Tropheryma whipplei Endocarditis Diagnosed by Tissue 16S rRNA Gene Sequencing: A Case Report

A 66-year-old man with arthralgia and fever of unknown origin developed progressive aortic and mitral regurgitation with vegetations. Despite a staged and extensive diagnostic work-up over six months, no pathogen was identified. Ultimately, valve replacement surgery was performed, and 16S rRNA gene sequencing of the excised valve tissue confirmed the presence of <i>T. whipplei</i>. The patient was successfully treated with ceftriaxone and long-term trimethoprim-sulfamethoxazole. <i>Tropheryma whipplei</i> is a rare cause of infective endocarditis (IE) that poses a diagnostic challenge. This case highlights the critical role of molecular diagnostics in identifying fastidious organisms in patients with culture-negative endocarditis.