Abstract
Lactobacillus rhamnosus endocarditis is a rare but significant complication in patients with mechanical heart valves. We present a case of a 73-year-old male with a mechanical aortic valve who developed endocarditis following a routine dental cleaning, despite receiving standard of care prophylactic antibiotics. Blood cultures confirmed L. rhamnosus, and imaging highlighted persistent inflammation around the mechanical valve. Management focused on evolving antibiotic therapy with close routine monitoring. This case underscores the diagnostic challenges and therapeutic complexities of Lactobacillus-related endocarditis and highlights the need for heightened vigilance in at-risk populations following invasive procedures. Further research is warranted to optimize management strategies for this uncommon pathogen. LEARNING POINTS: This case highlights the importance of considering Lactobacillus species as potential pathogens in patients with mechanical valves, particularly those with specific risk factors that may promote translocation of this bacterium.Early recognition with appropriate workup including blood cultures and imaging, with timely initiation of antibiotic therapy is key to ensuring positive outcomes for patients with Lactobacillus endocarditis.There remains the need for vigilant follow-up and monitoring in Lactobacillus endocarditis to assess for efficacy and complications through the disease course even in the setting of standard of care treatment, including prophylactic antibiotics.