Klebsiella Oxytoca: A Commonly Unrecognized Cause of Hemorrhagic Colitis

Abstract

Background: Antibiotic associated hemorrhagic colitis (AAHC) is described as infectious colitis that occurs following antibiotic usage with bloody diarrhea in the absence of Clostridium difficile. Klebsiella oxytoca, is a gram negative rod encapsulated bacterium that expresses beta-lactamase and was first reported in 2004 in the US as a cause of AAHC. Case A: 25 year old female who presented to an outside hospital with acute onset of abdominal cramping with bloody diarrhea. She had a history of dyspepsia was diagnosed with Helicobacter pylori by biopsy prompting treatment with amoxicillin, clarithromycin, and esomeprazole completed one week prior to presentation. Baseline CBC and chemistry panels were unremarkable. A contrasted CT abdomen and pelvis showed pan-colitis with pericolonic stranding. She was treated with IV fluid resuscitation, analgesia, and antibiotics for possible infectious colitis and admitted for ongoing pain control. While admitted her diarrhea improved, however she had ongoing abdominal pain and nausea with non-bloody emesis. Given ongoing symptoms she was transferred to our institution and colonoscopy was preformed nine days after symptom onset that showed mild erythema of the sigmoid colon; biopsies were obtained. With conservative management her symptoms improved and she was discharged. Ultimately, stool cultures returned positive for K. oxytoca. Colon biopsies were normal. At follow-up, her symptoms had completely resolved. Discussion: This case highlights AAHC from K. oxytoca which has beendescribed in case reports and case series over the past decade. Nonetheless, the clinical characteristics of AAHC caused by this opportunistic pathogen remain under recognized by the general medical community. In series of patients presenting with AAHC, K. oxytoca is linked to 83-87% of cases. K. oxytoca is primarily associated with recent use of penicillins, and less commonly, quinolones and cephalosporins. The typical clinical course occurs within a week of typical antibiotic use, with acute onset of bloody diarrhea with abdominal pain; often requiring hospitalization. On endoscopy, it is common to find segmental colitis (mucosal edema, erosions and longitudinal ulcerations) with rectal sparing. Histopathology reveals acute hemorrhagic colitis. Symptoms generally resolve with supportive care within a week. Treating providers should recognize K. oxytoca AAHC as a cause for hemorrhagic colitis especially in the setting of recent antibiotic use.