic (26;78.8%) followed by trimethoprim-sulfamethoxazole (24;72.7%). Among the 19 patients treated with proper antibiotic, 13(68.4%) showed clinical improvement. Among the 14 patients who did not receive appropriate antibiotic for Stenotrophomonas maltophilia infection, 8(57.1%) showed improvement. Two (6%) had blood culture positive for Stenotrophomonas maltophilia. Mortality rate was 21.2%. CONCLUSION Stenotrophomonas maltophilia is emerging as an important nosocomial pathogen with increased risk in patients on mechanical ventilation in ICU. Empiric therapy should include agents active against S.maltophilia such as newer flouroquinolones and trimethoprim-sulfamethoxazole.