LEGIONELLA MICDADEI: A CASE OF CULTURE NEGATIVE NATIVE MITRAL VALVE ENDOCARDITIS

Abstract

SESSION TITLE: Monday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM INTRODUCTION: Legionella is a Gram-negative bacteria that is most commonly associated with pneumonia. We describe a rare case of native valve endocarditis caused by a Legionella isolated from mitral valve tissue. CASE PRESENTATION: A 29-year-old male with a history of stroke with no residual deficits and Mitral valve (MV) endocarditis presented with slurred speech and left facial droop which lasted for 30 seconds after which it resolved completely. Prior to admission, he reported fevers, chills, and night sweats. Medical history was notable for lupus nephritis diagnosed one year ago on azathioprine and mycophenolate. He denied any intravenous drug use. A grade 2/6 holosystolic murmur was heard at the left lower sternal border to the apex. He was febrile to 101.2 F, heart rate of 114 bpm, blood pressure 106/62 mm Hg. Labs were significant for a small troponin leak. Blood cultures were sterile. CT head showed mild encephalomalacia on the left insula. Transthoracic echocardiogram showed severely dilated left atrium and new mobile echo density located laterally on the mitral annulus and transesophageal echocardiogram showed MV dehiscence. He was started on empirical coverage for culture-negative endocarditis and was transferred to surgery. He underwent Redo sternotomy and redo mitral valve replacement with a St. Jude’s mechanical prosthesis. The valve tissue appeared very friable, possibly infected and it was debrided and sent to microbiology for culture and polymerase chain reaction [PCR]. PCR was positive for Legionella micdadei. He was discharged with appropriate antibiotics. DISCUSSION: This case is another example of culture-negative legionella endocarditis diagnosed using infected valve tissue. Extrapulmonary manifestations of Legionella infections (septic arthritis, myocarditis, pericarditis, and endocarditis) often occur in immunocompromised patients and are most often treated with fluoroquinolones. Diagnostic tests for culture-negative endocarditis include special culturing techniques, molecular techniques e.g., PCR and serologic assays, and histopathology evaluation of valvular tissue when surgical excision is performed. CONCLUSIONS: Legionella species should be considered in the differential diagnosis of culture-negative endocarditis in both immunocompetent and immunocompromised patients. Reference #1: Pearce, M. M., Theodoropoulos, N., Noskin, G. A., Flaherty, J. P., Stemper, M. E., Aspeslet, T., ... Reed, K. D. (2011). Native valve endocarditis due to a novel strain of Legionella. Journal of Clinical Microbiology, 49(9), 3340-3342. Reference #2: Park D, Pugliese A, Cunha BA. Legionella micdadei prosthetic valve endocarditis. Infection. 1994;22(3):213–215. Reference #3: Chen TT, Schapiro JM, Loutit J. Prosthetic valve endocarditis due to Legionella pneumophila. J Cardiovasc Surg. 1996;37(6):631–633 DISCLOSURES: No relevant relationships by Mohammed Essa, source=Web Response No relevant relationships by Karthik Gonuguntla, source=Web Response No relevant relationships by Gaurav Manek, source=Web Response No relevant relationships by Shivaraj Patil, source=Web Response