Lactobacillus paracasei endocarditis of bioprosthetic aortic valve presenting with recurrent embolic strokes

Introduction: Lactobacillus prosthetic valve endocarditis is a rare infection caused by Lactobacillus bacteria. This bacterium is found in the normal flora of the human mouth, gastrointestinal tract and female genital tract. While there have been isolated cases of Lactobacillus bacteraemia and endocarditis, the infections are associated with comorbidities, immune deficiency, dental manipulation procedures and other medical history. This case of bioprosthetic valve endocarditis caused by Lactobacillus paracasei is unusual, as the patient was immune-competent and treated with pre-procedural antibiotics.

Case: We present a case of a 65-year-old male who underwent a dental extraction. He presented after 3 months of fever, chills and fatigue. On initial presentation, blood cultures were positive for alpha-haemolytic streptococcus bacteraemia. He was treated with IV penicillin and underwent aortic valve replacement with a bioprosthetic valve and excision of the mitral vegetation with repair of the mitral valve. Two years later, he had a tooth extraction after being treated properly with antibiotics. Three months later he presented with difficulty speaking, left leg weakness and increased drooling. All testing was normal. Three months later he presented with left side lower extremity weakness and expressive aphasia. He was diagnosed with bioprosthetic aortic valve endocarditis and was treated with IV penicillin and gentamicin for 6 weeks and then switched to oral penicillin. He remained stable.

Conclusions: L. paracasei can potentially be a cause of complicated endocarditis in patients with prosthetic heart valves undergoing dental procedures. Timely culture-guided antibiotic therapy is critical and may obviate the need for valve surgery.

Keywords: Lactobacillus paracasei; endocarditis.