The role of bacterial infection in the aetiology of the overactive bladder

The aim of this programme of work was to examine the role of bacterial infection in the aetiology of the Overactive Bladder (OAB). Recent studies in OAB have identified urinary inflammatory exudates occurring despite negative routine urine cultures. Detection of pyuria by microscopy of fresh unspun urine is established as the best surrogate marker of infection and pyuria has been described in over 33% of people with OAB. The routine methods of urinalysis; dipstick of mid-stream urine (MSU) specimens and MSU culture were scrutinised. New techniques of urine culture were sought by culturing the urinary sediment. Intracellular colonisation of urothelial cells was tested in patients and verified further by using a bladder epithelial cell line. In addition, a cytokine response in the urine was examined as surrogate evidence of an urothelial inflammatory reaction in patients with OAB. The dipstick test was found to have a low sensitivity and specificity in the context of OAB. In addition, culture of the urine sediment using non-selective culture media enhanced the isolation of bacteria from patients with OAB. The bacterial species isolated were predominantly Streptococcus spp and Enterococcus spp.IL-6 was found in higher concentrations in the urine specimens of patients with OAB symptoms and pyuria. Intracellular invasion assays and microscopic methods of identifying intracellular bacteria in this patient group identified adherent and intracellular bacteria

A prospective observational study of urinary cytokines and inflammatory response in patients with Overactive Bladder Syndrome

Background Contemporary studies have discredited the methods used to exclude urinary tract infection (UTI) when treating overactive bladder (OAB). Thus we must revisit the OAB phenotype to check that UTI has not been overlooked. Aims To examine the differences in urinary cytokines IL6 and lactoferrin in OAB patients compared to controls, with references to microscopy of urine and enhanced quantitative urine culture. Methods A blinded, prospective cohort study with normal controls using six repeated measures, achieved two-monthly, over 12 months. Results The differences between patients and controls in urine IL6 (F = 49.0, p < .001) and lactoferrin (F = 228.5, p < .001) were significant and of a magnitude to have clinical implications. These differences were for lactoferrin correlated to symptoms (9.3, p = .003); for both to pyuria (IL6 F = 66.2, p < .001, Lactoferrin F = 73.9, p < .001); and for IL6 microbial abundance (F = 5.1, p = .024). The pathological markers had been missed by urinary dipsticks and routine MSU culture. Conclusion The OAB phenotype may encompass patients with UTI that is being overlooked because of the failure of standard screening methods

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

Urinary ATP as an indicator of infection and inflammation of the urinary tract in patients with lower urinary tract symptoms

BACKGROUND: Adenosine-5'-triphosphate (ATP) is a neurotransmitter and inflammatory cytokine implicated in the pathophysiology of lower urinary tract disease. ATP additionally reflects microbial biomass thus has potential as a surrogate marker of urinary tract infection (UTI). The optimum clinical sampling method for ATP urinalysis has not been established. We tested the potential of urinary ATP in the assessment of lower urinary tract symptoms, infection and inflammation, and validated sampling methods for clinical practice. METHODS: A prospective, blinded, cross-sectional observational study of adult patients presenting with lower urinary tract symptoms (LUTS) and asymptomatic controls, was conducted between October 2009 and October 2012. Urinary ATP was assayed by a luciferin-luciferase method, pyuria counted by microscopy of fresh unspun urine and symptoms assessed using validated questionnaires. The sample collection, storage and processing methods were also validated. RESULTS: 75 controls and 340 patients with LUTS were grouped as without pyuria (n = 100), pyuria 1-9 wbc ?l(-1) (n = 120) and pyuria ?10 wbc ?l(-1) (n = 120). Urinary ATP was higher in association with female gender, voiding symptoms, pyuria greater than 10 wbc ?l(-1) and negative MSU culture. ROC curve analysis showed no evidence of diagnostic test potential. The urinary ATP signal decayed with storage at 23°C but was prevented by immediate freezing at ??-20°C, without boric acid preservative and without the need to centrifuge urine prior to freezing. CONCLUSIONS: Urinary ATP may have a role as a research tool but is unconvincing as a surrogate, clinical diagnostic marker

The molecular basis of antibiotic treatment failure in chronic urinary tract infections

Urinary tract infections (UTIs) are amongst the most common infections worldwide, and are becoming increasingly difficult to treat. In addition to the acceleration of classic antimicrobial resistance, recurrence after initial resolution is common. Our clinical experience is that chronically infected patients sometimes fail to respond to antibiotics predicted to be effective from culture-based sensitivity testing, while antibiotics predicted to be unsuitable can succeed. We hypothesized that the bladder environment could lead to differential bacterial gene expression, resulting in differences in minimum inhibitory concentration (MICs) compared with standard culture. Here, using strains of Escherichia coli evolved in the lab to be resistant to amoxicillin–clavulanic acid, we present data that MICs differ depending on which media the assay is performed in (M9, ISO, LB, human urine), as well as in urine-containing supernatant enriched from urothelial organoids. Next, we examined the behaviour of patient-derived Enterococcus faecalis, one of the main causative agents of chronic UTIs in the elderly. We are in the process of evaluating the MIC of first-line UTI antibiotics using growth media supplemented with urine, to more closely mimic the native uropathogen environment. Moreover, we are characterising the resistance genes expressed in those differing environments using next generation sequencing technology and comparing the results with those obtained from bacteria grown on standard diagnostic media. Our work demonstrates the danger of extrapolating biological behaviour from artificial culture substrates and may lead to better diagnostic tests and treatments for chronic UTI

An evidence-based perspective on lower urinary tract symptoms and telemedicine during the COVID-19 pandemic

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) causing the COVID-19 pandemic, has had an enormous effect on conventional clinical practice. Telemedicine has emerged as critical to the provision of healthcare services when reducing the transmission of COVID-19 among patients, families, and clinicians. It has been an essential tool for continuing care for patients with lower urinary tract symptoms (LUTS) during the COVID-19 pandemic and has been the link between socially distant patient contact. The aim of this perspective paper was to identify the strengths and limitations of technology-based care focusing on literature linked to patients with lower urinary tract symptoms (LUTS). We search PubMed and CINHAL Plus for grey literature and secondary research on LUTS and telemedicine during the COVID-19 pandemic. Publications dated between the year March 2020 and March 2021were searched. We gathered key specialist opinions in the field of LUTS from several countries around the world, including the countries that had been hit significantly with COVID-19. This perspective paper proposes that there is evidence to support the use of modern technology to facilitate continued healthcare services for patients with LUTS during the COVID-19 pandemic. Telemedicine has been recognised a crucial digital tool for diagnosis, treatment and follow-up appointments during a time of social distancing. Although there are many advantages of telemedicine, the older adult population and those economically disadvantaged with technology may not benefit from technology-based healthcare. The available literature on telemedicine during the COVID-19 pandemic has proven to be successful in the management of some patients with LUTS. It is certain that the COVID-19 pandemic has given telemedicine a significant drive for implementation now and in the immediate future. Robust data on long-term efficacy and safety of telemedicine is required to ensure there are governance protocols embedded when looking after patients with LUTS

Lower urinary tract symptoms that predict microscopic pyuria

INTRODUCTION AND HYPOTHESIS: Urinary dipsticks and culture analyses of a mid-stream urine specimen (MSU) at 10(5) cfu ml(-1) of a known urinary pathogen are considered the gold standard investigations for diagnosing urinary tract infection (UTI). However, the reliability of these tests has been much criticised and they may mislead. It is now widely accepted that pyuria (≥1 WBC μl(-1)) detected by microscopy of a fresh unspun, unstained specimen of urine is the best biological indicator of UTI available. We aimed to scrutinise the greater potential of symptoms analysis in detecting pyuria and UTI. METHODS: Lower urinary tract symptom (LUTS) descriptions were collected from patients with chronic lower urinary tract symptoms referred to a tertiary referral unit. The symptoms informed a 39-question inventory, grouped into storage, voiding, stress incontinence and pain symptoms. All questions sought a binary yes or no response. A bespoke software package was developed to collect the data. The study was powered to a sample of at least 1,990 patients, with sufficient power to analyse 39 symptoms in a linear model with an effect size of Cohen's f(2) = 0.02, type 1 error probability = 0.05; and power (1-β); 95% where β is the probability of type 2 error). The inventory was administered to 2,050 female patients between August 2004 and November 2011. The data were collated and the following properties assessed: internal consistency, test-retest reliability, inter-observer reliability, internal responsiveness, external responsiveness, construct validity analysis and a comparison with the International Consultation on Incontinence Modular Questionnaire for female lower urinary tract symptoms (ICIQ-FLUTS). The dependent variable used as a surrogate marker of UTI was microscopic pyuria. An MSU sample was sent for routine culture. RESULTS: The symptoms proved reliable predictors of microscopic pyuria. In particular, voiding symptoms correlated well with microscopic pyuria (χ(2) = 88, df = 1, p < 0.001). The symptom inventory has significant psychometric characteristics as below: test-retest reliability: Cronbach's alpha was 0.981; inter-observer reliability, Cronbach's alpha was 0.995, internal responsiveness F = 221, p < 0.001, external responsiveness F = 359, df = 5, p < 0.001. The correlation coefficients for the domains of the ICIQ-FLUTS were around R = 0.5, p < 0.001. CONCLUSION: This symptoms score performed well on the standard, psychometric validation. The score changed in response to treatment and in a direction appropriate to the changes in microscopic pyuria. It correlated with measures of quality of life. It would seem to make a good candidate for monitoring treatment progress in ordinary clinical practice

Recalcitrant chronic bladder pain and recurrent cystitis but negative urinalysis - what should we do?

Purpose: Lower urinary tract symptoms (LUTS) may be associated with chronic urinary tract infection (UTI) undetected by routine diagnostic tests. Antimicrobial therapy might confer benefit for these patients. Materials and Methods: Over ten years, we treated patients with chronic LUTS. Pyuria was adopted as the principal biomarker of infection. Urinary leucocyte counts were recorded from microscopy of fresh midstream urine (MSU) samples. Antibiotics were prescribed and the prescription adjusted to achieve a measurable clinical response and a reduction in pyuria. Results: We treated 624 women (mean age=53.4 years; sd=18) with chronic LUTS and pyuria. The mean duration of symptoms prior to presentation was 6.5 years. Only 16% of MSU cultures submitted were positive (≥105 cfu ml-1). Mean treatment length was 383 days (SD=347; 95% CI=337-428). Treatment was associated with a reduction in total LUTS (F=98; p=.0001), 24-hour frequency (F=75; p=.0001), urinary 3 urgency (F=90; p=.0001), lower urinary tract pain (F=108; p=.0001), voiding symptoms (F=10; p=.002) and pyuria (F=15.4; p=.0001). Full-dose first-generation urinary antibiotic (such as cefalexin, nitrofurantoin, or trimethoprim) was combined with Methenamine Hippurate. We recorded 475 adverse events (AEs) during 273,762 treatment days. There was only one serious adverse event (SAE). We observed no increase in the proportion of resistant bacterial isolates. Conclusion: This large case series demonstrates that patients with chronic LUTS and pyuria experience symptom regression and a reduction in urinary tract inflammation associated with antimicrobial therapy. Disease regression was achieved with a low frequency of AEs. These results provide preliminary data to inform a future RCT

A blinded observational cohort study of the microbiological ecology associated with pyuria and overactive bladder symptoms

INTRODUCTION AND HYPOTHESIS: This study sought to characterise the microbial ecology of the lower urinary tract in patients with symptoms of overactive bladder (OAB) using culture of the urinary urothelial cell sediment. The pathological significance of the microbiome was assessed through its relationship with known urothelial inflammatory markers and patient reported symptoms. METHODS: Adult female patients with OAB symptoms and asymptomatic controls were assessed at 12 study visits scheduled every 4 weeks. At each visit, all participants provided a clean-catch midstream urine (MSU) that was analysed to count white and uroepithelial cells, submitted to standard culture and spun urothelial-cell-sediment culture. Symptoms were assessed using validated questionnaires. RESULTS: This analysis shows that OAB patients differ consistently from controls, demonstrating differences in bacterial ecology (t -4.57, p 0.0001), in the microscopic pyuria count (t -6.37, p 0.0001) and presence of infected urothelial cells (t -4.21, p 0.0001). The primary outcome measure of bacterial growth [colony-forming units (CFU) ml-1] was higher in OAB patients than in controls throughout the 12 months. Data showed a correlation between symptoms and pyuria, with notable urgency correlating with pyuria and epithelial cell shedding. The routine urine cultures (with a threshold of reporting a positive result as 105 CFU/ml) were unable to distinguish OAB patients from controls. However, sediment cultures differed significantly, and there was a correlated increased immune response amongst OAB patients. CONCLUSIONS: This study supports the need to re-examine the OAB phenotype given this association with microbial colonisation