Does drinking cranberry juice produce urine inhibitory to the development of crystalline, catheter-blocking Proteus mirabilis biofilms?

Potential of Cranberry Jelly to Prevent Urinary Stone Formation After Cutaneous Ureterostomy: A Case Report

One complication of cutaneous ureterostomy is urinary stone formation, which may lead to recurrent pyelonephritis. Frequent catheter changes and the prophylactic administration of antibiotics are commonly used to prevent stone formation. Cranberry products have been reported to inhibit stone formation in indwelling urethral catheters. We herein examined the inhibitory effects of a cranberry product on stone formation in a case of catheter occlusion due to stone formation after cutaneous ureterostomy. The results obtained indicate the potential of cranberry products to prevent stone formation after cutaneous ureterostomy requiring catheter placement.

Proteus mirabilis Biofilm: Development and Therapeutic Strategies

Proteus mirabilis is a Gram negative bacterium that is a frequent cause of catheter-associated urinary tract infections (CAUTIs). Its ability to cause such infections is mostly related to the formation of biofilms on catheter surfaces. In order to form biofilms, P. mirabilis expresses a number of virulence factors. Such factors may include adhesion proteins, quorum sensing molecules, lipopolysaccharides, efflux pumps, and urease enzyme. A unique feature of P. mirabilis biofilms that build up on catheter surfaces is their crystalline nature owing to their ureolytic biomineralization. This leads to catheter encrustation and blockage and, in most cases, is accompanied by urine retention and ascending UTIs. Bacteria embedded in crystalline biofilms become highly resistant to conventional antimicrobials as well as the immune system. Being refractory to antimicrobial treatment, alternative approaches for eradicating P. mirabilis biofilms have been sought by many studies. The current review focuses on the mechanism by which P. mirabilis biofilms are formed, and a state of the art update on preventing biofilm formation and reduction of mature biofilms. These treatment approaches include natural, and synthetic compounds targeting virulence factors and quorum sensing, beside other strategies that include carrier-mediated diffusion of antimicrobials into biofilm matrix. Bacteriophage therapy has also shown successful results in vitro for combating P. mirabilis biofilms either merely through their lytic effect or by acting as facilitators for antimicrobials diffusion.

Bacterial biofilm formation on indwelling urethral catheters

Urethral catheters are the most commonly deployed medical devices and used to manage a wide range of conditions in both hospital and community care settings. The use of long-term catheterization, where the catheter remains in place for a period >28 days remains common, and the care of these patients is often undermined by the acquisition of infections and formation of biofilms on catheter surfaces. Particular problems arise from colonization with urease-producing species such as Proteus mirabilis, which form unusual crystalline biofilms that encrust catheter surfaces and block urine flow. Encrustation and blockage often lead to a range of serious clinical complications and emergency hospital referrals in long-term catheterized patients. Here we review current understanding of bacterial biofilm formation on urethral catheters, with a focus on crystalline biofilm formation by P. mirabilis, as well as approaches that may be used to control biofilm formation on these devices. SIGNIFICANCE AND IMPACT OF THE STUDY: Urinary catheters are the most commonly used medical devices in many healthcare systems, but their use predisposes to infection and provide ideal conditions for bacterial biofilm formation. Patients managed by long-term urethral catheterization are particularly vulnerable to biofilm-related infections, with crystalline biofilm formation by urease producing species frequently leading to catheter blockage and other serious clinical complications. This review considers current knowledge regarding biofilm formation on urethral catheters, and possible strategies for their control.

Conservative bladder management in advanced multiple sclerosis

Anticholinergics and intermittent catheterization are the cornerstones of bladder management in early multiple sclerosis (MS). In advanced MS however, bladder management is based more on tradition than on evidence. Nurses seem to deal with catheter problems and chronic incontinence. Despite the abundant use of indwelling catheters, there is a lack for guidelines on catheter-induced problems. The psychosexual and social impact of bladder problems in advanced MS is often neglected. The international multidisciplinary special interest group on sexual, urological and bowel dysfunction in MS (SUBDIMS) as a special interest group of the Rehabilitation in Multiple Sclerosis (RIMS) was confronted with a high variability in practice and a lack of guidelines. A literature review was prepared during three multidisciplinary expert meetings. This review will be the basis of further initiatives to improve the urological treatment of patients with advanced MS.

Cranberry derivatives enhance biofilm formation and transiently impair swarming motility of the uropathogen Proteus mirabilis HI4320

Proteus mirabilis is a major cause of catheter-associated urinary tract infection (CAUTI), emphasizing that novel strategies for targeting this bacterium are needed. Potential targets are P. mirabilis surface-associated swarming motility and the propensity of these bacteria to form biofilms that may lead to catheter blockage. We previously showed that the addition of cranberry powder (CP) to lysogeny broth (LB) medium resulted in impaired P. mirabilis swarming motility over short time periods (up to 16 h). Herein, we significantly expanded on those findings by exploring (i) the effects of cranberry derivatives on biofilm formation of P. mirabilis, (ii) whether swarming inhibition occurred transiently or over longer periods more relevant to real infections (∼3 days), (iii) whether swarming was also blocked by commercially available cranberry juices, (iv) whether CP or cranberry juices exhibited effects under natural urine conditions, and (v) the effects of cranberry on medium pH, which is an indirect indicator of urease activity. At short time scales (24 h), CP and commercially available pure cranberry juice impaired swarming motility and repelled actively swarming bacteria in LB medium. Over longer time periods more representative of infections (∼3 days), the capacity of the cranberry material to impair swarming diminished and bacteria would start to migrate across the surface, albeit by exhibiting a different motility phenotype to the regular "bull's-eye" swarming phenotype of P. mirabilis. This bacterium did not swarm on urine agar or LB agar supplemented with urea, suggesting that any potential application of anti-swarming compounds may be better suited to settings external to the urine environment. Anti-swarming effects were confounded by the ability of cranberry products to enhance biofilm formation in both LB and urine conditions. These findings provide key insights into the long-term strategy of targeting P. mirabilis CAUTIs.

Impact of cranberry juice on initial adhesion of the EPS producing bacterium Burkholderia cepacia

The impact of cranberry juice was investigated with respect to the initial adhesion of three isogenic strains of the bacterium Burkholderia cepacia with different extracellular polymeric substance (EPS) producing capacities, viz. a wild-type cepacian EPS producer PC184 and its mutant strains PC184rml with reduced EPS production and PC184bceK with a deficiency in EPS production. Adhesion experiments conducted in a parallel-plate flow chamber demonstrated that, in the absence of cranberry juice, strain PC184 had a significantly higher adhesive capacity compared to the mutant strains. In the presence of cranberry juice, the adhesive capacity of the EPS-producing strain PC184 was largely reduced, while cranberry juice had little impact on the adhesion behavior of either mutant strain. Thermodynamic modeling supported the results from adhesion experiments. Surface force apparatus (SFA) and scanning electron microscope (SEM) studies demonstrated a strong association between cranberry juice components and bacterial EPS. It was concluded that cranberry juice components could impact bacterial initial adhesion by adhering to the EPS and impairing the adhesive capacity of the cells, which provides an insight into the development of novel treatment strategies to block the biofilm formation associated with bacterial infection.

Vinegar for Decreasing Catheter-Associated Bacteriuria in Long-Term Catheterized Patients

Purpose: The purpose of this study was to evaluate the effect of rice vinegar administered via nasogastric feeding tube on catheter-associated bacteriuria in patients with long-term urinary catheterization. Method: The authors conducted a randomized controlled trial ( n = 60) to compare treatment with dilute vinegar and usual care. The authors recruited patients with chronic catheters from a long-term care facility in northern Taiwan. The experimental group received 100 ml of diluted rice vinegar each day for 4 weeks, whereas the control group received 100 ml of water. The authors analyzed urine weekly and cultured it on Day 28. Results: The generalized estimating equation results showed significant between-group differences in urinary pH, bacterial titer, and turbidity. No patient in the experimental group, but three in the control group, exhibited symptomatic urinary tract infection (UTI). Rice vinegar may decrease bacteriuria. Medicinal use of vinegar may decrease the risk of symptomatic UTI, but further study is needed to determine the effects of ingesting vinegar for a longer period and with a larger sample size.

Cranberry and urinary tract infections

Urinary tract infection (UTI) refers to the presence of clinical signs and symptoms arising from the genitourinary tract plus the presence of one or more micro-organisms in the urine exceeding a threshold value for significance (ranges from 102 to 103 colony-forming units/mL). Infections are localized to the bladder (cystitis), renal parenchyma (pyelonephritis) or prostate (acute or chronic bacterial prostatitis). Single UTI episodes are very common, especially in adult women where there is a 50-fold predominance compared with adult men. In addition, recurrent UTIs are also common, occurring in up to one-third of women after first-episode UTIs. Recurrences requiring intervention are usually defined as two or more episodes over 6 months or three or more episodes over 1 year (this definition applies only to young women with acute uncomplicated UTIs). A cornerstone of prevention of UTI recurrence has been the use of low-dose once-daily or post-coital antimicrobials; however, much interest has surrounded non-antimicrobial-based approaches undergoing investigation such as use of probiotics, vaccines, oligosaccharide inhibitors of bacterial adherence and colonization, and bacterial interference with immunoreactive extracts of Escherichia coli. Local (intravaginal) estrogen therapy has had mixed results to date. Cranberry products in a variety of formulations have also undergone extensive evaluation over several decades in the management of UTIs. At present, there is no evidence that cranberry can be used to treat UTIs. Hence, the focus has been on its use as a preventative strategy. Cranberry has been effective in vitro and in vivo in animals for the prevention of UTI. Cranberry appears to work by inhibiting the adhesion of type I and P-fimbriated uropathogens (e.g. uropathogenic E. coli) to the uroepithelium, thus impairing colonization and subsequent infection. The isolation of the component(s) of cranberry with this activity has been a daunting task, considering the hundreds of compounds found in the fruit and its juice derivatives. Reasonable evidence suggests that the anthocyanidin/proanthocyanidin moieties are potent antiadhesion compounds. However, problems still exist with standardization of cranberry products, which makes it extremely difficult to compare products or extrapolate results. Unfortunately, most clinical trials have had design deficiencies and none have evaluated specific key cranberry-derived compounds considered likely to be active moieties (e.g. proanthocyanidins). In general, the preventive efficacy of cranberry has been variable and modest at best. Meta-analyses have established that recurrence rates over 1 year are reduced approximately 35% in young to middle-aged women. The efficacy of cranberry in other groups (i.e. elderly, paediatric patients, those with neurogenic bladder, those with chronic indwelling urinary catheters) is questionable. Withdrawal rates have been quite high (up to 55%), suggesting that these products may not be acceptable over long periods. Adverse events include gastrointestinal intolerance, weight gain (due to the excessive calorie load) and drug-cranberry interactions (due to the inhibitory effect of flavonoids on cytochrome P450-mediated drug metabolism). The findings of the Cochrane Collaboration support the potential use of cranberry products in the prophylaxis of recurrent UTIs in young and middle-aged women. However, in light of the heterogeneity of clinical study designs and the lack of consensus regarding the dosage regimen and formulation to use, cranberry products cannot be recommended for the prophylaxis of recurrent UTIs at this time.

Cranberry juice for prophylaxis of urinary tract infections--conclusions from clinical experience and research

Cranberry juice (Vaccinium macrocarpon) is a widely used and recommended North-American folk remedy for prophylaxis of urinary tract infections (UTI). Clinical trials have documented its efficacy in women with recurrent UTI, but so far not in other groups of patients. The composition of effective cranberry products and its dosage in UTI prophylaxis have not been defined. Intriguing experimental research has identified an anti-adhesive mechanism of cranberry juice that prevents docking of bacteria on host tissues. This efficacy mechanism can be traced in patients' urine following oral intake of cranberry products and appears to be due to proanthocyanidins with an A-type linkage of flavanols. The application of this anti-adhesion mechanism of cranberry-proanthocyandins is currently also investigated in other common diseases of bacterial pathogenesis, for example Helicobacter pylori-associated gastritis and dental caries/periodontal disease. The use of cranberry products appears to be safe and provide additional benefits by anti-oxidant and cholesterol-lowering activity.

Effective evidence based catheter management

People who have long-term urinary catheters commonly experience problems with bypassing and leakage. Changing the catheter is not necessarily the most appropriate solution. Catheter related problems provide nurses with the opportunity to evaluate the clinical indications for continued catheterization and to remove catheters that are not clinically indicated. When catheters are clinically indicated nurses who use an evidence based approach to diagnose and treat problems provide effective care and reduce the risk of patient discomfort and recurrent problems.

Role of bacterial biofilms in urinary tract infections

Bacterial urinary tract infections represent the most common type of nosocomial infection. In many cases, the ability of bacteria to both establish and maintain these infections is directly related to biofilm formation on indwelling devices or within the urinary tract itself. This chapter will focus on the role of biofilm formation in urinary tract infections with an emphasis on Gram-negative bacteria. The clinical implications of biofilm formation will be presented along with potential strategies for prevention. In addition, the role of specific pathogen-encoded functions in biofilm development will be discussed.

The cranberry and the urinary tract

Cranberry products have been heralded as natural treatments for urinary tract infections (UTIs) and have been widely used for this purpose. Current evidence favours an antibacterial role for the cranberry's natural polyphenols or tannins. Although limited species- and strain-specific direct inhibition has been determined in vitro, it has been suggested that a key mechanism of inhibition, especially for the abundant uropathogenic E. coli, relies on anti-adhesion properties. Many studies of prevention have been complicated due to the enrollment of patients who have had complicated urinary tracts, and outcomes have not been consistently favourable. In contrast, significant prevention has been shown for acute cystitis among high-risk young females. While reasonably well tolerated and deplete from side effects, further scientific work is required to better place the role of cranberry products in the management of UTIs. Progress in this area has set the stage for further hypothesis testing studies.

Care of the Indwelling Urinary Catheter

This article reviews evidence-based practice guidelines for the care of indwelling urinary catheters in acute, long-term, and home care settings. Upon completion of this reading, the clinician will have a better understanding of urinary catheter management of short-term and long-term placement, possible complications from catheter use, the importance of alternative options for catheter placement, and recommendations for patient education. Basic infection prevention, existing catheter types, and the differences between men and women with the use of these catheters will also be addressed. Practices that are no longer recommended, as well as present research on the use of silver alloy catheters and their role in preventing infection, are summarized.

Modulation of crystalline Proteus mirabilis biofilm development on urinary catheters

The crystalline biofilms formed by Proteus mirabilis can seriously complicate the care of patients undergoing long-term bladder catheterization. The generation of alkaline urine by the bacterial urease causes calcium and magnesium phosphates to precipitate from urine and accumulate in the catheter biofilm, blocking the flow of urine from the bladder. The pH at which these salts crystallize from a urine sample, the nucleation pH (pH(n)), can be elevated by diluting the urine and by increasing its citrate content. The aim of this study was to examine whether manipulation of pH(n) in these ways modulated the rate at which crystalline biofilm developed. Experiments in laboratory models of the catheterized bladder infected with P. mirabilis showed that when the bladder was supplied with a concentrated urine (pH(n) 6.7) at a low fluid output (720 ml per 24 h), catheters blocked at 19-31 h. Diluting this urine 1:4 increased the pH(n) to 7.5 and models supplied with this urine at 2880 ml per 24 h took 110-137 h to block. When models were supplied with urine containing citrate at 1.5 mg ml(-1) or above (pH(n) 8.3-9.1), the catheters drained freely for the full 7 day experimental period. Scanning electron microscopy revealed that the catheter biofilms that developed in urine with high pH(n) values were devoid of crystalline formations. These observations should encourage a clinical trial to examine the effect of increasing a patient's fluid intake with citrate-containing drinks on the encrustation and blockage of catheters.

Awareness of Urine Flow in People With Long-Term Urinary Catheters

OBJECTIVES

The purpose of this study is to acquire knowledge about urine flow in relation to fluid intake and urinary output, catheter blockage, and urinary tract infection in people with long-term urinary catheters.

DESIGN

This was a community-based exploratory and descriptive study.

SETTING AND SUBJECTS

The research was conducted in the homes of participants, who were interviewed in North Carolina from October 2002 to June 2003. The sample included 21 males and 9 females, aged 23-96 years; almost half were members of minority groups.

INSTRUMENTS

A urinary diary was used, including intake and output recordings and narrative data, as well as a semistructured interview schedule.

METHODS

Three-day fluid intake and urinary diary data were collected, followed by face-to-face tape-recorded interviews in participants' homes related to catheter experiences and practices. Analysis of data involved descriptive statistics and content analysis of narrative data.

RESULTS

Although urine flow frequently was disrupted by urinary sediment or kinks in tubing, urinary tract infection was significantly related only to traumatic catheter manipulations or catheter blockage. Catheter problems associated with urinary tract infection included: (1) "rough" catheter insertions, (2) "difficult" insertions, and (3) catheter blockage.

CONCLUSION

Self-monitoring of urine flow may help prevent urinary tract infection episodes through careful attention to catheter position and by preventing blockage. Further study is needed to fully understand the role of fluid intake and determine what causes traumatic catheter insertions.

Factors affecting crystal precipitation from urine in individuals with long-term urinary catheters colonized with urease-positive bacterial species

Weekly urinalysis was conducted for 12 weeks on a group of 21 long-term catheter users with confirmed catheter encrustation and urinary tract colonization with urease-positive bacteria, in order to explore the cause of considerable variation in the severity of encrustation between sufferers. The rapidity of catheter blockage correlated significantly with the pH above which crystals precipitated from urine (the nucleation pH) but not the pH of the voided urine itself. Linear regression showed the nucleation pH to be significantly predicted by a combination of urinary calcium and magnesium concentrations, with calcium being the more influential variable. Reducing the rate of catheter encrustation could be achieved by lowering the urinary concentration of calcium and magnesium, which may only require catheter users to increase their fluid intake.

Prospective study of individuals with long-term urinary catheters colonized with Proteus species

OBJECTIVES

To characterize the variability in the times catheters take to block with encrustation in patients who have Proteus in their urinary flora, and to identify factors responsible for modulating the rate of catheter encrustation and blockage.

PATIENTS AND METHODS

Twenty patients were followed prospectively for > or = 12 weeks, with a bacteriological analysis on weekly urine samples. The pH of the voided urine samples and the pH at which crystals formed in them (the nucleation pH) were determined. Catheters were collected and examined for bacterial biofilm and crystal deposition.

RESULTS

The time that catheters took to block was 2-98 days. The mean pH of the urine voided by patients designated as slow encrusters (6.9) was not significantly different (P = 0.237) from that of rapid encrusters (7.2). However, patients whose catheters took longer to block had a significantly higher mean nucleation pH (8.1 vs 7.3, P = 0.002) and significantly higher mean safety margin between their nucleation pH and voided pH (1.17 pH units vs 0.13, P = 0.003).

CONCLUSION

The variation in the rate of catheter encrustation between individuals infected with Proteus is a function of the difference between the voided pH and the nucleation pH of their urine. The value of nucleation pH of an individual's urine varies widely, suggesting it should be possible to devise strategies to increase this value and thus reduce the rate of encrustation in those with urinary tract colonization by urease-positive bacteria.

Action of ciprofloxacin on planktonic bacteria and biofilm of Proteus mirabilis

Proteus mirabilis can persist in biofilms, with the bacteria in this state tending to resist antibiotic therapy. Until now, the relationship between the action of ciprofloxacin and the production of reactive oxygen species (ROS) has not been studied in planktonic and biofilmic P. mirabilis. Our results show that ciprofloxacin stimulates the production of ROS in planktonic P. mirabilis, but that the increase in ROS was observed in sensitive strains (n = 4) only in the absence of the extracellular matrix (ECM). This augmentation of ROS was principally intracellular, invoking an increase in intracellular superoxide dismutase (SOD). ROS were assayed by chemiluminescence (CL) and SOD by inhibition of reduction of nitroblue tetrazolium in the presence of methionine, riboflavin and light. The antibiotic-resistant strains (n = 4) did not suffer oxidative stress and exhibited a higher antioxidant capacity than antibiotic-sensitive ones, as indicated by tripyridyltriazine assay. Both types of bacterial strain showed a reduction in antioxidant capacity in the presence of ciprofloxacin, and only the resistant bacteria returned to normal count levels within 5 min of introduction of antibiotic. Ciprofloxacin stimulated ROS more than it did nitric oxide (NO) in planktonic bacteria, as determined by Griess's reaction. Proteus mirabilis biofilms treated with ciprofloxacin did not suffer any increase in ROS but there was an increase in NO and the ratio of intracellular ROS:NO decreased to 25%. Biofilms of P. mirabilis were neither stressed nor inhibited by 40 µg ciprofloxacin/ml, a dose higher than the minimum inhibitory concentration (i.e. supra MIC). Both resistant and sensitive strains maintained the number of viable bacteria in biofilms incubated with supra MIC ciprofloxacin at concentrations that stressed and reduced substantially the number of colony-forming units of planktonic bacteria per millilitre. These results contribute to understanding of the differences between biofilmic and planktonic bacteria, with respect to susceptibility to oxidative stress caused by ciprofloxacin and also the antioxidant effect of ECM.

Infección urinaria asociada a catéteres urinarios en la comunidad

The prevalence of urinary catheterization in the community ranges from 0.02% to 0.07%. Despite the generalized use of closed systems, the risk of bacteriuria in patients with urethral catheters is 3%-10% per day and its presence is universal when the device remains in place for 30 days or longer. Although most of these episodes of bacteriuria are asymptomatic, up to 30% of them lead to clinical symptoms and complications, including severe sepsis and death. The microorganisms infecting the urine of catheterized patients frequently belong to species less susceptible to antibiotics and form biofilms on both the device's surfaces and probably also on the urothelium. Biofilm formation greatly hampers eradication of the involved flora by antibiotics, probably favors the development of resistance and, in some instances, constitutes the substrate on which crystal precipitates are deposited, eventually resulting in blockage of the catheter lumen. Due to the scarce number of controlled studies, there are still many gaps in our knowledge of important issues concerning the clinical management of patients with indwelling urinary catheters in the community. The present study reviews the epidemiology, risk factors, microbiology, pathogenesis, clinical manifestations, diagnosis, prevention and treatment of catheter-related urinary tract infections in the community setting.

Encrustation of biomaterials in the urinary tract

This review considers the problem of the encrustation of biomaterials used for urinary prostheses. After a general discussion of the problem it deals with exciting new developments which may prove to be clinically applicable in preventing this costly and resource consuming complication. The widespread use of use of in vitro models which accurately simulate the conditions found in the human urinary tract will allow appropriate preliminary studies. Perhaps then clinical evaluation will be warranted.