Shewanella putrefaciens: A Rare Anaerobic Bacterium Mimicking Necrotizing Soft Tissue Infection

Abstract

Background:Shewanella putrefaciens, an anaerobic, gram-negative, iron-reducing bacterium found in marine environments, is described here as cause of septic shock and a rare type of soft tissue infection. Case Presentation: We report a case of a 52-year-old female who presented to our facility with findings of altered mental status, septic shock, and right lower extremity swelling, redness, bullae formation, and erysipelas. Intra-operative evaluation was undertaken out of concern for necrotizing soft tissue infection, which was ruled out clinically. Prospective follow-up of intra-operative cultures showed evidence of marine pathogen Shewanella putrefaciens in the tissue culture and a cause of bacteremia. Discussion: With only 255 cases reported in the literature since 1973, Shewanella putrefaciens is known for causing ear infections, abdominal, biliary tract infections, and rarely, soft tissue infections. Severe bacteremia with fulminant septic shock may develop in as much as 28% of patients. In our case, Shewanella infection mimicked necrotizing soft tissue infection in its clinical presentation and aggressive evolution. It is therefore prudent to be familiar with this rare pathogen as a cause of soft tissue infection and sepsis and to be able to differentiate it from necrotizing soft tissue infection. Conclusion: Diligence in surgical site debridement and surgical site exploration are paramount in dictating patient care for these types of infections.