[Biochemical and bacteriological investigation of six cases of purple urine bag syndrome (PUBS) in a geriatric ward for dementia]

Induction of Gut Microbial Tryptamine by SARS-CoV-2 in Nonhuman Primate Model Consistent with Tryptamine-Induced Model of Neurodegeneration

The author discussed recently the possible molecular mechanisms that cause the COVID-19 disease symptoms. Here the analysis of the recent experimental data supports the hypothesis that production of the gut microbial tryptamine can be induced by the SARS-CoV-2 fecal viral activity due to the selective pressure or positive selection of tryptamine-producing microorganisms. In this report, the author suggests that the mechanism of microbial selection bases on the abilities of tryptamine to affect the viral nucleic acid. In other words, the gut microorganisms producing tryptamine are more resistant to SARS-CoV-2 fecal viral activity than microorganisms producing no tryptamine. Earlier we demonstrated the induction of neurodegeneration by tryptamine in human cells and mouse brain. Furthermore, we were able to uncover the human gut bacteria associated with Alzheimer’s disease (AD) using PCR testing of human fecal samples with the new-designed primers targeting the tryptophan-tryptamine pathway. Likely, SARS-CoV-2 is one of the selective pressure factors in the cascade accelerating the neurodegenerative process in AD. This suggestion is consistent with a higher proportion of AD patients among COVID-19 related victims. Gut microbial tryptamine increase due to the viral infection-induced dysbiosis can synergize and potentiate the tryptamine cytotoxicity, necrotizing ability and other properties as a virulence factor.

Purple Urine Bag Syndrome: More Than Eyes Can See

BACKGROUND/AIMS

Purple urine bag syndrome (PUBS) is an uncommon clinical entity characterized by purple urine discoloration in the setting of urinary tract infections. Pa-thophysiology of PUBS has been correlated to aberrant metabolism of tryptophan. Multiple predisposing factors have been recognized, namely: female gender, advanced age, constipation, institutionalization, long-term catheter-ization, dementia and chronic kidney disease. Herein, we present a comprehensive review of all PUBS cases reported in PubMed, focusing on the predisposing factors and the microorganisms related to PUBS.

METHODS

We performed a search in PubMed database for articles referring to PUBS, published in English, French, Spanish and German from January 1978 until November 2017. The literature recruitment strategy was based on several keywords and Medical Subject Heading combination such as "purple urine bag syndrome" or PUBS or "urine discoloration". The finally selected articles were categorized into case reports/series (88 articles including 112 patients) and studies (10 articles including 134 patients). Demographical data as well as predisposing factors were recorded and further analyzed.

RESULTS

According to our findings, mean age of PUBS patients was 78.9 ± 12.3 years, 70.7% were female while 90.1% were suffering from constipation, 76.1% were in a bedridden situation, 45.1% were experiencing long-term catheterization, 42.8% had been diagnosed with dementia, 14.3% had recurrent urinary tract infections and 14.1% were chronic kidney disease patients. 91.3% of patients presenting with PUBS alkaline urine were observed while the most common microbe in urine cultures was E. coli.

CONCLUSIONS

PUBS is considered benign process in the majority of catheterized patients. Clinicians should be aware of the syndrome that may indicate serious comorbidities.

Trends in the epidemiology of purple urine bag syndrome: A systematic review

Purple urine bag syndrome (PUBS) is rarely observed in clinical practice. The present study aimed to identify the epidemiological trends in PUBS in recent decades. A search of PubMed articles published between 1980 October and 2016 August was conducted, in which 106 articles (174 cases) described PUBS. Of these cases, 58 cases were excluded: 14 cases without mention of gender, 4 cases without description of age, 37 cases without mention of white blood cell (WBC) count, shock status, fever status or description of etiology, and 3 cases without information on mortality. The remaining 116 PUBS cases were collected and analyzed in the present study. The articles were divided into three groups by publication year: 1991 to 2000, 2001 to 2010 and 2011 to 2016. The χ² test was used for statistical analysis, with P<0.05 (two-tailed) defined as the threshold for significance. Of the total enrolled cases, there were 47 men (40.5%) and 69 women (59.5%), with a mean age ± standard deviation of 75.6±12.8 years. Of these, 98 cases (84.5%) were elderly (≥65 years old). A total of 93.1% of cases had a urine pH >7 while 6.9% of cases had acidic urine (pH <7). Furthermore, although WBC count elevated progressively, the mortality rate of patients with PUBS decreased over subsequent decades. This necessitates the advancement of antibiotics and application of early goal-directed therapy. Additionally, the overall mortality rate of PUBS (1980-2016) was 6.8%, which decreased to 4.3% in the last 5 years (2011-2016). In conclusion, although PUBS has previously been considered a benign process in the majority of indwelling catheterized patients, emphasis is required on early examination and aggressive antibiotic administration.

Trends in the epidemiology of purple urine bag syndrome: A systematic review

Purple urine bag syndrome (PUBS) is rarely observed in clinical practice. The present study aimed to identify the epidemiological trends in PUBS in recent decades. A search of PubMed articles published between 1980 October and 2016 August was conducted, in which 106 articles (174 cases) described PUBS. Of these cases, 58 cases were excluded: 14 cases without mention of gender, 4 cases without description of age, 37 cases without mention of white blood cell (WBC) count, shock status, fever status or description of etiology, and 3 cases without information on mortality. The remaining 116 PUBS cases were collected and analyzed in the present study. The articles were divided into three groups by publication year: 1991 to 2000, 2001 to 2010 and 2011 to 2016. The χ² test was used for statistical analysis, with P<0.05 (two-tailed) defined as the threshold for significance. Of the total enrolled cases, there were 47 men (40.5%) and 69 women (59.5%), with a mean age ± standard deviation of 75.6±12.8 years. Of these, 98 cases (84.5%) were elderly (≥65 years old). A total of 93.1% of cases had a urine pH >7 while 6.9% of cases had acidic urine (pH <7). Furthermore, although WBC count elevated progressively, the mortality rate of patients with PUBS decreased over subsequent decades. This necessitates the advancement of antibiotics and application of early goal-directed therapy. Additionally, the overall mortality rate of PUBS (1980-2016) was 6.8%, which decreased to 4.3% in the last 5 years (2011-2016). In conclusion, although PUBS has previously been considered a benign process in the majority of indwelling catheterized patients, emphasis is required on early examination and aggressive antibiotic administration.

Two Cases of the Purple Urine Bag Syndrome

The purple urine bag syndrome, purple discoloration of urine, is an uncommon and alarming condition in patients requiring long-term urinary catheterization but the clinical course is usually benign. We report two cases of the syndrome with a literature review on its aetiology and management.

Morganella morganii, a non-negligent opportunistic pathogen

Morganella morganii belongs to the tribe Proteeae of the Enterobacteriaceae family. This species is considered as an unusual opportunistic pathogen that mainly causes post-operative wound and urinary tract infections. However, certain clinical M. morganii isolates present resistance to multiple antibiotics by carrying various resistant genes (such as blaNDM-1, and qnrD1), thereby posing a serious challenge for clinical infection control. Moreover, virulence evolution makes M. morganii an important pathogen. Accumulated data have demonstrated that M. morganii can cause various infections, such as sepsis, abscess, purple urine bag syndrome, chorioamnionitis, and cellulitis. This bacterium often results in a high mortality rate in patients with some infections. M. morganii is considered as a non-negligent opportunistic pathogen because of the increased levels of resistance and virulence. In this review, we summarized the epidemiology of M. morganii, particularly on its resistance profile and resistant genes, as well as the disease spectrum and risk factors for its infection.

An update on purple urine bag syndrome

Purple urine bag syndrome is characterized by the urinary drainage bag turning purple in patients on prolonged urinary catheterization, especially those in the bedridden state. It is associated with bacterial urinary tract infections caused by indigo-producing and indirubin-producing bacteria, usually affects women, and is associated with alkaline urine, constipation, and a high bacterial load in the urine. Almost all patients with purple urine bag syndrome are catheterized due to significant disability, and the urinary pH is 7.0 or more. In general, intensive treatment with antibiotics is not recommended. Purple urine bag syndrome per se almost always appears to be asymptomatic and harmless. However, caution is needed, because some cases have been reported to show progression to severe disease states, so further research into the morbidity and mortality of this infection is warranted.