Background: Erysipelothrix rhusiopathiae is a rare zoonosis. We present a case of E. rhusiopathiae bacteremia of unknown origin complicated by endocarditis of the aortic and mitral valves. Case Presentation: A 39-year-old man presented with fatigue, diaphoresis, fevers, and substantial weight loss. Upon physical examination, a gallop rhythm of the heart was heard. Blood cultures eventually revealed an E. rhusiopathiae infection. Vegetation on the non-coronary cusp of the aortic valve and the mitral valve were seen on echocardiography. The patient was treated with intravenous penicillin for 6 weeks. Following the treatment, the non-coronary cusp was found to be prolapsed and perforated. Aortic valve regurgitation had also led to dilatation and hypertrophy of the left ventricle. Conclusion: Erysipelothrix rhusiopathiae is a rare cause of infective endocarditis. As untreated E. rhusiopathiae can cause irreversible damage to the heart valves and death, prompt consideration of this infection is warranted in any patient at an increased risk.

Keywords: Erysipelothrix rhusiopathiae, erysipeloid, infective endocarditis, aortic valve, mitral valve, case report.