S3355 Leclercia adecarboxylata Bacteremia in a Patient With Ulcerative Colitis

Introduction: Leclerciaadecarboxylata, a gram-negative bacillus, is typically considered an opportunistic pathogen that rarely causes invasive infections in immunocompetent individuals. This organism is most commonly associated with gastrointestinal (GI) disorders, including ulcerative colitis (UC) and Crohn’s disease. Bacteremia due to L. adecarboxylata is often a result of bacterial translocation from the GI tract. Here, we present a case of L. adecarboxylata bacteremia in a patient with active UC. Case Description/Methods: Fifty-one-year-old man with a known history of ulcerative colitis presented to the hospital with a 3-month history of worsening GI symptoms, including abdominal pain, diarrhea, and blood in his stool. Despite ongoing treatment, symptoms persisted. The patient had no recent immunosuppressive use, travel history, or significant comorbidities. Examination revealed fever (38.2°C), abdominal tenderness, and signs of inflammation. Lab results showed elevated white blood cell count (15,000/µL), C-reactive protein (120 mg/L), and erythrocyte sedimentation rate (50 mm/h). Colonoscopy confirmed active UC with extensive mucosal ulcerations. Blood cultures were obtained, and empirical broad-spectrum antibiotics were initiated. Within 48 hours, Leclerciaadecarboxylata was identified in the blood cultures, confirmed by biochemical testing and 16S rRNA sequencing. The organism was sensitive to ceftriaxone and amikacin. The patient was treated with antibiotics and corticosteroids for UC. His symptoms improved, with resolution of fever and normalization of inflammatory markers. He was discharged with plans for follow-up with infectious disease and gastroenterology specialists. Discussion: Leclerciaadecarboxylata is a rare cause of bacteremia, particularly in immunocompetent individuals. In patients with UC, the integrity of the intestinal mucosal barrier is often compromised, making them susceptible to bacterial translocation and subsequent systemic infection. The present case supports the hypothesis that the patient’s active UC was the likely source of bacteremia. Literature suggests that UC and other inflammatory GI conditions increase the risk of invasive infections due to gut bacterial translocation.