# Ruminococcus gnavus Bacteremia in a SARS-CoV-2 Patient With Diverticulosis

## TL;DR

An elderly man with diverticulosis and SARS-CoV-2 infection developed bacteremia caused by Ruminococcus gnavus, a normally harmless gut bacterium, likely due to immunosuppression from corticosteroid therapy.

## Contribution

This case highlights a rare association between R. gnavus bacteremia, SARS-CoV-2 treatment with corticosteroids, and diverticulosis.

## Key findings

- R. gnavus bacteremia occurred in a patient with diverticulosis and SARS-CoV-2 infection treated with corticosteroids.
- Literature review identified 17 prior R. gnavus bacteremia cases, most linked to gastrointestinal conditions or immunosuppression.
- Corticosteroid-induced immunosuppression may have contributed to intestinal microbiome imbalance and subsequent bacteremia.

## Abstract

Ruminococcus gnavus is a constituent of the human intestinal microbiota, found in the commensal flora of healthy individuals. Changes in the intestinal microflora associated with chronic conditions and immunosuppression promote the bacterial translocation of R. gnavus.

We present a case of bacteremia due to R. gnavus in an elderly man with multiple comorbidities, including diverticular disease and moderate SARS-CoV-2 infection requiring corticosteroid therapy. He had a prolonged hospital stay and multiple infectious complications.

According to the literature review in databases such as PubMed (the last search was conducted in August 2023), a total of 17 cases were described. The reported cases had in common gastrointestinal symptoms such as gastrointestinal bleeding, diverticular disease, ulcerative colitis, cholecystitis, gastrointestinal fistula, or infection due to an orthopedic prosthesis. There was also a case in a patient with hemato-oncological disease, previously treated with a cycle of corticosteroids.

It was considered that, alongside the history of diverticular disease, the immunosuppression secondary to the corticosteroid therapy for the SARS-CoV-2 infection may have contributed to the imbalance of the intestinal microbiome, leading to the occurrence of bacteremia due to this commensal agent.