Urine Bacteria-Derived Extracellular Vesicles and Allergic Airway Diseases in Children.

BACKGROUND: Microbiota and human allergic airway diseases have been proven to be interrelated. Bacteria-derived extracellular vesicle (EV)s are known to play important roles in interbacterial and human-bacteria communications, but their relationship with allergies has not been examined yet. Urine EVs were investigated to determine whether they could be used as biomarkers for monitoring allergic airway diseases in children. METHODS: Subjects were 4 groups of chronic rhinitis (CR), allergic rhinitis (AR), atopic asthma (AS) and healthy controls. Single voided urine samples were collected. Urine EVs were isolated and their DNA was extracted for 16S-rDNA pyrosequencing. RESULTS: A total of 118 children participated in this study; 27, 39, 19, and 33 were in the CR, AR, AS, and control group, respectively. The AR had a significantly high Chao-1 index than that of controls. Principal component analysis revealed dysbiosis in the CR, AR, and AS compared to the controls. One phylum and 19 families and genera were significantly enriched or depleted in the disease groups compared to the controls; the Actinobacteria phylum and the Sphingomonadaceae family were more abundant in the AS and CR, the Comamonadaceae family, the Propionibacteraceae family, Propionibacterium and Enhydrobacter were more enriched in the CR, and the Methylobacteriaceae family and Methylobacterium were more abundant in each disease group, while the Enterobacteriaceae family was depleted in each disease group. CONCLUSIONS: CR, AR, and AS had a distinct composition of urine EVs. Urine EVs could be an indicator for assessing allergic airway diseases in children.

Proteomic analysis of uropathogenic Escherichia coli.

Urinary tract infections (UTIs) are among the most common of bacterial infections in humans. Although a number of Gram-negative bacteria can cause UTIs, most cases are due to infection by uropathogenic E. coli (UPEC). Genomic studies have shown that UPEC encode a number of specialized activities that allow the bacteria to initiate and maintain infections in the environment of the urinary tract. Proteomic analyses have complemented the genomic data and have documented differential patterns of protein synthesis for bacteria growing ex vivo in human urine or recovered directly from the urinary tracts of infected mice. These studies provide valuable insights into the molecular basis of UPEC pathogenesis and have aided the identification of putative vaccine targets. Despite the substantial progress that has been achieved, many future challenges remain in the application of proteomics to provide a comprehensive view of bacterial pathogenesis in both acute and chronic UTIs.

Decreased intravesical adenosine triphosphate in patients with refractory detrusor overactivity and bacteriuria.

PURPOSE: Although several studies have examined the relationship between adenosine triphosphate release from the urothelium and bladder sensations including painful filling and urgency, the association between bacteriuria and urothelial adenosine triphosphate release has not been well studied. We evaluated women with refractory detrusor overactivity who were experiencing an acute exacerbation of detrusor overactivity symptoms including frequency, urgency and nocturia (and/or urge incontinence). We measured changes in intravesical adenosine triphosphate levels in these women with and without bacteriuria. MATERIALS AND METHODS: In this prospective cohort study women with refractory detrusor overactivity were invited to our unit during acute symptomatic exacerbation. On presentation a catheter urine specimen was collected and 50 ml normal saline instilled into the bladder to evoke gentle stretch, with removal after 5 minutes. Adenosine triphosphate concentrations were determined on fresh washings using a bioluminescence assay. RESULTS: The incidence of bacteriuria 10(3) cfu/ml or greater was 27% (15 of 56 specimens) during the 16-month study period. Adenosine triphosphate concentrations were lower during episodes of bacteriuria in the overall cohort (p = 0.0013) and paired samples from individual patients (p = 0.031) compared to episodes of sterile urine. CONCLUSIONS: In the first study on the subject to our knowledge, we demonstrated a striking difference between adenosine triphosphate levels measured in the presence and absence of bacteriuria in this patient group.

Asymptomatic bacteriuria among the elderly residents of long-term care facilities in Taiwan.

BACKGROUND: asymptomatic bacteriuria (ASB) is common among the institutionalised elderly (IE). The cytokine levels and factors associated with ASB are unknown. OBJECTIVE: to analyse cytokines and factors associated with ASB among the IE living in long-term care facilities (LTCFs) in Taiwan. METHODS: this case-control study included residents ≥65 years in two LTCFs. The demographics, functional status, serum and urine levels of cytokines and proteins were compared between IE with ASB and those with sterile urine. Logistic regression was used to determine the factors associated with ASB. RESULTS: the IE with ASB had elevated IL-8 in blood and urine compared with the IE with sterile urine. The Barthel index score, serum creatinine, blood IL-8 and tumour necrosis factor-α levels were significant factors associated with ASB among the IE [odds ratio (OR) 0.957, 95% CI: 0.936-0.979, P < 0.0001; OR: 0.264, 95% CI: 0.076-0.912, P = 0.035 and OR: 1.088, 95% CI: 1.022-1.158, P = 0.009; OR: 0.828, 95% CI: 0.711-0.965, P = 0.016, respectively). CONCLUSION: functional status, renal function and blood cytokine levels were factors significantly associated with ASB among the IE living in Taiwan.

Comparison of Escherichia coli uropathogenic genes (kps, usp and ireA) and enteroaggregative genes (aggR and aap) via multiplex polymerase chain reaction from suprapubic urine specimens of young children with fever.

OBJECTIVE: Escherichia coli is the most frequently identified microbiological agent in childhood urinary tract infections (UTIs). However, the pathogenic role of this organism in young children remains to be clearly elucidated. So far, no studies have been conducted in which multiplex polymerase chain reaction (PCR) has been applied to determine the association between childhood UTIs and E. coli and urovirulent genes. MATERIAL AND METHODS: Altogether, 330 suprapubic urine specimens from febrile young children were cultured. In 33 of the cases, E. coli was identified; among these cases, 18 had a UTI (>10(4)-10(5) cfu/ml), four had a suspected UTI (>10(2)-10(3) cfu/ml) and 11 did not have UTIs (10(2) cfu/ml). Using multiplex PCR, three uropathogenic E. coli (UPEC) genes and two enteroaggregative E. coli (EAEC) genes were detected. RESULTS: In the UTI-UPEC cases, the kps gene was detected in 18 of 22 cases (82%) and the usp gene in 16 of 22 cases (73%). Among the 18 cases of children with UTIs characterized by 10(4)-10(5) E. coli cfu/ml, urinary tract abnormalities were identified via dimercaptosuccinic acid scans in seven of 18 cases (39%) and via voiding cystourethrograms in four of the 18 cases (22%). CONCLUSIONS: The UPEC kps and usp genes were clearly associated with childhood UTIs, and may also be associated with kidney or urinary tract dysfunctions in young children. Escherichia coli colony count numbers in excess of 10(4)-10(5) cfu/ml in the suprapubic urine were considered to be strong evidence of UTI in infants.

The asymptomatic bacteriuria Escherichia coli strain 83972 outcompetes uropathogenic E. coli strains in human urine.

Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU). In contrast to uropathogenic E. coli (UPEC), which causes symptomatic urinary tract infections (UTI), very little is known about the mechanisms by which these strains colonize the human urinary tract. The prototype ABU E. coli strain 83972 was originally isolated from a girl who had carried it asymptomatically for 3 years. Deliberate colonization of UTI-susceptible individuals with E. coli 83972 has been used successfully as an alternative approach for the treatment of patients who are refractory to conventional therapy. Colonization with strain 83972 appears to prevent infection with UPEC strains in such patients despite the fact that this strain is unable to express the primary adhesins involved in UTI, viz. P and type 1 fimbriae. Here we investigated the growth characteristics of E. coli 83972 in human urine and show that it can outcompete a representative spectrum of UPEC strains for growth in urine. The unique ability of ABU E. coli 83972 to outcompete UPEC in urine was also demonstrated in a murine model of human UTI, confirming the selective advantage over UPEC in vivo. Comparison of global gene expression profiles of E. coli 83972 grown in lab medium and human urine revealed significant differences in expression levels in the two media; significant down-regulation of genes encoding virulence factors such as hemolysin, lipid A, and capsular polysaccharides was observed in cells grown in urine. Clearly, divergent abilities of ABU E. coli and UPEC to exploit human urine as a niche for persistence and survival suggest that these key differences may be exploited for preventative and/or therapeutic approaches.

Molecular characterization of the Escherichia coli asymptomatic bacteriuria strain 83972: the taming of a pathogen.

Escherichia coli 83972 is a clinical asymptomatia bacteriuric isolate that is able to colonize the human urinary bladder without inducing an immune response. Here we demonstrate that one of the mechanisms by which this strain has become attenuated is through the mutation of its genes encoding type 1 and P fimbriae.

Bacteriuria detection with a urine dipstick applied to incontinence pads of nursing home residents.

The purpose of this study was to evaluate a new method of initial on-site evaluation of bacteriuria in an incontinent nursing home population. Nitrite and a composite of nitrite and/or leukocyte esterase results of the new method were compared with clean-catch urine culture results of each participant to determine sensitivity, specificity, positive and negative predictive values, and efficiency. These findings were compared with results of the traditional dipstick urinalysis for bacteriuria assessment. The new method was as effective as the traditional method in assessing both the presence and absence of bacteriuria. Results of this study indicate the new dipstick/pad method may assist in the assessment of bacteriuria in incontinent nursing home residents.

Visualization of Proteus mirabilis within the matrix of urease-induced bladder stones during experimental urinary tract infection.

The virulence of a urease-negative mutant of uropathogenic Proteus mirabilis and its wild-type parent strain was assessed by using a CBA mouse model of catheterized urinary tract infection. Overall, catheterized mice were significantly more susceptible than uncatheterized mice to infection by wild-type P. mirabilis. At a high inoculum, the urease-negative mutant successfully colonized bladders of catheterized mice but did not cause urolithiasis and was still severely attenuated in its ability to ascend to kidneys. Using confocal laser scanning microscopy and scanning electron microscopy, we demonstrated the presence of P. mirabilis within the urease-induced stone matrix. Alizarin red S staining was used to detect calcium-containing deposits in bladder and kidney tissues of P. mirabilis-infected mice.

Energy expenditure and nutritional adequacy of rehabilitation paraplegics with asymptomatic bacteriuria and pressure sores.

OBJECTIVE: To measure resting energy expenditure (REE) in a group of people with postacute paraplegia, quantify the impact of asymptomatic bacteriuria and pressure sore(s) on patients' metabolic rate, and estimate the adequacy of patients' nutritional intakes to preserve patients' protein levels. MATERIAL AND METHODS: Ten males with post-acute paraplegia aged 42.1+/-18.7 years. We evaluated: height, body mass index (BMI), resting energy expenditure (REE), total daily calorie requirement (E), 24-h urine creatinine excretion (Cru), creatinine index (CI), and nitrogen balance (NB). RESULTS: Subjects with paraplegia showed high erythrocyte sedimentation rates. As a group, they had normal resting calorie consumption when REE was normalized for unit of urine creatinine (REE/Cru), it was higher in patients than in controls. Six of the 10 patients had a low calorie intake: of these only three had a negative nitrogen balance. CONCLUSION: In conclusion, the resting energy expenditure of the subjects with significant bacteriuria and pressure sore(s) of 23.7 kcal/kg/day suggests that a large portion of patients may have an inadequate calorie protein intake to preserve their nutritional status. The clinical significance of this study is that 28.5 kcal/kg/day may be the lower calorie threshold to meet the metabolic demands of people with apyretic paraplegia with bacteriuria and pressure sore(s).

Cytokine secretion is impaired in women with diabetes mellitus.

BACKGROUND: As women with diabetes mellitus (DM) have an increased prevalence of asymptomatic bacteriuria (ASB) and it is known that a correlation exists between the increased prevalence of genitourinary tract infection and impaired cytokine production in women infected with Human Immunodeficiency Virus (HIV), we studied urinary cytokine excretion in diabetic women and compared it with that of nondiabetic controls. MATERIALS AND METHODS: To evaluate the cytokine secretion capacity of women with DM, both whole blood and isolated monocytes of women with and without DM were stimulated in vitro with lipopolysaccharide (LPS). RESULTS: Lower urinary interleukin-8 (IL-8) and interleukin-6 (IL-6) concentrations (P = 0.1 and P < 0.001, respectively) were found in diabetic women than in nondiabetic controls. A lower urinary leukocyte cell count correlated with lower urinary IL-8 and IL-6 concentrations (P < 0.05). Lower tumour necrosis factor-alpha (TNF-alpha) and IL-6, but comparable interleukin-10 (IL-10) concentrations were found in whole blood (P < 0.04) and isolated monocytes (P = 0.03) of women with DM type 1 compared to women without DM. CONCLUSIONS: Diabetic women with ASB have lower urinary IL-6 concentrations than nondiabetic bacteriuric controls. In addition, monocytes of women with DM type 1 secrete lower pro-inflammatory cytokines after stimulation with LPS than monocytes of women without DM. This is not due to an inhibitory effect of the anti-inflammatory cytokine IL-10. This can have important consequences for both host defense, endothelial cell functioning and atherogenesis.

Interleukin (IL)-6 and IL-8 in children with febrile urinary tract infection and asymptomatic bacteriuria.

Urine and serum interleukin (IL)-6 and IL-8 responses were higher in children with febrile urinary tract infection (n = 61) than in those with asymptomatic bacteriuria (n = 39). By univariate analysis, cytokine levels were related to age, sex, reflux, renal scarring, urine leukocytes, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and bacterial properties (P fimbriae but not hemolysin). Multivariate modeling showed that urine IL-6 responses were higher in girls than boys, increased with age, and were positively associated with CRP, ESR, serum IL-6, and urine leukocyte counts. The urine IL-8 response was not influenced by age, but it was influenced by P fimbriae and was associated with ESR, CRP, urine leukocytes, and female sex. The results show that cytokine responses to urinary tract infection vary with the severity of infection and that cytokine activation is influenced by a variety of host and bacterial variables.

Urinary pH and urea concentration correlate to the bacterial colonization rate in gastric, colonic, ileal and myoperitoneal bladder augmentation.

We investigated how various types of augmentation cystoplasty alter the native bacteriostatic properties of urine, particularly urinary urea and pH, in the Sprague-Dawley rat. The augmentation cystoplasties studied included 1 cm.2 and 2 cm.2 patches of colon, ileum and stomach as well as myoperitoneal bladder flaps. Augmentations in order of decreasing incidence of bacteriuria and urinary pH are 2 cm.2 ileal greater than 1 cm.2 ileal greater than 2 cm.2 colonic greater than 1 cm.2 colonic greater than myoperitoneal greater than cystotomy alone greater than 1 cm.2 gastric greater than 2 cm.2 gastric. Urinary urea concentrations were similar between cystotomy alone, and myoperitoneal and gastric augments. In contrast, all colonic and ileal augments had significantly lower urea concentrations compared to the aforementioned groups. Our findings suggest that the type and size of augmentation directly affect urinary pH and urea nitrogen concentration, and the incidence of bacteriuria.

Antibiotic-induced release of endotoxin in chronically bacteriuric patients.

A novel in vivo model for the study of antibiotic-induced release of endotoxin from gram-negative bacteria is described. The model uses the chronically colonized urinary tracts of patients whose spinal cords have been injured. At baseline, the organisms were present in the range of 1 x 10(3) to 2 x 10(7) CFU/ml, and the concentration of endotoxin ranged from 2 x 10(-1) to 1 x 10(3) ng/ml in 44 studies. In 10 control studies, the concentration of endotoxin and the numbers of viable gram-negative bacteria over time changed by an average of less than 0.15 log10 units from the baseline values. At 2 h after antibiotic administration, the average decrease in CFU was 0.93 log10 units, and because antibiotics cause the release of endotoxin, an average increase in endotoxin concentration of 0.59 log10 units was noted in 21 studies with susceptible bacteria. Similar changes in response to antibiotic exposure were seen in studies with susceptible Pseudomonas bacteria in comparison with those seen in studies with susceptible members of the family Enterobacteriaceae. These results provide evidence that this novel model may be useful for comparing the effects of antibiotics with different modes of action, both as single agents and in combination, on the concentration of endotoxin in relation to changes in the numbers of bacteria, under conditions of bacterial replication and antibiotic exposure more closely resembling those found in vivo than is possible in other models.

The nitroblue tetrazolium test in the estimation of urinary and serum leukocyte metabolism in urinary infections. A preliminary note.

For the study of leukocyte metabolism in the serum and the urine from 52 patients with urinary infections, the Nitroblue Tetrazolium (NBT) test was used for a qualitative estimation of leukocyturia. It was observed that 26 of the 52 patients (50%) presented higher values of NBT positive urinary neutrophils than in the control group. The NBT test might be useful in the estimation of the cellular immune response in the course of urinary infections.

Determination of in vivo concentration-time profiles of chlorhexidine and noxythiolin bladder irrigations.

The in vivo concentration-time profiles of chlorhexidine and noxythiolin bladder irrigations were determined by utilizing high-performance liquid chromatography techniques following a once daily irrigation. A total of 14 chlorhexidine irrigations established a mean concentration of 0.006% w/v, 2-3 h post irrigation. A total of 12 noxythiolin irrigations established a mean concentration of 0.266% w/v, 2-3 h post irrigation, which correlated to a mean formaldehyde concentration of 0.0119% w/v at 2-3 h, as estimated from N-methylthiourea. For both solutions the minimum inhibitory concentration was exceeded for up to 5 h post irrigation, which is sufficient contact time to establish a total kill, thus indicating the possibility that a once daily irrigation may be appropriate in asymptomatic bacteriuria which utilizes either chlorhexidine or noxythiolin.

Renal clearance of fluoride in children and adolescents.

Renal function and fluoride excretion have been studied in 38 children. The children were divided into three groups according to their glomerular filtration rate: normal (92 to 136 mL/min/1.73 m2 of body surface area [BSA]), low (less than 92 mL/min/1.73 m2 BSA, and super-normal (greater than 136 mL/min/1.73 m2 BSA). Standard clearance technique with infusion of inulin and p-aminohippuric acid during water diuresis was used. Mean renal fluoride clearance was 45.0 +/- 9.8 (SD) mL/min in the group of children with normal glomerular filtration rates and 31.4 +/- 8.8 mL/min in the group with low glomerular filtration rates. This difference was statistically significant. There was a close linear relationship between renal fluoride clearance and glomerular filtration rate, urinary flow, and free water clearance. The fractional fluoride excretion did not differ between the groups. About 60% of the filtered fluoride was reabsorbed. No evidence for tubular secretion exceeding the reabsorption could be found. The results suggest that children have lower renal fluoride clearance rates than adults and indicate that a moderate impairment of the renal function could lead to increased retention of fluoride.