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Purple catheter syndrome (PUBS): a mystery in a post stroke patient with Klebsiella - should we be concerned?

Induja K, Gaur R, Gonnade NM, Tak V, Sinha KK, Sheenam N, T K A

BMC urology, 2026

Abstract

Background: Purple urine bag syndrome (PUBS) is an unusual but recognizable manifestation characterized by a striking purple hue in the urinary collection system. This phenomenon results from bacterial enzymatic breakdown of tryptophan in the presence of alkaline urine. While often benign, PUBS can indicate an underlying infection, particularly in individuals with long-term catheterization and other risk factors, such as immobility and constipation.

Case presentation: We describe the case of a woman in her 40s with a prior cerebrovascular accident who was bedbound and dependent on a long-term indwelling catheter. She developed discoloration of her urine bag without systemic symptoms. Urine analysis revealed an alkaline pH and significant pyuria, and culture confirmed infection with Klebsiella pneumoniae. Management involves replacing the catheter, initiating culture-directed antibiotic therapy with levofloxacin, optimizing bowel habits, and promoting hydration. These interventions led to a full resolution of the discoloration and infection.

Conclusion: Although visually alarming, PUBS often serves as a subtle clinical indicator of underlying urinary tract pathology. This case highlights the necessity of a multifactorial management approach, including microbiological evaluation, catheter hygiene, bowel regulation, and patient education. Early recognition of PUBS may help prevent escalation to more severe complications in vulnerable, catheter-dependent patients.

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