Lactobacillus jensenii mitral valve endocarditis: Case report, literature review and new perspectives

Lactobacillus is a facultative anaerobic Gram-positive rod usually found in the normal microbiota of the gastrointestinal and genitourinary tract. Frequently dismissed as a contaminant, it is implicated in several diseases. We describe a rare case of endocarditis caused by Lactobacillus jensenii in an immunocompetent 40 year-old male patient, with a history of mitral valve repair. He presented complaining of asthenia and his laboratory results showed a moderate increase in inflammatory markers. A trans-thoracic echocardiography confirmed a vegetation on the posterior leaflet of the mitral valve, with associated severe mitral insufficiency. Blood cultures revealed the significant growth of L. jensenii. The patient developed an acute abdomen with intestinal ischemia and occlusion of the superior mesenteric artery, requiring urgent surgical laparotomy. A cerebral MRI showed multiple minor emboli in the frontal and left parietal cortex. The patient consequently underwent surgery to have his mitral valve replaced with a mechanical valve. L. jensenii was isolated in culture from the mitral valve and from a mesenteric artery thrombus. After one week of combined amoxicillin and gentamicin therapy, ampicillin alone was continued for a total of six weeks and the patient could be discharged in a good general condition. Only five cases of L. jensenii are described in literature, and they mainly affect immunocompromised hosts. In our case, a long delay between the start of symptoms and the full onset of the disease was observed. tolerance of Lactobacilli to penicillin is a key determinant of therapy choice.