Abstract
Rat bite fever is a rare infection and sometimes results in complications. This case report describes native mitral valve endocarditis in a 44-year-old male patient caused by Streptobacillus moniliformis. The diagnosis was confirmed by transesophageal echocardiography and blood cultures (BACTEC). The patient was treated with IV crystalline penicillin (6 weeks) and gentamicin (2 weeks). The fundamental importance of a high index of suspicion, interpreting investigations and appropriateness of therapy are highlighted.