Tackling catheter-associated urinary tract infections with next-generation antimicrobial technologies

Urinary catheters and other medical devices associated with the urinary tract such as stents are major contributors to nosocomial urinary tract infections (UTIs) as they provide an access path for pathogens to enter the bladder. Considering that catheter-associated urinary tract infections (CAUTIs) account for approximately 75% of UTIs and that UTIs represent the most common type of healthcare-associated infections, novel anti-infective device technologies are urgently required. The rapid rise of antimicrobial resistance in the context of CAUTIs further highlights the importance of such preventative strategies. In this review, the risk factors for pathogen colonization in the urinary tract are dissected, taking into account the nature and mechanistics of this unique environment. Moreover, the most promising next-generation preventative strategies are critically assessed, focusing in particular on anti-infective surface coatings. Finally, emerging approaches in this field and their likely clinical impact are examined.

Systematic review of the effect of D‑mannose with or without other drugs in the treatment of symptoms of urinary tract infections/cystitis (Review)

Several studies, reviews and meta-analyses have documented that D-mannose use lowers the risk of recurrent urinary tract infections (UTI), but its role in the treatment of UTI/cystitis-related symptoms is unclear. In particular, no systematic review has analyzed the role of treatment with D-mannose in acute UTI/cystitis. In this paper, we systematically reviewed the published data on the effect of D-mannose, alone or in association with other compounds, on the typical symptoms of UTI/cystitis. PubMed/Medline and EMBASE databases were searched, from 1990 to January 2022, using combinations of the following keywords: ‘urinary tract infections’, ‘cystalgia’, ‘recurrent next urinary tract infection’, ‘cystitis’, ‘mannose’, ‘mannoside’, ‘D-mannose’, ‘bacteriuria’, ‘pyuria’, ‘pyelocystitis’ with the appropriate Boolean modifiers (Limits: Human, English, full article). Studies were selected for the systematic review if they were clinical studies and reported original data, the number of patients using D-mannose alone or in association with other treatments, and the number of patients with symptoms of UTI/cystitis at trial entry and after the follow-up period. A total of seven studies were identified. D-mannose was given alone in two studies, and was associated with cranberry extract, Morinda citrifolia fruit extract, pomegranate extract, fructo-oligosaccharides, lactobacilli, and N-acetylcysteine in the others. All studies reported that symptoms decreased after treatment with D-mannose. Despite the limitations of the studies, the consistent results observed among all studies give support to the general findings that D-mannose may be useful in the treatment of UTI/cystitis symptoms.

Role of D-mannose in urinary tract infections - a narrative review

Urinary tract infections (UTIs) are one of the most prevalent bacterial diseases worldwide. Despite the efficacy of antibiotics targeted against UTI, the recurrence rates remain significant among the patients. Furthermore, the development of antibiotic resistance is a major concern and creates a demand for alternative treatment options. D-mannose, a monosaccharide naturally found in fruits, is commonly marketed as a dietary supplement for reducing the risk for UTIs. Research suggests that supplemented D-mannose could be a promising alternative or complementary remedy especially as a prophylaxis for recurrent UTIs. When excreted in urine, D-mannose potentially inhibits Escherichia coli, the main causative organism of UTIs, from attaching to urothelium and causing infection. In this review, we provide an overview of UTIs, E. coli pathogenesis and D-mannose and outline the existing clinical evidence of D-mannose in reducing the risk of UTI and its recurrence. Furthermore, we discuss the potential effect mechanisms of D-mannose against uropathogenic E.coli.

Mannose enhances the radio-sensitivity of esophageal squamous cell carcinoma with low MPI expression by suppressing glycolysis

BACKGROUND

To investigate the effect of mannose on radio-sensitivity of human esophageal squamous cell carcinoma (ESCC) cell line and its possible mechanism.

METHODS

The expression of mannose phosphate isomerase (MPI) in human esophageal cancer cell lines were detected by Western blot. The inhibitory effect of mannose on human esophageal cancer cell lines were observed by MTT assay. Plate clone formation assay was performed to investigate the efficacy of mannose on radio-sensitivity of human esophageal cancer cells. The apoptosis rates of tumor cells treated with mannose and/or radiation therapy was calculated by flow cytometry. Furthermore, we analyzed intracellular metabolites using liquid chromatography mass spectrometry to identify selective sugar metabolites.

RESULTS

MPI expression was various in human esophageal cancer cells. KYSE70 cells was associated with the highest MPI expression whereas KYSE450 cells had the lowest MPI expression level. When administrated with 11.1 mM/L mannose, the same inhibitory effect was observed in both KYSE70 and KYSE450 cell lines. Moreover, the inhibitory effect was significant on KYSE450 cell lines with an increased mannose concentration. The application of 11.1 mM/L mannose could significantly enhance the radio-sensitivity of KYSE450 cell line; and tumor cell apoptosis rate was also increased. However, there was limited efficacy of mannose on the radio-sensitivity and apoptosis rate of KYSE70 cell line. Additionally, intracellular metabolites analyzation revealed that glycolysis could be disturbed by mannose when combined with radiation therapy in esophageal cancer cells.

CONCLUSION

In esophageal cancer cell lines with low MPI expression, the administration of mannose was associated with enhanced radio-sensitivity.

D-mannose vs other agents for recurrent urinary tract infection prevention in adult women: a systematic review and meta-analysis

OBJECTIVE

We performed a systematic review and meta-analysis to determine whether D-mannose reduces urinary tract infection recurrence (ie, cumulative incidence) in adult women with recurrent urinary tract infection compared with other prevention agents. Secondary outcomes included side effects and compliance with D-mannose use.

DATA SOURCES

Ovid Medline 1946-, Embase 1947-, Scopus 1823-, Cochrane Library, Web of Science 1900-, and ClinicalTrials.gov were searched through 4/15/2020.

STUDY ELIGIBILITY CRITERIA

Systematic review inclusion: randomized controlled trials, prospective cohorts, and retrospective cohorts written in English of women ≥18 years old with recurrent urinary tract infection in which D-mannose was utilized as an outpatient prevention regimen. Systematic review exclusion: lab or animal-based research, study protocols only, and conference abstracts. Meta-analysis inclusion: stated D-mannose dose, follow-up time ≥6 months, a comparison arm to D-mannose, and data available from women ≥18 years of age.

STUDY APPRAISAL AND SYNTHESIS METHODS

Two independent reviewers made abstract, full text, and data extraction decisions. Study methodologic quality was assessed using the Cochrane Risk of Bias tool. Relative risks, confidence intervals, and heterogeneity were computed.

RESULTS

Searches identified 776 unique citations. Eight publications met eligibility: 2 using D-mannose only; 6 using D-mannose combined with another treatment. Seven studies were prospective: 2 randomized controlled trials, 1 randomized cross-over trial, and 4 prospective cohort studies. One retrospective cohort study was included. Three studies met meta-analysis eligibility (1 randomized controlled trial, 1 randomized cross-over trial, and 1 prospective cohort). Pooled relative risk of urinary tract infection recurrence comparing D-mannose to placebo was 0.23 (95% confidence interval, 0.14-0.37; heterogeneity=0%; D-mannose n=125, placebo n=123). Pooled relative risk of urinary tract infection recurrence comparing D-mannose to preventative antibiotics was 0.39 (95% confidence interval, 0.12-1.25; heterogeneity=88%; D-mannose n=163, antibiotics n=163). Adverse side effects were reported in 2 studies assessing D-mannose only (1 study (n=10) reported none; the other reported a low incidence (8/103 participants) of diarrhea). Two studies reported compliance, which was high.

CONCLUSION

D-mannose appears protective for recurrent urinary tract infection (vs placebo) with possibly similar effectiveness as antibiotics. Overall, D-mannose appears well tolerated with minimal side effects-only a small percentage experiencing diarrhea. Meta-analysis interpretation must consider the small number of studies with varied study design and quality and the overall small sample size.