(1615) Cerebral Septic Embolic Stroke: A Rare Complication of Bacteroides fragilis Endocarditis

Introduction: Bacteroides fragilis is an anaerobic Gram-negative bacillus that is part of the microbiota of the human colon and is associated with polymicrobial infections, including intra-abdominal, diabetic foot, and gynecological infections. We describe a rare case of B. fragilis endocarditis complicated by cerebral septic emboli.

Description: A 72-year-old female with coronary artery disease and end-stage renal disease presented after a fall at home. She was in rapid atrial fibrillation, hypotensive, and encephalopathic, all attributed to sepsis; broad-spectrum antibiotics were initiated. Blood cultures obtained at admission grew B. fragilis in the anaerobic bottles. An abdominal CT scan revealed a cirrhotic liver and splenic infarcts, but no evidence of intra-abdominal infection, and vaginal cultures were negative for B. fragilis. Four days after admission, she developed right-sided weakness, and MRI revealed acute, multifocal supratentorial infarcts concerning for embolic disease. A trans-esophageal echocardiogram disclosed a mitral valve vegetation and a large right atrial thrombus attached to a tunneled dialysis catheter, but no patent foramen ovale or left atrial appendage clot, raising concern for cerebral septic emboli. The patient was continued on metronidazole for a 6-week course. Given her high perioperative mortality risk, she was not considered a candidate for mitral valve replacement or surgical thrombectomy.

Discussion: Bacteroides fragilis is an uncommon cause of Infective Endocarditis, primarily affecting elderly patients with preexisting heart disease. Early diagnosis and treatment with metronidazole has led to improved mortality and reduced thromboembolic events. We report the first case of cerebral septic embolic stroke secondary to Bacteroides endocarditis.