ABSTRACT
Various causative organisms and predisposing factors were implicated in the pathogenic process behind prosthetic valve endocarditis. Lactobacillus paracasei, a classic constituent of probiotics, rarely causes infections in humans and was reported only in few case reports. The use of probiotics was hypothesized to be a risk factor for these infections; however, no causative relationship could be drawn. We describe a 75-year-old woman with history of Birt-Hogg-Dube syndrome and bioprosthetic aortic valve replacement who presented with worsening dyspnea was found to have Lactobacillus paracasei bacteremia and evidence of bacterial vegetations noted on transesophageal echocardiography (TEE) along with evidence of severe aortic insufficiency. Based on antibiotics sensitivity profile, she was treated with penicillin and gentamycin, which resulted in bacterial clearance on repeat blood cultures, and the patient was transferred to a different facility to undergo replacement of the prosthetic aortic valve. Although Lactobacillus paracasei is rarely involved in human infections, it should be suspected in patients with underlying structural heart/valvular disease, recent antibiotic exposure or recent probiotic use who are presenting with evidence of infective endocarditis. Combination antibiotics including beta lactams, aminoglycosides and clindamycin are suggested treatment of choice for this organism.
