Urinary incontinence and bacteriuria in women

We analyzed the urodynamic data and their relationship with significant bacteriuria in 103 consecutive female patients (mean age = 55.7 yrs) with urinary incontinence. Significant bacteriuria was observed in 25.2% of the cases. E. coli was the pathogen most frequently isolated (70.3%). Significant bacteriuria was demonstrated in 29.3% of the patients with urge-incontinence. The most frequent type of incontinence in patients with bacteriuria was no urodynamic reproduction of urinary incontinence (42.8%). Bladder instability was not associated with significant bacteriuria (27.2%). Significant bacteriuria was observed in 75% of the patients with lower urinary tract obstruction, 66.6% of the patients who voided by abdominal straining and 26.3% of those with postvoiding residual urine. These findings indicate that urine culture should be done in patients with no urodynamic reproduction of urinary incontinence. There was no statistically significant correlation between urge-incontinence/bladder instability and significant bacteriuria. Consequently, antibiotics should not be used routinely in female urinary incontinence.     

Responses of natural killer cell activity to acute laboratory stressors in healthy men at different times of day

BACKGROUND: Five renal recipients with neurovesical dysfunction (NVD) were retrospectively reviewed focusing on anatomical and urodynamic abnormalities of the lower urinary tract and their management prior to kidney transplantation. METHODS: The underlying anomalies in these 5 patients were a posterior urethral valve (1 with an imperforate anus; n = 2), meningomyelocele (n = 2) and a congenital short urethra with an imperforate anus (n = 1). Their urinary tracts were evaluated prior to transplantation with voiding cystourethrography, urethrocystoscopy, cystometrography and electromyography of the external urethral sphincter to identify a possible focus of urinary tract infection, urine storage and voiding function. RESULTS: All 5 patients had NVD proven by urodynamic studies or by documentation of urinary retention in the absence of mechanical outlet obstruction. Bilateral high grade vesicoureteral reflux was noted in all patients, requiring ureteroneocystostomy. Clean intermittent catheterization (CIC) was ultimately employed for bladder emptying in all patients. Two patients with poor bladder compliance underwent augmentation cystoplasty before transplantation. The Mitrofanoff procedure was used in 2 patients with structural urethral abnormalities to access the bladder for catheterization. After eradication of possible sources of infection and establishment of a low-pressure urine storage system with bladder emptying by CIC, kidney transplantation was performed. Following kidney transplantation, all of the recipients were asymptomatic for urinary tract infections using CIC. Although 1 patient lost his graft due to chronic rejection, the other 4 other patients have good renal function. CONCLUSION: Kidney transplantation in patients with NVD can be performed provided that their urinary tract problems are properly resolved.     

Alport syndrome with a peculiar pattern of distribution of the alpha3-alpha6 chains of type IV collagen in renal basement membrane

Chronic bacteriuria is a common occurrence among spinal-cord injury patients and others with neuropathic bladders. If bacteria are present in the urinary tract, the patient may develop symptoms of infection or remain asymptomatic. We have compared virulence properties of 28 Escherichia coli isolates from patients with symptomatic urinary tract infections (UTI) and 29 E. coli isolates from patients with asymptomatic bacteriuria (ABU). Bacteria from patients with symptomatic UTI were more likely to be hemolytic than isolates from patients with ABU (P = 0.05) or fecal isolates obtained from healthy volunteers (P < 0.001). Bacteria from patients with symptomatic UTI were also more likely than strains isolated from patients with ABU (P = 0.08) or fecal strains (P < 0.001) to exhibit D-mannose-resistant hemagglutination of human erythrocytes. The results suggest that E. coli isolates from nonimmunocompromised patients who require intermittent catheterization and who develop symptomatic UTI may be distinguished from bacteria recovered from patients who remain asymptomatic and possibly from normal fecal E. coli.     

A simple and efficient urine sampling method for bacteriological examination in elderly women

AIM: to determine how collecting urine voided directly into a container compares with urine obtained by suprapubic aspiration. METHOD: urine samples were collected in a sterile recipient placed in the toilet or in the bed-pan during voiding, after the vulval region had been cleaned by water. These samples were compared with samples of the same urine obtained by suprapubic aspiration. The samples were examined for pyuria and bacteriuria. Applying the Kass criteria on the voided urine specimen and assessing the presence of leucocyturia, it was possible to differentiate urinary tract infection, asymptomatic bacteriuria and contamination. RESULTS: all 13 cases of infection found on suprapubic aspiration were also identified by this sampling technique. The technique produced four false-positive results. CONCLUSION: this simple sampling method may not only obviate the need for suprapubic aspiration but also for bladder catheterization in the diagnosis of urinary tract infection in many elderly women.     

Hemagglutination ability and adherence to the Buffalo green monkey kidney cell line of uropathogenic Escherichia coli

The hemagglutination ability and adherence capacity to the Buffalo green monkey (BGM) kidney cell line of 160 wild-type strains of Escherichia coli isolated from bacteriuric patients were investigated. It was found that P-fimbriated E. coli strains adhered significantly better to BGM cells than did strains in which P-fimbriae were not detected, which is in accordance with the capacity of P-fimbriated strains to cause unobstructive pyelonephritis and with receptor distribution for P-fimbriae in the urinary tract. The strains which exhibited other adhesions, alone or simultaneously, showed reduced adherence to BGM cells, while non-agglutinating strains, mostly isolated from urine of patients with asymptomatic bacteriuria, did not adhere at all or adhered poorly to the utilized cell line. The BGM cells served as a good experimental model for investigation of uropathogenic E. coli adherence; because these cells originate from the upper urinary tract, they are viable and not coated with Tamm-Horsfall protein.     

The role of urinary potassium in the pathogenesis and diagnosis of interstitial cystitis

PURPOSE: We determined whether intravesical potassium absorption in normal bladders correlates with increased sensory urgency, and corroborated the hypothesis that mucus is important in the regulation of epithelial permeability. We compared sensory nerve provocative ability of sodium versus potassium, and determined whether intravesical potassium sensitivity discriminates patients with interstitial cystitis from normal subjects and those with other sensory disorders of the bladder. MATERIALS AND METHODS: A total of 231 patients with interstitial cystitis and 41 normal subjects underwent intravesical challenge with 40 ml. water and then 40 ml. of 40 mEq./100 ml. potassium chloride. Subjective responses of urgency or pain stimulation were recorded on a scale of 0 to 5. In 19 normal subjects potassium absorption was measured at baseline, after injury of the bladder mucus with protamine, after heparin treatment to reverse mucus damage and then for a final time. These subjects simultaneously recorded the symptoms of sensory urgency and pain at baseline, after protamine and after heparin. Another group of normal volunteers underwent a challenge with sodium versus potassium to determine which cation was more provocative. Patients with bladder outlet obstruction secondary to benign prostatic hyperplasia (BPH), detrusor instability, and acute and chronic urinary tract infection but no current infection were also evaluated for potassium sensitivity. RESULTS: Neither normal subjects nor patients with interstitial cystitis reacted to water administered intravesically. There was marked sensitivity to intravesical potassium in 75% of patients with interstitial cystitis versus 4% of controls (p <0.01). Only 1 patient with BPH responded to potassium and none of the 5 with chronic urinary tract infection responded. All 4 patients (100%) with a current acute urinary tract infection reacted positively to the potassium challenge. Of 16 patients with detrusor instability 25% responded. Normal subjects had minimal sensitivity to potassium before (11%) and markedly increased sensitivity after (79%) protamine treatment, and these symptoms were reversed by heparin in 42%. Potassium absorption directly correlated with symptoms (0.4, 3.0 and 1.3 mEq. before and after protamine, and after heparin reversal, respectively). In regard to sodium versus potassium provocation, potassium was far more provocative for causing urgency after protamine (10 versus 90%). Neither group underwent provocation before protamine. CONCLUSIONS: Chronic diffusion of urinary potassium into the bladder interstitium may induce sensory symptoms, damage tissue and be a major toxic factor in the pathogenesis of interstitial cystitis. Intravesical potassium sensitivity is a reliable method for detecting abnormal epithelial permeability. It discriminates between patients with interstitial cystitis and normal subjects with intact epithelial function, and it is a useful diagnostic test for interstitial cystitis. Potassium sensitivity correlates with increased potassium absorption in normal subjects, and potassium is far more provocative than sodium. Potassium sensitivity is also present in acute urinary tract infection and occasionally detrusor instability but not in BPH or chronic urinary tract infections.     

Elevated tryptase, nerve growth factor, neurotrophin-3 and glial cell line-derived neurotrophic factor levels in the urine of interstitial cystitis and bladder cancer patients

PURPOSE: The 2 prominent features of interstitial cystitis are pain and increased numbers of mast cells in the bladder. In this pilot study we determined the concentration of soluble mediators associated with activation of sensory neurons and/or mast cells that were present in the urine. MATERIALS AND METHODS: The study groups included 4 interstitial cystitis patients, 7 kidney donors with no history of bladder disease as negative controls, 6 bladder cancer patients and 7 patients with urinary tract infection as reference controls. Urine samples were assayed for different soluble mediators using immunoassays for tryptase (a marker for mast cell activation), neurotrophic factors (markers of neuronal plasticity) and chemokines (markers of inflammatory cell activity). Results were normalized based on creatinine concentration. RESULTS: There was a marked increase in the average amounts of tryptase and 3 neurotrophic factors in patient urine. Interestingly, the mediator profile in the urine of bladder cancer patients was indistinguishable from that of interstitial cystitis patients with respect to these same 4 proteins. There was no difference between normal control and urinary tract infection urine samples. CONCLUSIONS: These findings may account for several clinical and pathological features found in interstitial cystitis and bladder cancer. Although preliminary due to the limited numbers of patients, they also suggest that increased levels of neurotrophin-3, nerve growth factor, glial cell line-derived neurotrophic factor and tryptase in the urine could serve as a basis for adjunct diagnosis, monitoring and treatment of interstitial cystitis.     

The pseudo-obstructed bladder in enuretic children

In a minority of enuretic children with severe day symptoms, and especially when there is urinary infection, there a bladder diverticula and trabeculation and possbily also harmful vesicoureteric reflux which suggest the presence of an infravesical obstruction. However, in 11 children with this syndrome who underwent urodynamic studies, no anatomical or functional obstruction was demonstrable. It is contended that the obstructive signs are the result of uninhibited detrusor contractions being voluntarily resisted by contraction of the external urethral sphincter so that abnormallay high intravesical pressures result. Management involves the use of detrusor-inhibitory drugs. Ureteric reimplantation may be needed for reflux. In the majority of cases symptoms improve with time but the bladder diverticula persist.     

Comparison of Escherichia coli strains recovered from human cystitis and pyelonephritis infections in transurethrally challenged mice

Urinary tract infection, most frequently caused by Escherichia coli, is one of the most common bacterial infections in humans. A vast amount of literature regarding the mechanisms through which E. coli induces pyelonephritis has accumulated. Although cystitis accounts for 95% of visits to physicians for symptoms of urinary tract infections, few in vivo studies have investigated possible differences between E. coli recovered from patients with clinical symptoms of cystitis and that from patients with symptoms of pyelonephritis. Epidemiological studies indicate that cystitis-associated strains appear to differ from pyelonephritis-associated strains in elaboration of some putative virulence factors. With transurethrally challenged mice we studied possible differences using three each of the most virulent pyelonephritis and cystitis E. coli strains in our collection. The results indicate that cystitis strains colonize the bladder more rapidly than do pyelonephritis strains, while the rates of kidney colonization are similar. Cystitis strains colonize the bladder in higher numbers, induce more pronounced histologic changes in the bladder, and are more rapidly eliminated from the mouse urinary tract than pyelonephritis strains. These results provide evidence that cystitis strains differ from pyelonephritis strains in this model, that this model is useful for the study of the uropathogenicity of cystitis strains, and that it would be unwise to use pyelonephritis strains to study putative virulence factors important in the development of cystitis.     

Localization of a domain in the FimH adhesin of Escherichia coli type 1 fimbriae capable of receptor recognition and use of a domain-specific antibody to confer protection against experimental urinary tract infection

The FimH subunit of type 1-fimbriated Escherichia coli has been implicated as an important determinant of bacterial adherence and colonization of the urinary tract. Here, we sought to localize the functionally important domain(s) within the FimH molecule and to determine if antibodies against this domain would block adherence of type 1-fimbriated E. coli to the bladder mucosa in situ and in vivo in an established mouse model of cystitis. We generated translational fusion proteins of disparate regions of the FimH molecule with an affinity tag MalE, and tested each of the fusion products in vitro for functional activity. The minimum region responsible for binding mouse bladder epithelial cells and a soluble mannoprotein, horseradish peroxidase, was contained within residues 1-100 of the FimH molecule. We validated and extended these findings by demonstrating that antibodies directed at the putative binding region of FimH or at synthetic peptides corresponding to epitopes within the binding domain could specifically block type 1 fimbriae-mediated bacterial adherence to bladder epithelial cells in situ and yeast cells in vitro. Next, we compared the ability of mice passively immunized intraperitoneally with antisera raised against residues 1-25 and 253-264 of FimH or 1-13 of FimA to resist bladder colonization in vivo after intravesicular challenge with type 1-fimbriated E. coli. Only the antibody directed at the putative binding region of FimH (anti- s-FimH1-25) significantly reduced E. coli bladder infections in the experimental mouse model of urinary tract infections. Similar results were obtained when the mice were actively immunized with synthetic peptides corresponding to residues 1-25 and 253-264 of FimH or 1-13 of FimA. The mechanism of protection was attributed, at least in part, to inhibition of bacterial adherence to the bladder surface by s-FimH1-25-specific antibody molecules that had filtered through the kidneys into the urine. The level of FimH antibodies entering the bladder from the circulatory system of the immunized mice was found to be markedly enhanced upon bacterial challenge. The potential broad spectrum activity of the protective FimH antibody was indicated from its serologic cross-reactivity with various urinary tract bacterial isolates bearing type 1 fimbriae. These findings could be relevant in the design of an efficacious and broadly reactive FimH vaccine against urinary tract infections.     

Posterior urethral valves after infancy-urodynamic consequences

This study describes a subset of patients with posterior urethral valves (PUV) who presented late in childhood. The objective was to identify factors that lead to back-pressure effects on the upper tracts, which persist in spite of adequate valve ablation in some patients, and seek factors that may preserve the upper tracts despite untreated obstruction in other patients. Six children with PUV diagnosed after infancy were evaluated. The pre-operative work-up included renal biochemistry, ultrasonography, voiding cystourethrography, and uroflowmetry. Detailed urodynamic studies, including uroflowmetry and slow-fill cystometry, were performed in all cases 6 months after surgery. Adequacy of valve fulguration was confirmed by urethroscopy. Three of the six patients had normal upper tracts; in these, there was marked improvement in peak urine flow rates after fulguration and bladder pressures were normal. The other three patients had bilateral hydroureteronephrosis, and two had chronic renal failure. This group had markedly decreased functional bladder capacity with loss of compliance at low bladder volumes and significant residual urine volumes in spite of adequate valve fulguration, suggesting myogenic detrusor failure. We conclude that in patients with PUV presenting beyond the age of 5 years, upper-tract deterioration may accompany high storage pressures in the bladder. In some boys with long-standing obstruction the upper tracts may escape damage; in our series this was associated with normal bladder dynamics and appeared unrelated to the severity or duration of outflow obstruction.     

Transitional carcinomas of the urinary tract: synchronous and metachronous lesions

OBJECTIVE: The urothelium is a pseudostratified cylindrical epithelium that lines the calices, renal pelvis, urethers, bladder, part of the urethra and part of the prostate ducts. Transitional cell carcinoma (TCC) is a malignant neoplasia that can appear in any site where urothelium is present, being the bladder the most frequently affected organ. We performed an analysis of our experience and conducted a literature-based metanalysis to evaluate the coexistence of tumoral lesions at different locations in the urinary tract. MATERIAL AND METHODS: Between 1983 and 1993, 397 patients with TCC lesions involving the upper urinary tract (UUT), bladder, urethra or prostate, were diagnosed and treated. Coexistence, either synchronic or metachronic, of several lesions in different sites of the urinary tract was considered as a multiple tumor. RESULTS: Overall, 440 tumors were diagnosed in 397 patients. A single lesion appeared in 360 patients, while 37 presented multiple locations with a total of 79 tumors. The lesions were located at the following levels: 17 renal, 21 uretheral, 372 vesical, 13 in the urethra and 17 in the prostate ducts. According to the location, the frequency of single lesions was: UUT 58%, bladder 91%, urethra 8% and prostate ducts 35%. Synchronic UUT and intravesical tract tumors develops in 1% and 4% of patients with bladder TCC, respectively. Two percent of vesical tumors showed metachronic relationship with UUT tumors and the same rate was seen for intravesical lesions. CONCLUSIONS: Urothelial UUT tumors have a typical nosologic entity with specific features. Their coexistence with vesical tumors is frequent. When tumors of the bladder occur after a UUT tumor the interval of highest incidence between diagnoses is 2-3 years, and there are no histological risk factors among them for prognosis. Transitional cell prostatic urethral tumors are most often secondary to histologically similar, poor prognosis, bladder tumors, and usually synchronic.     

Relation between successful treatment of urinary tract inflammation and the disappearance of changes in the bladder mucosa in children and adolescents with cystoscopically proven cystitis cystica

Bladder epithelium nodular changes called cystitis cystica are commonly found in children and adolescents suffering from long-term lower urinary tract infection. Recurrent urinary infection was found in pediatric patients with urinary tract abnormalities as well as in others without it with nearly the same frequency. The authors studied 63 pediatric patients with recurrent urinary tract infection and cystitis cystica of which 59 (94%) were females. The age of the examined patients varied from 1 to 16 years, mean 7.35 years. Thirty five of them (55.5%) had diverse anomalies of the urinary tract. Vesicoureteric reflux was demonstrated on the cystogram in 41.1% patients. Escherichia coli was found to be the major pathogenic organism in the urine. Thirty eight (60.3%) children and adolescents were treated medically for months (two years mostly) by reason of prolonged recurrent urinary tract infection before nodular changes of the bladder mucosa at cystoscopy were detected. Even thirteen (39.7%) of all studied patients were treated medically more than five years. In the present study only 47 (74.6%) of the observed patients have had an adequate follow-up and might be considered. In these cases repeated cystoscopy was performed and the successively sterile urine cultures were obtained. Twenty-one (44.3%) patients were medically treated up to one year before the urinary tract infection was eradicated and nodular mucosal changes disappeared. In 6 (12.8%) patients more than five years were needed to achieve this result.     

Urodynamic and cardiovascular measurements in patients with micturition syncope

We describe the findings of urodynamic studies, together with blood pressure and heart rate monitoring, in five patients with micturition syncope. All patients had almost normal storage and evacuation function and no evidence of prostate hypertrophy. Conventional head-up tilt testing with an empty urinary bladder caused no change in arterial blood pressure, but a moderate increase in heart rate. Urinary bladder filling caused minimal increases of the arterial pressure and heart rate. The sitting posture with a distended bladder caused mild orthostatic hypotension. Urinary bladder evacuation caused a fall in arterial pressure with a decrease in heart rate. These responses were similar to those described in vasovagal syncope. The central mechanism for the initiation of urinary evacuation, or sensory input from the lower urinary tract, may trigger micturition syncope.     

Urinary incontinence in the elderly. 1: Forms of urinary incontinence--basic diagnosis--additional diagnosis

Every geriatric patient should routinely be questioned about possible urinary incontinence. The basic diagnostic work-up comprises the clinical history, wherever indicated a geriatric assessment, a nursing care history, a physical examination and a micturition protocol. Furthermore, determination of postvoid residual urine, laboratory investigations and a urine-analysis should be done in all patients. Ultrasonography of the urinary tract is a simple non-invasive procedure that can exclude the presence of large tumors, stones in the bladder and urinary retention. Only selected patients require a greater diagnostic effort prior to treatment, for example, urologic and/or gynecologic investigations or a urodynamic evaluation.     

Antireflux nipples or afferent tubular segments in 70 patients with ileal low pressure bladder substitutes: long-term results of a prospective randomized trial

PURPOSE: Intestinal low pressure orthotopic bladder substitutes have no major coordinated contractions during micturition. Therefore, the importance and type of reflux prevention were assessed in a prospective randomized study. MATERIALS AND METHODS: A total of 70 patients with an ileal low pressure bladder substitute was randomized to receive a nipple valve or an isoperistaltic afferent ileal tubular segment for reflux prevention. RESULTS: After median observation times of 57 and 45 months, respectively, the results regarding functional reservoir capacity, incidence of infected urine, urinary continence, voiding habits and serum electrolytes, urea and creatinine were similar in both groups. Severe upper tract dilatation due to ureteroileal or nipple stenosis occurred in 9 of 67 evaluable reno-ureteral units (13.5%) in patients with antireflux nipples and in 2 of 69 (3%) in patients with an afferent tubular segment. This difference in favor of the latter cases is significant (Fisher's exact test p < 0.03). Video urodynamics did not show reflux of contrast medium during voiding in either group. A simultaneous intravesical, intra-abdominal and intrapelvic pressure increase was noted during the Valsalva maneuver. CONCLUSIONS: While long-term upper tract preservation by an afferent tubular ileal segment must be confirmed in larger patient series with longer followup, our results indicate that reflux prevention in patients with orthotopic low pressure bladder substitutes is not a major concern and does not justify the use of antireflux mechanisms with a high complication rate.     

Bacterial urovirulence factors and their association with functional and anatomical abnormalities and recurrence of urinary tract infections in children

BACKGROUND: Urinary tract infections in children are associated with functional and anatomical abnormalities of the urinary tract, they tend to recur and can cause permanent kidney damage. AIM: To study in children with urinary tract infections, microbiological factors associated to recurrence, functional and anatomical abnormalities of the urinary tract. PATIENTS AND METHODS: A prospective sample of children was incorporated into a follow-up protocol after their first episode of bacteriologically-demonstrated urinary tract infection. In all patients an abdominal ultrasound examination and a mictional urethrocystography were done and the presence of fimbriae was studied in isolated strains of Escherichia coli. RESULTS: Two hundred fifteen cases bad an adequate adherence to the study protocol, 190 caused by E coli. Fimbriated E coli strains were isolated with greater frequency from children with pyelonephritis than from those with a low urinary tract infection (50 and 28% respectively). The absence of fimbriae in E coli strains was associated with a higher risk of recurrent infections (odds ratio = 3, confidence intervals = 2-9.2) and an abnormal urethrocystography (odds ratio = 3, confidence intervals = 1.1-10.2). CONCLUSIONS: These data are consistent with foreign reports and support the need to study adhesins in E coli strains isolated from children with urinary tract infections.     

Does the use of antibiotics in animals affect human health?

This study examined the prevalence of bacteriuria in early postpartum period after term vaginal delivery in Trinidad, West Indies. Asymptomatic bacteriuria occurred in 58 (34.5%) of 168 patients tested. The prevalence of bacteriuria was significantly higher in non-catheterized patients than in catheterized patients and occurred more commonly in patients who were 20 to 29 years old and who were primigravida rather than multigravida. Forty-four patients had a history of urinary tract infection; 18 (40.9%) of these patients had positive urine cultures. Although 10 patients had a vaginal discharge in the late third trimester, none presented with postpartum bacteriuria. Because of the high prevalence of postpartum bacteriuria and the potential to progress to pyelonephritis and chronic renal disease, quantitative urine cultures for all postnatal patients and curative treatment for all positive cultures are recommend.     

Comparison between results of ileal conduit and continent ileal bladder (VIP), after radical cystectomy

OBJECTIVES: The aim of the present study is to analyze the results achieved with the ileal bladder according to the VIP (vescica ileale Padovana) procedure. METHODS/RESULTS: We compared the results obtained in 31 patients with invasive bladder cancer who underwent radical surgery (22 underwent the ileal conduit procedure and 9 were treated by orthotopic bladder substitution) and analyzed the early complications, long-term results and physiological data of the group submitted to the VIP procedure. In the patient group submitted to the VIP procedure, there was only one case who required removal of the new bladder due to an enteroneovesical fistula. Another case developed medium serrate anular stricture of the bulbar urethra about 8 months postoperatively and was treated by endoscopic urethrotomy. The uroradiologic and urodynamic evaluations confirmed urinary tract stability integrity of renal function and good adaptation of the new reservoir. The andrological studies showed complete sexual potency in 2 of 9 patients. CONCLUSIONS: The VIP procedure appears to be a good technique, with complications no greater than those of traditional urinary diversion, and improves the quality of life of patients undergoing radical surgery for invasive bladder cancer.     

Clinical, and light and electron microscopical findings in sows with cystitis

The clinical findings, and urinary and morphological changes in the urinary bladder were investigated in 25 sows with a urinary tract infection. Eubacterium suis was isolated from 12 of the sows but not from the other 13. The clinical signs did not always correlate with the morphological changes. The only clinical sign indicating the beginning of cystitis appeared to be a significant bacteriuria. Other urinary changes occurred later when the inflammatory processes were more severe. In contrast with cystitis due to other bacteria, infection with E suis frequently resulted in a macrohaematuria and urinary pH values above 8.0. However, the light and electron microscopical findings in the bladder mucosa were similar in the sows with and without cystitis due to E suis. The transformation of goblet cells and the development of mucin cysts were probably due to the local bladder defence mechanisms. More severe lesions were observed with E suis infections, which resulted in changes in the ureterovesical junctions and in ascending renal infection and uraemia.