The Roles of the Host and the Pathogens in Urinary Tract Infections

Urinary Tract Infection Prevention and Treatment

Urinary tract infections are the most common bacterial infections encountered by health care professionals. In women, the lifetime incidence of urinary tract infections may be up to 40% to 50%, of whom a further 40% may have recurrent infections. Urinary tract infections are associated with significant morbidity and potential mortality-they may be complicated by frequent recurrences, kidney damage, sepsis, and preterm birth, as well as collateral damage of antimicrobial use, which includes Clostridium difficile colitis and selection of drug-resistant organisms. There are personal costs such as reduced quality of life in patients affected by recurrent urinary tract infections, and societal impacts resulting from absenteeism and health care costs. In this review, we discuss the definitions and classifications, pathogenesis, and current principles of management and prevention of urinary tract infections. Semin Nephrol 43:x-xx © 2023 Elsevier Inc. All rights reserved.

Vesicoureteral Reflux and Innate Immune System: Physiology, Physiopathology, and Clinical Aspects

Vesicoureteral reflux represents one of the most concerning topics in pediatric nephrology due to its frequency, clinical expression with the potential to evolve into chronic kidney disease, and last but not least, its socio-economic implications. The presence of vesicoureteral reflux, the occurrence of urinary tract infections, and the development of reflux nephropathy, hypertension, chronic kidney disease, and finally, end-stage renal disease represent a progressive spectrum of a single physiopathological condition. For the proper management of these patients with the best clinical outcomes, and in an attempt to prevent the spread of uropathogens' resistance to antibacterial therapy, we must better understand the physiopathology of urinary tract infections in patients with vesicoureteral reflux, and at the same time, we should acknowledge the implication and response of the innate immune system in this progressive pathological condition. The present paper focuses on theoretical aspects regarding the physiopathology of vesicoureteral reflux and the interconditionality between urinary tract infections and the innate immune system. In addition, we detailed aspects regarding cytokines, interleukins, antimicrobial peptides, and proteins involved in the innate immune response as well as their implications in the physiopathology of reflux nephropathy. New directions of study should focus on using these innate immune system effectors as diagnostic and therapeutic tools in renal pathology.

The Impact of Lactobacillus Plantarum PCS26 Supplementation on the Treatment and Recurrence of Urinary Tract Infections in Children-A Pilot Study

Urinary tract infections (UTI) are frequent bacterial infections in childhood. Considering the known beneficial effects of probiotics in the gastrointestinal field, they could also help to alleviate UTIs. In our clinical pilot study, we sought to verify the positive effects of the specific probiotic strain on the course and prevention of UTI in children. Thirty children with UTIs were enrolled and sequentially sampled into two groups (placebo/control and probiotic/test) in a double-blind, randomized, placebo-controlled clinical pilot study. We chose Lactobacillus plantarum PCS 26 (Lp26) derived from local Slovenian cheese in Pathogen Combat Project, which showed a good in vitro antimicrobial effect on Escherichia coli (E. coli). Several parameters were followed to look for differences between both groups in the acute phase of the UTI and after 6 months of taking probiotic or placebo supplementation. Our results showed no statistically significant differences between both groups; however, two children in the placebo group suffered a recurrence of febrile UTI within 6 months of the follow-up period, while there were no recurrences of UTI in the probiotic group. In the test group, the number of febrile days after the initiation of antibiotics with probiotics was shorter, although not reaching statistical significance (p = 0.084). According to our results, probiotics might be helpful in alleviating UTI symptoms and in UTI prevention. Further research with a larger sample size is warranted. Additionally, basic scientific studies for the selection of proper immunobiotic strains of probiotics should be performed.

Uropathogenic Escherichia coli can cause cystitis at extremely low inocula in a pig model

Urinary tract infection (UTI) is one of the most common bacterial infections worldwide. Experimental models that accurately reflect the high susceptibility to UTI in humans have, however, been lacking. This situation has limited detailed research into the early bladder colonization by uropathogens and the early innate defence mechanisms elicited to prevent this. We recently presented a model of urinary tract infection in pigs, animals that are naturally susceptible to UTI and have greater similarity to the physiology and anatomy of the human urinary tract than traditional rodent UTI models. In the current study, we used the pig model to investigate the minimal infectious inoculum of uropathogenic Escherichia coli, the most common cause of urinary tract infection. We show that in this animal a few individual bacteria that come into contact with the urothelium can give rise to fulminant cystitis, indicating the high infectious potential of uropathogenic E. coli.

Immunohistochemical expression of CD 14 in transitional cell carcinoma of the urinary bladder

CD14 is a co-receptor for bacterial lipolysaccharide (LPS) detection. It is found on myelomonocytic cells such as monocytes, macrophages, and Langerhans cells, CD14 expression in bladder cells is necessary for cytokine secretion and increased tumor growth. The goal of this study was to use immunohistochemistry (IHC) to assess CD14 expression in patients with transitional cell carcinoma of the urinary bladder in order to see if there was a link between CD14 marker expression in bladder cancer and cystitis. The immunoexpression of CD14 in paraffin sections from 30 bladder biopsy samples was separated into three groups: cystitis, low grade bladder cancer (L.G), and high grade bladder cancer (H.G), and studied using immunohistochemical assays (IHC). For bladder cancer (L.G & H.G), the percentage of samples that gave positive results for IHC/CD14 expression was 70% and 80%, respectively, compared to 30% for cystitis. The incidence of study samples appear in both sexes.

Whole-Person, Urobiome-Centric Therapy for Uncomplicated Urinary Tract Infection

A healthy urinary tract contains a variety of microbes resulting in a diverse urobiome. Urobiome dysbiosis, defined as an imbalance in the microbial composition in the microenvironments along the urinary tract, is found in women with uncomplicated urinary tract infection (UTI). Historically, antibiotics have been used to address UTI. An alternative approach to uncomplicated UTI is warranted as the current paradigm fails to take urobiome dysbiosis into account and contributes to the communal problem of resistance. A whole-person, multi-modal approach that addresses vaginal and urinary tract dysbiosis may be more effective in reducing recurrent UTI. In this review, we discuss strategies that include reducing pathogenic bacteria while supporting commensal urogenital bacteria, encouraging diuresis, maintaining optimal pH levels, and reducing inflammation. Strategies for future research are suggested.

Escherichia coli type-1 fimbriae are critical to overcome initial bottlenecks of infection upon low-dose inoculation in a porcine model of cystitis

Most uropathogenic Escherichia coli (UPEC) express type-1 fimbriae (T1F), a key virulence factor for urinary tract infection (UTI) in mice. Evidence that conclusively associates this pilus with uropathogenesis in humans has, however, been difficult to obtain. We used an experimental porcine model of cystitis to assess the role of T1F in larger mammals more closely related to humans. Thirty-one pigs were infected with UPEC strain UTI89 or its T1F deficient mutant, UTI89ΔfimH, at inoculum titres of 10² to 10⁸ colony forming units per millilitre. Urine and blood samples were collected and analysed 7 and 14 days post-inoculation, and whole bladders were removed at day 14 and analysed for uroepithelium-associated UPEC. All animals were consistently infected and reached high urine titres independent of inoculum titre. UTI89ΔfimH successfully colonized the bladders of 1/6 pigs compared to 6/6 for the wild-type strain. Intracellular UPEC were detectable in low numbers in whole bladder explants. In conclusion, low doses of UPEC are able to establish robust infections in pigs, similar to what is presumed in humans. T1F are critical for UPEC to surpass initial bottlenecks during infection but may be dispensable once infection is established. While supporting the conclusions from mice studies regarding a general importance of T1F in successfully infecting the host, the porcine UTI models’ natural high, more human-like, susceptibility to infection, allowed us to demonstrate a pivotal role of T1F in initial establishment of infection upon a realistic low-inoculum introduction of UPEC in the bladder.

A Novel Device-Integrated Drug Delivery System for Local Inhibition of Urinary Tract Infection

Background: Catheter-associated urinary tract infection (CAUTI) is a frequent community-acquired infection and the most common nosocomial infection. Here, we developed a novel antimicrobial catheter concept that utilizes a silicone-based interpenetrating polymer network (IPN) as balloon material to facilitate a topical slow-release prophylaxis of antibacterial agents across the balloon to the urinary bladder.

Methods: The balloon material was achieved by modifying low shore hardness silicone tubes with a hydrogel interpenetrating polymer in supercritical CO₂ using the sequential method. Release properties and antibacterial efficacy of the IPN balloon treatment concept was investigated in vitro and in a porcine CAUTI model developed for the study. In the latter, Bactiguard Infection Protection (BIP) Foley catheters were also assessed to enable benchmark with the traditional antimicrobial coating principle.

Results: Uropathogenic Escherichia coli was undetectable in urinary bladders and on retrieved catheters in the IPN treatment group as compared to control that revealed significant bacteriuria (>10⁵ colony forming units/ml) as well as catheter-associated biofilm. The BIP catheters failed to prevent E. coli colonization of the bladder but significantly reduced catheter biofilm formation compared to the control.

Conclusion: The IPN-catheter concept provides a novel, promising delivery route for local treatment in the urinary tract.

Potential Probiotics Bacillus subtilis KATMIRA1933 and Bacillus amyloliquefaciens B-1895 Co-Aggregate with Clinical Isolates of Proteus mirabilis and Prevent Biofilm Formation

A urinary tract infection (UTI) is a multi-factorial disease including cystitis, pyelonephritis, and pyelitis. After Escherichia coli, Proteus mirabilis is the most common UTI-associated opportunistic pathogen. Antibiotic resistance of bacteria and infection recurrence can be connected to biofilm formation by P. mirabilis. In this study, human and sheep isolates of P. mirabilis were investigated for antibiotic sensitivity using an antibiotic disk test. Co-aggregation of the tested potential probiotic bacilli, Bacillus amyloliquefaciens B-1895 and Bacillus subtilis KATMIRA1933, with the isolated pathogen was also evaluated. Then, the anti-biofilm activity of naturally derived metabolites, such as subtilin and subtilosin, in the bacilli-free supernatants was assessed against biofilms of P. mirabilis isolates. The isolated pathogens were sensitive to 30 μg of amikacin and 5 μg of ciprofloxacin but resistant to other tested antibiotics. After 24 h, auto-aggregation of B. amyloliquefaciens B-1895 was at 89.5% and higher than auto-aggregation of B. subtilis KATMIRA1933 (59.5%). B. amyloliquefaciens B-1895 strongly co-aggregated with P. mirabilis isolates from human UTIs. Cell-free supernatants of B. amyloliquefaciens B-1895 and B. subtilis KATMIRA1933 showed higher antimicrobial activity against biofilms of P. mirabilis isolated from humans as compared with biofilms of sheep isolates. According to our knowledge, this is the first report evaluating the anti-biofilm activity of probiotic spore-forming bacilli against clinical and animal UTI isolates of P. mirabilis. Further studies are recommended to investigate the anti-biofilm activity and the mode of action for the antimicrobial substances produced by these bacilli, subtilosin and subtilin.

Epidemiology, definition and treatment of complicated urinary tract infections

UTIs are amongst the most frequent bacterial infections. However, the clinical phenotypes of UTI are heterogeneous and range from rather benign, uncomplicated infections to complicated UTIs (cUTIs), pyelonephritis and severe urosepsis. Stratification of patients with UTIs is, therefore, important. Several classification systems exist for the description and classification of UTIs, with the common rationale that cUTIs have a higher risk of recurrence or chronification, progression or severe outcome than uncomplicated UTIs. The pathophysiology and treatment of cUTIs and pyelonephritis are driven more by host factors than by pathogen attributes. cUTIs and pyelonephritis are associated with high antimicrobial resistance rates among causative pathogens. However, antimicrobial resistance rates can differ substantially, depending on the population being studied and whether the data being analysed are from surveillance studies, registry data or interventional studies, in which specific inclusion and exclusion criteria are used for patient selection. For example, antibiotic resistance rates are higher in patients with urosepsis than in those with less severe infections. Thus, treatment outcomes differ substantially among studies, ranging from 50% to almost 100% clearance of infection, depending on the patient population analysed, the UTI entities included and the primary outcome of the study. Pyelonephritis and cUTIs have emerged as infection models for the study of novel antibiotics, including extensive investigation of novel substances active against Gram-negative bacteria.

Identification of pathogens from native urine samples by MALDI-TOF/TOF tandem mass spectrometry

Background

Reliable high-throughput microbial pathogen identification in human urine samples is crucial for patients with cystitis symptoms. Currently employed methods are time-consuming and could lead to unnecessary or inadequate antibiotic treatment. Purpose of this study was to assess the potential of mass spectrometry for uropathogen identification from a native urine sample.

Methods

In total, 16 urine samples having more than 10⁵ CFU/mL were collected from clinical outpatients. These samples were analysed using standard urine culture methods, followed by 16S rRNA gene sequencing serving as control and here described culture-independent MALDI-TOF/TOF MS method being tested.

Results

Here we present advantages and disadvantages of bottom-up proteomics, using MALDI-TOF/TOF tandem mass spectrometry, for culture-independent identification of uropathogens (e.g. directly from urine samples). The direct approach provided reliable identification of bacteria at the genus level in monobacterial samples. Taxonomic identifications obtained by proteomics were compared both to standard urine culture test used in clinics and genomic test based on 16S rRNA sequencing.

Conclusions

Our findings indicate that mass spectrometry has great potential as a reliable high-throughput tool for microbial pathogen identification in human urine samples. In this case, the MALDI-TOF/TOF, was used as an analytical tool for the determination of bacteria in urine samples, and the results obtained emphasize high importance of storage conditions and sample preparation method impacting reliability of MS2 data analysis. The proposed method is simple enough to be utilized in existing clinical settings and is highly suitable for suspected single organism infectious etiologies. Further research is required in order to identify pathogens in polymicrobial urine samples.

Intramuscular Immunization Induces Antigen-specific Antibodies in Urine

Towards the development of vaccines against urinary tract infections (UTI), we determined the ability of intramuscular (i.m.) immunization to result in antigen-specific antibodies in urine. As a model antigen/vaccine, levels of total and vaccine-specific antibodies were determined in urine as a spin-out study of a phase 1 trial. Non-muscle-invasive bladder cancer (NMIBC) patients at different risks of progression, undergoing intravesical bacillus Calmette-Guérin (BCG) immunotherapy or not, received an adjuvanted recombinant protein vaccine that resulted in high titers of vaccine-specific serum immunoglobulin G (IgG) in all patients, regardless of the risk group. Vaccine-specific IgG and immunoglobulin A (IgA) were detected in urine of half of the patients at low risk of progression NMIBC and in all the intermediary/high- (int/high) risk patients. Vaccine-specific IgG titers were correlated to total urinary IgG levels, the latter being higher in the int/high-risk patients. In contrast, vaccine-specific IgA did not correlate to urinary IgA levels. Furthermore, vaccine-specific antibodies were transiently increased by intravesical BCG instillations. Altogether, our data show that a standard i.m. immunization can effectively induce antigen-specific antibodies in urine, which, upon selection of optimal vaccine targets, may provide protection against UTI. Vaccine-specific IgG titers were dependent on conditions affecting total urinary IgG levels, while production of vaccine-specific IgA in situ might independently contribute to protection against infections in the bladder. PATIENT SUMMARY: Towards the development of vaccines able to protect against urinary tract infections, we examined the potential of the intramuscular vaccination using a model antigen. We found two types of specific antibodies in the urine, which together may locally contribute to protection against infections, thus supporting the use of such a standard immunization route.

Phylogenetic Group/Subgroups Distributions, Virulence Factors, and Antimicrobial Susceptibility of Escherichia coli Strains from Urinary Tract Infections in Hatay

INTRODUCTION

Nosocomial and community acquired urinary tract infections (UTIs) are one of the most encountered infections in the world.

METHODS

This study aimed to determine the antibiotic susceptibility, phylogeny, and virulence genes of 153 Escherichia coli strains isolated from UTIs. Antimicrobial susceptibility of the isolates to different classes of antimicrobials was determined by the VITEK-2 automated system. Presence of virulence genes and phylogenetic groups were investigated by PCR.

RESULTS

Regarding susceptibility to antimicrobials, ampicillin resistance was most abundant (67.3%), followed by amoxicillin-clavulanic acid (50.9%); least abundant was resistance to amikacin (1.3%) and nitrofurantoin (1.3%). Multi drug resistance (MDR) was observed in 34.6% of the isolates, and all isolates were found to be susceptible to imipenem, meropenem and fosfomycine. The majority of the isolates belonged to the phylogenetic group B23 (35.9%), followed by A1 (20.9%), D1 (18.9%), D2 (12.4%), A0 (%5.9), B1 (3.9%) and B2 (1.9%). Among E. coli strains examined, 49% had iucD, 32.7% papE-F, 26.1% papC, 15% cnf2, 11.1% sfa, 7.8% cnf1, 1.3% afaE, 1.3% afaD, 1.3% hlyA, 0.7% f17a-A, 0.7% clpG and 0.7% eaeA genes.

CONCLUSIONS

Our research demonstrated that virulence factors were distributed among different phylogroup/subgroups, which play a role in UTIs pathogenesis in humans. For this reason, complex and detailed studies are required to determine the relationship between virulence factors and specific E. coli strains that cause UTIs in humans.

Direct Identification of Pathogens in Urine by Use of a Specific Matrix-Assisted Laser Desorption Ionization-Time of Flight Spectrum Database

Urinary tract infections are among the most common reasons for antimicrobial treatment, and early diagnosis could have a significant impact by enabling rapid administration of the adapted antibiotic and preventing complications. The current delay between sample receipt and pathogen identification is about 24 to 48 h, which could be significantly shortened by use of an accurate direct method. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) is already used for the identification of pathogens in clinical laboratories and constitutes a promising tool for direct diagnosis. A simple preparation protocol was established for the processing of urine samples prior to MS analysis. MALDI-TOF spectra collected directly from 1,000 infected urine samples were used to create a specific reference database (named Urinf). A prospective study was then carried out to evaluate the Urinf database and compare the results obtained with the standard database provided by Bruker on the Biotyper Real Time Classification software. Seven hundred eighty urine specimens were processed and analyzed according to our method. Among them, almost 90% of 500 infected monobacterial samples could be correctly diagnosed with the Urinf database, compared to 50% using the standard database. The identification of Enterobacteriaceae, Staphylococcus aureus, Staphylococcus saprophyticus, Pseudomonas aeruginosa, Enterococcus faecalis, and Enterococcus faecium was greatly improved but not for Staphylococcus epidermidis The creation of a database adapted to a particular type of clinical sample has great potential to increase both the rate and rapidity of pathogen identification. Sensitivity still remains to be improved for bacterial species that exhibit few specific peaks on mass spectra.

Reassessment of Routine Midstream Culture in Diagnosis of Urinary Tract Infection

Midstream urine (MSU) culture remains the gold standard diagnostic test for confirming urinary tract infection (UTI). We previously showed that patients with chronic lower urinary tract symptoms (LUTS) below the diagnostic cutoff on MSU culture may still harbor bacterial infection and that their antibiotic treatment was associated with symptom resolution. Here, we evaluated the results of the United Kingdom's MSU culture in symptomatic patients and controls. Next, we compared the bacterial enrichment capabilities of the MSU culture with those of a 50-µl uncentrifuged culture, a 30-ml centrifuged sediment culture, and 16S rRNA gene sequencing. This study was conducted on urine specimens from 33 LUTS patients attending their first clinical appointment (mean age, 48.7 years; standard deviation [SD], 16.5 years), 30 LUTS patients on treatment (mean age, 47.8 years; SD, 16.5 years) whose symptoms had relapsed, and 29 asymptomatic controls (mean age, 40.7 years, SD, 15.7 years). We showed that the routine MSU culture, adopting the UK interpretation criteria tailored to acute UTI, failed to detect a variety of bacterial species, including recognized uropathogens. Moreover, the diagnostic MSU culture was unable to discriminate between patients and controls. In contrast, genomic analysis of urine enriched by centrifugation discriminated between the groups, generating a more accurate understanding of species richness. In conclusion, the United Kingdom's MSU protocol misses a significant proportion of bacteria, which include recognized uropathogens, and may be unsuitable for excluding UTI in patients with LUTS.

Use of Lactobacillus spp. to prevent recurrent urinary tract infections in females

Urinary tract infections (UTIs) are the most common bacterial infections seen in the community, especially amongst females. The widespread use of antibiotics has led to the increased occurrence of E. coli resistant isolates worldwide. A promising non-antibiotic approach is the use of probiotic lactobacilli strains. This paper hypothesizes that Lactobacillus spp. containing products are able to prevent recurrent urinary tract infections in females. Using the keywords [lactobacillus OR lactobacilli OR probiotic] and [urinary tract infection OR UTI OR cystitis], a preliminary search on the PubMed, Ovid, Google Scholar and ClinicalTrials.gov database yielded 1,647 papers published in English between 1-Jan-1960 and 1-May-2017. 9 clinical trials with a total of 726 patients were reviewed. Different lactobacilli strains (in either oral or suppository formulation) were utilized and they demonstrated varying efficacy in the prevention of recurrent UTIs. Using a random-effects model, pooled risk ratio of at least one recurrent UTI episode during the entire study duration was 0.684 (95% CI 0.438 to 0.929, p < 0.001), per-protocol analysis. However, key limitations include significant inter-study variability and the limited duration of follow-up of most studies. Our hypothesis on the chemoprophylactic effects of probiotics for UTIs is plausible and supported by current data. Lactobacillus rhamnosus GR1 and Lactobacillus reuteri RC14 were the most commonly studied lactobacilli strains. Further and more robust randomized controlled trials with standardized lactobacilli strains and formulation are required for confirmation of effects.

UroPathogenic Escherichia coli (UPEC) Infections: Virulence Factors, Bladder Responses, Antibiotic, and Non-antibiotic Antimicrobial Strategies

Urinary tract infections (UTIs) are one of the most common pathological conditions in both community and hospital settings. It has been estimated that about 150 million people worldwide develop UTI each year, with high social costs in terms of hospitalizations and medical expenses. Among the common uropathogens associated to UTIs development, UroPathogenic Escherichia coli (UPEC) is the primary cause. UPEC strains possess a plethora of both structural (as fimbriae, pili, curli, flagella) and secreted (toxins, iron-acquisition systems) virulence factors that contribute to their capacity to cause disease, although the ability to adhere to host epithelial cells in the urinary tract represents the most important determinant of pathogenicity. On the opposite side, the bladder epithelium shows a multifaceted array of host defenses including the urine flow and the secretion of antimicrobial substances, which represent useful tools to counteract bacterial infections. The fascinating and intricate dynamics between these players determine a complex interaction system that needs to be revealed. This review will focus on the most relevant components of UPEC arsenal of pathogenicity together with the major host responses to infection, the current approved treatment and the emergence of resistant UPEC strains, the vaccine strategies, the natural antimicrobial compounds along with innovative anti-adhesive and prophylactic approaches to prevent UTIs.

Concise synthesis of the pyruvic acid acetal containing pentasaccharide repeating unit of the cell wall O-antigen of Escherichia coli O156

The pentasaccharide repeating unit of the cell wall O-antigen ofEscherichia coliO156 containing 4,6-O-(R)-pyruvate acetal was synthesized using stereoselective [2 + 3] block glycosylation in satisfactory yield.

Urinary Tract Infections in Immunocompromised Patients with Diabetes, Chronic Kidney Disease, and Kidney Transplant

CONTEXT

This paper provides a brief overview of urinary tract infections (UTIs) in immunocompromised patients from the perspective of a practicing urologist.

OBJECTIVE

The primary objective was to provide an update on UTIs in immunocompromised patients. Diabetes mellitus (DM), chronic kidney disease, and kidney transplant (KT) are the most common clinical cases encountered by urologists. Diagnosis, management, and future research needs are summarised.

EVIDENCE ACQUISITION

We conducted a nonsystematic review of the literature. A comprehensive search of the PubMed database between 1996 and 2016 was performed.

EVIDENCE SYNTHESIS

Clinical diagnosis of UTIs in immunocompromised patients is challenging. Causative pathogens in DM are slightly different to those in the general population, but without any difference in resistance profiles. Keeping serum glucose under control is the most important preventive measure. The prevalence of UTIs in patients with autosomal dominant polycystic kidney disease (ADPKD) is 21-75%. Lipophilic antibiotics are effective in the treatment of infected cysts, albeit with a trend for lower effectiveness due to increasing resistance rates. UTIs are the most common infections in KT recipients, with a reported rate of 45-72%. Diagnostic challenges exist for both ADPKD and KT patients who develop UTIs. Treatment of UTIs should be tailored according to individual patient characteristics and the severity classification framework suggested by the European Society of Infections in Urology.

CONCLUSIONS

The underlying pathophysiology of UTIs in immunocompromised patients is not well known, which limits UTI management, including early diagnosis, treatment, and prevention. Future research to identify patients at higher risk of UTIs is necessary.

PATIENT SUMMARY

In this report we looked at patients with a weakened immune system who are more likely to develop a urine infection. We focused on the patient groups most commonly encountered in a urology setting. We found that these patients have a higher risk of urinary infection, but the signs of infection may be different to those in the general population. Early diagnosis is imperative in this group. Further research on early diagnosis and better individualised management strategies are necessary.