Antibiotic management of urinary tract infections in the post-antibiotic era: a narrative review highlighting diagnostic and antimicrobial stewardship

Bacterial cellulose-based scaffold with in-situ cationic micelle modification for urethral stricture disease: Sustained drug components release, cytokines recruitment, and bacterial microenvironment regulation

The treatment of urethral stricture disease and the prevention of restenosis present considerable challenges in the field of urology. Tissue-engineered materials, particularly bacterial cellulose scaffolds, have emerged as promising solutions due to their abundant sources, excellent mechanical properties, and biocompatibility. However, for attaining superior treatment for patients with USD, further modification of bacterial cellulose is necessary. We have fabricated a dual-network scaffold with enhanced antibacterial properties and cytokines absorption ability through in-situ polymerization of cationic polyurethane micelles and cyclodextrin on oxidized bacterial cellulose. This scaffold also enables long-term sustained release of loaded drug components. Animal model studies have confirmed that this scaffold can achieve urethral repair outcomes comparable to those of normal urethral tissue. This innovative material provides a robust foundation for advancing new concepts and methodologies in the treatment of urethral stricture disease, potentially transforming clinical approaches to this challenging condition.

Construction and validation of an interpretable XGBoost machine learning model to predict ESBL positivity rates based on urinalysis data

BACKGROUND

Microbiological culture and drug susceptibility testing of urine samples have lengthy turnaround times, increasing the risk of extended-spectrum β-lactamase (ESBL)-positive urinary tract infection (UTI) patients progressing to sepsis.

OBJECTIVE

To develop an efficient machine learning model for the identification of ESBL positivity in UTI patients.

METHODS

This retrospective study included 528 samples that had undergone drug susceptibility testing, based on inclusion and exclusion criteria. Variables were screened using Lasso regression, with 70% of the samples used to construct nine machine learning models (XGBClassifier, LogisticRegression, LGBMClassifier, AdaBoostClassifier, SVC, MLPClassifier, ComplementNB, GaussianNB, and GradientBoostingClassifier). Model selection was based on criteria including accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), F1 score, Kappa score, and Area Under the Curve (AUC). The best model type was identified through ten-fold cross-validation, which was then built using the remaining 30% of the data as a test set. Interpretations of predictive results were provided using the SHAP model, clarifying the impact of each feature on predictions and enhancing model transparency and interpretability.

RESULTS

The variables selected by the Lasso regression model are as follows: gender + urinary protein + urobilinogen + leukocytes + occult blood + age + pH + specific gravity + leukocyte count + erythrocyte count + epithelial cell count + cast count.The XGBoost model outperformed others in ten-fold cross-validation, with scores on the validation set as follows: AUC (95%CI): 0.924 (0.860-0.989); cutoff: 0.664(0.637-0.690); accuracy: 0.862(0.839-0.885); sensitivity: 0.9(0.879-0.920); specificity: 0.725(0.618-0.832); PPV: 0.923(0.896-0.950); NPV: 0.667(0.626-0.707); F1 score: 0.911(0.896-0.925); Kappa: 0.603(0.527-0.679). The final model achieved an AUC of 0.968 and accuracy of 0.943 on the test set.

CONCLUSION

This study developed a rapid and efficient machine learning model capable of identifying ESBL positivity based solely on routine urine test data.

One-year monitorization of the gut colonization by multidrug resistant bacteria in elderly of a single long-term care facility

Objective

To monitor the gut colonization by multidrug resistant (MDR) bacteria in residents of a single long-term care facility (LTCF) in relation to their clinical evolution, antibiotic consumption and mortality risk.

Methods

In a total of 187 voluntarily enrolled residents, five rectal swabs samples were recovered over 1 year. Selective media were used to isolate MDR bacteria. Clinical data related to infections, antibiotic consumption and mortality were recovered. Mortality risk among residents who were MDR colonized and non-colonized was compared by Kaplan-Meier curves.

Results

Globally, 25% of residents have gut colonization by ESBL-producing Escherichia coli with a lack of other pathogens such as Acinetobacter baumannii or Clostridioides difficile. Monitoring of ESBL-producing E. coli colonization for 1 year allowed to us to establish three categories among residents: 48.6% never colonized, 15.5% had a persistent colonization, and the remaining 35.8% presented intermittent colonization. The rates of mortality, infections and antibiotic exposure were comparable among ESBL-producing E. coli colonized and non-colonized residents, except for the intermittent colonization group in which a higher and statistically significant mortality rate was observed. As expected, urinary and respiratory tract infections were the most prevalent infectious pathologies in the LTCF, with amoxicillin/clavulanate and fluoroquinolones being the most prescribed antibiotics. A high percentage of ESBL-producing E. coli (28%), and fluoroquinolone resistance were detected in clinical samples.

Conclusions

The monitoring of gut colonization by MDR microorganisms in a single LTCF for 1 year demonstrated the predominance of ESBL-producing E. coli. Almost half of the residents were resistant to its colonization, whereas in 15.5% of them gut colonization was stable. Incidence of infectious episodes and antibiotic exposure were comparable between colonized and non-colonized subjects, but the group with the highest risk of mortality was that with intermittent colonization by ESBL-producing E. coli.

Factors affecting decisions to use antibiotic-sparing treatment approaches in women with uncomplicated urinary tract infections: a scoping review protocol

OBJECTIVE

This scoping review will explore the evidence on factors influencing the decisions to use antibiotic-sparing treatments in women with uncomplicated urinary tract infection.

INTRODUCTION

Overuse and misuse of antibiotics are the main drivers of antimicrobial resistance. Antibiotic-sparing treatments, such as symptomatic treatment with analgesics and delayed prescriptions, have considerable potential to reduce antibiotic consumption, but the majority of patients still receive antibiotics without delay. The reasons for the poor implementation of these alternative approaches are unknown. A better understanding of the factors influencing treatment decisions is needed.

INCLUSION CRITERIA

This review will consider the experiences and attitudes of health care professionals and women, in outpatient settings in high-income countries, regarding the use of antibiotic-sparing treatments for the diagnosis or suspected diagnosis of uncomplicated urinary tract infections (ie, healthy women aged 18-64 years who are not pregnant, immunosuppressed, and have no functional or structural urinary tract abnormalities).

METHODS

This review will follow the JBI methodology for scoping reviews. MEDLINE (Ovid), Embase, and the Cochrane Library will be searched to identify peer-reviewed articles: original research (quantitative or qualitative studies, experimental or observational), reviews, case reports, and case series. Gray literature will also be searched for. Sources in any language from 2000 to 2024 will be included. Three reviewers will screen the sources and extract data using a tool developed by the reviewers. The analysis will use counts and descriptive qualitative content analysis. The results will be presented in visual, tabular, and narrative formats.

DETAILS OF THIS REVIEW PROJECT CAN BE FOUND IN OPEN SCIENCE FRAMEWORK

https://osf.io/t8y5e/.

Identifying targets for antibiotic stewardship interventions in pediatric patients in Punjab, Pakistan: point prevalence surveys using AWaRe guidance

Introduction

Surveillance of antibiotic use is crucial for identifying targets for antibiotic stewardship programs (ASPs), particularly in pediatric populations within countries like Pakistan, where antimicrobial resistance (AMR) is escalating. This point prevalence survey (PPS) seeks to assess the patterns of antibiotic use in pediatric patients across Punjab, Pakistan, employing the WHO AWaRe classification to pinpoint targets for intervention and encourage rational antibiotic usage.

Methods

A PPS was conducted across 23 pediatric wards of 14 hospitals in the Punjab Province of Pakistan using the standardized Global-PPS methodology developed by the University of Antwerp. The study included all pediatric inpatients receiving antibiotics at the time of the survey, categorizing antibiotic prescriptions according to the WHO Anatomical Therapeutic Chemical classification and the AWaRe classification system.

Results

Out of 498 pediatric patients, 409 were receiving antibiotics, representing an antibiotic use prevalence of 82.1%. A substantial majority (72.1%) of the prescribed antibiotics fell under the WHO's Watch category, with 25.7% in the Access category and 2.2% in the Reserve group. The predominant diagnoses were respiratory infections, notably pneumonia (32.4%). The most commonly used antibiotics were ceftriaxone (37.2%) and Vancomycin (13.5%). Only 2% of antibiotic uses were supported by culture sensitivity reports, highlighting a reliance on empirical therapy.

Conclusion

The high prevalence of antibiotic use, particularly from the Watch category, and low adherence to culture-based prescriptions underscore the critical need for robust antibiotic stewardship programs in Pakistan. Strengthening these programs could help mitigate AMR and optimize antibiotic use, aligning with global health objectives.

Culture-free detection of β-lactamase-Producing bacteria in urinary tract infections using a paper sensor

Developing simple, inexpensive, fast, sensitive, and specific probes for antibiotic-resistant bacteria is crucial for the management of urinary tract infections (UTIs). We here propose a paper-based sensor for the rapid detection of β-lactamase-producing bacteria in the urine samples of UTI patients. By conjugating a strongly electronegative group -N+(CH3)3 with the core structures of cephalosporin and carbapenem antibiotics, two visual probes were achieved to respectively target the extended-spectrum/AmpC β-lactamases (ESBL/AmpC) and carbapenemase, the two most prevalent factors causing antibiotic resistance. By integrating these probes into a portable paper sensor, we confirmed 10 and 8 cases out of 30 clinical urine samples as ESBL/AmpC- and carbapenemase-positive, respectively, demonstrating 100% clinical sensitivity and specificity. This paper sensor can be easily conducted on-site, without resorting to bacterial culture, providing a solution to the challenge of rapid detection of β-lactamase-producing bacteria, particularly in resource-limited settings.

Using the Sysmex UF-4000 urine flow cytometer for rapid diagnosis of urinary tract infection in the clinical microbiological laboratory

BACKGROUND

Urinary tract infections are responsible for a significant worldwide disease burden. Performing urine culture is time consuming and labor intensive. Urine flow cytometry might provide a quick and reliable method to screen for urinary tract infection.

METHODS

We analyzed routinely collected urine samples received between 2020 and 2022 from both inpatients and outpatients. The UF-4000 urine flow cytometer was implemented with an optimal threshold for positivity of ≥100 bacteria/μL. We thereafter validated the prognostic value to detect the presence of urinary tract infection (UTI) based on bacterial (BACT), leukocyte (WBC), and yeast-like cell (YLC) counts combined with the bacterial morphology (UF gram-flag).

RESULTS

In the first phase, in 2019, the UF-4000 was implemented using 970 urine samples. In the second phase, between 2020 and 2022, the validation was performed in 42,958 midstream urine samples. The UF-4000 screen resulted in a 37% (n = 15,895) decrease in performed urine cultures. Uropathogens were identified in 18,673 (69%) positively flagged urine samples. BACT > 10.000/μL combined with a gram-negative flag had a >90% positive predictive value for the presence of gram-negative uropathogens. The absence of gram-positive flag or YLC had high negative predictive values (99% and >99%, respectively) and are, therefore, best used to rule out the presence of gram-positive bacteria or yeast. WBC counts did not add to the prediction of uropathogens.

CONCLUSION

Implementation of the UF-4000 in routine practice decreased the number of cultured urine samples by 37%. Bacterial cell counts were highly predictive for the presence of UTI, especially when combined with the presence of a gram-negative flag.

Resistance to first-line antibiotic therapy among patients with uncomplicated acute cystitis in Melbourne, Australia: prevalence, predictors and clinical impact

Background

Australian guidelines recommend trimethoprim or nitrofurantoin as first-line agents for uncomplicated urinary tract infections (UTIs). Laboratory surveillance indicates high rates of trimethoprim resistance among urinary bacterial isolates, but there are scant local clinical data about risk factors and impact of trimethoprim resistance.

Objectives

To determine the prevalence, risk factors, mechanism and impact of resistance to first-line antibiotic therapy for uncomplicated UTIs in the community setting.

Methods

A prospective observational study from October 2019 to November 2021 in four general practices in Melbourne, Australia. Female adult patients prescribed an antibiotic for suspected or confirmed uncomplicated acute cystitis were eligible. Primary outcome was urine isolates with resistance to trimethoprim and/or nitrofurantoin.

Results

We recruited 87 participants across 102 UTI episodes with median (IQR) age of 63 (47-76) years. Escherichia coli was the most common uropathogen cultured (48/62; 77%); 27% (13/48) were resistant to trimethoprim (mediated by a dfrA gene) and none were resistant to nitrofurantoin. Isolates with resistance to a first-line therapy were more common among patients reporting a history of recurrent UTIs [risk ratio (RR): 2.08 (95% CI: 1.24-3.51)] and antibiotic use in the previous 6 months [RR: 1.89 (95% CI: 1.36-2.62)]. Uropathogen resistance to empirical therapy was not associated with worse clinical outcomes.

Conclusions

Resistance to trimethoprim is common in uncomplicated UTIs in Australia but may not impact clinical outcomes. Further research is warranted on the appropriateness of trimethoprim as empirical therapy, particularly for patients with antimicrobial resistance risk factors.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and lateral flow immunochromatography for rapid identification of β-lactamase-gene-harboring Enterobacterales in urine specimens: Performance and cost-benefit analyses

In this single-center prospective study, we evaluated the performance to the MALDI-ToF MS based method in conjunction with lateral flow immunochromatographic (LFIC) in urine specimens for rapid diagnosis of bacterial Urinary Tract Infection (UTI) and detection of carbapenemase and/or extended-spectrum β- lactamase (ESBL) enzymes produced by the involved bacteria, compared to standard culture, and antimicrobial susceptibility testing/genotypic resistance markers characterization performed on culture-grown colonies. In addition, a cost-benefit analysis comparing this approach against standard procedures was conducted. A total of 324 urines were included in the study, of which 288 (88.9 %) yielded concordant results by the MALDI-ToF MS and conventional culture (Kappa agreement, 0.82; P<0.001). Direct LFIC testing could be carried out in 249/324 urines. Bacterial species carrying β-lactam genotypic resistance markers were identified in 35 urines (35 CTX-M and 2 OXA-48). Two ESBL-producing Escherichia coli were missed by LFIC (Kappa agreement with standard procedures of 0.96; P<0.001). The cost-benefit analysis indicated that our novel approach resulted in an improvement of clinical outcomes (less need of outpatient care) with a marginal incremental cost (€2.59).

A Common Polymorphism in RNASE6 Impacts Its Antimicrobial Activity toward Uropathogenic Escherichia coli

Human Ribonuclease (RNase) 6 is a monocyte and macrophage-derived protein with potent antimicrobial activity toward uropathogenic bacteria. The RNASE6 gene is heterogeneous in humans due to the presence of single nucleotide polymorphisms (SNPs). RNASE6 rs1045922 is the most common non-synonymous SNP, resulting in a G to A substitution that determines an arginine (R) to glutamine (Q) transversion at position 66 in the protein sequence. By structural analysis we observed that R66Q substitution significantly reduces the positive electrostatic charge at the protein surface. Here, we generated both recombinant RNase 6-R66 and -Q66 protein variants and determined their antimicrobial activity toward uropathogenic Escherichia coli (UPEC), the most common cause of UTI. We found that the R66 variant, encoded by the major SNP rs1045922 allele, exhibited superior bactericidal activity in comparison to the Q66 variant. The higher bactericidal activity of R66 variant correlated with an increase in the protein lipopolysaccharide binding and bacterial agglutination abilities, while retaining the same enzymatic efficiency. These findings encourage further work to evaluate RNASE6 SNP distribution and its impact in UTI susceptibility.

Budget impact analysis on the use of Sysmex PA-100 AST system as a point of care for uncomplicated urinary tract infections detection and treatment in Spanish females

OBJECTIVE

Efficient diagnostic methods, such as the Sysmex PA-100, provide rapid antimicrobial susceptibility test results directly from urine samples with high sensitivity and specificity, and improve treatment recommendations. Our study analyzes the economic impact of integrating the Sysmex PA-100 to assess its potential benefits and cost implications for uncomplicated urinary tract infection (uUTI) management in Spain.

METHODOLOGY

A budget impact model was developed using a decision tree framework to compare current UTI management practices with a new scenario incorporating the Sysmex PA-100. The clinical inputs were extracted from published literature. The model, representing adult females with uUTIs, assessed direct medical and indirect costs over three years, including diagnostic procedures, treatment costs, staff time costs, and productivity loss. The cost data was captured from two Spanish hospitals. Two scenario analyses were conducted in the model: scenario A included costs for antimicrobial resistance (AMR) emergence in patients receiving unnecessary empirical antibiotics, whereas scenario B assumed no AMR costs.

RESULTS

In scenario A, 100% implementation of PA-100 within various Spanish healthcare settings over one year resulted in total cost savings of EUR 323,657,712 (EUR 119.10 per patient per year). The total overall cost savings attributable to the implementation of PA-100 over three years were EUR 970,973,137. In scenario B, the total annual savings were EUR 4,254,795 (EUR 1.57 per patient per year), and the 3-year savings were EUR 12,764,385.

CONCLUSION

The adoption of this point-of-care system results in overall cost savings, driven by reductions in direct and indirect costs related to UTI management. The model highlights potential savings over three years owing to appropriate rapid management (reduction in time to diagnosis and treatment, which leads to fewer complications and secondary infections) and reduced staff time and productivity loss costs. These findings support the potential benefits of adopting the Sysmex PA-100 to enhance UTI management and allocate healthcare resource utilization in Spain.

Multiplex Polymerase Chain Reaction/Pooled Antibiotic Susceptibility Testing Was Not Associated with Increased Antibiotic Resistance in Management of Complicated Urinary Tract Infections

Objective

To compare antibiotic resistance results at different time points in patients with urinary tract infections (UTIs), who were either treated based upon a combined multiplex polymerase chain reaction (M-PCR) and pooled antibiotic susceptibility test (P-AST) or were not treated.

Methods

The M-PCR/P-AST test utilized here detects 30 UTI pathogens or group of pathogens, 32 antibiotic resistance (ABR) genes, and phenotypic susceptibility to 19 antibiotics. We compared the presence or absence of ABR genes and the number of resistant antibiotics, at baseline (Day 0) and 5-28 days (Day 5-28) after clinical management in the antibiotic-treated (n = 52) and untreated groups (n = 12).

Results

Our results demonstrated that higher percentage of patients had a reduction in ABR gene detection in the treated compared to the untreated group (38.5% reduction vs 0%, p = 0.01). Similarly, significantly more patients had reduced numbers of resistant antibiotics, as measured by the phenotypic P-AST component of the test, in the treated than in the untreated group (42.3% reduction vs 8.3%, p = 0.04).

Conclusion

Our results with both resistance gene and phenotypic antibiotic susceptibility results demonstrated that treatment based upon rapid and sensitive M-PCR/P-AST resulted in reduction rather than induction of antibiotic resistance in symptomatic patients with suspected complicated UTI (cUTI) in an urology setting, indicating this type of test is valuable in the management of these types of patients. Further studies of the causes of gene reduction, including elimination of ABR gene-carrying bacteria and loss of ABR gene(s), are warranted.

Impact of a Primary Care Antimicrobial Stewardship Program on Bacterial Resistance Control and Ecological Imprint in Urinary Tract Infections

Antimicrobial stewardship programs (ASPs) are a central component in reducing the overprescription of unnecessary antibiotics, with multiple studies showing benefits in the reduction of bacterial resistance. Less commonly, ASPs have been performed in outpatient settings, but there is a lack of available data in these settings. We implemented an ASP in a large regional outpatient setting to assess its feasibility and effectiveness. Over a 5-year post-implementation period, compared to the pre-intervention period, a significant reduction in antibiotic prescription occurred, with a reduction in resistance in E. coli urinary isolates. ASP activities also were found to be cost-effective, with a reduction in medication prescription.

Oral ciprofloxacin activity against ceftriaxone-resistant Escherichia coli in an in vitro bladder infection model

OBJECTIVES

Pharmacodynamic profiling of oral ciprofloxacin dosing for urinary tract infections caused by ceftriaxone-resistant Escherichia coli isolates with ciprofloxacin MIC ≥ 0.25 mg/L.

BACKGROUND

Urine-specific breakpoints for ciprofloxacin do not exist. However, high urinary concentrations may promote efficacy in isolates with low-level resistance.

METHODS

Ceftriaxone-resistant E. coli urinary isolates were screened for ciprofloxacin susceptibility. Fifteen representative strains were selected and tested using a dynamic bladder infection model. Oral ciprofloxacin dosing was simulated over 3 days (250 mg daily, 500 mg daily, 250 mg 12 hourly, 500 mg 12 hourly and 750 mg 12 hourly). The model was run for 96 h. Primary endpoint was change in bacterial density at 72 h. Secondary endpoints were follow-up change in bacterial density at 96 h and area-under-bacterial-kill-curve. Bacterial response was related to exposure (AUC0-24/MIC; Cmax/MIC). PTA was determined using Monte-Carlo simulation.

RESULTS

Ninety-three clinical isolates demonstrated a trimodal ciprofloxacin MIC distribution (modal MICs at 0.016, 0.25 and 32 mg/L). Fifteen selected clinical isolates (ciprofloxacin MIC 0.25-512 mg/L) had a broad range of quinolone-resistance genes. Following ciprofloxacin exposure, E. coli ATCC 25922 (MIC 0.008 mg/L) was killed in all dosing experiments. Six isolates (MIC ≥ 16 mg/L) regrew in all experiments. Remaining isolates (MIC 0.25-8 mg/L) regrew variably after an initial period of killing, depending on simulated ciprofloxacin dose. A >95% PTA, using AUC0-24/MIC targets, supported 250 mg 12 hourly for susceptible isolates (MIC ≤ 0.25 mg/L). For isolates with MIC ≤ 1 mg/L, 750 mg 12 hourly promoted 3 log10 kill at the end of treatment (72 h), 1 log10 kill at follow-up (96 h) and 90% maximal activity (AUBKC0-96).

CONCLUSIONS

Bladder infection modelling supports oral ciprofloxacin activity against E. coli with low-level resistance (ciprofloxacin MIC ≤ 1 mg/L) when using high dose therapy (750 mg 12 hourly).

Limited Therapeutic Options in Mexico for the Treatment of Urinary Tract Infections

The rise in antimicrobial resistance (AMR) has complicated the management of urinary tract infections (UTIs). The objective of this study was to evaluate the antimicrobial susceptibility patterns of Escherichia coli and Klebsiella pneumoniae. Design: prospective observational study. Bacteria were classified as susceptible or resistant to ampicillin-sulbactam, amikacin, gentamicin, ciprofloxacin, norfloxacin, nitrofurantoin, trimethoprim-sulfamethoxazole (TMP/SMZ), ertapenem, meropenem, and fosfomycin. The sensitivity to fosfomycin and chloramphenicol was evaluated by the disk diffusion method. Statistical analysis: the chi-square test and Fisher’s exact test were used to compare differences between categories. A p value < 0.05 was considered statistically significant. Isolates were collected from January 2019 to November 2020 from 21 hospitals and laboratories. A total of 238 isolates were received: a total of 156 E. coli isolates and 82 K. pneumoniae isolates. The majority were community-acquired infections (64.1%). Resistance was >20% for beta-lactams, aminoglycosides, fluoroquinolones, and TMP/SMZ. For E. coli isolates, resistance was <20% for amikacin, fosfomycin, and nitrofurantoin; for K. pneumoniae, amikacin, fosfomycin, chloramphenicol, and norfloxacin. All were susceptible to carbapenems. K. pneumoniae isolates registered a higher proportion of extensively drug-resistant bacteria in comparison with E. coli (p = 0.0004). In total, multidrug-resistant bacteria represented 61% of all isolates. Isolates demonstrated high resistance to beta-lactams, fluoro-quinolones, and TMP/SMZ.

The Production of Antibiotics Must Be Reoriented: Repositioning Old Narrow-Spectrum Antibiotics, Developing New Microbiome-Sparing Antibiotics

The development of broad-spectrum antibiotics to control multidrug-resistant bacteria is an outdated business model. This strategy has led to the introduction of highly effective antibiotics, but their widespread use has contributed to the emergence of even broader antibiotic resistance. In a strategy to combat antimicrobial resistance, we believe that the use of narrow-spectrum antibiotics should be promoted. This should involve both the repositioning of old antibiotics and the reorientation of research and development towards new narrow-spectrum antibiotics with a low ecological impact. These antibiotics could be prescribed for common conditions such as sore throats and cystitis, which account for the bulk of antibiotic use in humans. Narrow-spectrum, targeted, microbiome-sparing antibiotics could help control antibiotic resistance while being economically sustainable. Their development and production should be supported by governments, which would ultimately benefit from reduced health care costs.