Use and Effectiveness of Antimicrobial Intravesical Treatment for Prophylaxis and Treatment of Recurrent Urinary Tract Infections (UTIs): a Systematic Review

Intravesical Agents for Prevention of Recurrent Urinary Tract Infections

Recurrent urinary tract infections (rUTIs) are common and can significantly impact a patient's quality of life. The mainstay of treatment is antibiotic-based, which contributes to the global problem of antibiotic resistance among urinary pathogens, so many alternative therapies have been explored. In this mini-review we evaluate evidence for intravesical agents that prevent rUTI, including antibiotic and nonantibiotic options. The current evidence supports the use of intravesical agents that replenish the glycosaminoglycan layer and of aminoglycoside antibiotics as safe and effective therapies to prevent rUTI. PATIENT SUMMARY: We reviewed evidence on the use of bladder instillations to treat repeated urinary infections. Studies have shown that agents that improve the bladder surface and one specific antibiotic class are effective and safe treatments for prevention of recurrent infections.

Current and emerging strategies to curb antibiotic-resistant urinary tract infections

Rising rates of antibiotic resistance in uropathogenic bacteria compromise patient outcomes and prolong hospital stays. Consequently, new strategies are needed to prevent and control the spread of antibiotic resistance in uropathogenic bacteria. Over the past two decades, sizeable clinical efforts and research advances have changed urinary tract infection (UTI) treatment and prevention strategies to conserve antibiotic use. The emergence of antimicrobial stewardship, policies from national societies, and the development of new antimicrobials have shaped modern UTI practices. Future UTI management practices could be driven by the evolution of antimicrobial stewardship, improved and readily available diagnostics, and an improved understanding of how the microbiome affects UTI. Forthcoming UTI treatment and prevention strategies could employ novel bactericidal compounds, combinations of new and classic antimicrobials that enhance bacterial killing, medications that prevent bacterial attachment to uroepithelial cells, repurposing drugs, and vaccines to curtail the rising rates of antibiotic resistance in uropathogenic bacteria and improve outcomes in people with UTI.

Gentamicin loaded niosomes against intracellular uropathogenic Escherichia coli strains

Urinary tract infections (UTIs) are the most common bacterial infections and uropathogenic Escherichia coli (UPEC) is the main etiological agent of UTIs. UPEC can persist in bladder cells protected by immunological defenses and antibiotics and intracellular behavior leads to difficulty in eradicating the infection. The aim of this paper is to design, prepare and characterize surfactant-based nanocarriers (niosomes) able to entrap antimicrobial drug and potentially to delivery and release antibiotics into UPEC-infected cells. In order to validate the proposed drug delivery system, gentamicin, was chosen as "active model drug" due to its poor cellular penetration. The niosomes physical-chemical characterization was performed combining different techniques: Dynamic Light Scattering Fluorescence Spectroscopy, Transmission Electron Microscopy. Empty and loaded niosomes were characterized in terms of size, ζ-potential, bilayer features and stability. Moreover, Gentamicin entrapped amount was evaluated, and the release study was also carried out. In addition, the effect of empty and loaded niosomes was studied on the invasion ability of UPEC strains in T24 bladder cell monolayers by Gentamicin Protection Assay and Confocal Microscopy. The observed decrease in UPEC invasion rate leads us to hypothesize a release of antibiotic from niosomes inside the cells. The optimization of the proposed drug delivery system could represent a promising strategy to significatively enhance the internalization of antimicrobial drugs.

Alternative Antimicrobial Irrigation Strategies for the Treatment of Infections in Children: A Review of the Existing Literature

As a synergistic treatment approach with systemic antimicrobial therapy or a systemic antibiotic-sparing strategy, the local administration of antimicrobial agents has been proposed as an alternative route for complicated infections. With the rationale of concentrating the active principle in the desired target site, avoiding potentially toxic systemic levels and bypassing anatomical and physiological barriers, local irrigation or infusion of antibiotics may effectively shorten the antimicrobial therapy course and reduce both infection-related and systemic therapy-related complications. Although evidence from the adult population supports its use in selected patients with an acceptable safety profile, data specifically focused on the pediatric population are limited. To provide a rapid and easily accessible tool for clinical practice, we synthesized the most relevant evidence on the use of local antimicrobial agents in common severe infections in children: meningitis, mediastinitis, pleural infections, recurrent urinary infections, and peritonitis. A literature search was performed using predefined combined keywords through an electronic research database (PubMed). Described molecules, dosages, routes, treated age groups, and related efficacy have been summarized for prompt application to clinical practice. It should, however, be noted that the evidence for the pediatric population remains limited, and the local administration of several molecules remains off-label. A careful multidisciplinary and patient-tailored evaluation, as well as a rational use of available guidelines, should always be the basis of clinical decision making in settings where local administration of antibiotics may be considered.

Urinary Tract Infections: Prevention, Diagnosis, and Treatment

Urinary tract infections (UTIs) are common pathologies that can affect patients of every age and background [...].

Effective Treatments of UTI—Is Intravesical Therapy the Future?

Urinary tract infection (UTI) afflicts millions of patients globally each year. While the majority of UTIs are successfully treated with orally administered antibiotics, the impact of oral antibiotics on the host microbiota is under close research scrutiny and the potential for dysbiosis is a cause for concern. Optimal treatment of UTI relies upon the selection of an agent which displays appropriate pharmacokinetic-pharmacodynamic (PK-PD) properties that will deliver appropriately high concentrations in the urinary tract after oral administration. Alternatively, high local concentrations of antibiotic at the urothelial surface can be achieved by direct instillation into the urinary tract. For antibiotics with the appropriate physicochemical properties, this can be of critical importance in cases for which an intracellular urothelial bacterial reservoir is suspected. In this review, we summarise the underpinning biopharmaceutical barriers to effective treatment of UTI and provide an overview of the evidence for the deployment of the intravesical administration route for antibiotics.

Intravesical gentamicin instillation in the prevention of recurrent urinary tract infections in children with neurogenic bladder- a single-center retrospective observational study

BACKGROUND

Recurrent urinary tract infections (UTI) in children with neurogenic bladder (NGB) put them at high risk of morbidity and mortality from urosepsis and end-stage renal disease (ESRD). Since the efficacy of low-dose prophylactic antibiotics to prevent these recurrences has been declining since the emergence of extended-spectrum beta-lactamase (ESBL) organisms, intravesical gentamicin instillation has also been used, but only scarce data in children is available in the literature.

OBJECTIVE

We evaluate the efficacy of intravesical gentamicin instillation to reduce UTIs in children with NGB, compare it with oral antibiotic prophylaxis and determine its effect on pathogens resistance to antibiotics.

STUDY DESIGN

Retrospective observational study of 17 children with NGB managed in a tertiary center. Intravesical gentamicin instillation followed an initial period of oral antibiotic prophylaxis. In a conditional negative binomial regression model, a matched comparison of the rate of UTIs, the identified pathogens and their antibiotics susceptibility between the two therapies was performed for each individual child, RESULTS: When compared to antibiotic prophylaxis, intravesical gentamicin instillation showed no significant difference in the yearly rate of UTI, symptomatic UTI, or admissions for intravenous antibiotic therapy. However, it was associated with a 38% reduction in the incidence rate ratio of UTI (p = 0.04) and 75% of asymptomatic UTI (p = 0.006) After intravesical gentamicin instillation, five children (31%) had a gentamicin-resistant UTI, similar to before that treatment (p = 0.76).

DISCUSSION

Although the overall rate of UTI and of asymptomatic infections were significantly lower with intravesical gentamicin instillation than during oral antibiotic therapy, there was no significant difference in the rate of symptomatic UTIs or UTIs requiring admissions, probably because of the small sample size. In addition, neither an emergence of ESBL pathogens nor the rate of pathogens resistance to gentamicin was observed with intravesical gentamicin instillation. As to the potential nephrotoxicity of aminoglycosides, the calculated GFR for all children remained normal. Strengths of our study include the use of a matched paired comparison of each participant with him/herself with each treatment modality, thus eliminating potential confounding by some individual characteristics. In addition, and unlike previous studies, we have also used a robust multivariate statistical analysis to compare counts and rates of outcomes. Limitations include the absence of gentamicin serum levels monitoring, of hearing testing, and also the small sample size.

CONCLUSION

Intravesical gentamicin instillation decreases the overall rate of UTI and asymptomatic infections in children with NGB without increasing the rate of bacterial resistance to gentamicin.

Is There Any Benefit to the Use of Antibiotics with Indwelling Catheters after Urologic Surgery in Adults

Antibiotic stewardship in urologic reconstruction is critically important, as many patients will require indwelling catheters for days to weeks following surgery and thus are at risk of both developing catheter-associated urinary tract infections (CAUTI) as well as multi-drug resistant (MDR) uropathogens. Accordingly, limiting antibiotic use, when safe, should help reduce antibiotic resistance and the prevalence of MDR organisms. However, there is significant heterogeneity in how antibiotics are prescribed to patients who need indwelling urethral catheters post-operatively. We performed a literature review to determine if there are benefits in the use of antibiotics for various clinical scenarios that require post-operative indwelling catheters for greater than 24 h. In general, for patients undergoing prostatectomy, transurethral resection of the prostate, and/or urethroplasty, antibiotic administration may be limited without increased risk of CAUTI. However, more work is needed to identify optimal antibiotic regimens for these and alternative urologic procedures, whether certain sub-populations benefit from longer courses of antibiotics, and effective non-antibiotic or non-systemic therapies.

Unmet Needs in Complicated Urinary Tract Infections: Challenges, Recommendations, and Emerging Treatment Pathways

While urinary tract infections (UTIs) are one of the most common types of infections globally, the wide variety of presentations and of severity of disease can make it difficult to manage. The definition for uncomplicated UTIs (uUTIs) is generally regarded as UTIs in healthy, non-pregnant women whereas all other UTIs are considered complicated. There is, however, a lack of consensus definition of complicated UTIs (cUTIs), leading to global differences in management. In addition, the patients who develop complicated UTIs generally have other comorbidities that warrant more urgent intervention. One of the biggest challenges in treating cUTIs is the rise of antimicrobial resistance (AMR). While there have been recent drug approvals for new antibiotic to treat these resistant organisms, a multidisciplinary approach, including regulatory frameworks, provider education and public awareness campaigns, is crucial to limiting unnecessary treatments for asymptomatic bacteriuria (ASB) and uUTIs that can ultimately lead to more severe infections.

Intravesical gentamicin treatment for recurrent urinary tract infections: A systematic review over the last two decades

Objectives:

Recurrent urinary tract infections (rUTIs) have a significant effect on a patient’s quality of life and frequent use of antibiotics increases multi-drug resistance. Previous research on intravesical antibiotics suggests that this has a local effect on bacteria with reduced systemic absorption and associated side effects. We conducted a systematic review to assess the effectiveness and adverse effects of intravesical gentamicin treatment.

Methods:

Systematic review of all English published articles from January 2001 to October 2021 according to the Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards.

Results:

A total of 139 studies were identified, 20 full-text articles were screened and 6 subsequently included totalling 166 patients. All studies reported a decrease in the mean number of urinary tract infections (UTIs) with a significant reduction ( p = 0.0025 and p < 0.004) in two studies. When the number of breakthrough UTIs on prophylactic gentamicin installations was assessed, 65% ( n = 86/133) remained UTI free. Throughout treatment, 99% of serum gentamicin levels were <0.3 ng/dL, and reported instances of increased creatinine were low (2%). A decrease in the growth of multi-drug-resistant bacteria was reported in two papers ( p = 0.065 and p = 0.04).

Conclusion:

Intravesical gentamicin seems to be an effective treatment in patients with symptomatic rUTIs. The evidence suggests it also reduces UTIs caused by multi-drug-resistant bacteria with no systemic absorption and minimal renal toxicity.

Level of evidence:

2a

Intraoperative Gentamicin Intravesical Instillation for Prevention of Urinary Tract Infection After Urogynecologic Surgery: A Randomized Controlled Trial

IMPORTANCE

Currently available evidence for efficacy of postoperative antibiotics to prevent postoperative urinary tract infection (UTI) conflicts. Oral antibiotics rely on patient adherence and can cause unwanted systemic effects. Gentamicin is a broad-spectrum antibiotic with rapid bactericidal activity and, when administered intravesically, has no systemic absorption through intact urothelium.

OBJECTIVE

We aimed to determine whether a single intravesical instillation of gentamicin at the conclusion of urogynecologic surgery would reduce the proportion of women treated for UTI within 6 weeks postoperatively compared with sham instillation.

STUDY DESIGN

This was a multicenter, randomized (stratified by study site, route of prolapse repair ±suburethral sling, with balanced 1:1 randomization), participant-masked, sham-controlled, study. The primary outcome was the proportion of participants treated with antibiotics for UTI within 6 weeks postoperatively. An adjusted multivariable logistic regression model was constructed to determine predictors of postoperative UTI treatment.

RESULTS

Three hundred seventy participants were randomized (gentamicin, 185; sham, 185), and data from 363 participants were analyzed (gentamicin, 183; sham, 180). Nineteen women in the gentamicin group and 20 women in the sham group were treated for UTI within 6 weeks postoperatively (10.4% vs 11.1%, P = 0.87). There were no adverse events related to the instillations. Increasing age (odds ratio, 1.028 [1.000-1.057]) and number of intraoperative transurethral instrumentations (odds ratio, 1.342 [1.080-1.668]) were independent predictors of postoperative UTI treatment.

CONCLUSIONS

In women undergoing urogynecologic surgery, postoperative intravesical gentamicin did not reduce the incidence of postoperative UTI. The number of intraoperative transurethral instrumentations is an important, potentially modifiable risk factor for postoperative UTI treatment.

Intravesical Gentamicin: An Option for Therapy and Prophylaxis against Recurrent UTIs and Resistant Bacteria in Neurogenic Bladder Patients on Intermittent Catheterization

This is a retrospective study of our experience with Gentamicin intravesical instillation as therapy and prophylaxis in patients with lower urinary tract infections (UTIs) undergoing clean intermittent catheterization because of a neurogenic bladder. It is an alternative therapy when all other systemic treatments have failed as it is still an off-label prescription.

Are Intravesical Aminoglycosides the New Gold Standard in the Management of Refractory Urinary Tract Infection: A Systematic Review of Literature

Background: Antibiotic resistance in urinary pathogens is increasingly common, leading to rising cases of complicated urinary tract infections. Conventional antimicrobial treatment may be insufficient in these cases and broad-spectrum systemic antibiotics contribute to the problem. Intravesical aminoglycoside instillation is an alternative treatment option that delivers localized and high-dose treatment to the source of infection. This study summarizes the existing evidence for the efficacy and safety of this treatment. Methods: A systematic search was conducted of worldwide literature according to PRISMA methodology and Cochrane standards for systematic review. Studies were included if they reported outcome data for the prevention and reduction in urinary tract infections, eradication of antimicrobial-resistant organisms, or change in sensitivities allowing conventional oral antimicrobial treatment after the administration of intravesical aminoglycoside with or without polymyxin therapy. Results: The search identified 826 articles, of which, 19 were included in the final data analysis and narrative synthesis. A successful outcome was identified in 80.7% (n = 289) of patients treated with aminoglycoside alone and 79.5% (n = 163) treated with an aminoglycoside in combination with polymyxin. Discontinuation was noted in 6.2% of patients. An increase in antimicrobial sensitivity was seen in 15.3% (n = 55) and 16.3% (n = 36) in the aminoglycoside and aminoglycoside/polymyxin groups, respectively. Conclusions: Current evidence supports the use of intravesical aminoglycoside instillation as an efficacious and safe treatment for refractory UTIs. Nevertheless, data is limited, and larger volume studies with longer follow-up periods are required.

How to Prevent Catheter-Associated Urinary Tract Infections: A Reappraisal of Vico's Theory-Is History Repeating Itself?

New, contextualized modern solutions must be found to solve the dilemma of catheter-associated urinary infection (CAUTI) in long-term care settings. In this paper, we describe the etiology, risk factors, and complications of CAUTI, explore different preventive strategies proposed in literature from the past to the present, and offer new insights on therapeutic opportunities. A care bundle to prevent CAUTI mainly consists of multiple interventions to improve clinical indications, identifying a timeline for catheter removal, or whether any alternatives may be offered in elderly and frail patients suffering from chronic urinary retention and/or untreatable urinary incontinence. Among the various approaches used to prevent CAUTI, specific urinary catheter coatings according to their antifouling and/or biocidal properties have been widely investigated. Nonetheless, an ideal catheter offering holistic antimicrobial effectiveness is still far from being available. After pioneering research in favor of bladder irrigations or endovesical instillations was initially published more than 50 years ago, only recently has it been made clear that evidence supporting their use to treat symptomatic CAUTI and prevent complications is needed.

Synergism between the Synthetic Antibacterial and Antibiofilm Peptide (SAAP)-148 and Halicin

Recently, using a deep learning approach, the novel antibiotic halicin was discovered. We compared the antibacterial activities of two novel bactericidal antimicrobial agents, i.e., the synthetic antibacterial and antibiofilm peptide (SAAP)-148 with this antibiotic halicin. Results revealed that SAAP-148 was more effective than halicin in killing planktonic bacteria of antimicrobial-resistant (AMR) Escherichia coli, Acinetobacter baumannii and Staphylococcus aureus, especially in biologically relevant media, such as plasma and urine, and in 3D human infection models. Surprisingly, SAAP-148 and halicin were equally effective against these bacteria residing in immature and mature biofilms. As their modes of action differ, potential favorable interactions between SAAP-148 and halicin were investigated. For some specific strains of AMR E. coli and S. aureus synergism between these agents was observed, whereas for other strains, additive interactions were noted. These favorable interactions were confirmed for AMR E. coli in a 3D human bladder infection model and AMR S. aureus in a 3D human epidermal infection model. Together, combinations of these two novel antimicrobial agents hold promise as an innovative treatment for infections not effectively treatable with current antibiotics.

Clinical Pharmacogenetics Implementation Consortium Guideline for the Use of Aminoglycosides Based on MT-RNR1 Genotype

Aminoglycosides are widely used antibiotics with notable side effects, such as nephrotoxicity, vestibulotoxicity, and sensorineural hearing loss (cochleotoxicity). MT-RNR1 is a gene that encodes the 12s rRNA subunit and is the mitochondrial homologue of the prokaryotic 16s rRNA. Some MT-RNR1 variants (i.e., m.1095T>C; m.1494C>T; m.1555A>G) more closely resemble the bacterial 16s rRNA subunit and result in increased risk of aminoglycoside-induced hearing loss. Use of aminoglycosides should be avoided in individuals with an MT-RNR1 variant associated with an increased risk of aminoglycoside-induced hearing loss unless the high risk of permanent hearing loss is outweighed by the severity of infection and safe or effective alternative therapies are not available. We summarize evidence from the literature supporting this association and provide therapeutic recommendations for the use of aminoglycosides based on MT-RNR1 genotype (updates at https://cpicpgx.org/guidelines/ and www.pharmgkb.org).

Efficacy of antimicrobial intravesical treatment for uncomplicated recurrent urinary tract infections: a systematic review

INTRODUCTION AND HYPOTHESIS

Intravesical antimicrobials (IVA) provide a localized modality of treatment for recurrent urinary tract infections (rUTIs). Owing to the sporadic use of these treatments, we conducted a systematic review on the efficacy of IVA in the management of uncomplicated rUTIs.

METHODS

A systematic review was conducted for all English language articles from inception to April 2021 utilizing the Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards with the following databases: PubMed, OVID Embase, Biomed Central, and Scopus. References were cross-examined for further articles. Risk of bias was assessed in the articles included using the Cochrane and Joanna Briggs Institute tools.

RESULTS

The initial search resulting in 476 titles led to 15 full-text articles. Of the 13 in the final review (2 RCTs), 3 used gentamicin and 10 used hyaluronic acid IVA. These included 764 participants, mostly women, with a mean age range of 27-80 (median: 53.1). There was a reduction in UTI frequency in 12 out of 13 studies, with 10 studies showing a statistically significant decrease. Dosages of 80 mg of gentamicin per instillation and both 40 mg and 800 mg of hyaluronic acid per instillation were found to be effective in reducing the frequency of UTIs in most studies. Eleven participants reported gentamicin-resistant infections after IVA treatment. Despite high levels of bias in selected categories, the 13 studies were designated to be of high quality for inclusion.

CONCLUSIONS

The IVAs gentamicin and hyaluronic acid with chondroitin sulphate demonstrated efficacy in the management of uncomplicated rUTIs, mostly in women.

Recurrent urinary tract infections in adults: a practical guide

Recurrent urinary tract infections are a common problem faced by clinicians across many specialities. For the patient, recurrent urinary tract infections can be burdensome and detrimental to their quality of life. For the clinician, they can be challenging to manage, and the socioeconomic burden on healthcare systems can also be substantial. Investigations serve to rule out any underlying structural or pathological abnormalities. In conjunction with behavioural prevention methods, treatment strategies include antibiotic and non-antibiotic approaches and holistic management approaches. This article provides an overview of the investigation and treatment of urinary tract infections and includes algorithms which can be used in daily clinical practice.

Electrochemically activated solution as bladder irrigation-An individual curative trial in patients with neurogenic lower urinary tract dysfunction and recurrent urinary infections

AIMS

Driven by increasing awareness of antibiotic stewardship, especially in the vulnerable group of patients with neurogenic lower urinary tract dysfunction (NLUTD), whose frequent need for invasive interventions leads to a high incidence of recurrent urinary tract infections (rUTIs), the goal was to find an alternative to antibiotic treatment. Our intention was for the treatment to be locally administered and well-tolerated as well as to avoid the risk of antimicrobial resistance.

METHODS

A retrospective analysis of 12 catheterized NLUTD patients was performed within the setting of an individual curative trial. The decision to implement the investigational intervention was made on an individual basis with the aim of eliminating lower urinary tract bacteria before diagnostic procedures or to treat rUTI. Electrochemically activated solution (ECAS) was used as bladder irrigation (BI). The following assessments were undertaken: microbiological analysis of urine, analysis of leukocytes/erythrocytes (per µl urine); microbial resistance and sensitivity to antibiotics before and after therapy; clinical signs and patients' state of health.

RESULTS

Eradication of bacteria or an increase in microbial sensitivity to antibiotics was observed in 50%-70% of patients. No adverse events were seen. Due to the restrictions of an individual curative trial, the results are limited by the small number of patients and the absence of a control group.

CONCLUSION

In NLUTD patients with rUTIs, the use of ECAS BI to eliminate bacteriuria before invasive procedures (e.g., urodynamics, preoperative procedures) or to treat rUTI was shown to be a promising alternative to antibiotic treatment.

Methenamine hippurate compared with trimethoprim for the prevention of recurrent urinary tract infections: a randomized clinical trial

INTRODUCTION AND HYPOTHESIS

The objective was to find an alternative treatment to a low-dose antibiotic for the prevention of recurrent urinary tract infections (UTI) and to evaluate the difference in rates of reinfection within 1 year when treated with methenamine hippurate for prophylaxis compared with trimethoprim.

METHODS

We present a non-blinded randomized trial comparing methenamine hippurate with trimethoprim for the prevention of recurrent UTI at 12 months after starting treatment. Women over 18 who had at least two culture-positive UTI in the prior 6 months or three in the prior year were included. Ninety-two patients met enrollment criteria and were randomized to receive daily prophylaxis with methenamine hippurate or trimethoprim for a minimum of 6 months. Both intent-to-treat and per-protocol analyses if patients received the alternative drug after randomization were analyzed using Student's t test, Mann-Whitney U test, Kaplan-Meier curves, log-rank test, and a logistic and multivariate regression model. The primary outcome of this study was culture-proven UTI recurrence by 12 months after initiating prophylaxis.

RESULTS

In the intent-to-treat analysis, we found no difference between groups in recurrent UTI, with a 65% (28 out of 43) recurrence in the trimethoprim group versus 65% (28 out of 43) in the methenamine hippurate group (p = 1.00). In the per-protocol analysis, 65% (26 out of 40) versus 65% (30 out of 46) of patients had UTI recurrences in the trimethoprim group versus the methenamine hippurate group (p = 0.98).

CONCLUSIONS

Methenamine hippurate may be an alternative for the prevention of recurrent UTI, with similar rates of recurrence and adverse effects to trimethoprim.

Intravesical gentamicin instillation for the treatment and prevention of urinary tract infections in complex paediatric urology patients: evidence for safety and efficacy

BACKGROUND

Little has been reported to date on the instillation of antimicrobials directly into the bladder in children. Children with complex urinary tract anomalies struggle frequently with recurrent urinary tract infections (UTI), with frequent emergence of antibiotic resistance. Gentamicin bladder instillation to treat and prevent UTI was described in children since 2006.

OBJECTIVE

We adopted gentamicin bladder instillation in 2016 and evaluate herein our intermediate-term experience with it.

STUDY DESIGN AND METHODS

This study is a retrospective review of a prospectively initiated database and a clinical audit of our practice. The gentamicin bladder instillation was employed in 24 cases. A treatment regime was initiated for symptomatic documented UTI when resistance patterns precluded an oral alternative (14 cases), avoiding hospitalisation for parenteral antibiotics. A prophylaxis regime (19 cases-including 9 of the 14 who received an initial treatment regime) followed at least one breakthrough UTI while receiving oral prophylactic antibiotics. Two instillation volumes (8 mg gentamicin in 20 mL 0.9% NaCl or 20 mg gentamicin in 50 mL 0.9% NaCl) were used to suit different bladder capacities. The irrigation is given twice a day for 7 days in the treatment regime or once a day, every other day, in the prophylactic regime. Gentamicin serum levels (all cases) and audiology/audiometry testing (17/24 cases) were checked to assess the safety of this method.

RESULTS

The median age when either the treatment course or prophylaxis regime was started was 3.8 years. The treatment regime was 86% successful (12/14) to suppress an acute UTI. The mean duration of prophylaxis was 252 days (median: 256 days). The percentage of patients on the prophylactic regime who had no breakthrough UTI was 58%. No serum gentamicin was detectable secondary to the intravesical instillation. No attributable cases of sensorineural hearing loss were detected. Gentamicin resistance emerged in one case (4.16%).

DISCUSSION

Intravesical administration was feasible via various routes for a spectrum of complex lower urinary tract abnormalities (see Summary Figure). Concerns regarding systemic absorption, nephrotoxicity or ototoxicity were investigated and safety ensured. Limitations include being a small series of non-identical pathologies, albeit categorically similar and being a single-arm study, however, statistical significance was proven descriptively and analytically.

CONCLUSION

In selected cases and with the appropriate specialist support and logistics, intravesical gentamicin instillation is well-tolerated and safe to treat and/or prevent urinary tract infections in pateints with complex bladder conditions and lower urinary tract pathologies.

Intravesical acetic acid in combination with prophylactic methenamine and ascorbic acid to decrease the incidence of recurrent urinary tract infections associated with intermittent urinary self-catherization: A case report

A case is presented demonstrating improved efficacy of the use of oral methenamine hippurate and vitamin C urinary tract infection prophylaxis achieved by adding self-administered acetic acid irrigation twice daily during routine intermittent bladder self-catheterization in a post-menopausal female patient with multiple sclerosis.

The patient in this case report is me, a retired radiologist.

Intravesical Antibiotic Administration in the Treatment of Recurrent Urinary Tract Infections: Promising Results From a Case Series

OBJECTIVE

Intravesical antibiotic administration for the treatment of recurrent urinary tract infections (UTIs) provides targeted therapy that may be a useful alternative to oral antibiotics. The objective of the study was to assess the rate of UTIs before and after intravesical antibiotic instillations in community-dwelling postmenopausal women with recurrent UTIs.

METHODS

Patients with recurrent UTI who underwent antibiotic bladder instillations were included. Instillation was performed in the office by trained nursing staff using either gentamycin or tobramycin. Every instillation was preceded by bladder irrigation with sterile water. Retrospective chart review was performed to compare rates of UTIs for 6 months before and after intervention. Descriptive and nonparametric statistics were used for data analysis.

RESULTS

Twelve patients were evaluated. The average rate of UTIs decreased from a median of 2.5 to 1.5 infections (P = 0.025) after intravesical instillations. The number of pathogen types decreased from a median of 2.5 to 1.5 after therapy (P = 0.025). There was a reduction in bacterial antibiotic resistance after completion of instillations, with an estimated median difference of -5.250 (P = 0.065). There were no adverse effects reported during instillations.

CONCLUSIONS

Intravesical instillations offer a promising therapy for the treatment of recurrent UTIs in postmenopausal women who failed oral antibiotic therapy. Future prospective studies are needed to further elucidate the clinical utility and long-term benefits of antibiotic instillations.

Cystoscopy with antibiotic irrigation during pelvic reconstruction and minimally invasive gynecologic surgery: A double-blind randomized controlled trial

AIMS

After pelvic reconstructive surgery, the risk of postoperative urinary tract infection (UTI) is significant; intraoperative cystoscopy may contribute to this risk. Intravesical antibiotics are used in the ambulatory setting and may be applied to the surgical arena. Our objective was to evaluate the efficacy of antibiotic irrigation during intraoperative cystoscopy to prevent postoperative UTI.

METHODS

This double-blind randomized controlled trial enrolled 216 women undergoing cystoscopy with elective surgery for pelvic organ prolapse, stress urinary incontinence, or laparoscopic gynecologic surgery at an academic medical center 2016-2019. Participants were randomized to cystoscopic irrigation fluid type: normal saline (control) or 200,000 U polymyxin B + 40 mg neomycin solution in normal saline (antibiotic). Patients and providers who treated UTIs were blinded. The primary outcome was treatment of UTI within 6 weeks postoperatively, defined as positive culture or treatment for a symptomatic UTI. χ² and multivariable logistic regression analyses were performed.

RESULTS

We enrolled 216 women: 111 control (51.4%) and 105 antibiotic (48.6%). Mean age was 51.6 years. Groups were well matched in medical comorbidities and surgery type. Primary vaginal surgery was most common (n = 127, 58.8%). Overall, 10.7% of patients developed a postoperative UTI with no difference in incidence between groups: 9.9% of control (n = 11, 95% confidence interval [CI]: 4.0%-16.0%) versus 11.4% of antibiotic subjects (n = 12, 95% CI: 5.0%-18.0%), on χ² (p = .718) and logistic regression analysis (adjusted odds ratio, 1.3; CI: 0.53-3.16; p = .569).

CONCLUSION

When cystoscopy is performed during elective pelvic surgery, use of antibiotic irrigation does not impact the rate of postoperative UTI.

Treatment options for K. pneumoniae, P. aeruginosa and A. baumannii co-resistant to carbapenems, aminoglycosides, polymyxins and tigecycline: an approach based on the mechanisms of resistance to carbapenems

The management of carbapenem-resistant infections is often based on polymyxins, tigecycline, aminoglycosides and their combinations. However, in a recent systematic review, we found that Gram-negative bacteria (GNB) co-resistant to carbapanems, aminoglycosides, polymyxins and tigecycline (CAPT-resistant) are increasingly being reported worldwide. Clinical data to guide the treatment of CAPT-resistant GNB are scarce and based exclusively on few case reports and small case series, but seem to indicate that appropriate (in vitro active) antimicrobial regimens, including newer antibiotics and synergistic combinations, may be associated with lower mortality. In this review, we consolidate the available literature to inform clinicians dealing with CAPT-resistant GNB about treatment options by considering the mechanisms of resistance to carbapenems. In combination with rapid diagnostic methods that allow fast detection of carbapenemase production, the approach proposed in this review may guide a timely and targeted treatment of patients with infections by CAPT-resistant GNB. Specifically, we focus on the three most problematic species, namely Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii. Several treatment options are currently available for CAPT-resistant K. pneumonia. Newer β-lactam-β-lactamase combinations, including the combination of ceftazidime/avibactam with aztreonam against metallo-β-lactamase-producing isolates, appear to be more effective compared to combinations of older agents. Options for P. aeruginosa (especially metallo-β-lactamase-producing strains) and A. baumannii remain limited. Synergistic combination of older agents (e.g., polymyxin- or fosfomycin-based synergistic combinations) may represent a last resort option, but their use against CAPT-resistant GNB requires further study.

Recurrent urinary tract infections: from pathogenesis to prevention

Urinary tract infections are highly prevalent among women and when they are recurrent they can lead to patient discomfort and high healthcare costs, and they represent one of the most frequent causes of antibiotic consumption. There are several options to prevent RUTI which include both antibiotic treatment (continuous or postcoital antibiotic prophylaxis) and non-antibiotic measures (hygienic measures, vitamin D, blueberries, D-mannose, probiotics, oestrogens, vaccines, intravesical instillations), but with different levels of evidence, sometimes of poor quality, and therefore new randomized and comparative studies are needed to choose the best strategy.

Pharmacotherapeutic advances for recurrent urinary tract infections in women

INTRODUCTION

Treatment of recurrent Urinary tract infections (UTIs) has become challenging because of the dramatic increase in the rates of recurrent infection andof multidrug-resistant (MDR) infections.

AREAS COVERED

The authors review recurrent UTIs(rUTI) management in women.

EXPERT OPINION

Continuous or post-coital prophylaxis with low-dose antimicrobials or intermittent self-treatment has all been demonstrated to be effective in managing rUTIs in women. Intravaginal estrogen therapy , shows potential toward preventing rUTI. Oral vaccine Uro-Vaxom seems to reduce the number of UTIs. There is evidence that other therapies (e.g. cranberry, Methenamine hippurate, oral D-mannose) may decrease the number of symptomatic UTIs. The treatment of CRE-UTIs is focused on a colistin backbone. Carbapenems are considered first-line agents for UTIs caused by ESBL, but their use is associated with increased MDR. The usage of non-carbapenem for the treatment of ESBL UTIs is necessary. Cefepime, Piperacillin-Tazobactam, Ceftolozane-Tazobactam, and Ceftazidime-Avibactam are justified options. Oral therapy with Pivmecillinam, Fosfomycin, and Nitrofurantoin can be used against uncomplicated UTIs due to ESBL infection.

Trimethoprim-Loaded PLGA Nanoparticles Grafted with WGA as Potential Intravesical Therapy of Urinary Tract Infections-Studies on Adhesion to SV-HUCs Under Varying Time, pH, and Drug-Loading Conditions

Intravesical therapy, already used to treat bladder cancer, is a potential treatment option for urinary tract infections. However, short dwelling time and washout proved to be challenging obstacles. To circumvent these issues, PLGA 503H and PLGA 2300 nanoparticles were prepared and surface modified with wheat germ agglutinin (WGA). Nanoparticles of both poly(d,l-lactic-co-glycolic acid) (PLGA) types exhibited high inherent adhesion to human uroepithelial cells. Although surface-bound WGA could be easily increased, adhesion did not. Loading the nanoparticles with trimethoprim did not counteract cell adhesion. Varying the medium for instillation revealed highest adhesion in sodium bicarbonate buffer (pH 5). To evaluate dwelling time, nanoparticles were incubated with the cell monolayer for increasing time intervals. A contact time of 15 min seems to be too short for adhesion to the cells as less than 50% particles remained bound after washing. However, after 30 min 70% of the particles added were bound, and afterward, no further increase was observed. WGA only slightly increased the adhesion of the PLGA nanoparticles, but this approach might not be economically viable. However, PLGA nanoparticles displayed a high inherent adhesion to cells that might substantially foster intravesical therapy.

Trimethoprim-Loaded Microspheres Prepared from Low-Molecular-Weight PLGA as a Potential Drug Delivery System for the Treatment of Urinary Tract Infections

Commonly, therapy of urinary tract infections suffers from increasing resistance to antibiotics and the ability of uropathogenic Escherichia coli (UPEC) to invade bladder cells and cause recurring infections. As an alternative strategy for instillation into the bladder, trimethoprim-loaded microparticles with poly(d,l-lactic-co-glycolic acid) (PLGA) as a matrix were prepared. To reduce particle loss by washout, their surface was grafted with bioadhesive wheat germ agglutinin, providing biomimicry akin to UPEC. Since PLGA 503H has shown a slow drug release profile, the low-molecular-weight PLGA 2300 was studied. Whereas the drug loading of PLGA 503H particles amounted to 2.8%, the drug content of PLGA 2300 particles was twice as high. Although the drug release pattern started with an initial burst of 30% after 24 h for both PLGA types, half of the trimethoprim content was released after 4 days from PLGA 503H microparticles as opposed to 2 days in the case of PLGA 2300. Higher drug loading and accelerated release render PLGA 2300 a viable alternative to PLGA 503H.

Amniotic Membrane Preparation Crucially Affects Its Broad-Spectrum Activity Against Uropathogenic Bacteria

Urinary tract infections are among the most common bacterial infections in humans. Moreover, they are highly recurrent and increasingly often resistant to antibiotics. The antimicrobial properties of the amniotic membrane (AM), the innermost layer of fetal membranes, have been briefly reported in the literature, however, the results of published studies are often inconsistent and unclear; moreover, its effect on uropathogenic bacteria has not yet been investigated. Further, there is no data in the literature about the effect of AM preparation and storage on its antimicrobial properties. To examine the impact of several preparation procedures on the antimicrobial properties of AM, we prepared patches and homogenates of fresh (fAM) and cryopreserved (cAM) human AM and tested them on 14 selected Gram-positive and Gram-negative uropathogenic bacteria. By employing novel antimicrobial efficiency assays we showed that fAM and cAM homogenates have broad-spectrum antimicrobial activity against all here tested uropathogenic bacteria, except for Serratia marcescens. Moreover, they had a potent effect also on the multiple-resistant clinical strains of uropathogenic Escherichia coli. Interestingly, the patches of fAM and cAM had no antimicrobial effect on any of the tested strains. We therefore prepared and stored AM patches according to the standard procedure for clinical use in ophthalmology, which includes the cryopreservation of antibiotic-treated AM, and performed antimicrobial efficiency assays. Our findings suggest that the ultrastructure of AM patches could enable the retention of added antibiotics. In addition, we also prepared gentamicin-resistant uropathogenic E. coli strains, which confirmed that the antimicrobial effect of antibiotic-treated AM patches can be attributed to the antibiotic alone. To summarize, here we describe novel protocols for preparation and storage of AM to ensure the preservation of its antimicrobial factors. Moreover, we describe the mechanism of AM retention of antibiotics, based on which the AM could potentially be used as a drug delivery vehicle in future clinically applicable approaches.

Micro vs. nano: PLGA particles loaded with trimethoprim for instillative treatment of urinary tract infections

Recurring infections and increasing resistances continue to complicate treatment of urinary tract infections. To investigate alternative treatment options, trimethoprim loaded micro- (D[4;3] of 1-9 µm) and nanoparticles (Z-Avg of 200-400 nm) were prepared from two types of poly(d,l-lactic-co-glycolic acid) (PLGA) for instillative therapy. While PLGA 503H microparticles could not be loaded with more than 2.6% trimethoprim, PLGA 2300 entrapped 22%. When preparing nanoparticles, both types displayed an even higher drug load of up to 29% using PLGA 2300, while PLGA 503H drug load stagnated at 10%. After eight hours, drug release from microparticles amounted to 55% (503H) and 35% (2300) whereas total drug release occurred after 8 (503H) and 9 days (2300). In case of nanoparticles, trimethoprim was liberated much faster with 60% after 2 h and a complete release after 24 h from both polymers. PLGA 2300 seems to be the better choice for entrapment of trimethoprim in microparticles considering the drug load. Both polymers, however, seem to be viable options for nanoparticles. Due to the higher overall drug load, nanoparticles seem to be advantageous over microparticles for instillative therapy, especially when prepared with PLGA 2300.

Bactericidal Activity of Lipid-Shelled Nitric Oxide-Loaded Microbubbles

The global pandemic of antibiotic resistance is an ever-burgeoning public health challenge, motivating the development of adjunct bactericidal therapies. Nitric oxide (NO) is a potent bioactive gas that induces a variety of therapeutic effects, including bactericidal and biofilm dispersion properties. The short half-life, high reactivity, and rapid diffusivity of NO make therapeutic delivery challenging. The goal of this work was to characterize NO-loaded microbubbles (MB) stabilized with a lipid shell and to assess the feasibility of antibacterial therapy in vitro. MB were loaded with either NO alone (NO-MB) or with NO and octafluoropropane (NO-OFP-MB) (9:1 v/v and 1:1 v/v). The size distribution and acoustic attenuation coefficient of NO-MB and NO-OFP-MB were measured. Ultrasound-triggered release of the encapsulated gas payload was demonstrated with 3-MHz pulsed Doppler ultrasound. An amperometric microelectrode sensor was used to measure NO concentration released from the MB and compared to an NO-OFP-saturated solution. The effect of NO delivery on the viability of planktonic (free living) Staphylococcus aureus (SA) USA 300, a methicillin-resistant strain, was evaluated in a 96 well-plate format. The co-encapsulation of NO with OFP increased the total volume and attenuation coefficient of MB. The NO-OFP-MB were destroyed with a clinical ultrasound scanner with an output of 2.48 MPa peak negative pressure (in situ MI of 1.34) but maintained their echogenicity when exposed to 0.02 MPa peak negative pressure (in situ MI of 0.01. The NO dose in NO-MB and NO-OFP-MB was more than 2-fold higher than the NO-OFP-saturated solution. Delivery of NO-OFP-MB increased bactericidal efficacy compared to the NO-OFP-saturated solution or air and OFP-loaded MB. These results suggest that encapsulation of NO with OFP in lipid-shelled MB enhances payload delivery. Furthermore, these studies demonstrate the feasibility and limitations of NO-OFP-MB for antibacterial applications.

Antibiotic Killing of Diversely Generated Populations of Nonreplicating Bacteria

Nonreplicating bacteria are known to be (or at least commonly thought to be) refractory to antibiotics to which they are genetically susceptible. Here, we explore the sensitivity to killing by bactericidal antibiotics of three classes of nonreplicating populations of planktonic bacteria: (i) stationary phase, when the concentration of resources and/or nutrients are too low to allow for population growth; (ii) persisters, minority subpopulations of susceptible bacteria surviving exposure to bactericidal antibiotics; and (iii) antibiotic-static cells, bacteria exposed to antibiotics that prevent their replication but kill them slowly if at all, the so-called bacteriostatic drugs. Using experimental populations of Staphylococcus aureus Newman and Escherichia coli K-12 (MG1655) and, respectively, nine and seven different bactericidal antibiotics, we estimated the rates at which these drugs kill these different types of nonreplicating bacteria. In contrast to the common belief that bacteria that are nonreplicating are refractory to antibiotic-mediated killing, all three types of nonreplicating populations of these Gram-positive and Gram-negative bacteria are consistently killed by aminoglycosides and the peptide antibiotics daptomycin and colistin, respectively. This result indicates that nonreplicating cells, irrespectively of why they do not replicate, have an almost identical response to bactericidal antibiotics. We discuss the implications of these results to our understanding of the mechanisms of action of antibiotics and the possibility of adding a short-course of aminoglycosides or peptide antibiotics to conventional therapy of bacterial infections.

The etiology and management of recurrent urinary tract infections in postmenopausal women

Urinary tract infections (UTIs) are one of the most common infections and affect up to 50% of women in their lifetime, with almost half of these women experiencing a recurrence in 6-12 months. Menopause predisposes women to recurrent UTI (rUTI), as normally lower levels of estrogen lead to changes in the urogenital epithelium and subsequently urogenital microbiome. The recently discovered urobiome is now known to have different compositions in both healthy and unhealthy bladders, including a role in the pathophysiology of rUTI, and may be a therapeutic target for prevention and treatment options for rUTI. In postmenopausal women with frequent UTI, the diagnosis of acute UTI should be made using a combination of the symptom assessment and urine diagnostic studies. The choice of UTI antibiotic should include consideration of efficacy, collateral effects, and side-effects. Some women may be candidates for self-start therapy, in which the patient accurately recognizes her UTI symptoms and then starts previously prescribed antibiotics. A large component of the management of women with rUTI is prevention. Urobiome research for bladder health and disease is a young field of investigation with significant potential to improve care for postmenopausal women affected by rUTI through novel, evidence-based prevention and treatment strategies.

Intra-Vesical Colistin for Pseudomonas aeruginosa Urinary Tract Infections

The numbers of multiple drug-resistant Gram-negative bacterial infections are rising worldwide. The threat is increased by the lack of new antibiotics, so clinicians are turning to older drugs previously abandoned due to their recognized toxicity, such as colistin. However, the need to avoid kidney toxicity from colistin has led to its topical use. We present the case of a patient with type I cardiorenal syndrome with cystitis due to multiple drug-resistant Pseudomonas aeruginosa who was successfully treated with intravesical instillation of colistin.

LEARNING POINTS

The case report is one of the few in the literature on the intravesical instillation of colistin to address lower urinary tract infection.Isolated intravesical colistin instillation was effective in a patient with anuria.

Management of urinary tract infection in women: A practical approach for everyday practice

A common health-care problem worldwide, urinary tract infection (UTI), represents a disease of significant impact on every country's economy, being the most common cause of hospitalization among elderly people and the most common cause of antibiotic prescription in primary care. Diagnosing and managing upper and lower UTI have always been a challenge to physicians, given its high prevalence, risk of recurrence and improper treatment, and the fact of worldwide increase in antibiotic resistance, necessitating implementation of a proper antibiotic stewardship. Urinary infections are twice more likely to occur in females compared to males and its prevalence increases with increasing age. The following is a comprehensive review paper about UTI in females, discussing the various factors leading to a complicated infection. The various etiologies and microbiologies of UTI are also highlighted. In addition to various usual antibiotic regimens for treating UTI, a significant number of nonantimicrobial treatment modalities are highlighted and described in this manuscript, including the novel use of intravesical antibiotics and vaccines for suppression treatment. Finally, a pathway is suggested for the proper diagnosis and treatment that ensures antibiotic stewardship in order to decrease long-term complications.