Genetic risk for recurrent urinary tract infections in humans: a systematic review

VDR, CXCR1, CXCR2, PSCA Polymorphisms and Recurrent Urinary Tract Infections in Women: Genetic Association Study

INTRODUCTION AND HYPOTHESIS

Urinary tract infection (UTI) is one of the most common human infections. Evidence suggests that there might be a genetic predisposition to UTI. Previous small candidate gene studies have suggested that common variants in genes involved in the immune response to UTI could increase susceptibility to the development of recurrent UTI (rUTI). The objective was to conduct a gene association study to replicate previous gene association studies identifying single nucleotide polymorphisms (SNPs) putatively associated with rUTI in adult women.

METHODS

Women with a history of rUTI and healthy controls were recruited (n = 1,008) from gynaecology outpatient clinics. Participants completed a signed consent form and questionnaire for phenotyping. DNA was extracted from blood or saliva samples for each participant. Putative associated SNPs were identified from a comprehensive systematic review of prior gene association studies. Primers for each selected SNP were designed, and genotyping was conducted using a competitive polymerase chain reaction (PCR) method. The Chi-squared test was used to assess the association between each variant and rUTI. Genotyping quality was assessed by checking for deviation from Hardy-Weinberg equilibrium.

RESULTS

We found no association between SNPs tested in the VDR (p = 0.16, p = 0.09, p = 0.36), CXCR1 (p = 0.09), CXCR2 (p = 0.39), PSCA (p = 0.74) genes, and rUTI in adult women.

CONCLUSIONS

To our knowledge, this is the largest study to date, finding no significant associations. Previously reported positive associations may have been due to type 1 error, or genotyping errors. Future studies should adjust for confounders and employ adequate sample sizes. A greater understanding of the genetic components associated with rUTI may influence future treatment guidelines and screening for susceptible patients.

Recurrent urinary tract infection genetic risk: a systematic review and gene network analysis

INTRODUCTION AND HYPOTHESIS

The development of recurrent urinary tract infections (rUTIs) is not completely understood. This review is aimed at investigating the connection between genetics and rUTIs and summarizing the results of studies that have documented variations in gene expression among individuals with rUTIs compared with healthy individuals.

METHODS

A systematic search was conducted in Cochrane, Ovid, and PubMed, limiting the results to articles published between 1 January 2000, and 5 July 2022. Only studies comparing the difference in gene expression between individuals with rUTI and healthy individuals utilizing molecular techniques to measure gene expression in blood or urine samples were included in this systematic review. Gene network and pathways analyses were performed using Cytoscape software, with input data obtained from our systematic review of differentially expressed genes in rUTIs.

RESULTS

Six studies met our criteria for inclusion. The selected studies used molecular biology methods to quantify gene expression data from blood specimens. The analysis revealed that gene expressions of CXCR1 and TLR4 decreased, whereas CXCR2, TRIF, and SIGIRR increased in patients with rUTI compared with healthy controls. The analysis demonstrated that the most significant pathways were associated with TLR receptor signaling and tolerance, I-kappa B kinase/NF-kappa B signaling, and MyD88-independent TLR signaling.

CONCLUSIONS

This systematic review uncovered gene expression variations in several candidate genes and identified a number of underlying biological pathways associated with rUTIs. These findings could shift the treatment and prevention strategies for rUTIs.

Novel Insights on Plant Extracts to Prevent and Treat Recurrent Urinary Tract Infections

Urinary tract infections (UTI) represent one of the most widespread infections, and frequent recurrent episodes, induced mostly by uropathogenic Escherichia coli, make them increasingly difficult to treat. Long-term antibiotic therapy is an effective approach to treat recurrent UTI but generates adverse effects, including the emergence of pathogenic strains resistant to the vast majority of antibiotics. These drawbacks have enhanced the interest toward new alternatives based on plant extracts to prevent and treat recurrent UTI, especially in a synergistic antibiotic approach. Therefore, this review highlights the potential of some medicinal plants to be used in the management of recurrent UTI, including plants that have been approved for the treatment of urinary infections and promising, but less studied, plant candidates with proven anti-uropathogenic activity. Pomegranate (Punica granatum L.), black chokeberry (Aronia melanocarpa Michx.), and cornelian cherry (Cornus mas L.) have great potential to be used for prevention or in a combined antibiotic therapy to cure UTI, but more studies and clinical trials in specific population groups are required. Further progress in developing plant-based products to cure rUTI will be supported by advances in UTI pathogenesis and human-based models for a better understanding of their pharmacological activities.

Preterm birth and genitourinary tract infections: assessing gene-environment interaction

BACKGROUND

Preterm birth (PTB) is the leading cause of perinatal morbimortality worldwide. Genetic and environmental factors could raise PTB risk. The aim of this study was to analyze the contribution of the statistical interaction between genes and vaginal-urinary tract infections (VI-UTI) to the risk of PTB by clinical subtype.

METHODS

Twenty-four SNPs were genotyped in 18 candidate genes from 352 fetal triads and 106 maternal triads. Statistical interactions were evaluated with conditional logistic regression models based on genotypic transmission/disequilibrium test.

RESULTS

In PTB-idiopathic subtype mothers exposed to UTI, fetal SNPs rs11686474 (FSHR), rs4458044 (CRHR1, allele G), rs883319 (KCNN3), and maternal SNP rs1882435 (COL4A3) showed a nominal significant increment in prematurity risk. In preterm premature rupture of membranes (PPROM), fetal SNP rs2277698 (TIMP2) showed a nominal significant risk increment. In mothers exposed to VI, fetal SNP rs5742612 (IGF1) in PTB-PPROM and maternal SNP rs4458044 (CRHR1, allele C) in spontaneous PTB showed nominal significant increment in prematurity risk.

CONCLUSIONS

Certain maternal and fetal genes linked to infectious/inflammatory and hormonal regulation processes increase prematurity risk according to clinical subtype when mothers are exposed to UTI or VI. These findings may help in the understanding of PTB etiology and PTB prevention.

IMPACT

Preterm birth is a major cause of perinatal morbimortality worldwide and its etiology remains unknown. This work provides evidence on the statistical interaction of six genes with gestational vaginal or urinary infections leading to the occurrence of preterm births. Statistical interactions vary according to infection type, genotype (maternal and fetal), and clinical subtype of prematurity. Certain maternal and fetal genetic variants of genes linked to infectious/inflammatory and hormonal regulation processes would increase the risk of prematurity according to clinical subtype and infection type. Our findings may help in the study of etiology of preterm birth and its prevention.

Antibiotic resistance in childhood urinary tract infections: A single-center experience

Aim

Urinary tract infections are the most common genitourinary tract disease in children, and inappropriate antibiotic and/or dose selection increase the likelihood of resistance. The aim of this study was to determine the prevalence of urinary tract infection pathogens, patterns of resistance to antibiotics, and empirical treatment options.

Material and Methods

Between January 2013 and December 2017, urine culture and antibiogram results of pediatric patients aged 0 days to 16 years were analyzed retrospectively. Antibiotic susceptibilities were determined using disc diffusion according to methods of the Clinical and Laboratory Standards Institute.

Results

Of the 1326 children with culture growth, 1070 (80.6%) were female and 256 (19.3%) were male. The most common microorganism found was (1138, 85.8%) E. Coli, followed by Klebsiella spp. (71, 5.3%), Enterobacter spp. (44, 3.3%), and Proteus spp. (28, 2.1%). High frequency of resistance to ampicillin, ampicillin-sulbactam, amoxicillin-clavulanate, cefuroxime axetil, as TMP-SMX was detected in all microorganisms, whereas resistance to amikacin, meropenem, imipenem, ertapenem, fosfomycin, and nitrofurantoin was low.

Conclusion

E. coli was the most common causative agent of urinary tract infections in childhood. High resistance to ampicillin, ampicillin-sulbactam, amoxicillin-clavulanate, cefuroxime axetil, and TMP-SMX was detected in all agents in our center.

Symptoms, risk factors, diagnosis and treatment of urinary tract infections

Urinary tract infection (UTI) is a common microbial infection found in all ages and sexes which involves inflammation of the urinary tract. These infections can range from simple bladder inflammation, that is, cystitis, to severe cases of uroseptic shock. UTI ranks as the number 1 infection that leads to a prescription of antibiotics after a doctor's visit. These infections are sometimes distressing and even life threatening, and both males (12%) and females (40%) have at least one symptomatic UTI throughout their lives. Diagnostic failures in case of bacterial infections are the main contributing factor in improper use of antibiotics, delay in treatment and low survival rate in septic conditions. So, early diagnosis and appropriate therapy with antibiotics are the most significant requirements for preventing complicated UTI conditions such as urosepsis. This review article summarises the symptoms of the UTIs and the associated risk factors to it. The various conventional and recent diagnostic methods were also discussed in this review, along with treatment therapies with or without antibiotics.

Early Increased Urinary IL-2 and IL-10 Levels Were Associated With Development of Chronic UTI in a Murine Model

OBJECTIVES

To analyze factors during early stage of urinary tract infection (UTI) that are associated with development of chronic UTI.

METHODS

Mice were inoculated with Uropathogenic Escherichia coli (UPEC) 2 times 24 hours apart. At 1, 3, 7, 10, 14, 21 and 28 days post infection (dpi), urine bacterial loads and voiding behavior (voiding spot assay, VSA) were measured. At 1 and 28 dpi, 32 urine inflammatory cytokines/chemokines were measured using enzyme-linked immunosorbent assay (ELISA). Bladder and kidney cytokines/chemokines were measured on 28 dpi. Mice that had no more than 1 episode of urine bacterial load < 104 colony forming unit/ml during the entire 4 weeks were defined as susceptible to chronic UTI, otherwise, mice were considered resistant.

RESULTS

At 28 dpi, 64.3% mice developed chronic UTI (susceptible group) and 35.7% mice did not (resistant group). Factors at 1 dpi that were predictive of chronic UTI included increased urine IL-2 (OR 11.9, 95%CI 1.1-130.8, P = .043) and increased urine IL-10 (OR 14.0, 95%CI 1.0-201.2, P = .052). At 28 dpi, there were several significant differences between the susceptible vs resistant groups including urine/tissue bacterial loads and certain urine/tissue cytokines/chemokines.

CONCLUSIONS

Higher urine IL-2 and IL-10 at 1 dpi predicted chronic UTI infection in this model. There have been recent publications associating both of these cytokines to UTI susceptibility. Further explorations into IL-2 and IL-10 mediated pathways could shed light on the biology of recurrent and chronic UTI which are difficult to treat.

Urinary Tract Infection in Children

BACKGROUND

Urinary Tract Infection (UTI) is a common infection in children. Prompt diagnosis and appropriate treatment are very important to reduce the morbidity associated with this condition.

OBJECTIVE

To provide an update on the evaluation, diagnosis, and treatment of urinary tract infection in children.

METHODS

A PubMed search was completed in clinical queries using the key terms "urinary tract infection", "pyelonephritis" OR "cystitis". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. The search was restricted to English literature and the pediatric age group. Patents were searched using the key terms "urinary tract infection" "pyelonephritis" OR "cystitis" from www.google.com/patents, http://espacenet.com, and www.freepatentsonline.com.

RESULTS

Escherichia coli accounts for 80 to 90% of UTI in children. The symptoms and signs are nonspecific throughout infancy. Unexplained fever is the most common symptom of UTI during the first two years of life. After the second year of life, symptoms and signs of pyelonephritis include fever, chills, rigor, flank pain, and costovertebral angle tenderness. Lower tract symptoms and signs include suprapubic pain, dysuria, urinary frequency, urgency, cloudy urine, malodorous urine, and suprapubic tenderness. A urinalysis and urine culture should be performed when UTI is suspected. In the work-up of children with UTI, physicians must judiciously utilize imaging studies to minimize exposure of children to radiation. While waiting for the culture results, prompt antibiotic therapy is indicated for symptomatic UTI based on clinical findings and positive urinalysis to eradicate the infection and improve clinical outcome. The choice of antibiotics should take into consideration local data on antibiotic resistance patterns. Recent patents related to the management of UTI are discussed.

CONCLUSION

Currently, a second or third generation cephalosporin and amoxicillin-clavulanate are drugs of choice in the treatment of acute uncomplicated UTI. Parenteral antibiotic therapy is recommended for infants ≤ 2 months and any child who is toxic-looking, hemodynamically unstable, immunocompromised, unable to tolerate oral medication, or not responding to oral medication. A combination of intravenous ampicillin and intravenous/intramuscular gentamycin or a third-generation cephalosporin can be used in those situations. Routine antimicrobial prophylaxis is rarely justified, but continuous antimicrobial prophylaxis should be considered for children with frequent febrile UTI.

The Role of TLR4 Asp299Gly and TLR4 Thr399Ile Polymorphisms in the Pathogenesis of Urinary Tract Infections: First Evaluation in Infants and Children of Greek Origin

Urinary tract infections are one of the most common and serious bacterial infections in a pediatric population. So far, they have mainly been related to age, gender, ethnicity, socioeconomic level, and the presence of underlying anatomical or functional, congenital, or acquired abnormalities. Recently, both innate and adaptive immunities and their interaction in the pathogenesis and the development of UTIs have been studied. The aim of this study was to assess the role and the effect of the two most frequent polymorphisms of TLR4 Asp299Gly and Thr399Ile on the development of UTIs in infants and children of Greek origin. We studied 51 infants and children with at least one episode of acute urinary tract infection and 109 healthy infants and children. We found that 27.5% of patients and 8.26% of healthy children carried the heterozygote genotype for TLR4 Asp299Gly. TLR4 Thr399Ile polymorphism was found to be higher in healthy children and lower in the patient group. No homozygosity for both studied polymorphisms was detected in our patients. In the group of healthy children, a homozygote genotype for TLR4 Asp299Gly (G/G) as well as for TLR4 Thr399Ile (T/T) was showed (1.84% and 0.92 respectively). These results indicate the role of TLR4 polymorphism as a genetic risk for the development of UTIs in infants and children of Greek origin.

Zishenwan Decreases Kidney Damage in Recurrent Urinary Tract Infection through the Inhibition of Toll-Like Receptor 4 Signal

Objectives

To investigate the mechanism of the protective effect of Zishenwan on pyelonephritis rats.

Methods

In the rat model of pyelonephritis, protective effects of Zishenwan, the content of secretory immunoglobulin A (SIg A), and interleukins were detected by ELISA. The expressions of TLR4-NFκB pathway were detected by Western blot in renal and urinary tract mucosa. The protective effect and influence on TLR4-NFκB pathway of Zishenwan were studied.

Results

Zishenwan protected rats from pyelonephritis which related to the increase of SIgA, the regulation of interleukins, and the inhibition of TLR4-NFκB pathway. Serum containing Zishenwan can significantly decrease LPS-induced expression of TLR4, MyD88, and NFκB in vitro. And the inhibition of TLR4 signal by Zishenwan related to the degradation of TRAF3 and TRAF6.

Conclusions

Zishenwan protected rats from urinary tract infection by clearance of bacteria and decrease of tissue damage. 20S proteasomes mediated the degradation of TRAF3 which is important to the decrease of tissue damage from Zishenwan.

Influence of Plasminogen Activator Inhibitor -1 Gene Polymorphism on Renal Scarring After First Febrile Urinary Tract Infection in Infants

Background

The pathogenesis of renal scarring (RS) after first febrile urinary tract infection (UTI) in children is multifactorial. In addition to well-known risk factors, a role for genetic predisposition has been suggested.

Aims

To determine whether deoxyribonucleic acid (DNA) polymorphisms at the plasminogen activator inhibitor -1 (PAI-1) gene were associated with evolution to RS following a febrile UTI in infants.

Materials and Methods

Our research included 100 infants, 84 girls and 16 boys, ages up to 1 year with a first febrile UTI, increased inflammatory parameters and positive urine culture treated at the Pediatric Clinic II of the University Clinical Center Sarajevo (UCCS). The diagnostic was based on the imaging studies: ultrasonography, voiding cystourethrography (VCUG) and initial and control static renal scintigraphy (DMSA renal scan), to assess the renal parenchymal damage (RPD). The polymorphisms of the PAI-1 were determined based on polymerase chain reaction technique. The distribution of PAI-1 genotypes and the allele frequencies were compared between different groups of patients with febrile UTI.

Results

Results presented that 66 infants had acute pyelonephritis (APN) and 22 had vesicoureteral reflux (VUR). On initial DMSA renal scan examination, we detected no RPD in any patient. After 6 months, the repeat DMSA renal scan revealed the presence of RPD in 18 (27%) out of 66 infants with APN. Distribution of PAI-1 genotypes was not different between various groups of patients with febrile UTI.

Conclusions

The results of our study have not shown that individual genetic variation in PAI-1 is an independent variable that predispose same of children for RS after first febrile UTI. Maybe that yet unknown gene polymorphisms together with geographical and /or socio-economic differences can influence on the development of RS.

Race and 30-Day Morbidity in Pediatric Urologic Surgery

BACKGROUND AND OBJECTIVE

Quality improvement in surgery involves identifying patients at high risk for postoperative complications. We sought to assess the impact of race and procedure type on 30-day surgical morbidity in pediatric urology.

METHODS

The National Surgical Quality Improvement Program-Pediatrics (NSQIP-P) is a prospective registry of surgical cases from 50 and 56 pediatric hospitals in 2012 and 2013, respectively. We performed a cohort study of children followed in NSQIP-P who underwent urologic surgery. Forty unique operations were stratified into 6 clinically related procedure groups: ureteral, testicular, renal, urinary diversion, penile and urethral, or bladder procedures. Outcomes were 3 different composite measures of 30-day morbidity. Primary predictors were patient race and procedural group. Multivariate logistic regression was used to identify associations between race, procedure type, and postoperative morbidity.

RESULTS

Of 114 395 patients in the NSQIP-P cohort, 11 791 underwent pediatric urologic procedures. Overall 30-day complication rate was 5.9% and was higher in bladder and urinary diversion procedures. On multivariate analyses, non-Hispanic black compared with non-Hispanic white children had higher odds of 30-day overall complications (odds ratio 1.34; 95% confidence interval, 1.03-1.74) and 30-day hospital-acquired infection (odds ratio 1.54; 95% confidence interval, 1.08-2.20). Bladder and urinary diversion procedures relative to testicular procedures had significantly higher odds of surgical morbidity across all composite outcome measures.

CONCLUSIONS

Black race and bladder and urinary diversion operations were significantly associated with 30-day surgical morbidity. Future efforts should identify processes of care that decrease postoperative morbidity among children.

Anatomy and Physiology of the Urinary Tract: Relation to Host Defense and Microbial Infection

The urinary tract exits to a body surface area that is densely populated by a wide range of microbes. Yet, under most normal circumstances, it is typically considered sterile, i.e., devoid of microbes, a stark contrast to the gastrointestinal and upper respiratory tracts where many commensal and pathogenic microbes call home. Not surprisingly, infection of the urinary tract over a healthy person's lifetime is relatively infrequent, occurring once or twice or not at all for most people. For those who do experience an initial infection, the great majority (70% to 80%) thankfully do not go on to suffer from multiple episodes. This is a far cry from the upper respiratory tract infections, which can afflict an otherwise healthy individual countless times. The fact that urinary tract infections are hard to elicit in experimental animals except with inoculum 3-5 orders of magnitude greater than the colony counts that define an acute urinary infection in humans (105 cfu/ml), also speaks to the robustness of the urinary tract defense. How can the urinary tract be so effective in fending off harmful microbes despite its orifice in a close vicinity to that of the microbe-laden gastrointestinal tract? While a complete picture is still evolving, the general consensus is that the anatomical and physiological integrity of the urinary tract is of paramount importance in maintaining a healthy urinary tract. When this integrity is breached, however, the urinary tract can be at a heightened risk or even recurrent episodes of microbial infections. In fact, recurrent urinary tract infections are a significant cause of morbidity and time lost from work and a major challenge to manage clinically. Additionally, infections of the upper urinary tract often require hospitalization and prolonged antibiotic therapy. In this chapter, we provide an overview of the basic anatomy and physiology of the urinary tract with an emphasis on their specific roles in host defense. We also highlight the important structural and functional abnormalities that predispose the urinary tract to microbial infections.

The innate immune response during urinary tract infection and pyelonephritis

Despite its proximity to the fecal flora, the urinary tract is considered sterile. The precise mechanisms by which the urinary tract maintains sterility are not well understood. Host immune responses are critically important in the antimicrobial defense of the urinary tract. During recent years, considerable advances have been made in our understanding of the mechanisms underlying immune homeostasis of the kidney and urinary tract. Dysfunctions in these immune mechanisms may result in acute disease, tissue destruction and overwhelming infection. The objective of this review is to provide an overview of the innate immune response in the urinary tract in response to microbial assault. In doing so, we focus on the role of antimicrobial peptides-a ubiquitous component of the innate immune response.

Five-year assessment of causative agents and antibiotic resistances in urinary tract infections

AIM

To show the distribution and changes of causative agents of urinary tract infections in children and resistance rates by years and select the most appropriate antibiotics.

MATERIAL AND METHODS

In this study, the Başkent University Alanya Research and Application Hospital automation system microbiology recording book was screened retrospectively. Growth of a single microorganism above 105 colonies (cfu/mL) was included in the assessment. Throughout the study, 10 691 urinary cultures were studies and growth was found in 392 (3.7%).

RESULTS

Three hundred and nine (78.8%) of the samples with growth belonged to girls. Growth was found in the neonatal period in 32 patients (8.2%). The most commonly isolated microorganism was Escherichia coli (E. coli) which was found in 68.4% of the patients. Klebsiella spp. were found with a rate of 12.0%; Enterobacter spp. were found with a rate of 10.7% and proteus spp. were found with a rate of 5.1%. Resistance to cefalotin (62.1%), trimethoprim-sulfamethoxasole (43.1%), amoxycillin-clavulanate (34.8%), ampicillin (30.4%), cefixim (26.3%) and nitrofurantoin (3.6%) was found in E. coli species. The antibiotic which had the highest resistance rate was ampicillin with a rate of 93.2% for klebsiella and 83.4% for enterobacter. Klebsiella spp. were the most commonly grown pathogens in newborns (40.6%). In a follow-up period of 5 years, the resistance of E. coli to amoxycillin-clavulanate regressed from 40.3% to 31.3%, while the resistance to trimethoprim-sulfamethoxasole (TMP-SMX) regressed from 45.6% to 34.7%.

CONCLUSIONS

A high resistance against first-generation cephalosporins, ampicillin, amoxycillin-clavulanate and TMP-SMX which are the first-line antibiotics in childhood urinary tract infections was found. Carbapenem (meropenem, imipenem) resistance was not found in our center. Nitrofurantoin, aminoglycosides and cefixime can be recommended for empirical treatment in our hospital because of low resistance. Antibiotic treatment should be redecided according to in vitro antibiotic sensitivity results.

Urinary tract infections in older women: a clinical review

IMPORTANCE

Asymptomatic bacteriuria and symptomatic urinary tract infections (UTIs) in older women are commonly encountered in outpatient practice.

OBJECTIVE

To review management of asymptomatic bacteriuria and symptomatic UTI and review prevention of recurrent UTIs in older community-dwelling women.

EVIDENCE REVIEW

A search of Ovid (Medline, PsycINFO, Embase) for English-language human studies conducted among adults aged 65 years and older and published in peer-reviewed journals from 1946 to November 20, 2013.

RESULTS

The clinical spectrum of UTIs ranges from asymptomatic bacteriuria, to symptomatic and recurrent UTIs, to sepsis associated with UTI requiring hospitalization. Recent evidence helps differentiate asymptomatic bacteriuria from symptomatic UTI. Asymptomatic bacteriuria is transient in older women, often resolves without any treatment, and is not associated with morbidity or mortality. The diagnosis of symptomatic UTI is made when a patient has both clinical features and laboratory evidence of a urinary infection. Absent other causes, patients presenting with any 2 of the following meet the clinical diagnostic criteria for symptomatic UTI: fever, worsened urinary urgency or frequency, acute dysuria, suprapubic tenderness, or costovertebral angle pain or tenderness. A positive urine culture (≥105 CFU/mL) with no more than 2 uropathogens and pyuria confirms the diagnosis of UTI. Risk factors for recurrent symptomatic UTI include diabetes, functional disability, recent sexual intercourse, prior history of urogynecologic surgery, urinary retention, and urinary incontinence. Testing for UTI is easily performed in the clinic using dipstick tests. When there is a low pretest probability of UTI, a negative dipstick result for leukocyte esterase and nitrites excludes infection. Antibiotics are selected by identifying the uropathogen, knowing local resistance rates, and considering adverse effect profiles. Chronic suppressive antibiotics for 6 to 12 months and vaginal estrogen therapy effectively reduce symptomatic UTI episodes and should be considered in patients with recurrent UTIs.

CONCLUSIONS AND RELEVANCE

Establishing a diagnosis of symptomatic UTI in older women requires careful clinical evaluation with possible laboratory assessment using urinalysis and urine culture. Asymptomatic bacteriuria should be differentiated from symptomatic UTI. Asymptomatic bacteriuria in older women should not be treated.

Association of interleukin-10 gene promoter polymorphisms with susceptibility to acute pyelonephritis in children

Interleukin-10 (IL-10) is a potent inhibitor of leukocyte chemotaxis, bacterial killing in phagocytes and synthesis of pro-inflammatory cytokines and chemokines, and recent studies have suggested an important role for this immunoregulatory cytokine in the pathogenesis of urinary tract infections (UTIs). Therefore, the gene encoding IL-10 (IL10) is an attractive candidate for association studies attempting to identify susceptibility genes conferring risk of UTIs. In this case-control study, we aimed to investigate the association of single nucleotide polymorphisms (SNPs) in the promoter region of IL10 with acute pyelonephritis in the Slovak population. Polymerase chain reaction with sequence-specific primers was used to analyse IL10 -1082A/G (rs1800896), -819C/T (rs1800871) and -592C/A (rs1800872) SNPs in 147 children with acute pyelonephritis and 215 healthy controls. Comparison of patients with healthy controls using the logistic regression analysis revealed significantly increased risk of developing recurrent attacks of acute pyelonephritis for -1082 G allele in a dominant genetic model GG (GG + AG vs. AA, P = 0.019, odds ratio (OR) = 2.26). A similar tendency was also found when the recurrent acute pyelonephritis subgroup was compared to episodic pyelonephritis cases (GG + AG vs. AA, P = 0.009, OR = 3.38). In conclusion, our results suggest that IL10 -1082 A/G SNP is a susceptibility factor for development of recurrent attacks of acute pyelonephritis.

Counseling parents who are considering newborn male circumcision

The American Academy of Pediatrics recently issued a statement that the health benefits of newborn male circumcision exceed the risks and therefore justify access to the procedure for families who choose it. Further, clinicians are charged with providing factually correct information that communicates the risks and benefits of elective newborn male circumcision in a nonbiased manner. However, many clinicians lack adequate information to discuss the risks and benefits of male circumcision. The purpose of this review is to highlight evidence on the risks and benefits of newborn male circumcision and provide clinicians with counseling points that can be used to guide discussion with parents considering newborn male circumcision.

Uropathogenic Escherichia coli infection: potential importance of epigenetics

Patients suffering from recurrent urinary tract infections (UTIs) may be maintained on antibiotic prophylaxis, or even treated by surgery. However, there are no biological data on which to base such treatment selection for the individual patient. This highlights the need for a biological marker that might predict UTI recurrence risk. Infection of mammalian tissues with bacteria, viruses and other pathogens results in the modification of the host cell epigenome, particularly DNA methylation. We recently demonstrated that in vitro infection of bladder uroepithelial cells with uropathogenic Escherichia coli results in hypermethylation of the tumor suppressor gene CDKN2A, providing proof-of-concept that uropathogenic E. coli infection modulates the host cell epigenome. If postinfection persistence of UTI-induced uroepithelial DNA hypermethylation were to be associated with subsequent UTI propensity, these epigenetic marks could act as a potential biomarker for UTI recurrence risk and could be used to rationalize and improve treatment of patients with infection-associated uropathies.

LY96, UPKIB mutations and TLR4, CD14, MBL polymorphisms in children with urinary tract infection

OBJECTIVE

To evaluate genetic variations of innate immune system such as mannose binding lectin (MBL), Toll like receptor 4 (TLR4), CD14, LY96 (MD2) and Uroplakin 1B (UPK1B) genes in children with recurrent urinary tract infection (UTI).

METHODS

The study included 30 children with recurrent UTI and 30 healthy controls. Blood was drawn and analysed for genetic polymorphisms of MBL, TLR4 and CD14 genes by the PCR-RFLP method. Direct DNA sequencing analysis was performed for LY96 and UPK 1B gene mutation in 10 children from UTI group and 5 children from control group.

RESULTS

TLR4 gene Thr399Ile polymorphism was not observed in any child. Genotype distribution and allele frequency of Asp299Gly polymorphism was similar in both groups (p = 0.55). Codon 54 polymorphism of the MBL gene was similar in UTI and control groups (p = 0.49). -159 CC/CT/TT genotypes of CD14 gene was similar between the two groups (p = 0.14). UPK1B and LY96 gene DNA sequence analysis was similar in UTI and control groups.

CONCLUSIONS

This study is the first study in which different parts of the innate immune system were evaluated in UTI etiopathogenesis in Turkish children. The results did not point out a significant role of any of the genes evaluated in this study.

Uropathogenic E. coli infection provokes epigenetic downregulation of CDKN2A (p16INK4A) in uroepithelial cells

Host cell and bacterial factors determine severity and duration of infections. To allow for bacteria pathogenicity and persistence, bacteria have developed mechanisms that modify expression of host genes involved in cell cycle progression, apoptosis, differentiation and the immune response. Recently, Helicobacter pylori infection of the stomach has been correlated with epigenetic changes in the host genome. To identify epigenetic changes during Escherichia coli induced urinary tract infection (UTI), we developed an in vitro model of persistent infection of human uroepithelial cells with uropathogenic E. coli (UPEC), resulting in intracellular bacteria colonies. Cells inoculated with FimH-negative E. coli (N-UPEC) that are not internalized and non-inoculated cells were used as controls. UPEC infection significantly induced de novo methyltransferase (DNMT) activity (12.5-fold P=0.002 UPEC vs non-inoculated and 250-fold P=0.001 UPEC vs N-UPEC inoculated cells) and Dnmt1 RNA expression (6-fold P=0.04 UPEC vs non-inoculated cells) compared with controls. DNMT1 protein levels were significantly increased in three uroepithelial cell lines (5637, J82, HT-1197) in response to UPEC infection as demonstrated by confocal analysis. Real-time PCR analysis of candidate genes previously associated with bacteria infection and/or innate immunity, revealed UPEC-induced downregulation of the tumor suppressor gene CDKN2A (3.3-fold P=0.007 UPEC vs non-inoculated and 3.3-fold P=0.001 UPEC vs N-UPEC) and the DNA repair gene MGMT (9-fold P=0.03 UPEC vs non-inoculated). Expression of CDH1, MLH1, DAPK1 and TLR4 was not affected. Pyrosequencing of CDKN2A and MGMT CpG islands revealed increased methylation in CDKN2A exon 1 (3.8-fold P=0.04 UPEC vs N-UPEC and UPEC vs non-inoculated). Methylation of MGMT was not affected. UPEC-induced methylation of CDKN2A exon 1 may increase bladder cancer and presage UTI risk, and be useful as a biological marker for UTI susceptibility or recurrence.

Urinary tract infection in the newborn and the infant: state of the art

Urinary tract infection is one of the most common causes of infection in newborns. Obtaining a urinary tract infections (UTIs) diagnosis just on the basis of the clinical findings is frequently difficult, however, being the pediatrician's goal to reduce the risk of renal scarring, a prompt diagnosis and treatment is of extreme importance. The key instrument for the diagnosis of UTIs is represented today by urine culture. However, in reality, the caregivers and investigators are increasingly demanding fast and cheap methods for a rapid and effective diagnosis.