S5710 Listeria SBP After Flexible Sigmoidoscopy: A Case Report

Introduction: Listeria monocytogenes is an uncommon but emerging cause of spontaneous bacterial peritonitis (SBP), particularly in high-risk groups such as the immunocompromised. Our case involves the rare incidence of SBP due to Listeria, successfully treated with ampicillin/gentamicin. This case highlights the rising incidence of Listeria infections and emphasizes the need to consider Listeria SBP in patients with elevated ascitic fluid white cell counts, especially after gastrointestinal procedures. Case Description/Methods: A 72-year-old man with a history of alcoholic cirrhosis complicated by gastric antral vascular ectasia syndrome, esophageal varices, and chronic leukopenia presented with weakness and increasing ascites 2 days after outpatient flexible sigmoidoscopy. On presentation, patient recorded temperature of 101.2°F and physical exam demonstrated distended abdomen with fluid wave. Initial labs included leukocytes of 5.9 × 109/L (baseline of 3-4 × 109/L), lactate of 3.2 mmol/L, creatinine at 1.55 mg/dL and bilirubin at 2.7 mg/dL. Two days after admission, Listeria monocytogenes was isolated from blood cultures and patient was started on ampicillin/gentamicin. Paracentesis yielded 4.7 liters of fluid, which also grew Listeria. Ascitic fluid analysis demonstrated LDH 139 U/L, albumin 0.7 g/dL, amylase 122 U/L, NFC 3293 with serum-ascites albumin gradient of 2 g/dL. The patient denied consuming unpasteurized dairy and any exposure to animals. His course was uncomplicated and he discharged with 6 weeks of intravenous penicillin. Discussion: With the rising incidence of Listeria monocytogenes infections and association with invasive procedures, it is imperative for clinicians to maintain a high index of suspicion for listerial SBP in at-risk populations, particularly when initial assessments reveal significant leukocytosis in ascitic fluid. The vulnerability of patients with alcoholic cirrhosis to Listeria infections can be attributed to immunosuppression associated with chronic alcohol consumption and the immune dysfunction intrinsic to cirrhosis itself. Instrumentation may further increase the risk of bacterial translocation. Historically, Listeria monocytogenes was frequently misclassified as a contaminating diphtheroid, leading to underdiagnosis. Recent trends indicate a rise in Listeria monocytogenes outbreaks, with transmission routes extending beyond traditional sources and therefore is important to include on the differential for SBP in susceptible patients with recent instrumentation.