Case Report: Purple Urine Bag Syndrome with Surprisingly Acidic Urine

Purple Urine Bag Syndrome (PUBS) is a rare clinical phenomenon typically seen in elderly female patients. It occurs in patients who have chronic urethral catheterisation and comorbid conditions such as chronic urinary tract infections, immobility (bedridden or wheelchair-bound), dehydration, constipation, and chronic kidney disease. The pathophysiology of PUBS is thought to develop as a result of the complex metabolic pathway of essential amino acid tryptophan in the gastrointestinal system, forming urine metabolites converted by bacterial enzymes, sulphatase and phosphatase, turning urine bag and tubing purple. PUBS can emerge as asymptomatic bacteriuria or symptomatic urinary tract infection in a patient with an indwelling urinary catheter. This case report uniquely describes an elderly patient who had a prolonged urethral catheter and presented with a purple discolouration of the urine collection bag with acidic urine and a startling Klebsiella ozaenae species that has not been reported to cause this phenomenon before. In many literatures, it is noted to be a benign condition; however, it carries a significant morbidity and mortality. Thereupon, it is critical to vigilantly screen chronic catheterised patients and manage them accordingly. Management of PUBS includes: targeted antibiotic therapy, correcting underlying predisposing factors, aseptic changing of urethral catheter, and finally calming patient and caregivers regarding the condition.