Differentiating Asymptomatic Bacteriuria From Urinary Tract Infection in the Pediatric Neurogenic Bladder Population: NGAL As a Promising Biomarker.
ABSTRACT: Objective: To evaluate whether urinary antimicrobial peptides (AMPs) can discriminate between asymptomatic bacteriuria (ASB) and urinary tract infection (UTI) in pediatric patients with neurogenic bladder (NGB). Design/Methods: Bladder urine was collected from pediatric patients (?18 years old) with NGB without augmentation cystoplasty. Patients were divided into the following groups based on symptomatology and results of urinalysis/urine culture: (a) UTI, (b) ASB, and (c) sterile. Urine AMPs ? defense 1 (BD-1), neutrophil gelatinase-associated lipocalin (NGAL), cathelicidin (LL-37), hepatocarcinoma-intestine-pancreas/pancreatitis-associated protein (HIP/PAP), and human ? defensin 5 (HD-5) were compared between groups by enzyme-linked immunosorbent assays. In addition, urines from pediatric controls without NGB or UTI were also analyzed. Significance was determined using Student's t test for parametric or Mann-Whitney U test for nonparametric data. A p value of <.05 was considered significant. Results: Thirty-six patients with NGB from a spinal dysraphism were evaluated: UTI, n = 6; ASB, n = 18; sterile, n = 12. These groups did not differ significantly by age but did significantly differ by gender (p = .0139). NGAL significantly differed between UTI and ASB groups (median 38.5 ng/mg vs 15.5 ng/mg, respectively; p = .0197) with a sensitivity and specificity of 82.4% and 83.3%, respectively. HIP/PAP, BD-1, HD-5, LL-37, and NGAL levels were all significantly higher in sterile NGB urines compared to 17 non-NGB pediatric controls (p < .0001, p = .0020, p = .0035, p = .0006, and p = .0339, respectively). Conclusion: All five urinary AMPs evaluated were significantly elevated in NGB patients compared to controls. NGAL levels may help differentiate between UTI and ASB in pediatric NGB patients.
Project description:Introduction Asymptomatic bacteriuria (ASB) is the presence of bacteria in significant quantity in the absence of signs and symptoms of urinary tract infection (UTI). ASB, if it occurs during pregnancy, can cause serious complications both among fetus and pregnant women. Objective The aim of this study was to determine the prevalence of ASB, its associated factors, and antimicrobial susceptibility profile of bacterial isolates among pregnant women. Methods A cross-sectional study was conducted from July to September 2019 among 290 pregnant women at Saint Paul’s Hospital Millennium Medical College, Addis Ababa, Ethiopia. Clean-catch midstream urine specimens were collected using sterile containers and cultured on MacConkey agar and sheep blood agar to isolate bacteria. Socio-demographic and obstetric data were collected using a structured questionnaire. Data were analyzed by SPSS version 22. The association between ASB and risk factors was assessed using logistic regressions. A p-value??0.05 was considered as a cut point to determine the significant association. Results From 290 study participants, 16.9% with 95 CI [13.1, 21.5] were positive for ASB. The predominant bacteria were Escherichia coli (43%) and Staphylococcus aureus (20%). Majority of E. coli (91.0%) were susceptible to nitrofurantoin and gentamycin; most of them were resistant to amoxicillin (86.4%) and cotrimoxazole (77.7%). The proportion of multi-drug resistance (MDR) isolates was 57.1%. Previous infection with UTI, previous history of catheterization, and natural abortion were significantly associated with ASB. Conclusion In the study area, ASB is prevalent in the study area indicating the importance of screening of ASB and possible treatment to prevent its consequences.
Project description:BACKGROUND:Although several studies suggest that genetic factors are associated with human UTI susceptibility, the role of DNA variation in regulating early in vivo urine inflammatory responses has not been fully examined. We examined whether candidate gene polymorphisms were associated with altered urine inflammatory profiles in asymptomatic women with or without bacteriuria. METHODOLOGY:We conducted a cross-sectional analysis of asymptomatic bacteriuria (ASB) in 1,261 asymptomatic women ages 18-49 years originally enrolled as participants in a population-based case-control study of recurrent UTI and pyelonephritis. We genotyped polymorphisms in CXCR1, CXCR2, TLR1, TLR2, TLR4, TLR5, and TIRAP in women with and without ASB. We collected urine samples and measured levels of uropathogenic bacteria, neutrophils, and chemokines. PRINCIPAL FINDINGS:Polymorphism TLR2_G2258A, a variant associated with decreased lipopeptide-induced signaling, was associated with increased ASB risk (odds ratio 3.44, 95%CI; 1.65-7.17). Three CXCR1 polymorphisms were associated with ASB caused by gram-positive organisms. ASB was associated with urinary CXCL-8 levels, but not CXCL-5, CXCL-6, or sICAM-1 (P< or =0.0001). Urinary levels of CXCL-8 and CXCL-6, but not ICAM-1, were associated with higher neutrophil levels (P< or =0.0001). In addition, polymorphism CXCR1_G827C was associated with increased CXCL-8 levels in women with ASB (P = 0.004). CONCLUSIONS:TLR2 and CXCR1 polymorphisms were associated with ASB and a CXCR1 variant was associated with urine CXCL-8 levels. These results suggest that genetic factors are associated with early in vivo human bladder immune responses prior to the development of symptomatic UTIs.
Project description:Antimicrobial resistance is an emerging problem.To investigate the safety and efficacy of a live biotherapeutic product, ASB E. coli 2-12 for UTI treatment.Six healthy research dogs; nine client-owned dogs with recurrent UTI.Prospective noncontrolled clinical trial. For safety data, research dogs were sedated, a urinary catheter was inserted into the bladder; 1010 CFU/mL of ASB E. coli 2-12 was instilled. Urine was cultured on days 1, 3, and 8 post-instillation and dogs were observed for lower urinary tract signs (LUTS). For client-owned dogs, ASB E. coli 2-12 was instilled similarly and urine cultures analyzed on days 1, 7, and 14 days postinstillation.No LUTS were noted in any of the 6 research dogs after ASB E. coli 2-12 infusion. Pulse field gel electrophoresis (PFGE) studies confirmed the bacterial strains isolated matched that ASB E. coli 2-12 strain. Four of the nine client-owned dogs had complete or nearly complete clinical cures by day 14. Of these four dogs, 3 also had microbiologic cures at day 14; one of these dogs had subclinical bacteriuria (in addition to ASB E. coli 2-12). Three of these four dogs had ASB E. coli 2-12 isolated from their urine at day 14. With the exception of mild, temporary, self-limiting, hyporexia in two dogs on the day of biotherapeutic administration, there were no major adverse effects.These results suggest ASB E. coli 2-12 is safe and should be investigated in a larger controlled study evaluating clinical UTI in dogs.
Project description:Differential diagnosis of asymptomatic bacteriuria (ASB) and urinary tract infection (UTI) is based on the presence of diverse symptoms, including fever (?38.5°C), rigors, malaise, lethargy, flank pain, hematuria, suprapubic discomfort, dysuria, and urgent or frequent urination. There is consensus in the medical community that ASB warrants antibiotic treatment only for patients undergoing urological procedures that lead to mucosal bleeding, catheterized individuals whose ASB persists for more than 48 h after catheter removal, and pregnant women. Pyuria is associated with UTI and implicates host immune responses via release of antibacterial effectors and phagocytosis of pathogens by neutrophils. Such responses are not sufficiently described for ASB. Metaproteomic methods were used here to identify the pathogens and evaluate molecular evidence of distinct immune responses in cases of ASB compared to UTI in elderly patients who were hospitalized upon injury. Neutrophil-driven inflammatory responses to invading bacteria were not discernible in most patients diagnosed with ASB compared to those with UTI. In contrast, proteomic urine analysis for trauma patients with no evidence of bacteriuria, including those who suffered mucosal injuries via urethral catheterization, rarely showed evidence of neutrophil infiltration. The same enzymes contributing to the synthesis of leukotrienes LTB4 and LTC4, mediators of inflammation and pain, were found in the UTI and ASB cohorts. These data support the notion that the pathways mediating inflammation and pain in most elderly patients with ASB are not quantitatively different from those seen in most elderly patients with UTI and warrant larger clinical studies to assess whether a common antibiotic treatment strategy for elderly ASB and UTI patients is justified.
Project description:<h4>Background</h4>The specificity of the leukocyte esterase test (87%) is suboptimal. The objective of this study was to identify more specific screening tests that could reduce the number of children who unnecessarily receive antimicrobials to treat a presumed urinary tract infection (UTI).<h4>Methods</h4>Prospective cross-sectional study to compare inflammatory proteins in blood and urine samples collected at the time of a presumptive diagnosis of UTI. We also evaluated serum RNA expression in a subset.<h4>Results</h4>We enrolled 200 children; of these, 89 were later demonstrated not to have a UTI based on the results of the urine culture obtained. Urinary proteins that best discriminated between children with UTI and no UTI were involved in T cell response proliferation (IL-9, IL-2), chemoattractants (CXCL12, CXCL1, CXCL8), the cytokine/interferon pathway (IL-13, IL-2, INF?), or involved in innate immunity (NGAL). The predictive power (as measured by the area under the curve) of a combination of four urinary markers (IL-2, IL-9, IL-8, and NGAL) was 0.94. Genes in the pathways related to inflammation were also upregulated in serum of children with UTI.<h4>Conclusions</h4>Urinary proteins involved in the inflammatory response may be useful in identifying children with false positive results with current screening tests for UTI; this may reduce unnecessary treatment.
Project description:People with diabetes mellitus have increased infection risk. With diabetes, urinary tract infection (UTI) is more common and has worse outcomes. Here, we investigate how diabetes and insulin resistance impact the kidney's innate defenses and urine sterility. We report that type 2 diabetic mice have increased UTI risk. Moreover, insulin-resistant prediabetic mice have increased UTI susceptibility, independent of hyperglycemia or glucosuria. To identify how insulin resistance affects renal antimicrobial defenses, we genetically deleted the insulin receptor in the kidney's collecting tubules and intercalated cells. Intercalated cells, located within collecting tubules, contribute to epithelial defenses by acidifying the urine and secreting antimicrobial peptides (AMPs) into the urinary stream. Collecting duct and intercalated cell-specific insulin receptor deletion did not impact urine acidification, suppressed downstream insulin-mediated targets and AMP expression, and increased UTI susceptibility. Specifically, insulin receptor-mediated signaling regulates AMPs, including lipocalin 2 and ribonuclease 4, via phosphatidylinositol-3-kinase signaling. These data suggest that insulin signaling plays a critical role in renal antibacterial defenses.
Project description:Women with uncomplicated urinary tract infection (UTI) symptoms are commonly treated with empirical antibiotics, resulting in overuse of antibiotics, which promotes antimicrobial resistance. Available diagnostic tools are either not cost-effective or diagnostically sub-optimal. Here, we identified clinical and urinary immunological predictors for UTI diagnosis. We explored 17 clinical and 42 immunological potential predictors for bacterial culture among women with uncomplicated UTI symptoms using random forest or support vector machine coupled with recursive feature elimination. Urine cloudiness was the best performing clinical predictor to rule out (negative likelihood ratio [LR-]?=?0.4) and rule in (LR+?=?2.6) UTI. Using a more discriminatory scale to assess cloudiness (turbidity) increased the accuracy of UTI prediction further (LR+?=?4.4). Urinary levels of MMP9, NGAL, CXCL8 and IL-1? together had a higher LR+ (6.1) and similar LR- (0.4), compared to cloudiness. Varying the bacterial count thresholds for urine culture positivity did not alter best clinical predictor selection, but did affect the number of immunological predictors required for reaching an optimal prediction. We conclude that urine cloudiness is particularly helpful in ruling out negative UTI cases. The identified urinary biomarkers could be used to develop a point of care test for UTI but require further validation.
Project description:Resident bacterial communities (microbiota) and host antimicrobial peptides (AMPs) are both essential components of normal host innate immune responses that limit infection and pathogen induced inflammation. However, their interdependence has not been investigated in the context of urinary tract infection (UTI) susceptibility. Here, we explored the interrelationship between the urinary microbiota and host AMP responses as mechanisms for UTI risk. Using prospectively collected day of surgery (DOS) urine specimens from female pelvic floor surgery participants, we report that the relative abundance and/or frequency of specific urinary microbiota distinguished between participants who did or did not develop a post-operative UTI. Furthermore, UTI risk significantly correlated with both specific urinary microbiota and ?-defensin AMP levels. Finally, urinary AMP hydrophobicity and protease activity were greater in participants who developed UTI, and correlated positively with both UTI risk and pelvic floor symptoms. These data demonstrate an interdependency between the urinary microbiota, AMP responses and symptoms, and identify a potential mechanism for UTI risk. Assessment of bacterial microbiota and host innate immune AMP responses in parallel may identify increased risk of UTI in certain populations.
Project description:Recent evidence indicates that antimicrobial peptides (AMPs) serve key roles in defending the urinary tract against invading uropathogens. To date, the individual contribution of AMPs to urinary tract host defense is not well defined. In this study, we identified Regenerating islet-derived 3 gamma (RegIII?) as the most transcriptionally up-regulated AMP in murine bladder transcriptomes following uropathogenic Escherichia coli (UPEC) infection. We confirmed induction of RegIII? mRNA during cystitis and pyelonephritis by quantitative RT-PCR. Immunoblotting demonstrates increased bladder and urinary RegIII? protein levels following UPEC infection. Immunostaining localizes RegIII? protein to urothelial cells of infected bladders and kidneys. Human patients with UTI have increased urine concentrations of the orthologous Hepatocarcinoma-Intestine-Pancreas / Pancreatitis Associated Protein (HIP/PAP) compared to healthy controls. Recombinant RegIII? protein does not demonstrate bactericidal activity toward UPEC in vitro, but does kill Staphylococcus saprophyticus in a dose-dependent manner. Kidney and bladder tissue from RegIII? knockout mice and wild-type mice contain comparable bacterial burden following UPEC and Gram-positive UTI. Our results demonstrate that RegIII? and HIP/PAP expression is induced during human and murine UTI. However, their specific function in the urinary tract remains uncertain.
Project description:BACKGROUND:Unique characteristics of nursing homes (NHs) contribute to high rates of inappropriate antibiotic use for asymptomatic bacteriuria (ASB), a benign condition. A mobile clinical decision support system (CDSS) may support NH staff in differentiating urinary tract infections (UTI) from ASB and reducing antibiotic days. OBJECTIVES:We used Goal-Directed Design to: 1) Characterize information needs for UTI identification and management in NHs; 2) Develop UTI Decide, a mobile CDSS prototype informed by personas and scenarios of use constructed from Aim 1 findings; 3) Evaluate the UTI Decide prototype with NH staff. METHODS:Focus groups were conducted with providers and nurses in NHs in Denver, Colorado (n= 24). Qualitative descriptive analysis was applied to focus group transcripts to identify information needs and themes related to mobile clinical decision support for UTI identification and management. Personas representing typical end users were developed; typical clinical context scenarios were constructed using information needs as goals. Usability testing was performed using cognitive walk-throughs and a think-aloud protocol. RESULTS:Four information needs were identified including guidance regarding resident assessment; communication with providers; care planning; and urine culture interpretation. Design of a web-based application incorporating a published decision support algorithm for evidence-based UTI diagnoses proceeded with a focus on nursing information needs during resident assessment and communication with providers. Certified nursing assistant (CNA) and registered nurse (RN) personas were constructed in 4 context scenarios with associated key path scenarios. After field testing, a high fidelity prototype of UTI Decide was completed and evaluated by potential end users. Design recommendations and content recommendations were elicited. CONCLUSIONS:Goal-Directed Design informed the development of a mobile CDSS supporting participant-identified information needs for UTI assessment and communication in NHs. Future work will include iterative deployment and evaluation of UTI Decide in NHs to decrease inappropriate use of antibiotics for suspected UTI.