Bladder infection with uropathogenic Escherichia coli increases the excitability of afferent neurons

Urinary tract infections (UTIs) cause bladder hyperactivity and pelvic pain, but the underlying causes of these symptoms remain unknown. We investigated whether afferent sensitization contributes to the bladder overactivity and pain observed in mice suffering from experimentally induced bacterial cystitis. Inoculation of mouse bladders with the uropathogenic Escherichia coli strain UTI89 caused pelvic allodynia, increased voiding frequency, and prompted an acute inflammatory process marked by leukocytic infiltration and edema of the mucosa. Compared with controls, isolated bladder sensory neurons from UTI-treated mice exhibited a depolarized resting membrane potential, lower action potential threshold and rheobase, and increased firing in response to suprathreshold stimulation. To determine whether bacterial virulence factors can contribute to the sensitization of bladder afferents, neurons isolated from naïve mice were incubated with supernatants collected from bacterial cultures with or depleted of lipopolysaccharide (LPS). Supernatants containing LPS prompted the sensitization of bladder sensory neurons with both tetrodotoxin (TTX)-resistant and TTX-sensitive action potentials. However, bladder sensory neurons with TTX-sensitive action potentials were not affected by bacterial supernatants depleted of LPS. Unexpectedly, ultrapure LPS increased the excitability only of bladder sensory neurons with TTX-resistant action potentials, but the supplementation of supernatants depleted of LPS with ultrapure LPS resulted in the sensitization of both population of bladder sensory neurons. In summary, the results of our study indicate that multiple virulence factors released from UTI89 act on bladder sensory neurons to prompt their sensitization. These sensitized bladder sensory neurons mediate, at least in part, the bladder hyperactivity and pelvic pain seen in mice inoculated with UTI89.NEW & NOTEWORTHY Urinary tract infection (UTI) produced by uropathogenic Escherichia coli (UPEC) promotes sensitization of bladder afferent sensory neurons with tetrodotoxin-resistant and tetrodotoxin-sensitive action potentials. Lipopolysaccharide and other virulence factors produced by UPEC contribute to the sensitization of bladder afferents in UTI. In conclusion, sensitized afferents contribute to the voiding symptoms and pelvic pain present in mice bladder inoculated with UPEC.

[About the causes of inveterate cystitis in young women]

16 female patients,aged 28.6 +/- 3.2 years, with recrudescent inveterate cystitis were examined for the purpose of improvement of treatment of chronic cystitis. The examined patients noted relapse of disease after sex intercourse. Spectrum of diagnosed uropathogens in female patients corresponds to the structure of bacterio from urina taken after prostate milking and prostatic fluid of patients' intercourse partners. The given uropathogens also corresponds to the structure of contagium of urinary tract in young men. Connection between urogenital biotope and biotope of prostate as a vessel of persistence infection is related. Recrudescent inveterate cystitis in young women may be result from latent inveterate bacteritic prostatitis in their intercourse partners. Effectiveness of treatment and prophylaxis of recrudescence of inveterate cystitis in young women depends on timely diagnostics, treatment, and prophylaxis of inveterate bacteritic prostatitis in their intercourse partners.

[Bacterial mixed infection in women with chronic recurrent cystitis]

AIM

To study microbial repertoire of urine in healthy women and patients with chronic recurrent cystitis (CRC) including facultative anaerobic (FA) and non-clostridial anaerobic (NCA) bacteria. MATERIALS AND METHODS. Triple bacteriological study of urine was performed in three groups of women: group I--22 healthy virgin women aged 18- 25 years, group II--24 women aged 18 - 25 years with regular sexual contacts, group III--72 women aged 20 - 60 years with CRC, before antibacterial therapy. Bacteriological method was used to study qualitative and quantitative composition of urine microflora.

RESULTS

In all subjects from groups I and II aerobic-anaerobic associations with predomination of coagulase-negative staphylococci (CNS), corynebacteria, peptococci, and peptostreptococci were isolated from urine. Quantity of isolated NCA bacteria was significantly higher than that of FA. In etiologic structure of CRC, NCA bacteria, enterobacteria, and CNS predominated. Spectrum of NCA bacteria isolated from patients with CRC was wider and level of bacteriuria--higher (p < 0.05) compared to groups I and II. Bacteria were identified in aerobic-anaerobic associations. In 85.7% of cases following NCA were identified in biopsy samples: Propionibacterium sp. (41.8%), Peptococcus sp. (35.7%), Eubacterium sp. (28.6%), Peptostreptococcus sp. (14.3%), and Bacteroides sp. (14.3%). Aerobic-anaerobic associations were observed in 7.1% of samples.

CONCLUSION

Urine of healthy women is not sterile. Aerobic-anaerobic mixed infections were detected in patients with CRC that should take into account during diagnostics and treatment of this disease.

The natural history of urinary tract infection in women

Many women who suffer from the symptoms of urinary tract infection have a negative urine culture when conventional methods are used. Their condition is described as 'urethral' (or 'dysuria/frequency') syndrome' (US). As they may be indistinguishable clinically from those with positive cultures antibiotics are often prescribed. Their symptoms are usually recurrent and they may receive many courses of treatment. Some women are said to have 'interstitial cystitis' (IC); they have a long history of symptoms and antibacterial treatment. The urine contains white blood cells (pyuria) and biopsy of the bladder wall shows the histological changes of chronic inflammation. Additional culture techniques applied to urine from these two groups of patients consistently yield bacteria, most commonly lactobacilli in those with US. From the urine of women with IC, lactobacilli and some other 'fastidious' bacteria are isolated from catheter specimens and also from bladder wall biopsies. These bacteria are known to be constituents of the mixed commensal flora of the distal one-third of the urethra. It is proposed that these two syndromes are different stages in the natural history of UTI, and that antibacterial agents, by selection of resistant bacteria in the urethral commensal flora, are an important aetiological factor. It is possible that these bacteria may invade the paraurethral glands via their ducts - a situation analogous to invasion of the prostate in men. There is a considerable body of evidence supporting this hypothesis, but as it all emanates from one centre it needs to be confirmed elsewhere. Acceptance would bring great clinical benefit and considerable financial savings. A laboratory protocol which requires only small additional expenditure, and a clinical management regimen are proposed. At present, much antibacterial treatment is prescribed and many patients undergo radiological and invasive investigations such as cystoscopy and urethral dilatation, the latter incurring the risk of post-instrumentation UTI. There is evidence that 'US' responds gradually if antibiotics are withheld. 'IC' is a more difficult problem because bacteria may have invaded the bladder wall. Carefully targeted antibacterial treatment given for at least 10-14 days might be effective, but there are no data on this. Rational management of 'US' might prevent the development of 'IC'. A recent thorough review of published work on this condition states that the aetiology is still unknown. It appears, however, that no attempt has been made in any recent studies to use urine culture techniques capable of detecting bacteria other than the recognised aerobic pathogens.

The painful bladder: urinary tract infection and interstitial cystitis in women

Irritative voiding symptoms in women are most often due to uncomplicated urinary tract infection. A cost-effective approach to the treatment of urinary tract infections is a reasonable first step. However, in patients who have persistent or frequently recurrent symptoms, a more thorough evaluation is warranted. These women may be found to have interstitial cystitis, requiring further evaluation. While interstitial cystitis remains a difficult disease to treat, a multi-modality therapy provides excellent symptom relief.

Interstitial cystitis and infectious agents

Interstitial cystitis (IC) is a syndrome consisting of severe refractory bladder symptoms of unknown etiology. The disease tends to affect Caucasian women with a mean age of 40 years, with 25% of patients under the age of 30. Few population based epidemiological studies of IC have been performed. We analyzed a case of interstitial cystitis in a 42-year-old non-smoker woman. In two biopsy samples the presence of viral DNA of human polyomavirus BK (BKV), human herpes virus type 1 and type 2 (HHV- 1 and HHV-2), adenovirus, human papillomavirus (HPV) and bacterial DNA (Chlamydia trachomatis and Mycoplasma genitalium) were evaluated by means of polymerase chain reaction (PCR). Both samples resulted positive only for BKV and HPV DNA. HPV genotyping revealed the presence of HPV-66 that is associated with a high risk of cancer development. Thus the finding of a viral co-infection could support the hypothesis of the multi-factorial origin of this pathology.

A study to detect Helicobacter pylori in fresh and archival specimens from patients with interstitial cystitis, using amplification methods

OBJECTIVES

To detect Helicobacter pylori DNA in fresh and paraffin-embedded bladder biopsy specimens, and thus determine any possible role in interstitial cystitis (IC).

MATERIALS AND METHODS

Thirty-three bladder biopsy samples were examined from patients with IC (29 paraffin-embedded and four freshly frozen) diagnosed according to National Institute of Diabetes, Digestive and Kidney Disease criteria. The positive control was a gastric biopsy sample from a patient with a known gastric ulcer caused by H. pylori infection.

RESULTS

The anticipated polymerase chain reaction product size of 109 base pairs was obtained with the positive control, whereas none of the other biopsy samples (paraffin embedded or fresh) showed positive amplification specific for H. pylori.

CONCLUSIONS

As there was no H. pylori DNA in any of the samples from patients with IC, it is an unlikely candidate in the pathogenesis of IC.

Is interstitial cystitis an infectious disease?

Interstitial cystitis (IC) is a chronic bladder disorder of unknown aaetiology. Although several investigators have attempted to identify an infectious cause for IC, none has yet been found. Our own studies to search for an infectious cause discovered instead, a toxic factor in the urine of approximately 95% of IC patients that is made by and inhibits, the normal proliferation of bladder epithelial cells. Additional research is necessary to determine whether this factor is encoded by the eucaryotic cells themselves or an unidentified intracellular microorganism.

Dynamic interactions between host and pathogen during acute urinary tract infections

Urinary tract infections (UTIs) have traditionally been viewed as acute and often self-limiting infections caused predominantly by noninvasive Escherichia coli. However, this concept has been challenged by recent findings demonstrating that an acute bladder infection results from a complex series of host-pathogen interactions that can lead to bacterial invasion and persistence and that ultimately can determine the course of the infectious disease. The ability of E. coli to gain a foothold in the bladder is greatly facilitated by type 1 pilus-mediated attachment to and invasion of bladder epithelial cells. Invasion allows uropathogenic strains of E. coli to exploit the intracellular environment by replicating within these epithelial cells while evading a multitude of host defenses. An intracellular location also provides them a safe haven from many common antibiotic therapies. However, attachment and invasion also activates a cascade of innate host defenses, leading to the death and exfoliation of bladder cells and the production of inflammatory mediators. The ability of uropathogenic E. coli to flux out of cells and colonize surrounding cells provides them a mechanism to subvert these defense mechanisms and persist in the bladder epithelium for weeks following the acute infection. The persistence of E. coli in bladder tissue may be relevant to more chronic diseases of the urinary tract such as recurrent UTIs and interstitial cystitis.

Incidence of Helicobacter pylori in patients with interstitial cystitis

OBJECTIVE

Chronic gastritis has compelling similarities to interstitial cystitis (IC). It is characterised by chronic pain in a tubular organ. Histologically, epithelial damage, inflammatory response in the lamina propria and epithelial ulcerations are seen. An infective cause was rarely considered until the emergence of Helicobacter pylori over the past 15 years. We have had experience of patients with bladder pain and irritability reporting improvement with antihistamines. It has also been reported that IC symptoms improved dramatically after treatment for H. pylori infection. Previous studies have determined the incidence of H. pylori antibodies in women with IC but we examined bladder material histologically and performed the Campylobacter-like organism (CLO) test on the biopsy specimens.

MATERIALS AND METHODS

A prospective controlled study was performed. Patients with urinary symptoms fulfilling the National Institute of Diabetes and Digestive and Kidney Diseases criteria for IC underwent GA cystoscopy at which the macroscopic appearance of the bladder was noted and biopsies were taken. The biopsy material underwent histological examination and CLO test. Control patients who were undergoing cystoscopy for reasons other than investigation of IC also had biopsy taken and the CLO test was performed on these specimens.

RESULTS

Five of 15 patients with symptoms and signs of IC had a positive CLO test. Three of 15 patients of the control group had a positive CLO test. With the 2-sided chi(2) test there was no statistical difference between the 2 groups.

CONCLUSION

Our small prospective control study does not support the hypothesis that H. pylori is an important component in the pathogenesis of interstitial cystitis.

A study to detect Gardnerella vaginalis DNA in interstitial cystitis

OBJECTIVE

To investigate the possible role of Gardnerella vaginalis in interstitial cystitis (IC), using molecular methods to avoid difficulties with the culture and recovery of viable organisms, and the problems associated with the recovery of low numbers of culturable organisms.

MATERIALS AND METHODS

Thirty-three bladder biopsy samples (29 paraffin-embedded and four freshly frozen) from patients with IC, diagnosed according to National Institute of Diabetes, Digestive and Kidney Diseases criteria, were assessed. Biopsy samples were used as urine samples may be contaminated by normal vaginal flora. A positive control comprised a 'normal' biopsy sample from a patient with a previous bladder tumour, seeded with G. vaginalis NCTC 10915. Microbial DNA was extracted from all paraffin-embedded and fresh specimens, and subjected to in vitro amplification by polymerase chain reaction (PCR) with G. vaginalis-specific primers.

RESULTS

The anticipated PCR product of 333 base pairs was obtained with the positive control, whereas none of the other biopsy samples showed positive amplification specific for G. vaginalis.

CONCLUSION

As there was no G. vaginalis DNA in any of the samples from patients with IC, it is an unlikely candidate in the pathogenesis of IC.

Urinary bacterial flora of women with urethral syndrome and interstitial cystitis

The aerobic and anaerobic bacterial flora in the first voided and in the midstream urine of healthy females (n = 5) and female patients with either urethral syndrome (US) (n = 5) or interstitial cystitis (IC) (n = 14) were studied. Bacteria were grown on media enabling isolation of fastidious and aerobic as well as obligatory anaerobic species. In healthy females only gram-positive rods were found whereas US patients also harbored streptococci. Patients with IC presented also with Enterobacteriae and anaerobic bacteria. Five IC patients with severe symptoms were treated with metronidazole; 2 out of 3 patients with anaerobic bacteria in the pretreatment specimens had no anaerobes after metronidazole therapy and in 1 patient streptococci disappeared after the therapy. One patient with severe symptoms and Bacteroides fragilis in the midstream urine became symptom-free after 2 weeks of metronidazole treatment. Although there is uncertainty whether the US and IC are not related to an infectious etiology, the bacterial flora in urethral and in midstream urine in these conditions differs considerably from that of healthy females.

The role of Borrelia burgdorferi in interstitial cystitis

BACKGROUND/AIMS

Borrelia burgdorferi spirochete has been found both in bladder biopsies and the urine of patients with Lyme disease (LD) as well as in experimental animals. The urological symptoms in borreliosis resemble those of interstitial cystitis (IC): frequency, urgency and nocturia. The aim of this studies is to find the role of B. burgdorferi in interstitial cystitis.

METHODS

We studied antibodies against B. burgdorferi from serum samples of 50 IC patients with two separate EIA tests. Patients with positive serology in both tests underwent cystoscopy and a bladder biopsy was taken. The presence of borrelia DNA was studied with borrelia-specific polymerase chain reaction (PCR), and with universal bacterial PCR.

RESULTS

IgM class antibodies to B. burgdorferi were not found, but IgG antibodies were found in four samples (8%). This was higher than in the control material (2%). One patient's sample was strongly positive, whereas three samples were weakly positive. Bladder biopsies taken from the 4 patients were negative for borrelia DNA in both PCR tests. None of the seropositive patients had any symptoms consistent with LD.

CONCLUSION

These results indicate that persistent infection of B. burgdorferi has no role in the etiology of IC. On the other hand a connection with a past borrelia infection and IC is not excluded.

The incidence of Helicobacter pylori in patients with interstitial cystitis

PURPOSE

The cause of interstitial cystitis is unknown. We evaluated the incidence of Helicobacter pylori antibodies in patients with interstitial cystitis to determine whether such infection may be a causative factor.

MATERIALS AND METHODS

We obtained serum samples from 23 patients with interstitial cystitis and 23 control subjects. Samples were analyzed for the presence of H. pylori IgG antibodies.

RESULTS

The incidence of positive tests for H. pylori antibodies was 22% in the interstitial cystitis group and 35% in controls.

CONCLUSIONS

The incidence of infection with H. pylori is not increased in interstitial cystitis, and so it is unlikely to be a causative factor.

Polymerase chain reaction amplification of bacterial 16S rRNA genes in interstitial cystitis and control patient bladder biopsies

PURPOSE

Several characteristics of the chronic bladder disease called interstitial cystitis (IC) suggest an infectious etiology. However, a single causative organism has not been convincingly cultured in vitro, and DNA for a variety of microorganisms has been found inconsistently in bladder biopsies from IC patients. We therefore looked for a possible bacterial cause for IC by using a sensitive nested PCR assay on cystoscopic bladder biopsy specimens obtained from IC patients and controls.

MATERIALS AND METHODS

Bladder biopsies were obtained at cystoscopy from 6 IC patients and 6 controls. DNA was extracted from these specimens and PCR with 2-round amplification performed using nested primers from a highly conserved region of the bacterial 16s rRNA gene. Amplified DNA was purified and sequenced using the Sequenase PCR Product Sequencing Kit, and the sequences obtained were compared with bacterial rRNA gene sequences recorded in GenBank.

RESULTS

Biopsy specimens from all 6 patients and 6 controls were positive by PCR for DNA encoding bacterial 16s rRNA. Sequence data indicated a predominant microorganism in 10 of the 12 specimens, with > 95% homology to DNA from several different genera of bacteria including Acinetobacter, Propionobacterium, Salmonella, and Escherichia. None of the organisms identified by PCR had been cultured from tissue or urine obtained simultaneously from these persons, using sensitive culture techniques.

CONCLUSIONS

These data indicate no difference between IC patients and controls in the proportion of bladder biopsies with PCR positivity or the type(s) of organism present, providing additional evidence that IC is not associated with infection by a particular type of bacterium.

Detection of eubacteria in interstitial cystitis by 16S rDNA amplification

OBJECTIVE

To determine what role non-culturable microorganisms play in the etiology of interstitial cystitis (IC).

MATERIALS AND METHODS

Thirty patients fulfilling NIH criteria for the diagnosis of interstitial cystitis and sixteen control patients with culture negative urine gave written informed consent and underwent bladder biopsy. Polymerase chain reaction (PCR) using two sets of universal primers for bacterial 16S rDNA was performed on urine from the cystoscope and on a cold cup bladder biopsy specimen. Of the PCR positive bladder biopsies, three patients with interstitial cystitis and three controls were randomly selected and cloned. Ten clones from each were sequenced and putative taxonomic assignments made.

RESULTS

12/26 (46%) IC and 5/12 (42%) control urine specimens and 16/30 (53%) and 9/15 (60%) bladder biopsies were PCR positive, respectively. The bacterial populations in the two patient groups tested appeared to be different based upon analysis of the 16S rRNA sequences.

CONCLUSIONS

Both IC and control patients had non-culturable bacteria in their bladders. A random sampling of the two populations revealed that the bacterial populations are different, suggesting a possible link between one or more bacterial species and IC.

Do infectious agents cause interstitial cystitis?

The possibility that infectious agents play a role in the etiology of interstitial cystitis (IC) has been investigated for a number of years. Early studies were directed toward attempts to cultivate bacteria and fungi on routine culture media and microscopic examinations of urine or bladder tissue specimens for the presence of microorganisms. In more recent years, this approach has been expanded to include sophisticated culture techniques to search for the presence of fastidious and unusual organisms that would not be detected by routine culture methods. Similarly, the presence of viruses has been sought by incubating specimens from interstitial cystitis patients in mammalian cell cultures to detect cytopathic effects. None of these approaches has provided convincing evidence that micro-organisms or viruses are associated with IC. The latest attempts to search for the presence of bacteria have made use of the polymerase chain reaction (PCR) to amplify bacterial 16S rRNA genes that would be present if bacteria were present in bladder tissue or urine of IC patients. This approach allows bacteria to be detected and even identified without culture. However, the results from the great majority of bladder biopsy samples analyzed by these molecular techniques have been negative. PCR strategies have also been used to search for the presence of certain viruses in IC specimens, again without success. At this time, the results from laboratory culture, light and electron microscopy, and various molecular strategies to detect micro-organisms and viruses in IC specimens all argue against an infectious etiology for IC.

Absence of bacterial DNA in the bladder of patients with interstitial cystitis

PURPOSE

Although bacterial infection has been long considered a possible cause of interstitial cystitis (IC), no definitive proof for or against this hypothesis has been presented so far. We have used 16S rDNA bacterial polymerase chain reaction to study bladder biopsies and sterile urine samples from patients suffering from IC. This method is sensitive and detects all known eubacteria.

MATERIALS AND METHODS

Bladder biopsies and sterile urine samples obtained by transabdominal puncture were studied from 11 patients with IC. As controls we studied 4 patients with other urological problems leading to partly similar symptoms and 5 healthy individuals.

RESULTS

All samples from the IC patients were negative. One positive sample was obtained from a woman with a history of urinary tract infections who suffered from nonIC ulcerative cystitis. Her sterile urine sample yielded Lactobacillus acidophilus.

CONCLUSION

These results indicate that an ongoing bacterial infection is not the cause of interstitial cystitis.