A 58-year-old male presented with a two-month history of fever, weight loss, and fatigue, ultimately diagnosed with native valve endocarditis. Initial blood cultures were negative, and echocardiography revealed mitral valve vegetations. Despite empirical antibiotic therapy, his condition worsened. Diagnosis was challenging until plasma microbial cell-free DNA sequencing identified Tropheryma whipplei. This advanced diagnostic method enabled targeted treatment with doxycycline and hydroxychloroquine, leading to clinical improvement and discharge. This case highlights the critical role of mcfDNA sequencing in diagnosing culture-negative endocarditis caused by fastidious organisms like T. whipplei, preventing diagnostic delays and improving patient outcomes.
Key note: Plasma microbial cell-free DNA sequencing is a valuable tool for diagnosing culture-negative endocarditis, especially for difficult-to-cultivate pathogens.