Asymptomatic bacteriuria in girl entrants to Dundee primary schools

The Urine Microbiome of Healthy Men and Women Differs by Urine Collection Method

PURPOSE

Compared to the microbiome of other body sites, the urinary microbiome remains poorly understood. Although noninvasive voided urine specimens are convenient, contamination by urethral microbiota may confound understanding of the bladder microbiome. Herein we compared the voiding- versus catheterization-associated urine microbiome of healthy men and women.

METHODS

An asymptomatic, healthy cohort of 6 women and 14 men underwent midstream urine collection, followed by sterile catheterization of the bladder after bladder refilling. Urine samples underwent urine dipstick testing and conventional microscopy and urine cultures. Samples also underwent Illumina MiSeq-based 16S ribosomal RNA gene amplification and sequencing.

RESULTS

All organisms identified by urine culture were also identified by 16S amplification; however, next-generation sequencing (NGS) also detected bacteria not identified by cultivation. Lactobacillus and Streptococcus were the most abundant species. Abundances of the 9 predominant bacterial genera differed between the urethra and bladder. Voided and catheterized microbiomes share all dominant (>1%) genera and Operational Taxonomic Units but in similar or different proportions. Hence, urethra and bladder microbiomes do not differ in taxonomic composition, but rather in taxonomic structure. Women had higher abundance of Lactobacillus and Prevotella than men.

CONCLUSION

Our findings lend credence to the hypothesis that Lactobacilli are important members of the healthy urine microbiome. Our data also suggest that the microbiomes of the urethra and bladder differ from one another. In conclusion, urine collection method results in different 16S-based NGS data, likely due to the sensitivity of NGS methods enabling detection of urethral bacteria present in voided but not catheterized urine specimens.

P-fimbriated Escherichia coli in adults with renal scarring and pyelonephritis

The commonest organism in urinary tract infections (UTI) is Escherichia coli. Pyelonephritogenic E.coli strains possess P-fimbriae which firmly attach to uroepithelial cells by recognition of a carbohydrate structure, alpha-D-Galp-(1-4)-beta-D-Galp, which is confined within all glycosphingolipids related to the human P-blood group antigens. Several investigators have studied virulence properties of E.coli and host resistance in relation to UTI. Uroepithelial cells from children and women with recurrent UTI have an increased capacity to bind E.coli. In contrast to previous studies the present one deals with patients with renal scarring, who constitute the major risk group among patients with UTI. P-fimbriae mediated binding to uroepithelial cells was studied and the risk of recurrent UTI in patients with renal scarring was determined. Ninety per cent of the E.coli isolates from female patients with acute non-obstructive pyelonephritis in this study possess P-fimbriae (I). The fecal E.coli colonies obtained from these patients were P-fimbriated in 55% compared to 11% of the fecal E.coli colonies from healthy controls. The P-blood group distribution in 56 female patients with renal scarring and a history of febrile UTI was the same as in a control group of 39 healthy subjects (II). A history of recurrent and/or early infections did not increase the percentage of the P1 blood group phenotype. Forty-nine female patients with renal scarring were prospectively investigated for the incidence of symptomatic UTI in relation to fecal colonization with P-fimbriated E.coli (III). Fifty-three per cent of the patients had altogether 65 episodes of symptomatic UTI during the three-year follow-up (0.036 infections per month). Eight patients (16%) had nine attacks of acute pyelonephritis and 4/5 of the tested E.coli strains from these patients were P-fimbriated. No relationship was demonstrated between the presence of P-fimbriated E.coli in the fecal flora and the development of subsequent acute pyelonephritis. The binding of P-fimbriated E.coli to uroepithelial cells from 19 female patients with renal scarring was studied with the fluorescence-activated cell sorting (FACS) analysis (IV). The uroepithelial cells from the patients with renal scarring exhibited a significantly higher binding capacity (p less than 0.01) than uroepithelial cells from healthy controls. Furthermore, uroepithelial cells from the patients with renal scarring and kidney insufficiency had a higher availability of P-fimbriae receptors on their uroepithelial cells than cells obtained from patients with renal scarring and normal renal function (r = -0.75, p less than 0.001) (V).(ABSTRACT TRUNCATED AT 400 WORDS)

[Primary vesicoureteral reflux treatment in childhood: comparsion of two systematic review]

Many medical practices are being carried out unawares of their efficiency, or of their actual impact on the health of the patients, therefore it is necessary to consider the support of professional recommendations with scientific evidence.

THE PRIMARY OBJECTIVE

To perform a systematic review (SR) of the therapeutic management of primary VUR in pediatric urology.

MATERIAL AND METHODS

A systematic review has been performed, including scientific evidence-based medicine criteria, of the articles published in all of the available databases. Inclusion criteria concerning basic quality of the articles were considered essential, as well as exclusion criteria to be able to reject the articles.

RESULTS AND DISCUSSION

Subsequently, and following the critic reading of greater than 320 articles, statistical study of the grouped data was performed according to the type of treatment and to the benefits contributed by each treatment, and also to their undesirable effects. Finally we have made a comparison between our results and recent Cochrane Systematic Review. The following Conclusions were drawn from the results obtained and from the analysis of the texts. Both medical and surgical treatment present with similar effectiveness concerning resolution of grades I, II and III of VUR, and the former one is the recommended initial treatment following diagnosis. Endoscopic treatment is exactly as effective as open surgery for grades I, II and III with fewer undesirable effects secondary. There are no differences concerning the efficacy of the different injected substances. Not enough evidences exist for degrees IV and V that may recommend or advise against any of the treatments. In any degree of VUR, open surgical treatment is superior as far as medical treatment is concerned only regarding the number of acute pyelonephritis episodes during followup. This conclusion cannot be applied on endoscopic treatment.

The small scarred kidney in childhood

Reflux nephropathy is now a generally accepted term to describe small scarred kidneys discovered during childhood; it recognises the close association between this renal lesion and vesicoureteric reflux (VUR). This paper briefly reviews the pathogenic factors involved in reflux nephropathy and suggests that at least two main mechanisms operate: acquired segmental scarring due to intrarenal reflux and congenital maldevelopment (renal dysplasia). The spectrum of renal changes associated with VUR can be usefully divided on this basis and the opportunity to recognise by fetal ultrasound those renal lesions acquired in utero may further enhance our understanding of the congenital maldevelopment group.

Scintigraphic evaluation of pediatric urinary tract infection

Scintigraphic evaluation of urinary tract infection, pyelonephritis, and renal scarring represents a significant portion of a clinical pediatric nuclear medicine practice. Renal scarring from recurring infection remains an important cause of end-stage renal disease and hypertension in the pediatric population. However, the clinical presentation in infants and young children is often elusive, and clinical diagnosis of upper tract involvement is frequently unreliable. As a result, diagnostic imaging has a critical role to play in the localization of infection to the lower or upper urinary tract. Radionuclide cystography and renal cortical imaging have become mainstays of this evaluation. Direct radionuclide cystography is the preferred cystographic screening technique, because it has lower radiation exposure and greater sensitivity for the detection of vesicoureteral reflux than either indirect radionuclide cystography or fluoroscopic contrast cystography. Renal cortical scintigraphy has become the standard for the detection of pyelonephritis and renal scarring. Correlation with histopathology has demonstrated a high degree of diagnostic accuracy. Acute pyelonephritis has been shown to be the necessary etiologic factor for the development of subsequent renal scarring, and the mechanism of renal injury in pyelonephritis has been extensively studied in experimental models. The ability of prompt and appropriate antibiotic therapy to dramatically reduce the incidence of subsequent scarring also has been conclusively demonstrated both clinically and in the experimental model. Vesicoureteral reflux was once thought to be a necessary prerequisite for the development of renal scarring. Although it is clear that the intrarenal reflux of infected urine will create pyelonephritis in the experimental model, the high incidence of pyelonephritis and subsequent scarring in the absence of demonstrable vesicoureteral reflux leaves the role of reflux in question. Although the role of vesicoureteral reflux is incompletely understood, its detection nevertheless remains a standard part of the patient's evaluation.

Medical ethics and the public health

The development of preventive medicine is reviewed from an historical perspective. In its third and current stage of development preventive medicine has become involved in the life cycle of individual diseases and this presents a number of ethical difficulties for doctors and not least those concerned with the public health. Some proposed responses are considered and rejected. It is concluded that participants should be given more detailed information about screening tests and that doctors are under an ethical obligation to consider with the utmost care any contra-indications to a particular vaccination or a screening procedure in an individual patient. Serious reservations are expressed about the ethics and scientific justification of some government preventive medicine programmes currently in operation or projected.

Day wetting

About 1% of healthy children over the age of 5 years have troublesome daytime wetting. Two-thirds of those who wet by day are reliably dry at night. The problem is more common in girls and is usually the result of urge incontinence. Although the wetting may be exacerbated by giggling and/or stress, pure giggle micturition and isolated stress incontinence are both rare. There is a strong association with bacteriuria (50% prevalence) in girls who wet by day. A potentially important relationship exists between day wetting, infection, reflux and upper tract damage, which is expressed in an extreme form in the syndromes of incoordinated voiding and progressive renal damage. Most children who wet by day have unstable bladders. Many of them adopt characteristic "holding" postures. There is an increased incidence of emotional disorder compared with children who merely wet the bed. Between 10% and 15% of children who wet by day become dry during the next 12 months. The acquisition of dryness is accelerated by eradication of bacteriuria and a sympathetic and energetic management regime, which should place responsibility on the child and result in the child voiding more frequently and completely. Reminder alarms and other behaviour therapies have proved effective. There is no satisfactory evidence for the efficacy of drugs. More complex behavioural training regimes including biofeedback are valuable for severe cases.

Management of children with hypertension from reflux or obstructive nephropathy

During a ten-year period, 35 children presenting with vesicoureteral reflux, ureteropelvic junction obstruction, or a "small kidney" were found to be hypertensive. Of these, 15 subsequently underwent surgical procedures for relief of hypertension. Seven were "cured," six were "improved," and two were "unchanged." The severity of hypertension could not be correlated with the degree of reflux nor with the degree of obstructive uropathy. However, all children with reflux in our study who were hypertensive had some degree of calicectasis noted preoperatively on intravenous pyelogram. Also it was noted that hypertension may occur several years after successful anti-reflux surgery. Children with vesicoureteral reflux, ureteropelvic junction obstruction, or a small kidney need to have blood pressure determinations at regular intervals, even if all previous readings had been in the normotensive range and whether or not they were followed up medically or post surgically. We suggest that blood pressure determinations be made every three months for the first year after diagnosis of reflux or ureteropelvic junction obstruction, and at least once a year thereafter.

The small scarred kidney of childhood. A congenital or an acquired lesion?

The vast majority of small segmentally scarred kidneys seen in childhood are now recognised to be associated with vesicoureteric reflux and the term "reflux nephropathy" has been accorded general recognition as a description of this renal lesion. With regard to the pathogenic mechanisms responsible for the scarring process, the possible roles of intrauterine renal maldevelopment, bladder dysfunction, functional urinary obstruction and infection in relation to vesicoureteric reflux and the associated phenomenon of intrarenal reflux must all be considered. It is probable that in different clinical circumstances all of these factors may be important to varying degrees and discussion of their contributions to the spectrum of reflex nephropathy is the basis of this communication.

Prevalence of asymptomatic bacteriuria and comparison between different screening methods for its detection in infants

Urine was cultured from 441 healthy children, aged 3 to 36 months, simultaneously by standard pour plating and by dip-slide. Significant bacteriuria (greater than or equal to 10(5) colony-forming units/ml in two successive specimens) was found in 13 children (2.9%): 11 boys, 2 girls. Proteus mirabilis was the most frequently isolated organism. Of the 13 infants, 2 had malformations on intravenous pyelography. All 13 had a negative antibody-coated bacteria test. Nitrite test (N-Multistix) and microscopic examination were also performed. The results suggest that asymptomatic bacteriuria cannot be accurately predicted either by microscopic examination or by the nitrite test, and that the quantitative urine culture by dip-slide is the easiest and most reliable way of diagnosing urinary tract infections. However the criteria of Kass were found to be too strict.

Urinary infections in children 1985

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Excretory urography and cystourethrography in the evaluation of children with urinary tract infection

One hundred and ninety-one children with a first episode of urinary tract infection (UTI) underwent intravenous pyelography (IVP) and voiding cystourethrography (VCU). Only three children (1.5%) had positive findings in the IVP that were of prognostic significance and were confined to that particular investigation alone. In contrast, 97 (50.7%) of the VCUs showed anatomical abnormalities. Vesico-ureteral reflux (VUR) of varying grades was diagnosed in 77 children (40.3%). These findings stress the importance of radiological investigation of the urinary tract after the first incidence of UTI, but suggest that IVP will give information of therapeutic and/or prognostic value in a small number of cases.

Glomerular filtration rate in schoolgirls with covert bacteriuria

Clearance of technetium-99m-labelled diethylenetriaminepenta-acetic acid was used to measure total and individual kidney glomerular filtration rates in 48 girls with covert bacteriuria. The mean (+/- SD) of the total rates of 18 girls with scarred kidneys (99 +/- 24 ml/min/1.73 m2) was significantly (0.005 greater than p greater than 0.002) lower than that in 30 girls with unscarred kidneys (119 +/- 18 ml/min/1.73 m2). This reduction in glomerular filtration was related to the loss of kidney substance associated with scarring rather than to vesicoureteric reflux. The glomerular filtration rate was unrelated to the duration of bacteriuria. These findings suggest that in girls aged 4 and over neither vesicoureteric reflux nor covert bacteriuria contributes to the progression of kidney damage.

Micturition symptoms and unstable bladder activity in girls with primary vesicoureteric reflux

A series of 37 girls with primary vesicoureteric reflux of grade II and greater severity underwent urodynamic investigations. Twenty-eight (75%) were found to have unstable bladder activity. Disordered micturition patterns were common and persisted after urinary tract infections had been eradicated. Twenty-six girls had urgency of micturition and 19 urge incontinence occurring once per week or more. The correlation between these symptoms and unstable bladder activity was significant (P less than 0.01), but there was no correlation between bladder instability and the incidence of renal scarring.

Asymptomatic bacteriuria in healthy preterm babies

Urine was cultured from 51 healthy preterm babies. If the initial bag specimen grew more than 50 000 organisms/ml, a second bag specimen was cultured. After two positive bag specimens a suprapubic urine was cultured. Significant bacteriuria was excluded on the basis of one or two bag specimens in 90% of the babies. Suprapubic urine was sterile in a further 11 babies. Four babies with positive bag specimens were unfortunately not completely investigated: 2 had mixed growths and 2 had pure growths of 100 000 organisms/ml. As we and others consider that bacteriuria can only be diagnosed on a suprapubic sample of urine the incidence of proved infection in our series was zero. If both the babies with a pure growth of 100 000 organisms/ml had true bacteriuria, the incidence would rise to 1.3%. In view of the difficulties in obtaining clean urine samples in preterm babies and as the incidence of bacteriuria is so low, we do not recommend that healthy preterm babies be screened for bacteriuria.

Observer variation in assessing renal scarring

To examine the extent of variation between experienced observers in recognizing renal scarring, 60 intravenous urograms from schoolgirls with bacteriuria were presented separately to three radiologists with a major interest in the radiology of the urinary tract. Observers were asked to state whether scarring was "absent", "doubtful" or "present" at each of three sites in each kidney: the poles and the midportion. The proportion of overall agreement, i.e. the proportion of coincident opinions, was 86% to 89%. Results were also analysed by using the kappa statistic, which corrects for agreement due to chance. Kappa values ranged from 0.67 to 0.73. These values indicate higher levels of inter-observer agreement than those recorded for many other radiological examinations and are much greater than those noted by others for inter-observer variation in the recognition of renal scarring in urograms in adults. The likely explanations for these high levels of agreement are discussed. Observers disagreed about the extent of scarring in one-third of cases. Studies of the prevalence of scarring should take account of observer variation and should be based on judgments by more than one experienced observer.

Urine microscopy and infection in general practice

To test the value of urine microscopy 100 consecutive specimens were examined in the surgery and the results correlated with the subsequent laboratory culture reports.An assessment of the degree of pyuria was made by low power microscopy of a thick drop of fresh urine. A second specimen was examined under high power for the presence or absence of motile bacilli. The techniques used are described and quantified.The laboratory report was definitive in 88 of the 100 cultures. All the 33 specimens with 10(5) bacteriuria had some degree of pyuria and in 27 (82 per cent) motile bacilli had been found. In the 50 with no significant bacteriuria no motile bacilli had been seen in 38 (76 per cent).In these 88 specimens a diagnosis made in the surgery based entirely on bacterial microscopy would have been correct in 80 per cent, combined with cytological microscopy in 87 per cent, and with the addition of clinical features in 92 per cent.In the remaining 12 cases the laboratory report was inconclusive and would have made no difference to my conclusions.

Psychiatric disturbance, urgency, and bacteriuria in children with day and night wetting

Forty children with day and night wetting were compared with 46 with night wetting only to see if day wetting was then associated with particular clinical features. Interviews with mothers, questionnaries completed by teachers, physical investigations, and measurement of functional bladder capacities were used. Day wetting combined with bed wetting occurred equally in boys and girls and was associated with daytime urgency and greater frequency of psychiatric disturbance. In boys, soiling was also associated. In girls, bacteriuria, which appeared to be caused by the day wetting, occurred in about 50%. Neither daytime frequency nor small functional bladder capacity were specifically related to day wetting.

Physical health of 7-year-old children. An epidemiological study of school entrants and a comparison with their preschool health

At 7 years of age, all 649 7-year-old children in a school district underwent a physical examination, a vision screening and an auditory screening. 210 of the children were previously examined in an extensive health control at 4 years of age. The purpose of the present study was to describe the children's health situation and to evaluate the special health control performed at 4 years of age. In 15% of the children, functionally important health problems were found. Visual defects were most common, comprising 7.5%, then came physical health problems such as motor disturbances, obesity, bacteriuria in 6.5%, and hearing defects in 1%. About half of the important health problems were previously known. Children who had passed the special health control at 4 years of age had fewer newly detected important health problems and more previously known ones than other children, which means that many children with above all visual defects but also motor disturbances, bacteriuria and testis retention, were detected and treated earlier than would have happened without the special control at 4 years. It is concluded that the "ordinary" preschool Child Health Services did fulfill their purpose to detect handicapping disorders in an acceptable way; by the introduction of the special health control at 4 years of age, this function was further improved.

Urinary tract in schoolgirls with covert bacteriuria

During screening of 16,800 primary schoolgirls, aged 4-12 years, in Cardiff and Oxford, significant bacteriuria was found in 294 (1-7%). Intravenous urography and micturating cystography were performed in 246 of these girls. The urinary tract was abnormal in 47%. Pyelonephritis with or without vesicoureteric reflux was present in 26% and reflux without renal abnormality in a further 16%. The prevalence of pyelonephritis and reflux was independent of age. With few exeptions kidneys without pyelonephritic scars appeared to be normal in size, even when ureteric reflux was present.

High incidence of 'asymtomatic' urinary tract infection in infant schoolgirls

Two thousand one hundred and sixty five Renfrewshire entrant schoolchildren were screened for bacteriuria and pyuria. The correlation between these two criteria of urinary tract infection was found to be very high.

Two of 960 boys and 31 of 1205 girls were found to have persistent significant bacteriuria and pyuria.

The method used is described and compared with other methods. Investigation, treatment and follow-up of the affected children is described.

Covert bacteriuria of childhood. A clinical and epidemiological study

A 4-year screening programme for covert bacteriuria in Dundee primary schoolgirl entrants showed a prevalence of 1·6% and an annual incidence of 0·9%. Among 109 children with bacteriuria, 70% had symptoms of lower urinary tract infection, 35% had vesicoureteric reflux, and 23% radiological evidence of pyelonephritis. Both pyuria and a past history of urinary infection were related to radiological evidence of reflux or pyelonephritis. Covert bacteriuria was found more frequently in children from social classes IV and V; and their housing, home circumstances, and home care were worse than a control group, even when allowance was made for their social class differences. The children appeared generally healthy but were smaller than a control group. The data suggest that the great majority of these children are not seriously at risk and that there is at present not sufficient evidence to warrant prescriptive screening.

Urinary infection in two selected neonatal populations

The urines from 204 infants admitted to a neonatal special care unit and from 25 infants whose mothers had bacteriuria in the last trimester of pregnancy were cultured and examined for white cells. A comparison of 39 bag collected urines with suprapubic specimens showed that growth in a bag collection was usually due to contamination, and that the presence of more than 10 WBC/cu.mm. in the suprapubic aspirate was not usually associated with a positive culture. Only 2 infants from a total of 70 studied in the special care unit had more than 100,000 organisms/ml. with more than 10 WBC/cu.mm. in the bladder urine. All urines, which were obtained from infants whose mothers had bacteriuria in the last trimester of pregnancy, were sterile. These results support the view that neonatal urinary infection is uncommon and that infants of this age is not justified.

Study of childhood urinary tract infection in general practice

A study of bacteriuria was conducted among 426 of the 436 children under the age of 13 in a general practice in north-west London. Three girls and one boy were found to have asymptomatic bacteriuria, and a further girl with bacteriuria presented with abdominal pain and fever. The calculated incidence of urinary tract infection was 1.4% per annum. Most of the childhood urinary infections in this practice occurred before the age of 5 years, and the incidence of significant bacteriuria in this age group was 4.9% per annum. Five other children (four girls and one boy) in the practice were known to have had proved urinary tract infection. Of the total of eight children known to have had significant bacteriuria and investigated radiologically, three girls and two boys had radiological abnormalities in the urinary tract.Pyuria and proteinuria did not prove to be useful in the prediction of asymptomatic bacteriuria. Urinary tract infection with renal tract abnormality was found in this practice to be at least five times as common as diabetes in childhood.