Healthcare-Associated Stenotrophomonas maltophilia Bacteraemia: Retrospective Evaluation of Treatment and Outcome

Introduction Stenotrophomonas maltophilia (SM) is one of the common gram-negative pathogens that cause nosocomial infections. The aim of the present study is to evaluate the treatment and outcome of SM bacteraemia. Materials and Methods We retrospectively evaluated antimicrobial treatment in adult patients with nosocomial SM bacteraemia, with the 14th and 30th-day mortality as the outcome. Results In total, 140 adult patients with SM bacteraemia who were diagnosed between January 1, 2002, and December 31, 2016 were enrolled in the present study. Seventy-one (50.7%) patients were in the intensive care unit (ICU). The 14th and the 30th-day mortality rates were 32.9% (n=46) and 45.7% (n=64), respectively. Female sex (OR, 7.47; 95% CI 1.61-34.47, p<0.01), steroid use within the last month (OR, 10.2; 95% CI 1.27-82.27, p=0.029), Pittsburgh bacteraemia score (PBS) ≥4 (OR, 39.9; 95% CI 4.96-321.32, p<0.001) and solid organ malignancy (OR, 9.6; 95% CI 1.73-53.72, p<0.01) were independent risk factors for 14th day mortality. Removal of the catheter was an independent protective factor for both 14th (OR, 0.05; 95% CI 0.22-0.010, p<0.001) and 30th day (OR, 0.039;95% CI 0.164-0.009, p<0.001) mortality. We did not detect any difference between treatment regimens including trimethoprim-sulfamethoxazole (TMP/SMX) or levofloxacin in terms of mortality. We found that TMP/SMX and levofloxacin combination did not significantly improve patient prognosis. Conclusion  Due to the high mortality rates associated with nosocomial SM bacteraemia, adequate antibiotic therapy should be initiated immediately in the suspicion of infection, and prompt removal of any indwelling central venous catheter is important.