A Randomized, Double-Blind, Parallel-Group, Multicenter Clinical Study of Escherichia coli-Lyophilized Lysate for the Prophylaxis of Recurrent Uncomplicated Urinary Tract Infections

Bacterial Vaccines for the Management of Recurrent Urinary Tract Infections: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVE

Several bacterial immunisations have been developed to reduce the socioeconomic burden of urinary tract infections (UTIs) and the use of prophylactic antibiotics in the management of recurrent UTIs (rUTIs). This systematic review evaluates the effectiveness of vaccinations in preventing rUTIs.

METHODS

Medline, Embase, and Web of Science were searched from inception to December 2023. Data were collected from cohort studies with a comparator arm and randomised controlled trials (RCTs) investigating vaccination efficacy in adult rUTI patients according to predefined selection criteria (PROSPERO registration: CRD42022356662). A pooled analysis took place for RCTs, with a subgroup analysis for vaccine types and booster regimens. Other studies were synthesised narratively. The risk of bias was assessed using Cochrane Risk-of-Bias tools. The Grading of Recommendations, Assessment, Development, and Evaluations framework evaluated the quality of evidence.

KEY FINDINGS AND LIMITATIONS

Fourteen comparative studies were selected, including 2822 patients across five vaccination types. The pooled risk ratio of eight placebo-controlled studies of the percentage of patients UTI free in the short term (6-12 mo) was 1.52 (95% confidence interval [CI] 1.05-2.20) with a number needed to treat of 6.45 (95% CI 2.80-64.80). There is substantial heterogeneity and a slight risk of a publication bias.

CONCLUSIONS AND CLINICAL IMPLICATIONS

There is limited evidence to suggest that vaccinations are effective at reducing UTI recurrence in adult female patients in the short term. Owing to low quality of evidence, the literature requires further long-term RCTs with large sample sizes utilising standardised definitions for conclusive evidence of the long-term efficacy of vaccination in rUTI prevention.

PATIENT SUMMARY

We explored whether vaccines could help stop urinary tract infections (UTIs) from happening again. The latest information shows that these vaccines are safe and may help lower the chances of women getting UTIs again for about 6-12 mo.

Advances in Bacterial Lysate Immunotherapy for Infectious Diseases and Cancer

Antigenic cell fragments, pathogen-associated molecular patterns, and other immunostimulants in bacterial lysates or extracts may induce local and systemic immune responses in specific and nonspecific paradigms. Based on current knowledge, this review aimed to determine whether bacterial lysate has comparable functions in infectious diseases and cancer treatment. In infectious diseases, including respiratory and urinary tract infections, immune system activation by bacterial lysate can identify and combat pathogens. Commercially available bacterial lysates, including OM-85, Ismigen, Lantigen B, and LW 50020, were effective in children and adults in treating respiratory tract infections, chronic obstructive pulmonary disease, rhinitis, and rhinosinusitis with varying degrees of success. Moreover, OM-89, Uromune, Urovac, Urivac, and ExPEC4V showed therapeutic benefits in controlling urinary tract infections in adults, especially women. Bacterial lysate-based therapeutics are safe, well-tolerated, and have few side effects, making them a good alternative for infectious disease management. Furthermore, a nonspecific immunomodulation by bacterial lysates may stimulate innate immunity, benefiting cancer treatment. "Coley's vaccine" has been used to treat sarcomas, carcinomas, lymphomas, melanomas, and myelomas with varying outcomes. Later, several similar bacterial lysate-based therapeutics have been developed to treat cancers, including bladder cancer, non-small cell lung cancer, and myeloma; among them, BCG for in situ bladder cancer is well-known. Proinflammatory cytokines, including IL-1, IL-6, IL-12, and TNF-α, may activate bacterial antigen-specific adaptive responses that could restore tumor antigen recognition and response by tumor-specific type 1 helper cells and cytotoxic T cells; therefore, bacterial lysates are worth investigating as a vaccination adjuvants or add-on therapies for several cancers.

The clinical implications of bacterial pathogenesis and mucosal immunity in chronic urinary tract infection

Urinary tract infections (UTIs) exert a significant health and economic cost globally. Approximately one in four people with a previous history of UTI continue to develop recurrent or chronic infections. Research on UTI has primarily concentrated on pathogen behavior, with the focus gradually shifting to encompass the host immune response. However, these are centered on mouse models of Escherichia coli infection, which may not fully recapitulate the infective etiology and immune responses seen in humans. The emerging field of the urobiome also inadvertently confounds the discrimination of true UTI-causing pathogens from commensals. This review aims to present a novel perspective on chronic UTI by linking microbiology with immunology, which is commonly divergent in this field of research. It also describes the challenges in understanding chronic UTI pathogenesis and the human bladder immune response, largely conjectured from murine studies. Lastly, it outlines the shortcomings of current diagnostic methods in identifying individuals with chronic UTI and consequently treating them, potentially aggravating their disease due to mismanagement of prior episodes. This discourse highlights the need to consider these knowledge gaps and encourages more relevant studies of UTIs in humans.

Effectiveness and health cost analysis between immunoprophylaxis with MV140 autovaccine, MV140 vaccine and continuous treatment with antibiotics to prevent recurrent urinary tract infections

INTRODUCTION

The objective of this study was to compare the results on prevention of uncomplicated recurrent UTI between continuous use of antibiotics, MV140 autovaccine and MV140 polybacterial vaccine from collection strain.

METHODS

377 patients were prospectively analyzed from January 2017 to August 2019 and divided into 3 groups according to the prophylaxis. Group A (126): antibiotics, Group B (126): MV140 autovaccine, Group C (125): MV140 polybacterial vaccine from the collection strain. Variables analyzed were: gender, age, menopause, number of UTI at baseline and 3 and 6 months after the end of prophylaxis, health cost along follow-up at 3 and 6 months.

RESULTS

At 3 months, group A had 0-1 UTI in 65%, group B had 0-1 UTI in 80.8% and group C in 81.7%. At 6 months, group A had 0-1 UTI in 44.4%, group B had 0-1 UTI in 61.6% and group C in 74.6%. Regarding health cost along follow-up, at 3 months group A had euro21,171.87, group B had euro20,763.73 and group C euro18,866.14. At 6 months, health cost was euro32,980.35 in group A, euro28,133.42 in group B, and euro23,629.19 in group C.

CONCLUSIONS

MV140 autovaccine and MV140 polybacterial vaccine were more efficient with lower number of UTI at 3 and 6 months and lower health cost along follow-up compared to continued prophylaxis with antibiotics (p < 0.05). Polybacterial MV140 vaccine from collection strain had higher effect to reduce the number of UTI and less health cost than autovaccine.

Prospective multicentre randomized double-blind placebo-controlled parallel group study on the efficacy and tolerability of StroVac® in patients with recurrent symptomatic uncomplicated bacterial urinary tract infections

PURPOSE

To evaluate efficacy and safety of vaccination with StroVac compared to placebo in patients with recurrent urinary tract infections (rUTI).

MATERIAL AND METHODS

We performed a prospective, double-blinded, placebo-controlled study in patients with uncomplicated rUTI. Patients received three single intramuscular injections with StroVac every two weeks. Primary endpoint was the number of bacterial urinary tract infections (UTI) over 13.5 months after randomization and adjusted by the respective "baseline" value when comparing verum and placebo group. Secondary endpoints were the number of patients with non-recurrence, time to first recurrence, frequency of recurrences, and patients' self-assessment of quality of life using a validated questionnaire.

RESULTS

376 patients were randomized to both groups between January 2012 and March 2015. Mean age was 44.4 years. Patients were mainly female (98.4%). In the StroVac group (n = 188), the number of UTIs was reduced from 5.5 to 1.2, in the placebo group (n = 188) from 5.4 to 1.3 (p = 0.63). In patients with ≥ 7 UTIs prior to study inclusion, StroVac was statistically significantly superior to placebo (p = 0.048). However, in all other secondary endpoints, no statistical differences between the two groups could be seen (all p > 0.3).

CONCLUSION

StroVac reduced the number of clinically relevant UTIs like in former studies but did not show statistically significant better results than the chosen placebo. Most likely, that was due to a, since confirmed, prophylactic effect of the chosen placebo itself. Therefore, placebo-controlled and double-blinded studies using a different ineffective placebo preparation are needed to determine the importance of StroVac in prophylaxis of rUTI.

Management of urinary tract infections in the era of antimicrobial resistance

Urinary tract infections (UTIs) are among the most common infections globally, imposing a substantial personal and economic burden on individuals and health resources. Despite international health concerns and sustained public awareness campaigns about the emergence of resistant microorganisms through the inappropriate therapeutic use of antimicrobial agents, the problem of antimicrobial resistance (AMR) is worsening, and AMR in UTIs represents a critical global healthcare issue. This narrative review summarizes evidence-based scientific material, recommendations from the current medical literature, and the latest clinical guidelines on antibiotic and antibiotic-sparing strategies for managing urological infections, including practical approaches to improve the management of patients with acute and recurrent UTIs (rUTIs) in routine clinical practice. Novel emerging therapies and prophylaxis options are described as potential alternatives to overcome the abuse and overuse of antibiotics and the practical application of the guideline recommendations and issues relating to best practice in managing UTIs.

Efficacy of vaccination with StroVac for recurrent urinary tract infections in women: a comparative single-centre study

PURPOSE

To assess the efficacy of prophylaxis for urinary tract infections (UTI) in a two-year follow-up in women with StroVac compared to a therapy with Nitrofurantoin over three months.

MATERIALS AND METHODS

All patients with documented recurrent urinary tract infections (rUTI) were offered vaccination with StroVac or therapy with three months Nitrofurantoin 100 mg once daily for three months at patient's choice. Only patients with a follow-up of at least 24 months were included. All episodes with signs of UTI were documented and urine culture was performed. Success was defined as one or none UTI per 12 months, documented by urine culture. StroVac booster injection was offered 12 months after primary vaccination at patient's choice.

RESULTS

173 patients were included in this study, 124 in the StroVac group, 49 chose Nitrofuratoin. In the first 12 months, 86.8% of patients in the StroVac group and 91.8% in Nitrofurantoin group were successful (p = 0.22). Side effects were noted in 2.3% in the StroVac group causing discontinuation of therapy, whereas in the Nitrofurantoin group 18.4% stopped medication premature, mostly due to mild diarrhoea. In the second year 79.3% of patients in the StroVac group were still successful, most of them had undergone booster injection. In contrast, in the Nitrofurantoin group only 59.2% of patients were still successful (p = 0.03).

CONCLUSION

StroVac is an effective and lasting non-antibiotic prophylaxis for rUTI, easy to administer with low rates of adverse events and should be offered to patients with rUTI.

The current state of immunization against Gram-negative bacteria in children: a review of the literature

PURPOSE OF REVIEW

Gram-negative bacteria (GNB) are a major cause of infection worldwide and multidrug resistance in infants and children. The major pathogens include Klebsiella pneumoniae, Escherichia coli, Enterobacter spp., Pseudomonas aeruginosa and Acinetobacter baumannii. With new antibiotic options limited, immunization is likely to play a critical role in prevention. This review discusses their epidemiology, the current state of vaccine research and potential immunization strategies to protect children. A comprehensive review of the literature, conference abstracts along with web searches was performed to identify current and investigational vaccines against the major GNB in children.

RECENT FINDINGS

Phase I--III vaccine trials have been undertaken for the major Gram-negative bacteria but not in infants or children. E. coli is a common infection in immune-competent children, including neonatal sepsis. Several vaccines are in late-phase clinical trials, with some already licensed for recurrent urinary tract infections in women. Klebsiella spp. causes community-acquired and hospital-acquired infections, including sepsis in neonates and immunocompromised children although no vaccine trials have extended beyond early phase 2 trials. P. aeruginosa is a common pathogen in patients with cystic fibrosis. Phase 1--3 vaccine and monoclonal antibody trials are in progress, although candidates provide limited coverage against pathogenic strains. Enterobacter spp. and A. baumannii largely cause hospital-acquired infections with experimental vaccines limited to phase 1 research.

SUMMARY

The current immunization pipelines for the most prevalent GNB are years away from licensure. Similar to incentives for new antibiotics, global efforts are warranted to expedite the development of effective vaccines.

Strategies to Tackle Antimicrobial Resistance: The Example of Escherichia coli and Pseudomonas aeruginosa

Traditional antimicrobial treatments consist of drugs which target different essential functions in pathogens. Nevertheless, bacteria continue to evolve new mechanisms to evade this drug-mediated killing with surprising speed on the deployment of each new drug and antibiotic worldwide, a phenomenon called antimicrobial resistance (AMR). Nowadays, AMR represents a critical health threat, for which new medical interventions are urgently needed. By 2050, it is estimated that the leading cause of death will be through untreatable AMR pathogens. Although antibiotics remain a first-line treatment, non-antibiotic therapies such as prophylactic vaccines and therapeutic monoclonal antibodies (mAbs) are increasingly interesting alternatives to limit the spread of such antibiotic resistant microorganisms. For the discovery of new vaccines and mAbs, the search for effective antigens that are able to raise protective immune responses is a challenging undertaking. In this context, outer membrane vesicles (OMV) represent a promising approach, as they recapitulate the complete antigen repertoire that occurs on the surface of Gram-negative bacteria. In this review, we present Escherichia coli and Pseudomonas aeruginosa as specific examples of key AMR threats caused by Gram-negative bacteria and we discuss the current status of mAbs and vaccine approaches under development as well as how knowledge on OMV could benefit antigen discovery strategies.

Alternative Therapeutic Options to Antibiotics for the Treatment of Urinary Tract Infections

Urinary tract infections (UTIs) mainly caused by Uropathogenic Escherichia coli (UPEC), are common bacterial infections. Many individuals suffer from chronically recurring UTIs, sometimes requiring long-term prophylactic antibiotic regimens. The global emergence of multi-drug resistant uropathogens in the last decade underlines the need for alternative non-antibiotic therapeutic and preventative strategies against UTIs. The research on non-antibiotic therapeutic options in UTIs has focused on the following phases of the pathogenesis: colonization, adherence of pathogens to uroepithelial cell receptors and invasion. In this review, we discuss vaccines, small compounds, nutraceuticals, immunomodulating agents, probiotics and bacteriophages, highlighting the challenges each of these approaches face. Most of these treatments show interesting but only preliminary results. Lactobacillus-containing products and cranberry products in conjunction with propolis have shown the most robust results to date and appear to be the most promising new alternative to currently used antibiotics. Larger efficacy clinical trials as well as studies on the interplay between non-antibiotic therapies, uropathogens and the host immune system are warranted.

The EAU and AUA/CUA/SUFU Guidelines on Recurrent Urinary Tract Infections: What is the Difference?

For diagnosis of urinary tract infection (UTI), low bacterial counts in urine culture need to be considered more often. Non-antibiotic prophylaxis should be prioritized before antibiotic prophylaxis in patients with uncomplicated, recurrent UTI. Immunoprophylaxis in patients with rUTI deserves better consideration.

Avoiding antibiotics in the management of recurrent UTIs in women: What are our options?

Urinary tract infections are one of the most common infections worldwide, accounting in the United Kingdom for 1–3% of all medical consultations. Fifty per cent of women will experience one episode of urinary tract infection in their lifetimes and of these, up to 30% will develop recurrent urinary tract infections. Such women often rely on long-term low dose antibiotics.

Level of evidence: Not applicable for this multicentre audit.

Nonantibiotic prevention and management of recurrent urinary tract infection

Urinary tract infections (UTIs) are highly prevalent, lead to considerable patient morbidity, incur large financial costs to health-care systems and are one of the most common reasons for antibiotic use worldwide. The growing problem of antimicrobial resistance means that the search for nonantibiotic alternatives for the treatment and prevention of UTI is of critical importance. Potential nonantibiotic measures and treatments for UTIs include behavioural changes, dietary supplementation (such as Chinese herbal medicines and cranberry products), NSAIDs, probiotics, D-mannose, methenamine hippurate, estrogens, intravesical glycosaminoglycans, immunostimulants, vaccines and inoculation with less-pathogenic bacteria. Some of the results of trials of these approaches are promising; however, high-level evidence is required before firm recommendations for their use can be made. A combination of these agents might provide the optimal treatment to reduce recurrent UTI, and trials in specific population groups are required.

Prevention and treatment of uncomplicated lower urinary tract infections in the era of increasing antimicrobial resistance-non-antibiotic approaches: a systemic review

Purpose

Urinary tract infections (UTIs) are one of the more common infections encountered in everyday clinical practice. They account for 10–20% of all infections treated in primary care units and 30–40% of those treated in hospitals. The risk of UTI in the female population is considered to be 14 times higher than in the male population. The prevalence of bacterial etiology results in a large consumption of broad-spectrum antibiotics, which in turn leads to increased rates of resistant uropathogens. Therefore, non-antibiotic prevention and treatment options are now of great importance.

Methods

A systematic literature search was performed for the last 20 years (1999–2019) and the efficiencies of these eight different non-antibiotic interventions were analysed and discussed.

Results

This article provides an overview on non-antibiotic options for management of UTI, including the application of cranberry products, the phytodrug Canephron N, probiotics, nonsteroidal anti-inflammatory drugs (NSAID), d-mannose, estrogens, vitamins, and immunotherapy.

Conclusions

The last 20 years of research on non-antibiotic approaches in UTI have not brought conclusive evidence that antibiotic usage can be replaced completely by non-antibiotic options. Hence, antibiotics still remain a gold standard for UTI treatment and prevention. However, changing the therapeutic strategy by including non-antibiotic measures in the management of UTI could be successful in avoiding antimicrobial resistance at least to some extent.

Vaccines for the prevention of recurrent urinary tract infections: a systematic review

OBJECTIVES

To systematically review the evidence regarding the efficacy of vaccines or immunostimulants in reducing the recurrence rate of urinary tract infections (UTIs).

MATERIALS AND METHODS

The Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica dataBASE (EMBASE), PubMed, Cochrane Library, World Health Organization (WHO) International Clinical Trials Registry Platform Search Portal, and conference abstracts were searched up to January 2018 for English-titled citations. Randomised placebo-controlled trials evaluating UTI recurrence rates in adult patients with recurrent UTIs treated with a vaccine were selected by two independent reviewers according to the Population, Interventions, Comparators, and Outcomes (PICO) criteria. Differences in recurrence rates in study populations for individual trials were calculated and pooled, and risk ratios (RRs) using random effects models were calculated. Risk of bias was assessed using the Cochrane Collaboration's tool and heterogeneity was assessed using chi-squared and I² testing. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to evaluate the quality of evidence (QOE) and summarise findings.

RESULTS

In all, 599 records were identified, of which 10 studies were included. A total of 1537 patients were recruited and analysed, on whom data were presented. Three candidate vaccines were studied: Uro-Vaxom^® (OM Pharma, Myerlin, Switzerland), Urovac^® (Solco Basel Ltd, Basel, Switzerland), and ExPEC4V (GlycoVaxyn AG, Schlieren, Switzerland). At trial endpoint, the use of vaccines appeared to reduce UTI recurrence compared to placebo (RR 0.74, 95% confidence interval [CI] 0.67-0.81; low QOE). Uro-Vaxom showed the greatest reduction in UTI recurrence rate; the maximal effect was seen at 3 months compared with 6 months after initial treatment (RR 0.67, 95% CI 0.57-0.78; and RR 0.78, 95% CI 0.69-0.88, respectively; low QOE). Urovac may also reduce risk of UTI recurrence (RR 0.75, 95% CI 0.63-0.89; low QOE). ExPEC4V does not appear to reduce UTI recurrence compared to placebo at study endpoint (RR 0.82, 95% CI 0.62-1.10; low QOE). Substantial heterogeneity was observed across the included studies (chi-squared = 54.58; P < 0.001, I²  = 84%).

CONCLUSIONS

While there is evidence for the efficacy of vaccines in patients with recurrent UTIs, significant heterogeneity amongst these studies renders interpretation and recommendation for routine clinical use difficult at present. Further randomised trials using consistent definitions and endpoints are needed to study the long-term efficacy and safety of vaccines for infection prevention in patients with recurrent UTIs.

Current Evidence on Nonantibiotic Prevention of Recurrent Urinary Tract Infections

Clinicians should be aware of the limited evidence on nonantibiotic prophylactic treatment for recurrent urinary tract infections. Owing to the rising antibiotic resistance rates worldwide, nonantibiotic prevention strategies should be considered for patient care. Further research is necessary to evaluate nonantibiotic treatment strategies using a robust randomised controlled trial methodology to contribute to a strong evidence basis.

The role of nonantibiotic treatment of community-acquired urinary tract infections

PURPOSE OF REVIEW

To summarize evidence on the efficacy of nonantibiotic treatments in the prevention of recurrent urinary tract infections (UTIs). The need for antibiotic-free regimens seems to be imperative given the worldwide rates of resistance of uropathogens to available antibiotics.

RECENT FINDINGS

In the recently published literature, cranberry products and probiotics are the focus of research. They both seem to be effective in preventing recurrent UTIs compared with placebo, but their benefit becomes less clear when they are compared with antibiotics.

SUMMARY

A number of nonantibiotic-containing alternatives are available for the prevention of recurrent UTIs. For the majority of these alternatives, contradictory results have been published. These can be, at least partially, explained by variation in doses administered and duration of treatment. Selection of patients more likely to benefit from these interventions seems to be a realistic approach from a clinical-practice perspective, as well a worthwhile focus for future research.

Vaccines Against Escherichia coli

Escherichia coli has a complex and versatile nature and continuously evolves from non-virulent isolates to highly pathogenic strains causing severe diseases and outbreaks. Broadly protective vaccines against pathogenic E. coli are not available and the rising in both, multi-drug resistant and hypervirulent isolates, raise concern for healthcare and require continuous efforts in epidemiologic surveillance and disease monitoring. The evolving knowledge on E. coli pathogenesis mechanisms and on the mediated immune response following infection or vaccination, together with advances in the "omics" technologies, is opening new perspectives toward the design and development of effective and innovative E. coli vaccines.

Non-Antibiotic Prophylaxis for Urinary Tract Infections

Increasing antimicrobial resistance has stimulated interest in non-antibiotic prophylaxis of recurrent urinary tract infections (UTIs). Well-known steps in the pathogenesis of UTIs are urogenital colonization and adherence of uropathogens to uroepithelial cell receptors. To prevent colonization in postmenopausal women, vaginal, but not oral, estrogens have been shown to restore the vagina lactobacilli flora, reduce vaginal colonization with Enterobacteriaceae, and reduce the number of UTIs compared to placebo. Different lactobacilli strains show different results in the prevention of recurrent UTIs. Intravaginal suppositories with Lactobacillus crispatus in premenopausal women and oral capsules with Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 in postmenopausal women are promising. Ascorbic acid (vitamin C) cannot be recommended for the prevention of UTIs. Cranberries are thought to contain proanthocyanidins that can inhibit adherence of P-fimbriated E. coli to the uroepithelial cell receptors. Cranberry products decreased UTI recurrences about 30%-40% in premenopausal women with recurrent UTIs, but are less effective than low-dose antimicrobial prophylaxis. However, the optimal dose of cranberry product has still to be determined. Initially OM-89, a vaccine with 18 heat-killed E. coli extracts, seemed promising, but this was not confirmed in a recently randomized trial.