Sphingomonas paucimobilis Bacteremia in Humans: 16 Case Reports and a Literature Review

Background/Purpose: Sphingomonas paucimobilis is a glucose-nonfermenting Gram-negative bacillus that is widely distributed in both natural environment and hospitals. Various infections in humans have been reported, but most have been limited to sporadic case reports. The aim of this study was to describe the clinical characteristics and manifestations of S. paucimobilis bacteremia. We also reviewed the literature on S. paucimobilis bacteremia. Methods: Cases of S. paucimobilis bacteremia were identified retrospectively at a university-affiliated hospital in Taiwan. In addition, relevant case reports were identified through PubMed and reviewed. Results: From April 2004 to April 2008, 42 cases of S. paucimobilis bacteremia were identified in this study. Among them, 16 cases were identified from E-Da hospital, Kaohsiung, Taiwan and 26 cases from the literature review. The median age of patients was 48.5 years and 57.1% were male. The most common comorbidities included malignancy (57.1%), immunosuppressant use (40.5%), and diabetic mellitus (11.9%). Hospital-acquired bacteremia accounted for 69.0% of infections. Primary bacteremia and catheter-related bloodstream infection were found in 35.7% and 33.3% respectively. The most effective antibiotics were fluoroquinolones, carbapenems, and β-lactam/β-lactamase inhibitor combinations. All 42 patients survived the S. paucimobilis bacteremic episodes, but three patients experienced septic shock. Conclusion: S. paucimobilis can cause infections in healthy as well as immunocompromised individuals. Although it is an organism of low clinical virulence, infection caused by S. paucimobilis can lead to septic shock. Further clinical research is required to characterize this infection.