Community-Acquired Pneumonia With Sphingomonas paucimobilis

Abstract

INTRODUCTION: Sphingomonas paucimobilis is an omnipresent gram negative bacillus in both environmental and hospital settings. When reported, it is most commonly from nosocomial infections associated with catheters, urinary tract infections, soft tissue infections, and very rarely pneumonias. There are only two comprehensive literature reviews concerning bacteremia associated with S. paucimobilis with a total of 97 cases. Only 4 cases of bacteremia were associated with Community Acquired Pneumonia (CAP), and no cases of CAP with empyema. We report the first known case of Sphingomonas paucimobilis CAP complicated by empyema. CASE PRESENTATION: 36 year old African American male with medical history significant for alcohol dependence presented to an outside hospital with 2 days of fevers, chills, non-bloody emesis, and progressive dyspnea. CXR and CT revealed bilateral air space disease with pleural effusions. Blood and thoracentesis cultures grew S. paucimobilis, and the patient was empirically treated with piperacillin/tazobactam, ceftriaxone, and azithromycin. Patient was transferred to our center after failure to improve over 6 days of therapy. Repeat CT revealed progressive bilateral lower air space disease with loculated pleural effusions. His antibiotic regimen was changed to vancomycin, levofloxacin, and meropenem and subsequently patient was taken to the OR for Video Assisted Thorascopic Surgery for decortication. After a prolonged hospital stay, patient was discharged home in good condition. DISCUSSION: Classically, three causative bacteria make up 85% of CAP cases in an inpatient setting including Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis which are well covered by empiric fluoroquinolones or ceftriaxone/azithromycin combinations. In patients presenting in a critically ill setting, risk factors such as age, concomitant chronic disease, recent hospitalizations, and social factors must inform empiric coverage. This case illustrates the need to keep broad clinical suspicion for causative agents in the community setting. Risk factors of diabetes mellitus and alcohol dependence were described by Toh et al in a retrospective cohort study of 55 cases S. paucimobilis bacteremia. Toh et al also found that their strains typical susceptibilities included carbapenems, SMX-TMP, and aminoglycosides, with variable resistance to other classes of antibiotics. CONCLUSIONS: S. paucimobilis is a common bacterium in nature, and can be causative of several types of infections in human hosts. Although the virulence is low, its capacity to cause extensive infections with high morbidity in at-risk hosts makes it a pathogen we cannot afford to forget.