Molecular epidemiology of Proteus mirabilis infections of the catheterized urinary tract

Proteus mirabilis compromises the care of many patients undergoing long-term indwelling bladder catheterization. It forms crystalline bacterial biofilms in catheters which block the flow of urine, causing either incontinence due to leakage or painful distention of the bladder due to urinary retention. If it is not dealt with, catheter blockage can lead to pyelonephritis and septicemia. We have examined the epidemiology of catheter-associated P. mirabilis infections by use of pulsed-field gel electrophoresis (PFGE) of NotI restriction enzyme digests of bacterial DNA. This technique was shown to be more discriminatory than the classical phenotypic Dienes typing technique. We demonstrated that each of 42 isolates from diverse environmental sources and 10 of 12 isolates from blood, wound swabs, and mid-stream urine samples of hospitalized patients had distinct genotypes. Examination of a set of 55 isolates of P. mirabilis, each from a different clinical or environmental source, identified 49 distinct genotypes and 43 Dienes types. The index of discrimination was 0.993 for the PFGE method and 0.988 for the Dienes method. Applying the PFGE method to isolates from catheter-associated urinary tract infections confirmed that the strains present in the crystalline catheter biofilms were identical to those isolated from the same patient's urine. An analysis of samples taken during a prospective study of infections in catheterized nursing home patients revealed that a single genotype of P. mirabilis can persist in the urinary tract despite many changes of catheter, periods of noncatheterization, and antibiotic therapy.     

Intermittent versus indwelling urinary catheterization in older female patients

OBJECTIVES: To compare the use of intermittent and indwelling catheterization in older female patients with urinary retention. METHODS: A randomized, 2-week prospective study in a geriatric rehabilitation ward. Female patients of age 65 years and older with post-voiding residual urine volume (PVRU) persistently > or = 300 ml were randomly assigned to one of the two groups: intermittent catheterization (IMC group, n=36) and indwelling catheterization (IDC group, n=45). The primary outcome was the proportion of subjects being catheter-free and had a PVRU < 150 ml on day 14. The secondary outcomes were the time to become catheter-free and the rate of bacteriuria on day 14. RESULTS: Sixteen out of 27 (59.3%) in the IMC group versus 27 out of 39 (69.2%) in the IDC group achieved the primary outcome on day 14 (P=.403) without significant difference in the PVRU. The IMC and IDC groups took a mean of 8.6+/-3.3 and 9.2+/-4.0 days to become catheter-free, respectively (P=.609). Fourteen out of 22 (63.6%) in the IMC group versus 21 out of 34 (61.8%) in the IDC group had bacteriuria on day 14 (P=.888). CONCLUSION: Given the similar success rate of regaining bladder voiding function, the similar rate of bacteriuria and considering that the IMC group only underwent a median of 3 times of intermittent catheterization, we believe that the approach of intermittent urinary catheterization when required would be justified in managing elderly female urinary retention in rehabilitation ward as the presence of indwelling catheters would hinder rehabilitation and adversely affect patient quality of life.     

Urinary bladder adenocarcinoma arising in a spina bifida patient

Urinary bladder adenocarcinomas are rare malignancies accounting for approximately 2.5% of all urothelial neoplasms. Intestinal metaplasia of the urothelium indicates the presence of intestinal-type goblet cells and was generally observed to coexist with or to precede the diagnosis of bladder adenocarcinomas. Controversy continues of whether intestinal metaplasia is an acquired precancerous lesion, secondary to different insults to the urothelium, or a concomitant lesion in glandular carcinogenesis. Patients with neurogenic bladders are particularly at risk for developing bladder cancer, mostly squamous cell carcinoma and rarely adenocarcinoma. In these patients, chronic irritation of the urothelium as well as long-term indwelling urinary catheters were the most significant risk factors. Spina bifida is a congenital developmental abnormality that may result in neurogenic bladder. There is only one previously reported case of urothelial carcinoma with associated squamous metaplasia of the bladder occurring in a spina bifida patient. We report the first case of bladder adenocarcinoma associated with intestinal metaplasia occurring in a spina bifida occulta patient. The patient had a complicated clinical course and suffered recurrent urinary tract infections, renal calculi, and urinary incontinence and was managed with intermittent as well as indwelling catheterization.     

Efficacy of a single intravenous dose of amphotericin B for Candida urinary tract infections: further favorable experience

Studies in experimental animals and humans have shown that Amphotericin B (AmB) persists in urine for days to weeks after a single IV dose in levels that should inhibit candidal organisms and thereby obviate the need for frequent dosing. Including data from four previously described patients, we have now treated a total of 11 patients (12 episodes) with Candida urinary tract infections with single-dose AmB (six, Candida albicans ; two, C. tropicalis ; four, other non albicans Candida ). The duration of candiduria prior to entry ranged from 18 to 180 days. Predisposing conditions included renal transplantation (1), diabetes mellitus (8), genitourinary stones (1) or anomalies (4), catheterization (2), and antibacterial therapy (11). A single patient was intolerant of AmB. Out of 11 evaluable candiduric episodes, eight resolved. Failure occurred in one patient with a chronic indwelling bladder catheter and in the allograft recipient. The data suggest that the sustained urinary excretion of AmB may permit successful single- or paucidose therapy of Candida urinary tract infections in some patients with a minimum of toxicity.     

脊髓损伤后神经源性膀胱患者护理中集束化康复护理的应用分析

目的 研究脊髓损伤后神经源性膀胱患者护理中集束化康复护理的应用。方法 选取于2016年2月~2017年5月入院68例脊髓损伤后神经源性膀胱患者作为研究对象,按照随机数字表法分为对照组和研究组,每组39例。对照组选用常规方式予以护理,研究组基于常规方式选用集束化康复护理模式;比较两组脊髓损伤后神经源性膀胱患者护理后满意度与护理前后膀胱容量、残余尿量。结果 研究组护理后满意度为97.44%,高于对照组79.49%,差异有统计学意义（P＜0.05）。研究组护理前后膀胱容量分别为（199.64±20.05）ml、（408.87±23.14）ml,护理前后残余尿量分别为（185.29±19.86）ml、（69.71±11.75）ml,对照组护理前后膀胱容量分别为（199.73±20.12）ml、（300.41±19.88）ml,护理前后残余尿量分别为（184.93±19.94）ml、（107.64±15.28）ml,两组患者护理后膀胱容量、残余尿量优于护理前,差异有统计学意义（P＜0.05）;研究组护理后膀胱容量、残余尿量优于对照组,差异有统计学意义（P＜0.05）。结论 脊髓损伤后神经源性膀胱患者护理中集束化康复护理的应用效果显著,可供临床参考。     

Urinary-bladder management after total joint-replacement surgery

We conducted a randomized study of 100 patients to examine the efficacy and risks of two methods of urinary-bladder management after total joint-replacement surgery. Patients who had hip or knee replacement were randomly assigned either to Group I, in which indwelling catheters were placed during the operation and removed the next morning, or Group II, in which urinary retention was treated by intermittent catheterization as needed. After the removal of the indwelling catheter, the patients in Group I had a lower incidence of urinary retention than those in Group II (27 vs. 52 percent; P less than 0.01). Bladder distention (volume above 700 ml) was more common in Group II (45 percent as compared with 7 percent in Group I; P less than 0.01) and was associated with an increased need for subsequent long-term catheterization. There was no significant difference between the groups in the rates of urinary tract infection (11 vs. 15 percent). We could not identify patients at high risk for retention or infection on the basis of preoperative urinary symptoms, previous urinary tract surgery, previous urinary tract infection or urinary retention, high-risk medical conditions, sex, type of anesthesia, or age (in the absence of prophylactic treatment). We conclude that the short-term use of an indwelling catheter after extended surgery, such as joint replacement, reduces the incidence of urinary retention and bladder overdistention, without increasing the rate of urinary tract infection.     

Integrated next-generation sequencing of 16S rDNA and metaproteomics differentiate the healthy urine microbiome from asymptomatic bacteriuria in neuropathic bladder associated with spinal cord injury

ABSTRACT: BACKGROUND: Clinical dogma is that healthy urine is sterile and the presence of bacteria with an inflammatory response is indicative of urinary tract infection (UTI). Asymptomatic bacteriuria (ABU) represents the state in which bacteria are present but the inflammatory response is negligible. Differentiating ABU from UTI is diagnostically challenging, but critical because overtreatment of ABU can perpetuate antimicrobial resistance while undertreatment of UTI can result in increased morbidity and mortality. In this study, we describe key characteristics of the healthy and ABU urine microbiomes utilizing 16S rRNA gene (16S rDNA) sequencing and metaproteomics, with the future goal of utilizing this information to personalize the treatment of UTI based on key individual characteristics. METHODS: A cross-sectional study of 26 healthy controls and 27 healthy subjects at risk for ABU due to spinal cord injury-related neuropathic bladder (NB) was conducted. Of the 27 subjects with NB, 8 voided normally, 8 utilized intermittent catheterization, and 11 utilized indwelling Foley urethral catheterization for bladder drainage. Urine was obtained by clean catch in voiders, or directly from the catheter in subjects utilizing catheters. Urinalysis, urine culture and 16S rDNA sequencing were performed on all samples, with metaproteomic analysis performed on a subsample. RESULTS: A total of 589454 quality-filtered 16S rDNA sequence reads were processed through a NextGen 16S rDNA analysis pipeline. Urine microbiomes differ by normal bladder function vs. NB, gender, type of bladder catheter utilized, and duration of NB. The top ten bacterial taxa showing the most relative abundance and change among samples were Lactobacillales, Enterobacteriales, Actinomycetales, Bacillales, Clostridiales, Bacteroidales, Burkholderiales, Pseudomonadales, Bifidobacteriales and Coriobacteriales. Metaproteomics confirmed the 16S rDNA results, and functional human protein-pathogen interactions were noted in subjects where host defenses were initiated. CONCLUSIONS: Counter to clinical belief, healthy urine is not sterile. The healthy urine microbiome is characterized by a preponderance of Lactobacillales in women and Corynebacterium in men. The presence and duration of NB and method of urinary catheterization alter the healthy urine microbiome. An integrated approach of 16S rDNA sequencing with metaproteomics improves our understanding of healthy urine and facilitates a more personalized approach to prevention and treatment of infection.     

Studies on the clinical significance of nonesterified and total cholesterol in urine

Summary Gas-liquid chromatographic determinations of nonesterified and total urinary cholesterol were performed in 137 normals, 264 patients with various internal diseases without evidence of neoplasias or diseases of the kidney or urinary tract, 497 patients with malignancies and 236 patients with diseases of the kidney, urinary tract infections or prostatic adenoma with residual urine. A normal range (mean±2 SD) of 0.2–2.2 mg/24 hours nonesterified cholesterol (NEC) and of 0.3–3.0 mg/24 hours total cholesterol (TC) was calculated.Values of urinary cholesterol excretion were independent of age and sex and did not correlate with cholesterol levels in plasma. Patients with various internal diseases, without evidence of neoplasias nor diseases of the kidney or obstruction of the urinary tract, showed normal urinary cholesterol excretions, as did patients with infections of the urinary tract.However, elevated urinary cholesterol was found in patients with diseases of the kidney or urinary tract obstruction (prostatic adenoma with residual urine), malignant diseases of the urogenital tract and metastasing carcinoma of the breast. In patients with other malignant diseases urinary cholesterol was usually normal.Lesions of the urothelial cell membranes are considered to be the most likely cause of urinary cholesterol hyperexcretion. The clinical value of urinary cholesterol determinations as a possible screening test for urogenital carcinomas in unselected populations is limited by lacking specificity, expensive methodology and low prevalence of the mentioned carcinomas, although elevated urinary cholesterol excretions have been observed in early clinical stages of urogenital cancers.     

Bacterial adherence to bladder uroepithelial cells in catheter-associated urinary tract infection

To assess the role of bacterial adherence to uroepithelial cells in the pathogenesis of nosocomial urinary tract infection, we prospectively studied 55 patients with indwelling urinary catheters. We obtained uroepithelial cells from the bladder and urine for culture on the patients' entry into the study and every two to four days during catheterization. In all, 235 collections of uroepithelial cells from these patients were used in an in vitro adherence assay with six gram-negative bacterial strains. With uroepithelial cells from patients who did not have bacterial infections, the adherence of the bacteria used in the assay differed significantly according to species. The least adherence occurred with Escherichia coli GR12; the adherence increased with (in order) Proteus mirabilis, E. coli J96, Klebsiella pneumoniae, Serratia marcescens, and Pseudomonas aeruginosa. With cells collected just before the onset of bacteriuria, adherence of these gram-negative strains was higher in patients in whom gram-negative rod infections developed than in those with gram-positive coccal infections (P = 0.005). Analysis with the Cox proportional-hazards model demonstrated that a significant increase in bacterial adherence to uroepithelial cells in the bladder occurred two to four days before the onset of bacteriuria, but that adherence returned to base-line values with the onset of bacteriuria. These results suggest that a transient increase in the adherence of gram-negative bacteria to bladder epithelial cells may be an important early event in the development of catheter-associated bacteriuria.     

Role of Enterococcus faecalis surface protein Esp in the pathogenesis of ascending urinary tract infection

Enterococcus faecalis bacteria isolated from patients with bacteremia, endocarditis, and urinary tract infections more frequently express the surface protein Esp than do fecal isolates. To assess the role of Esp in colonization and persistence of E. faecalis in an animal model of ascending urinary tract infection, we compared an Esp(+) strain of E. faecalis to its isogenic Esp-deficient mutant. Groups of CBA/J mice were challenged transurethrally with 10(8) CFU of either the parent or mutant strain, and bacteria in the urine, bladder, and kidneys were enumerated 5 days postinfection. Significantly higher numbers of bacteria were recovered from the bladder and urine of mice challenged with the parent strain than from the bladder and urine of mice challenged with the mutant. Colonization of the kidney, however, was not significantly different between the parent and mutant strains. Histopathological evaluations of kidney and bladder tissue done at 5 days postinfection did not show marked histopathological changes consistent with inflammation, mucosal hyperplasia, or apoptosis, and there was no observable difference between the mice challenged with the parent and those challenged with the mutant. We conclude that, while Esp does not influence histopathological changes associated with acute urinary tract infections, it contributes to colonization and persistence of E. faecalis at this site.     

Diagnosis of histoplasmosis in urine cytology: reactive urothelial changes, a diagnostic pitfall. Case report and literature review of urinary tract infections

Histoplasmosis not uncommonly causes systemic infection, particularly in immunocompromised patients. In systemic infection, the urinary tract is often involved, although the diagnosis of histoplasmosis in urine cytologic specimens has never been reported. Urinary tract histoplasmosis may present with gross hematuria, raising clinical suspicion for malignancy. The index case presented with intermittent gross hematuria, suprapubic pain, significant weight loss, hoarse voice, and a painful tongue ulcer. Examination of the patient revealed an ulcerated tongue lesion, an anal ulcer, a polypoid lesion on the vocal cord, and cystoscopic examination of the urinary bladder revealed erythematous patchy areas. Surgical biopsy sections from the vocal cord and tongue lesion were diagnostic of histoplasma infection. Urine cytologic examination showed atypical urothelial cells suspicious for malignancy. However, fungal stains performed on the urine specimen showed histoplasma organisms. We conclude that with a high index of suspicion, and the use of special stains, histoplasma organisms can be identified in urine.     

Enhanced Susceptibility to Urinary Tract Infection in the Spinal Cord-Injured Host with Neurogenic Bladder

Neurogenic bladder predisposes to recurrent urinary tract infections (UTI) and renal failure, and susceptibility is commonly ascribed to urinary stasis from elevated residual urine volumes. Escherichia coli UTI was modeled in the spinal cord-injured (SCI) rat with the hypothesis that SCI animals would require fewer bacteria to establish infection, have an exaggerated inflammatory response, and have delayed clearance of infection compared to normal-voiding controls. T10 SCI rats and controls had median infectious doses (ID₅₀) of 10² and 10⁵ CFU, respectively. Mean residual volumes in the SCI animals did not correlate with susceptibility to initiation of UTI or outcome. In the acute infection, control and SCI rats developed acute cystitis and pyelitis without acute differences in histopathological scores of inflammation. However, in vivo imaging of infected animals revealed persistently higher levels of bacteria in the SCI urine and bladders than were seen for controls over 2 weeks. Likewise, at 2 weeks, acute and chronic inflammatory infiltrates persisted in the bladders and kidneys of SCI rats, whereas inflammation largely resolved within the controls. Together these data demonstrate that SCI rats exhibit delayed clearance of infection and exaggerated inflammatory responses in bladders and kidneys; however, the severity of residual volumes does not predict increased susceptibility to UTI. These studies suggest that host-dependent mechanisms that are discrete from alterations in bladder physiology influence UTI susceptibility with the SCI-neurogenic bladder. This model will allow elucidation of SCI-neurogenic bladder-mediated changes in host response that yield UTI susceptibility and may lead to new preventative and therapeutic options.     

Sonographic assessment of postvoid residual urine volumes in patients with benign prostatic hyperplasia

OBJECTIVE: To derive a formula that defines the postvoid residual (PVR) urine volume more accurately in patients with prostatic gland enlargement. DESIGN: Prospective. SETTING: Department of Radiology, University of Ilorin Teaching Hospital, Ilorin. SUBJECT: Fifty-two consecutive patients with benign prostatic hyperplasia. The mean age was 64.98+/-9.57 years. METHOD: PVR urine was evaluated by ultrasonography. Each patient had two examinations, the first of which was with a full bladder and the second of which was immediately after voiding. Two orthogonal diameters were measured on each bladder section (longitudinal and transverse) in the supine position. Fifty-two paired sets of ultrasonic measurements were thus obtained. Catheterized postvoid urine residue was regarded as the gold standard. RESULTS: Using these measurements, an equation--[PVR(CUBIC)=374.057+(-196.94+V1)+(32.5539+V1(2))+(-1.1480+V1(3)) where V1=average of the length (L), width (T), and the anteroposterior distance on transverse section (Dt) of the postvoid urinary bladder]--more accurate than previously existing ones was obtained by cubic regression analysis. Mean ultrasound estimated volume was 220.51 ml as against 220.76 ml after catheterization. The mean difference was 0.25 ml (not significant, p<0.01) with 95% confidence interval of +/-10 ml. With this equation, the ultrasonographic residual urine volume showed a higher correlation coefficient with the catheterized volume at p<0.01 (Pearson r=0.982, r2=0.96) than previously defined formulas. The standard error of the mean was 5.11 ml (mean=220.5+/-190.4 ml). CONCLUSION: With the above equation, we consider conventional transabdominal ultrasonography a reliable method for assessing the residual urine volume in patients with benign prostatic hyperplasia. This equation, though complex when compared to some of the pre-existing formulas, can be integrated into the memory of modern ultrasound machines for easy and faster computation.     

The pathogenesis of recurrent urinary tract infection: the bowel, bladder hypokalemia connection

A conceptual approach to the understanding of the pathogenesis of recurrent nonobstructive urinary tract infections is presented. Abnormal colonic function is associated with potassium wastage which alters smooth muscle function of both the bowel and bladder. Hypokalemia additionally results in the elaboration of an alkaline urine and bladder dysfunction leads to urinary stasis. Vaginal and perineal contamination from the bowel flora are etiologically important in the genesis of such infections. Thus, a linkage exists between bowel dysfunction, potassium wastage and recurrent urinary tract infection.     

Urodynamic evaluation of lower urinary tract function in relation to total abdominal hysterectomy.

This study was performed to evaluate lower urinary tract functions in asymptomatic patients by urodynamic measurements after total abdominal hysterectomy and bilateral salpingo-oophorectomy. Twenty asymptomatic patients who had undergone hysterectomy for benign diseases were included in the study and urodynamic measurements were performed before and 6 weeks after total abdominal hysterectomy and bilateral salpingo-oophorectomy. There was no postoperative difference in first urge, normal urge, urgency and maximum bladder capacity but average urethral length, functional urethral length and maximum urethral closing pressure were decreased and also bladder discharging time was increased. Voided volume and residual urine volume were unchanged. It was concluded that total abdominal hysterectomy and bilateral salpingo-oophorectomy did not change the postoperative bladder loading functions in asymptomatic patients but that significant changes occurred in urethral functions.     

Establishment of a persistent Escherichia coli reservoir during the acute phase of a bladder infection

The vast majority of urinary tract infections are caused by strains of uropathogenic Escherichia coli that encode filamentous adhesive organelles called type 1 pili. These structures mediate both bacterial attachment to and invasion of bladder epithelial cells. However, the mechanism by which type 1 pilus-mediated bacterial invasion contributes to the pathogenesis of a urinary tract infection is unknown. Here we show that type 1-piliated uropathogens can invade the superficial epithelial cells that line the lumenal surface of the bladder and subsequently replicate, forming massive foci of intracellular E. coli termed bacterial factories. In response to infection, superficial bladder cells exfoliate and are removed with the flow of urine. To avoid clearance by exfoliation, intracellular uropathogens can reemerge and eventually establish a persistent, quiescent bacterial reservoir within the bladder mucosa that may serve as a source for recurrent acute infections. These observations suggest that urinary tract infections are more chronic and invasive than generally assumed.     

Role of bacterial growth rates in the epidemiology and pathogenesis of urinary infections in women.

The mean minimum generation time in shake culture in urine of 6 urinary isolates of Escherichia coli (21.7 +/- 0.6 min) was significantly shorter (P = 0.0003) than that of 14 isolates of less common urinary pathogens (46.0 +/- 18.6 min). Mixed populations of approximately equal numbers of E. coli cells paired with other urinary, fecal, and urethral organisms were introduced into a laboratory model of the lower human urinary tract. This model used urine as a medium and reproduced some features of the balance between bacterial growth and the flushing effect of urine. After 24 h E. coli formed greater than or equal to 99% of the bacterial population in the bladder model for 16 our of 18 pairs of isolates examined. Relatively high oxygen tensions in urine sample from 18 healthy women (10.9 +/- 22. kPA) and 18 infected patients (8.0 +/- 4.3 kPa) may explain why anaerobic urinary infections are uncommon. The rapid growth rate of E. coli may be one explanation why it is the commonest cause of urinary infection even though it is relatively uncommon at the urethral meatus.     

Urinary tract infections in the critical care unit: A brief review

The use of indwelling catheters in the Critical Care Units (CCUs) has a major role in determining the incidence and the morbidity as well as mortality from hospital-acquired urinary tract infections (UTIs). Instituting evidence-based protocols can significantly reduce both the prevalence of indwelling catheterization as well as the incidence of hospital-acquired UTIs. The prevalence of catheter-associated urinary tract infections (CAUTIs) in the CCUs is directly linked to the widespread use of indwelling catheters in these settings. CAUTIs result in significant cost escalation for individual hospitals as well as the healthcare system as a whole. A UTI is an inflammatory response to colonization of the urinary tract, most commonly by bacteria or fungi. A UTI should be differentiated from the mere detection of bacteria in the urinary tract. This condition, referred to as asymptomatic bacteriuria, is common and does not require treatment, especially in the patient with an indwelling urinary catheter. A CAUTI occurs when a patient with an indwelling urinary catheter develops 2 or more signs or symptoms of a UTI such as hematuria, fever, suprapubic or flank pain, change in urine character, and altered mental status. CAUTI is classified as a complicated UTI. The current review highlights the important management issues in critical care patients having CAUTI. We performed a MEDLINE search using combinations of keywords such as urinary tract infection, critical care unit and indwelling urinary catheter. We reviewed the relevant publications with regard to CAUTI in patients in CCU.     

Bladder afferent pathway and spinal cord injury: possible mechanisms inducing hyperreflexia of the urinary bladder

Lower urinary tract dysfunction is a common problem in patients with spinal cord injury (SCI). Since the coordination of the urinary bladder and urethra is controlled by the complex mechanisms in spinal and supraspinal neural pathways, SCI rostral to the lumbosacral level disrupts voluntary and supraspinal control of voiding and induces a considerable reorganization of the micturition reflex pathway. Following SCI, the urinary bladder is initially areflexic. but then becomes hyperreflexic because of the emergence of a spinal micturition reflex pathway. Recent electrophysiologic and histologic studies in rats have revealed that chronic SCI induces various phenotypic changes in bladder afferent neurons such as: (1) somal hypertrophy along with increased expression of neurofilament protein; and (2) increased excitability due to the plasticity of Na+ and K+ ion channels. These results have now provided detailed information to support the previous notion that capsaicin-sensitive, unmyelinated C-fiber afferents innervating the urinary bladder change their properties after SCI and are responsible for inducing bladder hyperreflexia in both humans and animals. It is also suggested that the changes in bladder reflex pathways following SCI are influenced by neural-target organ interactions probably mediated by neurotrophic signals originating in the hypertrophied bladder. Thus, increased knowledge of the plasticity in bladder afferent pathways may help to explain the pathogenesis of lower urinary tract dysfunctions after SCI and may provide valuable insights into new therapeutic strategies for urinary symptoms in spinal cord-injured patients.     

Estrogenic action on innate defense mechanisms in the urinary tract

Clinical data suggest an impact of estrogen on the pathogenesis of urinary tract infections (UTI). In particular, women after menopause often suffer from recurrent UTI, characterized by at least three acute UTI episodes within a year. Aside from bacterial factors promoting persistence within the urinary bladder, the low estrogen levels induce structural and chemical changes in the urogenital tract which facilitate UTI. Increased residual urine volume and changes in the vaginal microflora are well documented risk factors. Local supplementation with estrogen can at least partly reverse these changes. Treatment allows the re-establishment of a lactobacilli-dominated vaginal microflora and improves epithelial differentiation and integrity in the urogenital tract. This estrogenic effect on the epithelium is marked by an increased production of antimicrobial peptides and a tighter intercellular connection, preventing bacteria from reaching cells where they can hide and later emerge and cause a new infection. Estrogen in the dosages and applications used to date is considered safe for the endometrium in the majority of women. Based on the actions and safety of estrogen, local supplementation thus offers a treatment option for postmenopausal women suffering from recurrent UTI.