SciELO - Scientific Electronic Library Online

vol.38 issue4Hypercalcemia and renal function impairment associated with vitamin D toxicity: case reportNodular glomerulosclerosis in a non-diabetic hypertensive, dyslipidemic, smoker patient: a case report author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand




Related links


Jornal Brasileiro de Nefrologia

Print version ISSN 0101-2800On-line version ISSN 2175-8239

J. Bras. Nefrol. vol.38 no.4 São Paulo Oct./Dec. 2016 

Case Report

Purple urine bag syndrome: case report for Streptoccocus agalactiae and literature review

Klaus Nunes Ficher1 

Amanda Azevedo Neves de Araújo1 

Sandra Gomes de Barros Houly1 

Paulo Ricardo Gessolo Lins1 

Moacyr Silva Jr1 

Aecio Flavio Teixeira de Góis1 

1Disciplina de Medicina de Urgência e Medicina Baseada em Evidências. Departamento de Medicina. Escola Paulista de Medicina. Universidade Federal de São Paulo.


We report a case of purple urine bag syndrome, associated to Streptococcus agalactiae urinary tract infection, progressing to septic shock and death. We present a review of the literature on the subject and take the opportunity to attend readers about increasing incidence with population aging and its potential bad outcome.

Keywords: sepsis; shock, septic; urinary tract infections; urine specimen collection

Case report

A 83 years-old female with a history of arterial hypertension, diastolic heart failure, chronic kidney disease non-dialysis (CKD-EPI e-GFR = 52.2 ml/min/1.73m2, paroxysmal atrial fibrillation in anticoagulation treatment with rivaroxaban and a stroke 2 years ago, who had been recently hospitalized due to decompensation of cardiomyopathy, being discharged home with loss of previous functionality.

The patient was admitted to a tertiary hospital emergency with a 1-day history of darkened and fetid feces in the diaper, associated to prostration. No melena was detected through rectal exam and upper gastrointestinal endoscopy did not reveal any signs of bleeding. The patient evolved with a consciousness level decreasing, being intubated for protection of airway, and posteriorly presented septic shock, being transferred to the ICU.

During indwelling urinary catheter insertion, the patient exteriorized pyuria. She undergone a urine culture and started an antibiotic therapy with piperacillin-tazobactam, due to recent hospitalization. On hospital day 2 the patient evolved with refractory shock and her urine was noted to be purple in urine bag (Figure 1), being expanded antibiotic therapy through meropenem empirically. Urine culture done on patient's admittance presented Streptoccocus agalactiae development. Despite the use of vancomycin after culture's result, patient came to death.

Figure 1 Bag showing purple urine 

Literature review

Purple urine case was first noted by Barlow and Dickson in a letter to The Lancet in 1978, having identified the presence of indigo through spectrometry and raising the hypothesis of it being result of the excretion of indoxyl sulfate, generated from degradation of intestinal triptophan.1

Subsequently, other authors questioned urine color, as indigo would be related to blue coloration, formulating the hypothesis that the urine would turn purple only when in contact with the urine bag; they have also associated it to the presence of bacteria as Pseudomonas aeruginosa and Proteus spp.2

In these initial reports, authors already related the syndrome to elderly women with a history of dementia and constipation. McSherry3 has also corroborated the idea of purple urine bag being attributed to the presence of indigo as an indoxyl sulfate metabolite product from the degradation of intestinal triptophan, but later studies pointed indicanuria as cause of purple coloration.4,5

Dealler et al.6 have studied six cases of the syndrome and associated it to urinary infection by Providencia suartii and Klebsiella pneumonia with presence of indigo and indirubin in urine; they have also found in laboratory that only these species and Enterobacter agglomerans were capable of producing indigo in vitro.

In the decade of 1990, Umeki7 noted that the indoxyl sulfate ability of changing into indigo (blue) and indirubin (red) was mediated by bacterial enzymes called indoxyl phosphatase and sulfatase, produced by Proteus mirabilis and Klebisiella Pneumoniae, being catalyzed in alkaline urine. Almost a decade later, the purple urine bag syndrome was associated to women and alkaline urine, being urinary infection the most important risk factor in its occurrency.8

Literature shows purple urine bag syndrome occurrence is more common in elderly women, users of indwelling urinary catheter, constipated and presenting alkaline urine.8-12 The presence of alkaline urine was posteriorly reported in a case-control study.13

Recently, a cohort demonstrated the incidence of purple urine bag syndrome in 16.7% of institutionalized patients relating it to women with presence of gram-negative in their urine culture Pseudomonas aeruginosa, Citrobacter koseri, Providencia rettgeri, Morganella morganii and Escherichia coli, questioning the necessity of alkaline pH in urine for its occurrence.14

Recent literature reviews established that constipation associated to bacterial hyperproliferation leads to loss of amino radical tryptophan and indole formation, conjugated into indoxyl sulfate in the liver; the action of bacterial enzymes in the urine, sulfatase and phosphatase, produces indigo (blue) and/or its oxidation into indirubin (red), that occurs while in touch with the urine bag.15,16

Bar-Or et al.17 reported a few years ago the occurrence of purple urine bag syndrome in non-alkaline environment, also associated to the presence of índigo. Chung et al.18 registered the syndrome in acid urine with gram-negative bacteria development in urine culture. In 2007, the syndrome was first related to death.19 More recently, awareness around the uncertainty of the syndrome benignity rose due to another death case. On this occasion, the urine culture revealed the presence of Pseudomonas aeruginosa and Enterococcus resistent to vancomicyn.20


The reported patient had been recently hospitalized due to heart failure decompensation and, reviewing medical records, there was no registry of the use of antibiotics on the occasion. Despite the suspicion that brought the patient suggesting occurrence of high digestive hemorrhage, the performance of endoscopic study in the emergency room revealed no bleedings.

In quick evolution, patient evolved into a consciousness level decreasing and hypotension, being transferred to our ICU; on indwelling urinary catheter, patient exteriorized dark colored pyuria. The laboratory tests done on admission revealed an acute renal lesion (KDIGO stage 3) and a count of 62,000 leukocyte/mL in urine, with bacteriuria and pH = 5.0; CBC did not showed signs of leukocytosis.

The patient received piperacillin-tazobactam empirically immediately after the collection of cultures and intensive support for septic shock following both institutional and international protocols. The empirical choice of broad-spectrum antibiotics therapy was due to recent hospitalization. On day 2 of hospitalization, the presence of purple urine in the urinary bag was observed.

In a fast literature review, we broadened the spectrum of antibiotics therapy to meropenem, to cover ESBL (extended-spectrum beta-lactamase) germs producers, common in our services. The blood cultures collected on admittance of the patient did not show any bacterial development, but the urine culture revealed presence of Streptococcus agalactiae (superior to 1,000.000 UFC/mL). Despite the efforts and all the support, perhaps due to several comorbidities and advanced age, the patient came to death on day 3 of hospitalization.

In this report, we noted the occurrence of purple urine bag syndrome in non-alkaline environment, which could be related to a laboratory error - since we just had a single sample, and associated to urinary infection by an uncommonly germ linked to the syndrome. Despite many case reports relate the syndrome occurrence with benignity, we warn the readers to its possible mortality, as other authors have already reported.


1 Barlow GB, Dickson JAS. Purple urine bags. Lancet 1978;311:220-1. DOI: ]

2 Sammons HG, Skinner C, Fields J, Payne B, Grant A. Purple urine bags. Lancet 1978;311:502. DOI: ]

3 McSherry JA. The purple bag syndrome. Can Fam Physician 1980;26:1410-1. PMID: 21293710 [ Links ]

4 Stott A, Khan M, Roberts C, Galpin IJ. Purple urine bag syndrome. Ann Clin Biochem 1987;24:185-8. PMID: 3109308 DOI: ]

5 Nobukuni K, Kawahara S, Nagare H, Fujita Y. Study on purple pigmentation in five cases with purple urine bag syndrome. Kansenshogaku Zasshi 1995;69:1269-71. PMID: 8708407 DOI: ]

6 Dealler SF, Hawkey PM, Millar MR. Enzymatic degradation of urinary indoxyl sulfate by Providencia stuartii and Klebsiella pneumoniae causes the purple urine bag syndrome. J Clin Microbiol 1988;26:2152-6. [ Links ]

7 Umeki S. Purple urine bag syndrome (PUBS) associated with strong alkaline urine. Kansenshogaku Zasshi 1993;67:1172-7. DOI: ]

8 Mantani N, Ochiai H, Imanishi N, Kogure T, Terasawa K, Tamura J. A case-control study of purple urine bag syndrome in geriatric wards. J Infect Chemother 2003;9:53-7. DOI: ]

9 Tang MW. Purple urine bag syndrome in geriatric patients. J Am Geriatr Soc 2006;54:560-1. PMID: 16551343 DOI: ]

10 Su FH, Chung SY, Chen MH, Sheng ML, Chen CH, Chen YJ, et al. Case analysis of purple urine-bag syndrome at a long-term care service in a community hospital. Chang Gung Med J 2005;28:636-42. [ Links ]

11 Vallejo-Manzur F, Mireles-Cabodevila E, Varon J. Purple urine bag syndrome. Am J Emerg Med 2005;23:521-4. DOI: ]

12 Harun NS, Nainar SK, Chong VH. Purple urine bag syndrome: a rare and interesting phenomenon. South Med J 2007;100:1048-50. DOI: ]

13 Tsumura H, Satoh T, Kurosaka S, Fujita T, Matsumoto K, Baba S. Clinical characteristics in patients with purple urine bag syndrome. Hinyokika Kiyo 2008;54:185-8. PMID: 18411773 [ Links ]

14 Shiao CC, Weng CY, Chuang JC, Huang MS, Chen ZY. Purple urine bag syndrome: a community-based study and literature review. Nephrology (Carlton) 2008;13:554-9. DOI: ]

15 Khan F, Chaudhry MA, Qureshi N, Cowley B. Purple urine bag syndrome: an alarming hue? A brief review of the literature. Int J Nephrol 2011;2011:419213. DOI: ]

16 Hadano Y, Shimizu T, Takada S, Inoue T, Sorano S. An update on purple urine bag syndrome. Int J Gen Med 2012;5:707-10. DOI: ]

17 Bar-Or D, Rael LT, Bar-Or R, Craun ML, Statz J, Garrett RE. Mass spectrometry analysis of urine and catheter of a patient with purple urinary bag syndrome. Clin Chim Acta 2007;378:216-8. DOI: ]

18 Chung SD, Liao CH, Sun HD. Purple urine bag syndrome with acidic urine. Int J Infect Dis 2008;12:526-7. DOI: ]

19 Su YJ, Lay YC, Chang WH. Purple urine bag syndrome in a dead-on-arrival patient: case report and articles reviews. Am J Emerg Med 2007;25:861.e5-6. DOI: ]

20 Bhattarai M, Bin Mukhtar H, Davis TW, Silodia A, Nepal H. Purple urine bag syndrome may not be benign: a case report and brief review of the literature. Case Rep Infect Dis 2013;2013:863853. DOI: ]

Received: December 02, 2015; Accepted: January 07, 2016

Correspondence to: Klaus Nunes Ficher. Universidade Federal de São Paulo. Rua Botucatu, nº 740, 3º Andar, Vila Clementino, São Paulo, SP, Brazil. CEP: 04023-900. E-mail:

Creative Commons License This is an Open Access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.