Bacterial Growth In Urine Research Articles

Daily and Weekly Urine Variations in Bacterial Growth Susceptibility in Postmenopausal Women With no History of Urinary Tract Infection: A Pilot Study

ObjectivesTo evaluate bacterial growth in the bladder as a major virulence factor during urinary tract infections (UTIs), we assessed the variability of uropathogenic bacterial growth in urine samples over multiple timepoints from three postmenopausal women with no history of UTI. MethodsFollowing IRB approval, postmenopausal women who never had a UTI provided mid-stream urine samples three times daily (8 a.m., 12 p.m. and 4 p.m.), twice a week over two weeks, as well as dietary intake logs. Each sample was studied for pH and bacterial growth using three uropathogenic Escherichia coli (E.coli) strains (LRPF007, KE40, UTI89), one uropathogenic Enterococcus faecalis strain (HRH40), and one non-pathogenic E. coli strain (W3110). ResultsSimilar mean growth yields were observed for the uropathogenic strains (mean ∆OD600 = 0.1 – 0.13) with high variability (standard deviation (SD) = 0.13 – 0.28) and lower mean growth for the non-pathogenic strain (mean ∆OD600 = 0.05). Urine from each individual at different collection times never had the same bacterial growth potential for any bacterial strain. There were significant associations between urine pH decrease with higher fat (p=0.017), vitamin D (p=0.02), magnesium (p=0.049), fluid (p=0.013), and ash (p=0.01) intake. ConclusionsMajor variations were observed in the bacterial growth response in the urine of the same individuals. These variations imply a requirement for a normalization procedure, e.g., growth in synthetic urine, for analysis of bacterial growth in urine. There were significant associations between decreased urine pH and several nutrients found in foods that are classified as highly acidic.

Bacterial Growth of Uropathogenic Escherichia coli in Pooled Urine Is Much Higher than Predicted from the Average Growth in Individual Urine Samples.

ABSTRACTUrinary tract infections (UTIs), mostly caused by uropathogenic E. coli (UPEC), affect most women, and often recur. Genomic and transcriptomic analyses have not identified a common set of virulence genes, which has suggested complex host-pathogen interactions and multiple virulence mechanisms. One aspect of the host-pathogen interaction is rapid UPEC growth in urine in vivo. When bacterial growth in urine is studied in vitro, urine is pooled, which is assumed to diminish individual variation. We grew one nonpathogenic and two pathogenic E. coli strains in urine from individuals who never had a UTI, had a UTI history but no current infection, and had a UTI history with a current infection. Bacterial growth showed large variations in individual urine samples, and pooled urine often supported significantly more growth than the average growth from individual urine samples. Total nutrient content tended to be higher in current group urine samples than the never and history grouped samples urine. We propose that pooling optimizes a nutrient mixture in the never and history group urine samples, which are often studied, whereas urine from current group individuals may have a more optimal nutrient mixture because of additional nutrient sources. We conclude that a pooled urine is not “an average urine sample,” and that the best comparisons of results between labs using pooled urine would also include results with a standardized synthetic urine.IMPORTANCE Urinary tract infections (UTIs) will affect most women, can recur especially in postmenopausal women, and can become antibiotic recalcitrant. Escherichia coli causes most community-acquired UTIs and recurrent UTIs. Current theories of virulence, based on studies of UTI-associated E. coli, propose multiple virulence mechanisms and complex host-pathogen interactions. Studies of bacterial growth in urine samples—one aspect of the host-pathogen interaction—invariably involve pooled urine that are assumed to eliminate variations between individuals. Our results show that a pooled urine is not necessarily an average urine sample, and we suggest that quantitative and qualitative variations in nutrient content are the basis for this discrepancy. Knowledge of growth-promoting urinary components is important for understanding host-pathogen interactions during UTIs and could contribute to developing nonantibiotic-based therapies.

Urine influences growth and virulence gene expressions in Uropathogenic E. coli: a comparison with nutrient limited medium

Objective. The interactions between environmental factors and microbial biological process are well known. Urine has been selected to provide host conditions probably affecting bacterial growth and gene expressions. The aim of this study was to detect the modulations of growth and gene expressions [sfa/foc, cnf1, usp and aer] of UPEC in urine by comparing the results with serum supplemented Standart American Petroleum Institute medium which is defined as host-like medium. Methods. UPECs were incubated 37°C and growth alterations were detected by measuring the changes in the absorbance at 600 nm in four-,six- and 24 hours periods. Gene expression levels were analysed by quantitative polymerase chain reaction (qPCR). Statistical analysis of fold changes in gene expression values and growths were calculated using one-way ANOVA Tukey's post hoc test. Results. The increase of bacterial growth in urine was found to be statistically significant (p<0.0001). The alterations of aer and sfa/foc expression levels were statistically significant (p<0.001); whereas the expression levels of cnf1 and usp genes were not altered (p>0.05). Conclusion. According to our results, urine as an environment in vivo affected both the growth and gene expression in UPEC.

Characteristics associated with bacterial growth in urine in 451 proteinuric dogs (2008-2018).

BackgroundUrine cultures are frequently recommended to rule out infection as a postrenal cause of proteinuria.ObjectiveIdentify characteristics associated with bacterial growth in urine in proteinuric dogs.AnimalsFour hundred and fifty‐one dogs admitted to a teaching hospital between January 2008 and January 2018 with urine protein‐to‐creatinine ratios (UPCs) >0.5.MethodsRetrospective study included dogs with a UPC, urinalysis, and quantitative urine culture (QUC) performed within a 72‐hour period by searching electronic records. Dogs with recent antimicrobial therapy, urine collected by methods other than cystocentesis, or UPC ≤0.5 were excluded. Signalment, comorbidities, serum BUN and creatinine concentrations, urinalysis findings, and QUC results were recorded. The association between these characteristics and presence of bacterial growth in urine was assessed by univariable and multivariable analysis.ResultsThirty of four hundred fifty‐one dogs (6.7%) had bacterial growth in urine. Of these, 18 (60.0%) had active urine sediment. Bacterial growth in urine was associated with pyuria (odd ratio [OR] 25.1, 95% confidence interval [CI] 7.9‐79.6, P < .001), bacteriuria (OR 11.1, 95% CI 3.2‐39.1, P < .001), and lower urinary tract disease (OR 6.7, 95% CI 1.9‐23.0; P = .0028). If QUC was prompted based on these criteria, 8/451 (1.8%) of proteinuric dogs would have had undetected bacterial growth.Conclusions and Clinical ImportanceThe proportion of proteinuric dogs with both inactive urine sediment and bacterial growth in urine was low, suggesting that QUC might not be necessary in the evaluation of all proteinuric dogs. An active urine sediment or lower urinary tract disease should prompt QUC for proteinuric dogs.

Reduction of bacterial growth in urine after an ayurvedic treatment protocol – A case report

Reduction of bacterial growth in urine after an ayurvedic treatment protocol – A case report

1989. Evaluation of Laser Light Scattering Technology in Rapid Diagnosis of Urinary Tract Infections in Children

BackgroundUrinalysis (UA) has been routinely used as a screening tool prior to microbial culture set-up in many laboratories. BacterioScan 216Dx instrument utilizes laser light scattering technology to detect bacterial growth in urine and results are available in 3 hours. The aim of this study was to compare the performance of 216 DX and UA against culture as gold standard.MethodsClean-catch, unpreserved, either UA positive (leukocyte esterase > trace, or nitrite positive or white blood cells >5/hpf) or UA negative samples from children aged ≤18 years were tested by 216Dx within 24 hours of sample collection. “ Likely positive” samples by 216Dx were tested by MALDI-TOF for direct bacterial identification. Sensitivity and specificity of 216Dx and UA was determined against urine culture.ResultsTotal of 205 urine samples were included in this study, of which 48.0% (98/205) and 52.0% (107/205) were UA positive and negative, respectively. 77.0% of samples were collected from female and median age was 108 months. Overall sensitivity, specificity, positive, and negative predictive value (PPV and NPV) of 216Dx and UA are shown in table below. Of 27 true positive (TP) samples by 216Dx, 77.0% (21/27) were successfully identified by MALDI-TOF. There were a total of 96 samples identified as contamination/normal flora by culture. Among these, 63 samples (65.0%) were detected as true negative (TN) by 216Dx vs. 50 samples (53.1%) as TN by UA. Two false negative (FN) samples by 216Dx and one FN by UA were K. oxytoca, S. epidermidis (both >100 K cfu/ml) and E. coli (>100 K cfu/mL), respectively.ConclusionAlthough sensitivity of both 216Dx and UA is comparable, specificity of 216Dx was higher than UA. Also, 216Dx showed better performance in detecting urine contamination, thus reducing laboratory reagent and labor cost. Faster turn-around-time of 216Dx coupled with rapid identification of uropathogen by MALDI-TOF has the potential to reduce unnecessary antibiotic use, improve patient management and reduce overall healthcare-related cost.AssayTPFPTNFN%Sensitivity (95% CI)%Specificity (95% CI)%PPV (95% CI)%NPV (95% CI)216Dx2736140293.1 (75.7–98.8)79.5 (72.6.0-85.1)42.8 (30.6–55.9)98.6 (94.4–99.7)UA2870106196.5 (80.3–99.8)60.2 (52.5–67.4)28.5 (20.1–38.7)99.0 (94.1–99.9)Disclosures All authors: No reported disclosures.

The Basics of Bacteriuria: Strategies of Microbes for Persistence in Urine.

Bacteriuria, the presence of bacteria in urine, is associated with asymptomatic, as well as symptomatic, urinary tract infection (UTI). Bacteriuria underpins some of the dynamics of microbial colonization of the urinary tract, and probably impacts the progression and persistence of infection in some individuals. Recent molecular discoveries in vitro have elucidated how some key bacterial traits can enable organisms to survive and grow in human urine as a means of microbial fitness adaptation for UTI. Several microbial characteristics that confer bacteruric potential have been identified including de novo synthesis of guanine, relative resistance to D-serine, and catabolism of malic acid. Microbial characteristics such as these are increasingly being defined through the use of synthetic human urine (SHU) in vitro as a model to mimic the in vivo environment that bacteria encounter in the bladder. There is considerable variation in the SHU model systems that have been used to study bacteriuria to date, and this influences the utility of these models. In this review, we discuss recent advances in our understanding of bacteruric potential with a focus on the specific mechanisms underlying traits that promote the growth of bacteria in urine. We also review the application of SHU in research studies modeling UTI and discuss the chemical makeup, and benefits and limitations that are encountered in utilizing SHU to study bacterial growth in urine in vitro.

Implication of Low Bacteria Counts with UTI in Infants

Urine specimens for diagnosis of urinary tract infection (UTI) in infants are often difficult to obtain and interpret. Classic definitions of UTI require ≥100,000 colony-forming units (CFU)/mL of a single bacterial organism, although recent recommendations accept fewer bacteria, and any bacterial growth in urine collected by suprapubic aspiration (SPA) is often accepted as diagnostic. In …

Restoring the glycosaminoglycans layer in recurrent cystitis: Experimental and clinical foundations

Restoring the bladder glycosaminoglycans layer has recently been introduced as prophylactic treatment for recurrent urinary tract infections. Herein, we analyze the latest main clinical and experimental studies to support this therapeutic option. An electronic research was carried out in the most common databases in order to identify any published studies. Retrieved studies were categorized as experimental or clinical according to their setting. For the clinical studies, the evidence level was assigned. A total of 13 laboratory studies showed how bladder glycosaminoglycans instillations act: attenuation of the inflammation process, reduction of bladder contraction amplitude and frequency, reduction of epithelium damage, and lower bacterial growth in urine and tissue samples. Likewise, two randomized clinical trials with grade 2 evidence level and two case series with grade 4 evidence level reported glycosaminoglycans as an alternative to reduce episodes and to prolong recurrence time in patients with recurrent urinary tract infections. At least 12 months of follow up was completed. No serious adverse events were reported. Compared with a placebo, in one randomized study a significantly higher maximum cystometric capacity was obtained, whereas in the other study a significant increase in quality of life scores was reported too. An improvement in the urinary symptoms score was reported by the two randomized trials. Although the clinical use of glycosaminoglycans replacement therapy for recurrent urinary tract infections is supported by a small number of clinical studies with different evidence levels, the laboratory studies show that glycosaminoglycans could have a protective role against inflammatory factors, supporting the idea "to restore the glycosaminoglycans bladder layer to prevent chronic disease course".

Effect of ingesting cranberry juice on bacterial growth in urine

Cranberry juice has been shown to have a significant effect in preventing urinary tract infections (UTIs) in a number of clinical trials.[1][1]–[5][2] This property of cranberry juice has been attributed to an ability to inhibit bacterial adherence to cells[6][3],[7][4] and possibly its urine

Intravesical Nitric Oxide Delivery for Prevention of Catheter-Associated Urinary Tract Infections

The use of indwelling urinary catheters is a major risk factor for urinary tract infection; and despite the availability of numerous preventive regimens, this condition is still extremely common. In earlier studies we have demonstrated the inhibitory effects of nitrite and ascorbic acid on bacterial growth in urine. When combined, these compounds generate antibacterial reactive nitrogen species, including the gas nitric oxide. We have now tested in a laboratory model of the urinary bladder whether filling of the catheter retention balloon with nitrite and ascorbic acid would generate measurable amounts of NO outside the membrane and whether this would affect bacterial growth in the surrounding urine. Two strains of Escherichia coli, one strain isolated from a patient (U1106024) and one reference strain (ATCC 25922), were tested. Nitric oxide gas was generated in the silicone balloon and readily diffused into the urine. When control catheters with ascorbic acid but without nitrite were used, bacterial counts increased from 9.0 x 10(5) to 2.0 x10(8) CFU/ml (strain U1106024) and from 2.5 x 10(6) to 2.7 x 10(8) CFU/ml (strain ATCC 25922) after 24 h. In contrast, in test catheters with ascorbic acid and nitrite, both strains tested were effectively killed. The NO donor {DETA NONOate, (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate} also showed antibacterial activity in the same model, thereby supporting a central role of NO in achieving the observed effects. Future clinical trials will reveal whether this novel approach for the intravesical delivery of an antibacterial gas could be used to prevent catheter-associated infections.

IMPACT OF POST-EJACULATORY PAIN IN MEN WITH CATEGORY III CHRONIC PROSTATITIS/CHRONIC PELVIC PAIN SYNDROME

Chronic Pelvic Pain Syndrome (CPPS) is a common debilitating condition in which ejaculation relieves symptoms for some but exacerbates them in others. We studied ejaculatory pain in a cohort with CPPS to investigate associations with symptoms, quality of life and risk factors. The 486 men in the National Institutes of Health Chronic Prostatitis Cohort study were stratified into 4 subgroups according to the presence of ejaculatory pain at baseline visit and at each of 3 monthly followup contacts. Subgroups were based on answers and labeled NO (always "no"), Nvar ("no" at baseline but "yes" or missing at least once), Yvar ("yes" at baseline but "no" or missing at least once) and YES (always "yes"). Demographic and quality of life data were obtained at baseline, together with medical and sexual history, symptoms, and cultures and microscopy of urine and seminal fluids. Associations among selected baseline risk factors, symptoms and post-ejaculatory pain were analyzed. Overall 128 men were classified as NO, 106 as Nvar, 137 as Yvar and 115 as YES. There was a progressive increase in baseline National Institutes of Health-Chronic Prostatitis Symptom Index total score (modified to exclude post-ejaculatory pain) from 18.5 for the NO subgroup to 25.5 for the YES subgroup (p <0.0001). Mental and physical quality of life were also progressively lower from the NO to the YES subgroup (p <0.001). There were no significant differences in white blood cell count or bacterial growth in urine, prostate fluid or semen among subgroups. Men in the YES subgroup were younger, more likely to live alone, had lower income and a greater variety of sexual practices than those without ejaculatory pain (NO subgroup). Patients with CPPS and persistent ejaculatory pain have more severe symptoms, are less likely to improve with time, and have differences in demographic and sexual history compared to other patients with CPPS.

Effects of pH, Nitrite, and Ascorbic Acid on Nonenzymatic Nitric Oxide Generation and Bacterial Growth in Urine

Nitrite may be generated by bacteria in urine during urinary tract infections. Acidification of nitrite results in the formation of nitric oxide (NO) and other reactive nitrogen oxides, which are toxic to a variety of microorganisms. We have studied NO formation and bacterial growth in mildly acidified human urine containing nitrite and the reducing agent vitamin C. Urine collected from healthy subjects was incubated in closed syringes at different pH values with varying amounts of nitrite and/or ascorbic acid added. NO generation was measured in headspace gas using a chemiluminescence technique. A similar setup was also used to study the growth of three strains of bacteria in urine. Mildly acidified nitrite-containing urine generated large amounts of NO and this production was greatly potentiated by ascorbic acid. The growth of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus saprophyticus was markedly reduced by the addition of nitrite to acidified urine. This inhibition was enhanced by ascorbic acid. In conclusion, we show that the growth of three common urinary pathogens is markedly inhibited in mildly acidified urine when nitrite is present. The bacteriostatic effect of acidified nitrite is likely related to the release of NO and other toxic reactive nitrogen intermediates. These results may help to explain the well-known beneficial effects of urinary acidification with, e.g., vitamin C in treatment and prevention of urinary tract infection.

Inhibitors of bacterial growth in urine: what is the role of betaines?

It has long been recognised that some individuals produce urine that is inhibitory to uropathogens. This may be partly explained by inhibitors. Several inhibitors have been identified in urine including urea and organic acids. Bacteria adapt to high osmolarity by activating osmoregulated betaine porters and accumulating organic osmolytes intracellularly. The preferred substrate is glycine betaine, which is present in urine, and promotes rapid growth by balancing osmotic forces and stabilising macromolecular structures against the toxicity of urea and low pH. Other dietary betaines such as trigonelline may also be taken but enhance urea toxicity. The importance of such compounds in vivo is unknown.

The Effect of Iontophoresis on Bacterial Growth in Urine

The Effect of Iontophoresis on Bacterial Growth in Urine

The Effect of Iontophoresis on Bacterial Growth in Urine

Purpose To determine the effect of iontophoresis (electrical current for therapeutic purposes) on the growth of pathogenic bacteria in human urine. Materials and Methods Pathogenic bacteria were isolated and inoculated into a dynamic in vitro artificial bladder model. Pooled sterile human urine was regulated through the artificial bladder by intravenous tubing and pumps to simulate filling and emptying of the human bladder. The effect of electrical current on bacterial growth in the system was then studied. Results When iontophoresis is applied at low bacterial concentrations (less than 10 8 colony forming units [CFU]/l.), inhibition of bacterial growth occurs. However, when iontophoresis is applied after fulminant growth of bacteria (greater than 10 8 CFU/l.), no inhibition of bacterial growth occurs. Iontophoresis was not found to enhance the antibacterial action of gentamicin to resistant Pseudomonas aeruginosa. Conclusions Iontophoresis inhibits bacterial growth at low bacterial concentrations. It does not inhibit bacterial growth after infectious levels have been attained, and it does not potentiate the action of gentamicin on resistant Pseudomonas aeruginosa.

Suppression of bacterial growth and ammonia formation by citrate buffer in urine collected in ileal loop receptacles

Bacterial growth in urine collected in ileal loop receptacles is greatly suppressed by the presence of 5 to 10 ml. 1-M. citrate buffer, pH 4. The suppression of bacterial growth by the citrate buffer prevents the formation of ammonia and perhaps other noxious metabolites which are believed responsible for the irritation and inflammation of the skin exposed to infected urine. The citrate buffer is placed in the ileal loop receptacle at the beginning of each urine collection period.

The in vitro effect of ascorbic acid on the bacterial growth in urine.

The in vitro effect of ascorbic acid on the bacterial growth in urine.

The cellular content in non-timed specimens of urine.

Abstract The present investigation is a report on the cellular content in non‐timed midstream specimens of urine from 643 ambulant males and females and was performed in connection with an examination of blood pressure in the population of Bergen, Norway. Special regard was paid to the influence of the specific gravity of the urine and to bacteriuria (including bacterial contamination: &lt; 104 bacteria/ml).Specimens from males and females without previous urinary tract disorders contained ≤ 7–8 non‐disrupted erythrocytes/mm3 in approximately 95% of the cases, and this value was therefore assumed to be a suitable upper limit for “normal” counts in routine work. The number of erythrocytes was found to be lower in specimens at specific gravities below about 1.010 than above, hypotonic haemolysis being the probable cause of the difference.Correspondingly, ≤ 13 leucocytes + non‐squamous epithelial cells/mm3 were found in approximately 95% of the sterile specimens from males and females without previous urinary tract disorders. Sterile specimens from females did not contain more cells than specimens from males, but specimens with bacterial contamination contained slightly greater numbers of cells than sterile specimens. In males greater numbers of leucocytes + nonsquamous epithelial cells were recorded in specimens at high than at lower specific gravities; in females high cell counts were most frequently observed at the lower specific gravities. Less than 10 leucocytes + non‐squamous epithelial cells were recorded in about half of the specimens from individuals with bacteriuria. A definite borderline between normal and pathological counts can therefore not be established.In females bacteriuria at the level 104–105 bacteria/ml was most often observed in specimens at specific gravities ≥ 1.019. An inhibitory effect on bacterial growth in urine of high specific gravity is suggested.

Cranberry juice and the antibacterial action of hippuric acid.

Abstract Cranberry juice, given in maximal tolerable amounts to normal subjects, increases the acidity of the urine slightly and increases the hippuric acid content of the urine by several grams a day. Hippuric acid, in concentrations of 0.02 – 0.04 M, is bacteriostatic at pH 5.0 for the common pathogens of the urinary tract, and its activity decreases about fivefold as the pH is raised to 5.6. Only occasionally does cranberry juice contribute enough hippuric acid to the urine to achieve concentrations which are bacteriostatic at pH 5.O. Hippuric acid, in doses of 12 to 14 Gm. per day, usually lowers the pH of the urine to 5.2 or less, and is excreted in sufficient concentration to induce inhibition of bacterial growth in urine at this pH. The data suggest that the use of hippuric acid as a urinary antiseptic deserves further study.