# Plesiomonas shigelloides Bacteremia: A Scoping Review of Epidemiology, Clinical Characteristics, Outcomes, and Implications of Antimicrobial Stewardship

## TL;DR

This review summarizes the rare but severe bloodstream infections caused by Plesiomonas shigelloides, highlighting risk factors, clinical features, and the importance of timely treatment.

## Contribution

The first scoping review to focus specifically on P. shigelloides bacteremia, summarizing global cases and clinical outcomes.

## Key findings

- P. shigelloides bacteremia has a 27.3% case fatality rate and is more common in immunocompromised individuals.
- The bacteria show intrinsic resistance to ampicillin but remain susceptible to other antimicrobial classes.
- Poor outcomes are more linked to host factors and delayed treatment than antimicrobial resistance.

## Abstract

Plesiomonas shigelloides, an aquatic Gram-negative bacillus often associated with self-limiting gastroenteritis, has been reported worldwide. However, to date, no reviews have specifically investigated P. shigelloides bacteremia, which is rare and potentially fatal. This scoping review aimed to examine the existing literature to identify the epidemiology, clinical characteristics, antimicrobial susceptibility, and outcomes of P. shigelloides bacteremia. A PRISMA-ScR-guided search of PubMed, Scopus, Web of Science, and Embase identified 22 published cases, all reported as single-patient case reports. Cases were globally distributed, with the majority reported from the Americas and Europe. The median patient age was 46 years. The case fatality rate was 27.3% (n = 6/22). Most patients had identifiable host risk factors, particularly hematological disorders, neonatal status, or immunocompromised status, and environmental exposure such as raw seafood consumption or contact with freshwater. Clinical presentations were heterogeneous, commonly including fever and sepsis or septic shock. Microbiologically, P. shigelloides demonstrated consistent intrinsic resistance to ampicillin while retaining susceptibility to multiple antimicrobial classes. Poor outcomes were more closely associated with host factors and delayed presentation than with antimicrobial resistance. Early diagnosis, targeted therapy, and antimicrobial stewardship are essential for optimizing outcomes in this rare but severe infection.