# Case report of extensive embolic complications in culture-negative mitral valve endocarditis due to Rothia dentocariosa

## TL;DR

A man with culture-negative mitral valve endocarditis caused by Rothia dentocariosa had severe embolic complications and was successfully treated with valve replacement after molecular diagnosis.

## Contribution

This case highlights the use of next-generation sequencing to identify a rare pathogen in culture-negative endocarditis and the importance of multidisciplinary care.

## Key findings

- NGS identified Rothia dentocariosa from a calf abscess in a case of culture-negative endocarditis.
- Multidisciplinary care and timely valve replacement improved outcomes despite neurological complications.
- Persistent vegetations and embolic risk necessitated surgical intervention after medical stabilization.

## Abstract

Culture-negative infective endocarditis presents significant diagnostic and therapeutic challenges, especially in patients with systemic embolic complications.

A middle-aged man with a history of intravenous drug use presented with fever, new apical systolic murmur, and widespread embolic phenomena affecting the brain, spleen, kidneys, and lower limb. Transthoracic echocardiography revealed a large posterior mitral leaflet vegetation with moderate–severe mitral regurgitation. Blood and tissue cultures were negative. Next-generation sequencing (NGS) of an aspirated calf muscle abscess identified Rothia dentocariosa. Despite prolonged antimicrobial therapy and multidisciplinary care, persistent vegetations and high embolic risk prompted mitral valve replacement after interval stabilization of intracranial haemorrhages. He recovered without recurrent emboli and with stable prosthetic valve function.

Advanced molecular diagnostics such as NGS can be crucial for identifying pathogens in culture-negative endocarditis.

Multidisciplinary collaboration and individualized surgical timing are important for achieving optimal outcomes in complex cases with neurological complications.