Not Your Usual Culprit: Relapsing Salmonella enterica Serovar Infantis Urinary Tract Infection

TL;DR

A rare case of recurring urinary tract infection caused by Salmonella Infantis in a 60-year-old woman with multiple health conditions is reported.

Contribution

This case highlights the unusual recurrence of S. Infantis UTI and the role of genomic sequencing and hygiene measures in its resolution.

Findings

S. Infantis UTI recurred three times in a year in a high-risk patient.

Genomic sequencing confirmed relapse from intestinal colonization.

A seven-day antibiotic regimen and improved hygiene led to sustained resolution.

Abstract

Urinary tract infection due to Salmonella enterica serovar Infantis (S. Infantis) is exceptionally rare and typically linked to host vulnerabilities. We report a case of a woman in her 60s with metastatic renal cancer, diabetes, chronic kidney disease, and prior splenectomy who developed three episodes of UTI within a year. Repeated urine cultures grew S. Infantis, and whole-genome sequencing confirmed relapse from intestinal colonization. After sequential short antibiotic courses, sustained resolution followed a seven-day regimen combined with reinforced pet-related hygiene measures. This case highlights the importance of considering unusual uropathogens, using genomic tools to confirm persistence, and addressing potential zoonotic reservoirs.