LACTOBACILLUS ENDOCARDITIS, A SINISTER CONSEQUENCE OF AN INNOCUOUS BACTERIUM

Abstract

TOPIC: Cardiovascular Disease TYPE: Medical Student/Resident Case Reports INTRODUCTION: Lactobacillus species are gram positive rods that are part of the normal flora in gastrointestinal, oropharyngeal and genital tracts. Rarely they are implicated as causative agents of endocarditis in patients who are immunocompromised, undergo dental procedures, use probiotics or have a valvulopathy or prosthetic device. We describe the case of lactobacillus jensenii causing aortic valve endocarditis in an immunocompetent patient with a bicuspid aortic valve. It is important to recognize lactobacillus species as an emerging cause of endocarditis. Treatment involves a synergistic combination of penicillin and gentamicin. CASE PRESENTATION: 55 years old female with past medical history of bicuspid aortic valve presented to the emergency department with chief complaint of fever of 3 weeks' duration. COVID-19 testing was negative. Her medical history was significant for bicuspid aortic valve with aortic regurgitation and hyperlipidemia. Vitals signs were significant for a fever of 103 F. Physical exam was remarkable for a diastolic murmur heard best in the left third intercoastal space. Labs showed a normal blood count, and electrolytes. Patient's blood and urine cultures were obtained, and they were sent home with an oral antibiotic only to be called two days later for a positive blood culture. Blood cultures initially grew gram positive bacilli and patient was started on vancomycin and piperacillin-tazobactam pending final cultures. Due to her history of bicuspid aortic valve, endocarditis was suspected, and patient underwent transesophageal echocardiogram (TEE) which showed a 10-millimeter vegetation attached to the non-coronary cusp of aortic valve. Blood cultures came back positive for lactobacillus jensenii. Patient satisfied the Duke's criteria for endocarditis and was switched to penicillin and gentamicin. Further history did not elicit further risk factors of lactobacillus endocarditis including probiotic use, recent dental work, and immunodeficiency. Patient completed six weeks of antibiotics and had negative final blood cultures. DISCUSSION: This case highlights the importance of lactobacillus species to be a causative factor of endocarditis in patients with a predisposing risk factor. These risk factors include, in order of decreasing frequency, valvulopathy, dental procedures, probiotic use and immunosuppression. It is important to consider lactobacilli as a causative agent of infection if they are isolated on routine blood cultures in predisposed patients with a compatible clinical picture. TEE should be done if endocarditis is suspected. Lactobacilli are highly sensitive to penicillin G and synthetic penicillins. However, they are usually resistant to vancomycin. This is important as vancomycin is an integral regimen of most initial sepsis regimens. CONCLUSIONS: . REFERENCE #1: Campagne, J., J. F. Guichard, M. C. Moulhade, H. Kawski, and F. Maurier. "Lactobacillus endocarditis: a case report in France and literature review." IDCases 21 (2020): e00811. REFERENCE #2: Prendergast, B. D. "Diagnostic criteria and problems in infective endocarditis." Heart 90, no. 6 (2004): 611-613. DISCLOSURES: No relevant relationships by Muhammad Hasib Khalil, source=Web Response