A male patient aged 32 developed infectious endocarditis on a congenital (and repaired) stenotic aortic valve defect. He presented with prolonged fever and wasting symptoms and also referred recurrent gingivitis. At admission, fever, systolic and diastolic aortic murmurs, and periodontitis were registered. Ultrasound imaging showed aortic vegetations reaching a maximal diameter of 49 mm and a severe aortic stenosis and insufficiency. Patient received treatment with vancomycin and gentamycin due to penicillin allergy but developed a progressive non-oliguric acute renal failure. Blood cultures revealed bacilli of uncertain gram stain that were recognized as gram negative bacilli and identified as Capnocytophaga sputigena at the National Reference Laboratory. Patient remained stable but murmurs increased and new imaging studies revealed the development of a unique septal abscess despite antibiotic therapy with intravenous ciprofloxacin. Intraoperative finding showed a perforated aortic coronary leaflet