# Bacteroides thetaiotaomicron With Concomitant Streptococcus milleri as a Cause of Purulent Pericarditis: A Case Report

## TL;DR

This case report describes a rare instance of purulent pericarditis caused by two bacteria, Bacteroides thetaiotaomicron and Streptococcus milleri, in a 56-year-old man.

## Contribution

The novelty lies in the simultaneous identification of B. thetaiotaomicron and S. milleri as causative agents of purulent pericarditis, a previously unreported combination.

## Key findings

- Bacteroides thetaiotaomicron and Streptococcus milleri were isolated from pericardial fluid in a patient with purulent pericarditis.
- This is the first reported case of purulent pericarditis caused by these two bacteria occurring together.
- The case highlights the importance of considering less common pathogens in bacterial pericarditis.

## Abstract

Purulent pericarditis secondary to bacterial infections is rarely seen in the current era of broad-spectrum antibiotics. Complications tend to be higher in comparison to viral or idiopathic etiologies in cases of bacterial pericarditis. Staphylococcal aureus, Streptococcus pneumoniae, or Haemophilus influenza are the more commonly identified pathogens in cases of bacterial pericarditis. We report a case of purulent pericarditis from Bacteroides thetaiotaomicron and Streptococcus milleri occurring in conjunction in a 56-year-old male. To our knowledge, there are no published case reports describing purulent pericarditis from B. thetaiotaomicron and S. milleri occurring simultaneously in the literature.