Contamination Of Urine Samples Research Articles

Discrimination of Common E. coli Strains in Urine by Liquid Chromatography-Ion Mobility-Tandem Mass Spectrometry and Machine Learning.

Accurate identification of bacterial strains in clinical samples is essential to provide an appropriate antibiotherapy to the patient and reduce the prescription of broad-spectrum antimicrobials, leading to antibiotic resistance. In this study, we utilized the combination of a multidimensional analytical technique, liquid chromatography-ion mobility-tandem mass spectrometry (LC-IM-MS/MS), and machine learning to accurately identify and distinguish 11 Escherichia coli (E. coli) strains in artificially contaminated urine samples. Machine learning was utilized on the LC-IM-MS/MS data of the inoculated urine samples to reveal lipid, metabolite, and peptide isomeric biomarkers for the identification of the bacteria strains. Tandem MS and LC separation proved effective in discriminating diagnostic isomers in the negative ion mode, while IM separation was more effective in resolving conformational biomarkers in the positive ion mode. Using hierarchical clustering, the strains are clustered accurately according to their group highlighting the uniqueness of the discriminating biomarkers to the class of each E. coli strain. These results show the great potential of using LC-IM-MS/MS and machine learning for targeted omics applications to diagnose infectious diseases in various environmental and clinical samples accurately.

Urine soluble TLR4 levels may contribute to predict urinary tract infection in children: the UTILISE Study.

One of the most common bacterial infections in childhood is urinary tract infection (UTI). Toll-like receptors (TLRs) contribute to immune response against UTI recognizing specific pathogenic agents. Our aim was to determine whether soluble TLR4 (sTLR4), soluble TLR5 (sTLR5) and interleukin 8 (IL-8) can be used as biomarkers to diagnose UTI. We also aimed to reveal the relationship between urine Heat Shock Protein 70 (uHSP70) and those biomarkers investigated in this study. A total of 802 children from 37 centers participated in the study. The participants (n = 282) who did not meet the inclusion criteria were excluded from the study. The remaining 520 children, including 191 patients with UTI, 178 patients with non-UTI infections, 50 children with contaminated urine samples, 26 participants with asymptomatic bacteriuria and 75 healthy controls were included in the study. Urine and serum levels of sTLR4, sTLR5 and IL-8 were measured at presentation in all patients and after antibiotic treatment in patients with UTI. Urine sTLR4 was higher in the UTI group than in the other groups. UTI may be predicted using 1.28ng/mL as cut-off for urine sTLR4 with 68% sensitivity and 65% specificity (AUC = 0.682). In the UTI group, urine sTLR4 levels were significantly higher in pyelonephritis than in cystitis (p < 0.0001). Post-treatment urine sTLR4 levels in the UTI group were significantly lower than pre-treatment values (p < 0.0001). Urine sTLR4 may be used as a useful biomarker in predicting UTI and subsequent pyelonephritis in children with UTI. A higher resolution version of the Graphical abstract is available as Supplementary information.

Reduction of Patient Harm Through Decreasing Urine Culture Contamination in an Emergency Department Using Multiple Process Improvement Interventions

BACKGROUND: From August 2018 to January 2019, the baseline urine sample contamination rate at an acute care hospital emergency department (ED) was 51%. Urine culture contamination is associated with unnecessary antibiotic use, repeat culture costs, and unnecessary inpatient admissions. These outcomes can lead to additional cost to the patient and healthcare system while leading to additional poor outcomes. METHODS: Culture results were reviewed and the project definition of contamination was applied. Contaminated cultures were reviewed further via manual electronic health record review of ED notes to determine documentation of collection source, education prior to clean catch collection, the cognitive and physical documented descriptions of the patient, and the name of the staff member who collected the sample. INTERVENTION: Staff were educated on appropriate midstream and straight catheter collection techniques, verbal along with picture education for patients, and appropriate identification of patients who may benefit from straight catheterization instead of clean catch. RESULTS: The combined interventions resulted in a six-month decrease of contaminated urine samples from the initial 51% to &lt;10%, resulting in an 80% decrease. CONCLUSION: Urine culture contamination in an acute care ED was sustainably decreased through multiple process improvement interventions. Secondary outcomes included reduction in unnecessary antibiotic use, repeat urine cultures, and unnecessary admissions.

Do external urine collection devices reduce contamination in urine samples for women with symptoms of urinary tract infection? A systematic review

IntroductionTo evaluate the impact of external urine collection devices (UCD) on contamination of urine samples in women with symptoms of urinary tract infection. MethodsThis review was conducted according to the Systematic Reviews of Diagnostic Test Accuracy guidelines (PROSPERO CRD42021241758). PubMed was searched for paired sample studies and controlled trials. Studies comparing UCDs with non-invasive urine collection procedures were considered. ResultsOnly two studies were found. Neither of the two studies found any difference regarding contamination between specimens collected with the UCDs compared and non-invasive techniques. In the largest study, including 1264 symptomatic women, 18.8% of those allocated to UCDs failed to collect urine samples successfully. ConclusionsMore studies involving women with symptoms of urinary tract infection are needed to produce more robust data on the impact of these devices on urine contamination rates.

Formation of ethyl glucuronide by beta-glucuronidase

Substantial amounts of endogenous and xenobiotic compounds are transformed to ß-D-Glucuronides in the human body. The conjugation reaction, which requires uridine-5′-diphospho (UDP)-alpha-D-glucuronic acid as a cosubstrate is catalyzed by UDP-glucuronosyltransferases (UGTs). Beta-glucuronidase (GUSB), which is widely distributed in mammalians, microbiota, insects, molluscs, nematodes, fishes and plants, opposes this reaction: ß-D-glucuronides are hydrolyzed to ß-D-glucuronic acid and the corresponding aglycon in a configuration retaining manner. This study investigated GUSB activity in the presence of ethanol. Phenolphthalein-ß-D-glucuronide (PHPH-G), 4-nitrophenol-ß-D-glucuronide (4NP-G), morphine-3-O-ß-D-glucuronide, quercetin-3-O-ß-D-glucuronide and 1-/2-propyl-ß-D-glucuronide were used as substrates. Enzymatic reactions were carried out at 37 °C in buffer solution fortified with different amounts of ethanol (0–70% by volume) using GUSB from different sources ( E. coli , H. pomatia , bovine and human recombinant). The enzymatic reactions were stopped after 60 minutes and all samples were tested for ß-D-ethyl glucuronide (EtG) by a validated LC/MS/MS assay. In incubations of PHPH-G and 4NP-G, the release of aglyca was additionally measured by colorimetrical methods. It was found that EtG, which is a minor metabolite of ethanol but one of the most important direct biomarkers of alcohol consumption in man today, builts up from all investigated ß-D-glucuronides by GUSB activity in the presence of ethanol. The glucuronyl transfer reaction, which was neither observed in absence of ethanol nor in absence of GUSB, is detectable but minor at ethanol concentrations which are commonly observed in blood and tissues after consumption of alcoholic beverages. At higher ethanol concentrations (> 5% by volume), the transfer reaction is predominant and the majority of glucuronyl from ß-D-glucuronides is transferred to ethanol. Different types of donor substrates yielded different amounts of EtG in the presence of the same GUSB-activity and different types of GUSB yielded different amounts of EtG from the same donor substrate. The detection of EtG in several settings independent from human UGT-metabolism (e.g., EtG post collection synthesis in E.coli contaminated urine samples, EtG in wine and ethanolic herbal preparations) can be explained by the observed mechanism. A contribution of GUSB activity to EtG kinetics in man is suspected and should be further investigated since high concentrations of ethanol (oral intake of alcoholic beverages) and high concentrations of ß-D-glucuronides (hepatobiliary secretion) are present in the gut, where the main GUSB activity is localized. Finally, the findings could be of interest in context of EtG hair analysis, since the prerequisites for in vitro formation of EtG in this study may also be found on head. There is an additional biochemical path and another source of EtG which deserves further attention in context of alcohol biomarker applications.

Urinary HSP70 improves diagnostic accuracy for urinary tract infection in children: UTILISE study.

The accuracy of conventional urinalysis in diagnosing urinary tract infection (UTI) in children is limited, leading to unnecessary antibiotic exposure in a large fraction of patients. Urinary heat shock protein 70 (uHSP70) is a novel marker of acute urinary tract inflammation. We explored the added value of uHSP70 in discriminating UTI from other infections and conditions confused with UTI. A total of 802 children from 37 pediatric centers in seven countries participated in the study. Patients diagnosed with UTI (n = 191), non-UTI infections (n = 178), contaminated urine samples (n = 50), asymptomatic bacteriuria (n = 26), and healthy controls (n = 75) were enrolled. Urine and serum levels of HSP70 were measured at presentation in all patients and after resolution of the infection in patients with confirmed UTI. Urinary (u)HSP70 was selectively elevated in children with UTI as compared to all other conditions (p < 0.0001). uHSP70 predicted UTI with 89% sensitivity and 82% specificity (AUC = 0.934). Among the 265 patients with suspected UTI, the uHSP70 > 48ng/mL criterion identified the 172 children with subsequently confirmed UTI with 90% sensitivity and 82% specificity (AUC = 0.862), exceeding the individual diagnostic accuracy of leukocyturia, nitrite, and leukocyte esterase positivity. uHSP70 had completely normalized by the end of antibiotic therapy in the UTI patients. Serum HSP70 was not predictive. Urine HSP70 is a novel non-invasive marker of UTI that improves the diagnostic accuracy of conventional urinalysis. We estimate that rapid urine HSP70 screening could spare empiric antibiotic administration in up to 80% of children with suspected UTI. A higher resolution version of the Graphical abstract is available as Supplementary information.

Do external urine collection devices reduce contamination in urine samples for women with symptoms of urinary tract infection? A systematic review

IntroductionTo evaluate the impact of external urine collection devices (UCD) on contamination of urine samples in women with symptoms of urinary tract infection. MethodsThis review was conducted according to the Systematic Reviews of Diagnostic Test Accuracy guidelines (PROSPERO CRD42021241758). PubMed was searched for paired sample studies and controlled trials. Studies comparing UCDs with non-invasive urine collection procedures were considered. ResultsOnly two studies were found. Neither of the two studies found any difference regarding contamination between specimens collected with the UCDs compared and non-invasive techniques. In the largest study, including 1264 symptomatic women, 18.8% of those allocated to UCDs failed to collect urine samples successfully. ConclusionsMore studies involving women with symptoms of urinary tract infection are needed to produce more robust data on the impact of these devices on urine contamination rates.

The position during urine sample collection from young precontinent children through a bag does not limit contamination rates: Results from a randomized controlled trial: Does infant position influence quality of urine collection?

AimDespite its limitation, bag collection is still widely used for a preliminary urine screening test in non-toilet-trained children suspected of febrile urinary tract infection. A previous study conducted by our group raised the hypothesis that the absence of direct contact between urine and the perinea during urine collection could limit urine contamination by perineal flora. The aim of this study was to evaluate the impact of the patient's position during urine collection (upright standing position versus free position) on the rate of contaminated urine samples in non-toilet-trained children with suspected febrile urinary tract infection. MethodsThis prospective, randomized, controlled study took place in seven pediatric emergency departments. Two groups were compared: the intervention group (infants held in an upright standing position during urination) and the control group (free position during urination). ResultsAmong the 800 pediatric patients randomized to the study, 124 had a urine culture, 60 in the intervention group and 64 in the control group. Among the 124 urine cultures, 12 (9.7%) were contaminated: eight (13.3%) in the intervention group and four (6.3%) in the control group (p = 0.1824). ConclusionThe results show that the patient's position does not have a significant impact on the quality of urine samples collected by bag.

A novel, time-effective approach for capturing bacteria from contaminated urine samples.

A fundamental step in the race to design a rapid diagnostic test for antimicrobial resistance is the separation of bacteria from their matrix. Many recent studies have been focused on the development of systems capable of separating and capturing bacteria from liquid environments. Herein, we introduce a new approach to this issue by using the natural bacteria tendency to accumulate at naturally-occurring interfaces, such as liquid-gas and liquid-solid interfaces, where also organic molecules like lipids, proteins, and polysaccharides accumulate. This bacterial behavior leads to the formation of a superficial layer close to the interface rich in bacteria, from which it is possible to capture a consistent amount of bacteria by means of surfaces with high chemical affinity to the outer bacteria surface. This paper demonstrates how to capture bacteria from contaminated urine samples, by means of commercial microscope slides coated with positively charged biomolecules, without the utilization of the bacterial culture step for multiplying the bacteria. This approach is an easy, quick and economical method to concentrate living bacteria in a well-defined position onto a microscope slide, thus making them easily available for further diagnostic investigations.

Determination of β-Agonists in Urine Samples at Low µg/kg Levels by Means of Pulsed Amperometric Detection at a Glassy Carbon Electrode Coupled with RP-LC

A method for the determination of β-agonists was developed by combining the separation of analytes through high-performance liquid chromatography, with a reversed-phase column, coupled to the pulsed amperometric detection at a glassy carbon electrode. Preliminary experiments, using cyclic voltammetry, allowed for an understanding of the electrochemical behavior of clenbuterol, fenoterol, and terbutaline. By analyzing the electrochemical response, the conditions for detecting the analytes and for cleaning the working electrode were identified. The proposed potential-time profile was designed to prevent contamination of the carbon electrode following consecutive analyses, so ensuring a reproducible and sensitive quantitative determination. The waveform electrochemical parameters, including detection and delay times, have been optimized in terms of sensitivity, detection limits, and long-term response stability. The chromatographic separation was carried out using a C8 column in isocratic mode, and a mixture of acetic acid and acetonitrile. The optimized experimental conditions were used for the analysis of standard solutions and real samples. Detection limits, lower than the maximum residue limit set for clenbuterol by European directives, were obtained for all β-agonists investigated. The method validation was performed by evaluating the linearity, selectivity, precision, and recovery. Calf urine samples were used to verify the applicability of the proposed method, analyzing both enriched and naturally contaminated urine samples.

Comparing CxBladder to Urine Cytology as Adjunct to Cystoscopy in Surveillance of Non-muscle Invasive Bladder Cancer-A Pilot Study.

Purpose: Guidelines advocate cystoscopy surveillance (CS) for non-muscle invasive bladder cancer (NMIBC) post-resection. However, cystoscopy is operator dependent and may miss upper tract lesions or carcinoma in-situ (CIS). Urine cytology is a common adjunct but lacks sensitivity and specificity in detecting recurrence. A new mRNA biomarker (CxBladder) was compared with urine cytology as an adjunct to cystoscopy in detecting a positive cystoscopy findings during surveillance cystoscopy in our center.Materials and Methods: Consented patients older than 18, undergoing CS for NMIBC, provide paired urine samples for cytology and CxBladder test. Patients with positive cystoscopy findings would undergo re-Trans Urethral Resection of Bladder Tumor (TURBT).Results: Thirty-five patients were enrolled from April to June 2019. Seven contaminated urine samples were excluded. The remaining cohort of 23 (82%) and 5 (18%) females had a mean age of 66.69 (36–89). Eight (29%) patients with positive cystoscopy finding underwent TURBT. All 8 patients also had positive CxBladder result. This shows that CxBladder has a sensitivity and negative predictive value (NPV) of 100%, specificity of 75% and positive predictive value (PPV) of 62% in predicting a positive cystoscopy finding. TURBT Histo-pathological findings showed Low-grade Ta NMIBC in one patient (4%), and 7 (25%) patients had inflammatory changes. Urine cytology was only positive in one patient with a positive cystoscopy finding. This led to a sensitivity of merely 13% and NPV of 74%, while specificity and PPV was 100% in predicting a positive cystoscopy finding.Conclusion: CxBladder had high NPV and sensitivity which accurately predicted suspicious cystoscopy findings leading to further investigation. It has great potential for use as adjunct to cystoscopy for surveillance of NMIBC.

Accuracy of urine flow cytometry and urine test strip in predicting relevant bacteriuria in different patient populations

BackgroundUrinary tract infection (UTI) is diagnosed combining urinary symptoms with demonstration of urine culture growth above a given threshold. Our aim was to compare the diagnostic accuracy of Urine Flow Cytometry (UFC) with urine test strip in predicting bacterial growth and in identifying contaminated urine samples, and to derive an algorithm to identify relevant bacterial growth for clinical use.MethodsSpecies identification and colony-forming unit (CFU/ml) quantification from bacterial cultures were matched to corresponding cellular (leucocytes/epithelial cells) and bacteria counts per μl. Results comprise samples analysed between 2013 and 2015 for which urine culture (reference standard) and UFC and urine test strip data (index tests, Sysmex UX-2000) were available.Results47,572 urine samples of 26,256 patients were analysed. Bacteria counts used to predict bacterial growth of ≥105 CFU/ml showed an accuracy with an area under the receiver operating characteristic curve of > 93% compared to 82% using leukocyte counts. The relevant bacteriuria rule-out cut-off of 50 bacteria/μl reached a negative predictive value of 98, 91 and 89% and the rule-in cut-off of 250 bacteria/μl identified relevant bacteriuria with an overall positive predictive value of 67, 72 and 73% for microbiologically defined bacteriuria thresholds of 105, 104 or 103 CFU/ml, respectively. Measured epithelial cell counts by UFC could not identify contaminated urine.ConclusionsPrediction of a relevant bacterial growth by bacteria counts was most accurate and was a better predictor than leucocyte counts independently of the source of the urine and the medical specialty ordering the test (medical, surgical or others).

Non-invasive assessment of metabolic responses to food restriction using urinary triiodothyronine and cortisol measurement in macaques

Regulation of energy allocation and metabolic rate plays an important role in determining behavior and fitness in wild animals, calling for the validation of non-invasive markers of energetic condition. Recently, the thyroid hormone triiodothyronine (T3) has emerged as a promising marker as concentrations decrease to lower the metabolic rate during energetically challenging periods. However, it remains largely unclear whether T3 merely represents an alternative or provides additional information compared to other compounds involved in the regulation of energy acquisition and allocation, like cortisol and C-peptide, as few joint measurements have been conducted to date in non-invasively collected samples. We aimed to validate the non-invasive measurement of immunoreactive urinary total T3 (uTT3), in comparison to urinary cortisol (uCort) and urinary C-peptide (uCP), as a marker of metabolic response to variation in food intake in macaques, and to address a number of issues regarding the collection, storage and processing of samples which are important for application of uTT3 measurements under field conditions. We used daily samples and body mass measures from a prior food restriction-refeeding experiment over 4 weeks with six captive macaques and analyzed concentrations of uTT3 and uCort in samples collected prior to (fasting) and after morning feeding (non-fasting). Concentrations of uTT3 decreased in response to restriction in food supply and were also lower during weeks of food restriction compared to weeks of refeeding. Variation in uTT3 also correlated positively with variation in body mass and concentrations of uCP. As expected, uCort showed the reverse pattern, increasing during food restriction and decreasing following refeeding, but was not associated with variation in body mass. Generally, compared to fasting samples, concentrations were higher in post-morning feeding, i.e. non-fasting, samples for uTT3 but not uCort. Contamination of urine samples with fecal matter, but not soil, and exposure to UV light led to a decrease in uTT3. uTT3 was largely unaffected by repeated freeze–thaw cycles and by refrigeration for medium-term storage (2 days) but degraded substantially when stored at ambient temperature for the same period. In conclusion, uTT3 measurements inform on the effect of food intake and its associated metabolic response to variation in energetic status. Since uTT3 is reasonably robust to many issues associated with collection and storage of urine samples under field conditions, it is a promising biomarker for studies of energetic condition and basal metabolic rate in wild macaques.

Improving the Management of Pediatric Upper Urinary Tract Infections at Odorheiu Secuiesc Hospital

Abstract The primary goal of our retrospective analysis was to check the correctness of the diagnosis, and to identify the potential diagnostic errors among patients coded with N10 diagnosis in 2009, 2014 and 2019 in the pediatric ward of Odorheiu Secuiesc Hospital; we also assessed protocol-adherence in treatment and prophylaxis, and changes in antibiotic resistance of the isolated E. coli strains. During this 10 year-period significant improvements have been achieved in the treatment of upper urinary tract infections: in 2009 the diagnosis could be disputed in 31 out of 61 cases, while in 2019 this ratio is only 2 out of 31 cases; the number of cases pretreated with antibiotics decreased to a third, contaminated urine samples are rare to occur, the unmotivated antibiotics prophylaxis is essentially nonexistent, and there are no major documentation deficiencies either. In our study we present the antibiotic susceptibility of 50 E. coli strains isolated from the study group, which suggests some favorable changes.

Rapid Detection and Antibiotic Susceptibility of Uropathogenic Escherichia coli by Flow Cytometry.

Background: Early preliminary data on antibiotic resistance patterns available before starting the empiric therapy of urinary tract infections (UTIs) in patients with risk factors for acquiring antibiotic resistance could improve both clinical and epidemiological outcomes. The aim of the present study was two-fold: (i) to assess the antibiotic susceptibility of uropathogenic Escherichia coli isolates, exhibiting different antibiotic resistance phenotypes, directly in artificially contaminated urine samples using a flow cytometry (FC) based protocol; (ii) to optimize the protocol on urine samples deliberately contaminated with bacterial suspensions prepared from uropathogenic E. coli strains. Results: The results of the FC based antimicrobial susceptibility testing (AST) protocol were compared with the reference AST methods results (disk diffusion and broth microdilution) for establishing the sensitivity and specificity. The proposed FC protocol allowed the detection and quantification of uropathogenic E. coli strains susceptibility to nitrofurantoin, trimethoprim–sulfamethoxazole, ciprofloxacin, and ceftriaxone within 4 h after the inoculation of urine specimens. The early availability of preliminary antibiotic susceptibility results provided by direct analysis of clinical specimens could essentially contribute to a more targeted emergency therapy of UTIs in the anticipation of AST results obtained by reference methodology. Conclusions: This method will increase the therapeutic success rate and help to prevent the emergence and dissemination of drug resistant pathogens.

Contamination in Urine Samples Collected Using Bladder Stimulation and Clean Catch Versus Urinary Catheterization in Infants Younger Than 90 Days.

The objective of this study was to compare the risk of contamination for urine samples collected from patients younger than 90 days using 2 different techniques: bladder stimulation and "clean catch" (CC) and urinary catheterization (CATH). A case-control study was carried out in the pediatric emergency room of a tertiary hospital between January 2016 and September 2017. All urine samples collected from patients younger than 90 days by CC or CATH were included. The incidence of contaminated urine samples was compared for both methods, and the risk of contamination was estimated using univariate and multivariate analyses. A total of 473 urine samples were collected, 310 via CATH (65.5%) and 163 via CC (34.5%). The median age was 1.4 months (interquartile range, 0.8-2.1 months), and 54.1% were males. Seventeen patients had a history of urinary tract infection (3.6%), and 16 were diagnosed with a congenital urorenal anomaly (3.4%). Sixteen urine samples were found to be contaminated (3.4%): 5 collected via CATH (1.6%) and 11 via CC (6.8%). The univariate analysis revealed a greater risk of contamination in specimens obtained using CC versus CATH (odds ratio, 4.41; 95% confidence interval, 1.51-12.93), and the multivariate analysis confirmed CC collection as an independent risk factor for contamination (odds ratio, 5.61; 95% confidence interval, 1.83-17.19). The number of contaminated urine samples in infants younger than 90 days in our pediatric emergency department is low. However, using the CC urine collection technique seems to be an independent risk factor for sample contamination.

The development of an analysis protocol based on flow cytometry for rapid detection of uropathogenic E. coli in artificially contaminated urine samples

The development of an analysis protocol based on flow cytometry for rapid detection of uropathogenic E. coli in artificially contaminated urine samples

A prospective study to assess the association of body mass index and contamination of urinalysis samples

BackgroundThere is a commonly held belief that overweight women are more likely to offer contaminated urine samples (UAs) in the emergency department (ED) than women with normal body mass index (BMI). However, there is a paucity of research evaluating this potential concern. ObjectiveWe hypothesized that patients with higher BMI would be more likely to provide contaminated urine samples than women with low BMI. MethodsThis was a prospective, observational, cohort study evaluating consenting, adult, women that provided a clean catch, mid-stream sample at an inner-city ED. UAs were ordered at the discretion of the caring physician, cultures based on standardized parameters. The primary outcome parameter was the presence of UA contamination as defined by our microbiology lab. Demographic/historical data and BMI were recorded on a structured data sheet. Categorical data were analyzed by chi-square; continuous data by t-tests. Multivariable logistic regression was performed to control for confounding. ResultsThere were 350 patients in the study group; 22% overweight, 35% obese, 17% morbidly obese, mean BMI 31. 5, and 60% provided contaminated specimens. The mean BMIs of the subjects with contaminated vs. uncontaminated UAs were significantly different (32.7 ± 10.2 vs 29.7 ± 8.8, p < 0.01). Within our multiple variable logistic regression model, obese and morbidly obese patients were more likely to provide contaminated UAs, while there were no significant associations for contamination with other variables except for hypertension (OR = 1.85, p = 0.02). ConclusionObesity was significantly associated with contamination of clean catch mid-stream samples in our population.

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The method of urine sampling is not a valid predictor for vesicoureteral reflux in children after febrile urinary tract infections

The likelihood of detecting vesicoureteral reflux (VUR) after febrile urinary tract infections (UTI) in children logically should correlate with the correct diagnosis of the UTI. Beneath the unspecific symptoms of fever urine analysis is the main diagnostic criterion for the exact diagnosis of febrile UTIs in children. Use of inadequate urine sampling techniques during diagnosis may lead to impaired accuracy in UTI diagnosis. This could lead to the assumption that children, having diagnosed their UTI by the use of possibly inadequate urine sampling techniques should not be evaluated as consequently compared to those, where the diagnosis relied on sterile urine sampling techniques. We hypothesized that children with possibly contaminated urine samples during the initial diagnosis may show a lower rate of VUR in subsequent VCUGs because of a wrong diagnosis initially compared to children, where accurate urine sampling techniques were used. Between 2009 and 2014, a total of 555 patients underwent a primary VCUG at our department indicated because of febrile UTIs. Patients with urine collection methods other than bag urine and catheter/suprapubic aspiration (SPA) were excluded from this study (mid-stream urine, potty urine, n=149). We evaluated 402 patients (male/female 131/271, mean age 1.91 years), VUR rates and grades were compared between patients where urine was sampled by the use of a urine bag only at the time of diagnosis (n=296, 73.6%) and those where sterile urine sampling (catheter, suprapubic puncture) was performed (n=106, 26.3%). 4 patients were excluded due to equivocal data on urine sampling. VUR rate in children after sterile urine sampling using a catheter or SPA accounted to 31.1%. In those where urine samples acquired by the use of urine bags were used, 33.7% showed VUR on subsequent VCUG (p=0.718). There were no significant differences as to VUR grades or gender, although VUR was much more commonly diagnosed in female patients (37.0% vs 28.2%, p=0.227) (Figure). Children diagnosed with their UTI by use of bag urine in our experience carried the same risk of showing a VUR in a subsequent VCUG compared to those, where the initial diagnosis relied - beneath clinical criteria - on urine samples acquired by suprapubic puncture or catheterization. Consequently urine-sampling technique during initial UTI diagnosis alone should not be used as predictor for the reliability of UTI diagnosis and should not influence the further management after UTI.