Clinical characteristics and prognostic factors of patients with Stenotrophomonas maltophilia infections.

INTRODUCTION: Stenotrophomonas maltophilia earlier had limited pathogenic potential, but now with growing degree of immunosuppression in general population, it is being recognized as an important nosocomial pathogen.

METHODOLOGY: A retrospective 7 years study was carried out to determine the clinical characteristics of all patients with Stenotrophomonas infections, antibiotic resistance pattern, and risk factors associated with hospital mortality. All patients with Stenotrophomonas culture positivity were identified and their medical records were reviewed. Risk factor associated with hospital mortality was analyzed.

RESULTS: A total of 123 samples obtained from 88 patients were culture positive. Most patients presented with bacteremia (45, 51%) followed by pneumonia (37, 42%) and skin and soft tissue infections (6, 7%). About 23 of 88 Stenotrophomonas infected patients had co-infection. Percentage resistance to cotrimoxazole; 8 (5.4%) was lower than that for levofloxacin; 18 (12%). Twenty-eight patients died during hospital stay. Intensive Care Unit admission ( P = 0.0002), mechanical ventilation ( P = 0.0004), central venous catheterization ( P = 0.0227), urethral catheterization ( P = 0.0484), and previous antibiotic intake ( P = 0.0026) were independent risk factors associated with mortality.

CONCLUSION: Our findings suggest that Stenotrophomonas can cause various infections irrespective of patient's immune status and irrespective of potential source. Thus, Stenotrophomonas should be thought of as potential pathogen and its isolation should be looked with clinical suspicion.