Purple urine bag syndrome in a hemodialysis patient

Purple urine bag syndrome (PUBS) is an uncommon disorder, in which the plastic disposable urinary catheter bag turns purple or blue following hours or days of urinary catheterization. The purple discoloration results from indirubin dissolved in the plastic mixing with indigo in the urine. Bacteria possessing indoxyl sulfatase degrade indoxyl sulfate into indirubin and indigo. Indoxyl sulfate is derived from the metabolism of tryptophan. PUBS usually occurs in chronic catheterized elderly women who are constipated and poorly ambulant. The clinical course is benign and rarely causes sepsis. This investigation reports a 61-year-old female diabetic patient with end-stage renal disease on maintenance hemodialysis, who had two episodes of blue or purple urine bag discoloration. The urine culture of the first episode yielded Klebsiella pneumoniae, whereas that of the second episode yielded Escherichia coli, Enterococcus faecalis, and Proteus vulgaris. Both episodes resolved following oral antibiotics treatment and placement of new foley catheters. To our knowledge, this is the first recorded case of PUBS in a dialysis patient.