Urinary tract infection: economic considerations

Longitudinal molecular analysis of clinical and fecal Escherichia coli isolates at a Veterans Affairs Medical Center in Minnesota, USA, 2012-2019

Introduction

Extraintestinal Escherichia coli infections represent a growing public health threat, However, current studies often overlook important factors such as temporal patterns of infection, phylogenetic and clonal background, or the host gut E. coli population, despite their likely significance.

Methods

In this study, we analyzed >7000 clinical E. coli isolates from patients at the Minneapolis Veterans Affairs Health Care System (2012-2019), and concurrent fecal E. coli from uninfected veterans. We assessed phylogenetic group distribution, membership in selected sequence types (STs), and subsets thereof-including the pandemic, resistance-associated ST131-H30R, and ST1193 lineages-and strain type, as defined by pulsed-field gel electrophoresis. We then analyzed these features alongside the temporal patterns of infection in individual hosts.

Results

The H30R lineage emerged as the leading lineage, both overall and among fluoroquinolone-resistant isolates, with ST1193 following among fluoroquinolone-resistant isolates. Recurrences were common, occurring in 31% of subjects and 41% of episodes, and often multiple and delayed/prolonged (up to 23 episodes per subject; up to 2655d post-index). Remarkably, these recurrences typically involved the subject's index strain (63% of recurrences), even when affecting extra-urinary sites. ST131, H30R, ST1193, and fluoroquinolone-resistant strains generally caused significantly more recurrences than did other strains, despite similar recurrence intervals. ST131 strain types shifted significantly over the study period. Infection-causing strains were commonly detectable in host feces at times other than during an infection episode; the likelihood of detection varied with surveillance intensity and proximity to the infection. H30R and ST1193 were prominent causes of fecal-clinical clonal overlap.

Discussion

These findings provide novel insights into the temporal and clonal characteristics of E. coli infections in veterans and support efforts to develop anti-colonization interventions.

Cranberries for treating urinary tract infections

BACKGROUND

Cranberries (particularly in the form of cranberry juice) have been used widely for several decades for the prevention and treatment of urinary tract infections (UTIs). The aim of this review is to assess the effectiveness of cranberries in treating such infections.

OBJECTIVES

To assess the effectiveness of cranberries for the treatment of UTIs.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 1 August 2023 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Portal (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs) or quasi-RCTs of cranberry juice or cranberry products for the treatment of UTIs. Studies of men, women or children were to be included.

DATA COLLECTION AND ANALYSIS

Titles and abstracts of studies that were potentially relevant to the review were screened and studies that were clearly ineligible were discarded. Further information was sought from the authors where papers contained insufficient information to make a decision about eligibility.

MAIN RESULTS

No studies were found that fulfilled all of our inclusion criteria. Seven studies were excluded because they were the wrong study design, mixed interventions or did not report any relevant outcomes. One study is ongoing; however, its current status is unknown.

AUTHORS' CONCLUSIONS

After a thorough search, no RCTs which assessed the effectiveness of cranberry juice for the treatment of UTIs were found. Therefore, at the present time, there is no good quality evidence to suggest that it is effective for the treatment of UTIs. Well-designed parallel-group, double-blind studies comparing cranberry juice and other cranberry products versus placebo to assess the effectiveness of cranberry juice in treating UTIs are needed. Outcomes should include a reduction in symptoms, sterilisation of the urine, side effects and adherence to therapy. The dosage (amount and concentration) and duration of therapy should also be assessed. Consumers and clinicians will welcome the evidence from these studies.

Cranberries for preventing urinary tract infections

BACKGROUND

Cranberries contain proanthocyanidins (PACs), which inhibit the adherence of p-fimbriated Escherichia coli to the urothelial cells lining the bladder. Cranberry products have been used widely for several decades to prevent urinary tract infections (UTIs). This is the fifth update of a review first published in 1998 and updated in 2003, 2004, 2008, and 2012.

OBJECTIVES

To assess the effectiveness of cranberry products in preventing UTIs in susceptible populations.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register up to 13 March 2023 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs) or quasi-RCTs of cranberry products compared with placebo, no specific treatment or other intervention (antibiotics, probiotics) for the prevention of UTIs were included.

DATA COLLECTION AND ANALYSIS

At least two authors independently assessed and extracted data. Information was collected on methods, participants, interventions and outcomes (incidence of symptomatic UTIs, positive culture results, side effects, adherence to therapy). Risk ratios (RR) with 95% confidence intervals (CI) were calculated where appropriate. Study quality was assessed using the Cochrane risk of bias assessment tool. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

For this update, 26 new studies were added, bringing the total number of included studies to 50 (8857 randomised participants). The risk of bias for sequence generation and allocation concealment was low for 29 and 28 studies, respectively. Thirty-six studies were at low risk of performance bias, and 23 studies were at low risk of detection bias. Twenty-seven, 41, and 17 studies were at low risk of attrition bias, reporting bias and other bias, respectively. Forty-five studies compared cranberry products with placebo, water or no specific treatment in six different groups of participants. Twenty-six of these 45 studies could be meta-analysed for the outcome of symptomatic, culture-verified UTIs. In moderate certainty evidence, cranberry products reduced the risk of UTIs (6211 participants: RR 0.70, 95% CI 0.58 to 0.84; I² = 69%). When studies were divided into groups according to the treatment indication, cranberry products probably reduced the risk of symptomatic, culture-verified UTIs in women with recurrent UTIs (8 studies, 1555 participants: RR 0.74, 95% CI 0.55 to 0.99; I² = 54%), in children (5 studies, 504 participants: RR 0.46, 95% CI 0.32 to 0.68; I² = 21%) and in people with a susceptibility to UTIs due to an intervention (6 studies, 1434 participants: RR 0.47, 95% CI 0.37 to 0.61; I² = 0%). However, there may be little or no benefit in elderly institutionalised men and women (3 studies, 1489 participants: RR 0.93, 95% CI 0.67 to 1.30; I² = 9%; moderate certainty evidence), pregnant women (3 studies, 765 participants: RR 1.06, 95% CI 0.75 to 1.50; I² = 3%; moderate certainty evidence), or adults with neuromuscular bladder dysfunction with incomplete bladder emptying (3 studies, 464 participants: RR 0.97, 95% CI 0.78 to 1.19; I² = 0%; low certainty evidence). Other comparisons were cranberry products with probiotics (three studies) or antibiotics (six studies), cranberry tablets with cranberry liquid (one study), and different doses of PACs (two studies). Compared to antibiotics, cranberry products may make little or no difference to the risk of symptomatic, culture-verified UTIs (2 studies, 385 participants: RR 1.03, 95% CI 0.80 to 1.33; I² = 0%) or the risk of clinical symptoms without culture (2 studies, 336 participants: RR 1.30, 95% CI 0.79 to 2.14; I² = 68%). Compared to probiotics, cranberry products may reduce the risk of symptomatic, culture-verified UTIs (3 studies, 215 participants: RR 0.39, 95% CI 0.27 to 0.56; I = 0%). It is unclear whether efficacy differs between cranberry juice and tablets or between different doses of PACs, as the certainty of the evidence was very low. The number of participants with gastrointestinal side effects probably does not differ between those taking cranberry products and those receiving a placebo or no specific treatment (10 studies, 2166 participants: RR 1.33, 95% CI 1.00 to 1.77; I² = 0%; moderate certainty evidence). There was no clear relationship between compliance with therapy and the risk for repeat UTIs. No difference in the risk for UTIs could be demonstrated between low, moderate and high doses of PACs.

AUTHORS' CONCLUSIONS

This update adds a further 26 studies, taking the total number of studies to 50 with 8857 participants. These data support the use of cranberry products to reduce the risk of symptomatic, culture-verified UTIs in women with recurrent UTIs, in children, and in people susceptible to UTIs following interventions. The evidence currently available does not support its use in the elderly, patients with bladder emptying problems, or pregnant women.

α-Hemolysin promotes uropathogenic E. coli persistence in Bladder epithelial cells Via abrogating bacteria-harboring lysosome acidification

There is a growing consensus that a significant proportion of recurrent urinary tract infections are linked to the persistence of uropathogens within the urinary tract and their re-emergence upon the conclusion of antibiotic treatment. Studies in mice and human have revealed that uropathogenic Escherichia coli (UPEC) can persist in bladder epithelial cells (BECs) even after the apparent resolution of the infection. Here, we found that, following the entry of UPEC into RAB27b+ fusiform vesicles in BECs, some bacteria escaped into the cytoplasmic compartment via a mechanism involving hemolysin A (HlyA). However, these UPEC were immediately recaptured within LC3A/B+ autophagosomes that matured into LAMP1+ autolysosomes. Thereafter, HlyA+ UPEC-containing lysosomes failed to acidify, which is an essential step for bacterial elimination. This lack of acidification was related to the inability of bacteria-harboring compartments to recruit V-ATPase proton pumps, which was attributed to the defragmentation of cytosolic microtubules by HlyA. The persistence of UPEC within LAMP1+ compartments in BECs appears to be directly linked to HlyA. Thus, through intravesicular instillation of microtubule stabilizer, this host defense response can be co-opted to reduce intracellular bacterial burden following UTIs in the bladder potentially preventing recurrence.

Cranberries for preventing urinary tract infections

BACKGROUND

Cranberries contain proanthocyanidins (PACs), which inhibit the adherence of p-fimbriated Escherichia coli to the urothelial cells lining the bladder. Cranberry products have been used widely for several decades to prevent urinary tract infections (UTIs). This is the fifth update of a review first published in 1998 and updated in 2003, 2004, 2008, and 2012.

OBJECTIVES

To assess the effectiveness of cranberry products in preventing UTIs in susceptible populations.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register up to 13 March 2023 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register Search Portal (ICTRP) and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs) or quasi-RCTs of cranberry products compared with placebo, no specific treatment or other intervention (antibiotics, probiotics) for the prevention of UTIs were included.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed and extracted data. Information was collected on methods, participants, interventions and outcomes (incidence of symptomatic UTIs, positive culture results, side effects, adherence to therapy). Risk ratios (RR) with 95% confidence intervals (CI) were calculated where appropriate. Study quality was assessed using the Cochrane risk of bias assessment tool. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

For this update 26 new studies were added, bringing the total number of included studies to 50 (8857 randomised participants). The risk of bias for sequence generation and allocation concealment was low for 29 and 28 studies, respectively. Thirty-six studies were at low risk of performance bias, and 23 studies were at low risk of detection bias. Twenty-seven, 41, and 17 studies were at low risk of attrition bias, reporting bias and other bias, respectively. Forty-five studies compared cranberry products with placebo or no specific treatment in six different groups of participants. Twenty-six of these 45 studies could be meta-analysed for the outcome of symptomatic, culture-verified UTIs. In moderate certainty evidence, cranberry products reduced the risk of UTIs (6211 participants: RR 0.70, 95% CI 0.58 to 0.84; I² = 69%). When studies were divided into groups according to the treatment indication, cranberry products probably reduced the risk of symptomatic, culture-verified UTIs in women with recurrent UTIs (8 studies, 1555 participants: RR 0.74, 95% CI 0.55 to 0.99; I² = 54%), in children (5 studies, 504 participants: RR 0.46, 95% CI 0.32 to 0.68; I² = 21%) and in people with a susceptibility to UTIs due to an intervention (6 studies, 1434 participants: RR 0.47, 95% CI 0.37 to 0.61; I² = 0%). However, in low certainty evidence, there may be little or no benefit in elderly institutionalised men and women (3 studies, 1489 participants: RR 0.93, 95% CI 0.67 to 1.30; I² = 9%), pregnant women (3 studies, 765 participants: RR 1.06, 95% CI 0.75 to 1.50; I² = 3%), or adults with neuromuscular bladder dysfunction with incomplete bladder emptying (3 studies, 464 participants: RR 0.97, 95% CI 0.78 to 1.19; I² = 0%). Other comparisons were cranberry products with probiotics (three studies) or antibiotics (six studies), cranberry tablets with cranberry liquid (one study), and different doses of PACs (two studies). Compared to antibiotics, cranberry products may make little or no difference to the risk of symptomatic, culture-verified UTIs (2 studies, 385 participants: RR 1.03, 95% CI 0.80 to 1.33; I² = 0%) or the risk of clinical symptoms without culture (2 studies, 336 participants: RR 1.30, 95% CI 0.79 to 2.14; I² = 68%). Compared to probiotics, cranberry products may reduce the risk of symptomatic, culture-verified UTIs (3 studies, 215 participants: RR 0.39, 95% CI 0.27 to 0.56; I = 0%). It is unclear whether efficacy differs between cranberry juice and tablets or between different doses of PACs as the certainty of the evidence was very low. The number of participants with gastrointestinal side effects probably does not differ between those taking cranberry products and those receiving placebo or no specific treatment (10 studies, 2166 participants: RR 1.33, 95% CI 1.00 to 1.77; I² = 0%; moderate certainty evidence). There was no clear relationship between compliance with therapy and the risk for repeat UTIs. No difference in the risk for UTIs could be demonstrated between low, moderate and high doses of PACs.

AUTHORS' CONCLUSIONS

This update adds a further 26 studies taking the total number of studies to 50 with 8857 participants. These data support the use of cranberry products to reduce the risk of symptomatic, culture-verified UTIs in women with recurrent UTIs, in children, and in people susceptible to UTIs following interventions. The evidence currently available does not support its use in the elderly, patients with bladder emptying problems, or pregnant women.

The Microbiome’s Function in Disorders of the Urinary Bladder

The introduction of next generation sequencing techniques has enabled the characterization of the urinary tract microbiome, which resulted in the rejection of the long-held notion of urinary bladder sterility. Since the discovery and confirmation of the human bladder microbiome, an increasing number of studies have defined this microbial community and understand better its relationship to urinary pathologies. The composition of microbial communities in the urinary tract is linked to a variety of urinary diseases. The purpose of this review is to provide an overview of current information about the urinary microbiome and diseases as well as the development of novel treatment methods.

Microbiological Features and Clinical Factors Associated with Empirical Antibiotic Resistance in Febrile Patients with Upper Urinary Tract Calculi

BACKGROUND

To investigate the clinical and microbiological features of febrile patients with upper urinary tract calculi and factors that affect empirical antibiotic resistance.

METHODS

A retrospective analysis was performed on 203 febrile patients hospitalized between January 2011 and December 2016 with antibiotic treatment for urinary tract infections and upper urinary tract calculi at three institutions. We collected and analyzed data, including patients' age, sex, body mass index, underlying diseases, stone-related factors, and the results of urine and blood culture examinations and antibiotic sensitivity tests.

RESULTS

The male-to-female ratio was 1:2.3. Bacteria were identified in 152 of the 203 patients (74.9%). The most commonly cultured microorganisms included Escherichia coli (44.1%), followed by Enterococci spp. (11.8%), Proteus spp. (8.6%), Streptococcus agalactiae (6.6%), Klebsiella spp. (5.3%), Pseudomonas spp. (4.6%), coagulase-negative Staphylococcus (4.0%), Staphylococcus epidermidis (4.0%), Serratia spp. (2.6%), Enterobacter spp. (0.7%), Acinetobacter spp. (0.7%), and mixed infections (7.2%). Cultured bacterial species showed sex-specific differences. Multivariate analysis revealed that calculi's multiplicity was an independent predictive factor for quinolone resistance (P = 0.008). Recurrent infections were a significant predictor of cefotaxime resistance during multivariable analysis (P = 0.041).

CONCLUSION

Based on the present study results, quinolone was not recommended as the empirical treatment in febrile patients with upper urinary tract calculi. Combination antibiotic therapy is recommended in cases of recurrent infections due to the possible occurrence of cefotaxime resistance.

Potential clinical application of an automated fluorescent microbial cell counter in the detection of urinary tract infection

Background

Urinary tract infections (UTI) account for millions of office visits and approximately 400 000 hospital admissions every year in the United States; as a result, the cost burden of UTI in the USA is estimated at approximately $2.8 billion. There is a great deal of interest in finding newer, faster, and more reliable methods for diagnosing UTI as compared to the standard urine culture.

Methods

An automated fluorescent microbial cell counter was used to compare urine samples found to be positive for Escherichia coli UTI via cell culturing (n = 11) with UTI‐negative samples (n = 10).

Results

Patients with a positive urine culture had significantly higher cell count results using the microbial cell counter (1.01 × 10⁸ cells/mL) as compared to the negative samples (2.35 × 10⁶ cells/mL; P = .0022).

Conclusions

These observations suggest that automated microbial cell counters may serve as a rapid, objective method for the detection of bacteriuria in urine samples submitted for evaluation of suspected UTI.

Susceptibility of Urinary Tract Bacteria to Newer Antimicrobial Drugs

Urinary tract infections (UTIs) are among the commonest types of bacterial infections. The antibiotic treatment for UTIs is associated with important medical and economic implications. Many different microorganisms can cause UTIs though the most common pathogens are E. coli and members of family Enterobacteriaceae. The knowledge of etiology and antibiotic resistance pattern of the organisms causing urinary tract infection is essential. The present study was undertaken to evaluate trends of antibiotic susceptibility of commonly isolated uropathogens using newer antimicrobial agents, prulifloxacin, fosfomycin (FOM) and doripenem. We conclude that maintaining a record of culture results and the antibiogram may help clinicians to determine the empirical and/or specific treatment based on the antibiogram of the isolate for better therapeutic outcome.

Why Serological Responses during Cystitis are Limited

The high frequency of urinary tract infections (UTIs), some of which appear to be endogenous relapses rather than reinfections by new isolates, point to defects in the host's memory immune response. It has been known for many decades that, whereas kidney infections evoked an antibody response to the infecting bacteria, infections limited to the bladder failed to do so. We have identified the existence of a broadly immunosuppressive transcriptional program associated with the bladder, but not the kidneys, during infection of the urinary tract that is dependent on bladder mast cells. This involves the localized secretion of IL-10 and results in the suppression of humoral immune responses in the bladder. Mast cell-mediated immune suppression could suggest a role for these cells in critically balancing the needs to clear infections with the imperative to prevent harmful immune reactions in the host.

Asymptomatic group B streptococcal bacteriuria among pregnant women in Saudi Arabia

This study aims to determine the asymptomatic bacteriuria in pregnancy due to GBS and its antimicrobial sensitivity pattern for planning strategy for the management of these cases and also to determine the relationship between asymptomatic bacteriuria and pyuria. A total of 3863 consecutive urine specimens were collected from 3863 pregnant women with asymptomatic bacteriuria attending the obstetrics and gynaecology department of our hospital over a period of two years. Specimens were processed using standard microbiological procedures. All the subjects were evaluated for bacteriuria. The prevalence of asymptomatic bacteriuria due to group B streptococci (GBS) was 82/3863 (2.1%) among pregnant women in Saudi Arabia. Among these, 69/82 patients (84.2%) had clinical and microbiological features consistent with cystitis, versus 13/82 (15.8%) for pyelonephritis. About 51.2% (42/82) of the patients who had urine analysis performed had positive results based on positive urinary leucocyte esterase and pyuria. Disc-diffusion analysis of all 82 GBS isolates showed that they were highly susceptible to Augmentin and linezolid. Screening for bacteriuria in pregnancy and proper treatment must be considered as an essential part of antenatal care in this community. To prevent asymptomatic bacteriuria complications, all pregnant women should be screened at the first antenatal visit. A negative test for pyuria is not a reliable indicator of the absence of asymptomatic bacteriuria in pregnant women. Further, ongoing surveillance and evaluation of outcomes in pregnancies complicated by GBS bacteriuria is required to optimise maternal and newborn care.

Urinary catheters: history, current status, adverse events and research agenda

For more than 3500 years, urinary catheters have been used to drain the bladder when it fails to empty. For people with impaired bladder function and for whom the method is feasible, clean intermittent self-catheterization is the optimal procedure. For those who require an indwelling catheter, whether short- or long-term, the self-retaining Foley catheter is invariably used, as it has been since its introduction nearly 80 years ago, despite the fact that this catheter can cause bacterial colonization, recurrent and chronic infections, bladder stones and septicaemia, damage to the kidneys, the bladder and the urethra, and contribute to the development of antibiotic resistance. In terms of medical, social and economic resources, the burden of urinary retention and incontinence, aggravated by the use of the Foley catheter, is huge. In the UK, the harm resulting from the use of the Foley catheter costs the National Health Service between £1.0-2.5 billion and accounts for ∼2100 deaths per year. Therefore, there is an urgent need for the development of an alternative indwelling catheter system. The research agenda is for the new catheter to be easy and safe to insert, either urethrally or suprapubically, to be retained reliably in the bladder and to be withdrawn easily and safely when necessary, to mimic natural physiology by filling at low pressure and emptying completely without damage to the bladder, and to have control mechanisms appropriate for all users.

Occurrence of urinary tract infection in adolescent and adult women of shanty town in Dhaka City, Bangladesh

BACKGROUND

Urinary tract infection (UTI) is commonly experienced by women of various age groups especially elderly ones. We planned to find out the prevalent microbial strains causing UTI in slum inhabitant adolescent and adult women in Dhaka City, Bangladesh.

METHODS AND MATERIALS

Urine sample was collected from 462 UTI suspected female subjects. Pathogenic bacteria were identified using standard microbiological tests, and antimicrobial sensitivity profiles of the pathogens were determined.

RESULTS

Bacteriuria was present in 9% of the subjects. A higher incidence (16.8%) of UTI was noted among adult women aged above 19 years. Escherichia coli (69%), Streptococcus spp. (15%) and Pseudomonas aeruginosa (7%) were more frequently isolated from the urine samples compared to Enterococcus faecalis (3%), Staphylococcus aureus (2%), Klebsiella pneumoniae (2%) and Hafnia alvei (2%). The E. coli isolates showed complete resistance to commonly used drugs, and 58% of these isolates were multidrug resistant (MDR). Minimum Inhibitory Concentration (MIC) values for ciprofloxacin ranged between 64µg/ml and 512µg/ml, and the Minimum Bactericidal Concentration (MBC) values against the isolates were 128µg/ml or above. Isolated strains of E. coli exhibited equal extent of ciprofloxacin resistance irrespective of the presence or absence of plasmid in them.

CONCLUSION

The extent of drug resistance among the uropathogens if ignored may render them uncontrollable. This study suggests regular monitoring of drug resistance phenotype of the UTI pathogens to reduce the morbidity of female UTI patients and offer better treatment strategy in the healthcare sectors of Bangladesh.

Clinical and Microbiological Profile of Urinary Tract Infection at a Tertiary-Care Center in Lebanon

We compared community-acquired urinary tract infection (UTI) with hospital-acquired UTI at the American University of Beirut Medical Center. Escherichia coli was the most frequently isolated organism. Hospital-acquired E. coli isolates were often rnultidrug resistant. These results can be used to improve empiric treatment of UTI.

Antibiotic treatment for urinary tract infections: pharmacokinetic/pharmacodynamic principles

Bacterial urinary tract infections (UTIs) frequently occur in the outpatient as well as in the nosocomial setting. The stratification into uncomplicated and complicated UTIs has proven to be clinically useful. Bacterial virulence factors on the one hand, and the integrity of the host defense mechanisms on the other, determine the course of the infection. Late complications or sequelae might ensue if the defense mechanisms are disturbed, either by a genetic or an acquired cause. Escherichia coli is the most prevalent organism in uncomplicated UTIs, whereas the bacterial spectrum is much broader in complicated UTIs, including Gram-negative and -positive, and often multiresistant organisms. Therapy for uncomplicated UTIs is almost exclusively antibacterial, whereas in complicated UTIs the complicating factors need to be treated as well. The success of antibiotic therapy of UTIs in a population can be estimated by four parameters: the minimal inhibitory concentrations of the clinical isolates, the pharmacokinetic and pharmacodynamic profiles, and the protein binding of the treatment drug. In uncomplicated UTIs, antimicrobial therapy is usually empiric, whereas in complicated UTIs antibiotic therapy should be more individualized; tailored to the individual patient.

Distribution of phylogenetic groups, sequence type ST131, and virulence-associated traits among Escherichia coli isolates from men with pyelonephritis or cystitis and healthy controls

Urinary tract infections (UTI), which are mostly caused by Escherichia coli, are an important public health problem worldwide. Although men experience diverse UTI syndromes, there have been relatively few molecular-epidemiological studies of UTI pathogenesis in men. We studied the distribution of 22 E. coli virulence factor (VF) genes, major phylogenetic groups, sequence type ST131, and UTI-associated O antigens among 101 pyelonephritis, 153 cystitis and 135 fecal healthy control E. coli isolates from men aged 30-70 years in a regional area of NSW, Australia. Overall, the studied traits exhibited a prevalence gradient across these groups, highest in pyelonephritis, intermediate in cystitis, and lowest among fecal isolates. Differences in virulence gene prevalence between cystitis and pyelonephritis isolates were limited to eight genes. The UTI-associated O antigens were also distributed widely, but types O6, O25 and O75 were significantly associated with pyelonephritis. The ST131 clonal group, which accounted for 13% of isolates overall (22% of group B2 isolates), likewise exhibited a significant descending prevalence gradient from pyelonephritis (36%), through cystitis (8%), to fecal (0%) isolates. These findings contribute to better understanding of the pathogenesis of UTIs in men and identify specific VF genes and O types, and a prominent clonal group (ST131), as being important in UTI pathogenesis in this population.

Prognostic value of semi-quantitative bacteruria counts in the diagnosis of group B streptococcus urinary tract infection: a 4-year retrospective study in adult patients

Background

Semi-quantitative bacteruria counts (s-QBC) are important in the diagnosis of urinary tract infection (UTI) due to most uropathogens. The prognostic value of s-QBC for diagnosis of UTI due to group B streptococcus (GBS) is unknown. In this study, we assessed the value of s-QBC for differentiating acute GBS UTI from asymptomatic bacteruria (ABU), independent of other potential prognostic indicators.

Methods

Medical record review and urinalysis (UA) values for 1593 patients who had urinary GBS isolated (10³ to ≥10⁵ CFU/ml) during a four-year period were analyzed using binary logistic regression to determine the predictive values of s-QBC, age, and gender for infection category (acute UTI, ABU) based on the clinical diagnosis.

Results

s-QBC alone had a strong predictive value for infection category but only for ABU. Multivariate logistic regression showed similar predictive power of s-QBC for infection category using age as a co-predictor, which was also independently associated with infection category. Typical s-QBC cut-off values that are commonly used in diagnostic settings had no significant power in predicting infection category. Among other UA measures, proteinuria and hematuria were significantly associated with acute infection.

Conclusions

Together, these data show that s-QBC is not useful in the differential diagnosis of GBS UTI. Among the patients in this study, age was an equally effective prognostic indicator compared to s-QBC for identifying high- and low-risk patients for acute GBS UTI. Collectively, these findings indicate that age-based associations may be equally as useful as s-QBC for predicting infection category in the setting of adult patients with GBS-positive urine cultures.

Cranberries for preventing urinary tract infections

BACKGROUND

Cranberries have been used widely for several decades for the prevention and treatment of urinary tract infections (UTIs). This is the third update of our review first published in 1998 and updated in 2004 and 2008.

OBJECTIVES

To assess the effectiveness of cranberry products in preventing UTIs in susceptible populations.

SEARCH METHODS

We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL in The Cochrane Library) and the Internet. We contacted companies involved with the promotion and distribution of cranberry preparations and checked reference lists of review articles and relevant studies.Date of search: July 2012

SELECTION CRITERIA

All randomised controlled trials (RCTs) or quasi-RCTs of cranberry products for the prevention of UTIs.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed and extracted data. Information was collected on methods, participants, interventions and outcomes (incidence of symptomatic UTIs, positive culture results, side effects, adherence to therapy). Risk ratios (RR) were calculated where appropriate, otherwise a narrative synthesis was undertaken. Quality was assessed using the Cochrane risk of bias assessment tool.

MAIN RESULTS

This updated review includes a total of 24 studies (six cross-over studies, 11 parallel group studies with two arms; five with three arms, and two studies with a factorial design) with a total of 4473 participants. Ten studies were included in the 2008 update, and 14 studies have been added to this update. Thirteen studies (2380 participants) evaluated only cranberry juice/concentrate; nine studies (1032 participants) evaluated only cranberry tablets/capsules; one study compared cranberry juice and tablets; and one study compared cranberry capsules and tablets. The comparison/control arms were placebo, no treatment, water, methenamine hippurate, antibiotics, or lactobacillus. Eleven studies were not included in the meta-analyses because either the design was a cross-over study and data were not reported separately for the first phase, or there was a lack of relevant data. Data included in the meta-analyses showed that, compared with placebo, water or not treatment, cranberry products did not significantly reduce the occurrence of symptomatic UTI overall (RR 0.86, 95% CI 0.71 to 1.04) or for any the subgroups: women with recurrent UTIs (RR 0.74, 95% CI 0.42 to 1.31); older people (RR 0.75, 95% CI 0.39 to 1.44); pregnant women (RR 1.04, 95% CI 0.97 to 1.17); children with recurrent UTI (RR 0.48, 95% CI 0.19 to 1.22); cancer patients (RR 1.15 95% CI 0.75 to 1.77); or people with neuropathic bladder or spinal injury (RR 0.95, 95% CI: 0.75 to 1.20). Overall heterogeneity was moderate (I² = 55%). The effectiveness of cranberry was not significantly different to antibiotics for women (RR 1.31, 95% CI 0.85, 2.02) and children (RR 0.69 95% CI 0.32 to 1.51). There was no significant difference between gastrointestinal adverse effects from cranberry product compared to those of placebo/no treatment (RR 0.83, 95% CI 0.31 to 2.27). Many studies reported low compliance and high withdrawal/dropout problems which they attributed to palatability/acceptability of the products, primarily the cranberry juice. Most studies of other cranberry products (tablets and capsules) did not report how much of the 'active' ingredient the product contained, and therefore the products may not have had enough potency to be effective.

AUTHORS' CONCLUSIONS

Prior to the current update it appeared there was some evidence that cranberry juice may decrease the number of symptomatic UTIs over a 12 month period, particularly for women with recurrent UTIs. The addition of 14 further studies suggests that cranberry juice is less effective than previously indicated. Although some of small studies demonstrated a small benefit for women with recurrent UTIs, there were no statistically significant differences when the results of a much larger study were included. Cranberry products were not significantly different to antibiotics for preventing UTIs in three small studies. Given the large number of dropouts/withdrawals from studies (mainly attributed to the acceptability of consuming cranberry products particularly juice, over long periods), and the evidence that the benefit for preventing UTI is small, cranberry juice cannot currently be recommended for the prevention of UTIs. Other preparations (such as powders) need to be quantified using standardised methods to ensure the potency, and contain enough of the 'active' ingredient, before being evaluated in clinical studies or recommended for use.

The management of urinary infections: what have we learned in the past decade?

User-friendly, cost-effective practices to manage urinary infection should become routine. The vast majority of inflections are relatively easy to treat and many of these can be prevented with appropriate interventions. Additional research is urgently needed to compare various clinical strategies and determine which is most acceptable to patients at a reasonable cost with satisfactory health outcomes.

Virulence plasmid harbored by uropathogenic Escherichia coli functions in acute stages of pathogenesis

Urinary tract infections (UTIs), the majority of which are caused by uropathogenic Escherichia coli (UPEC), afflict nearly 60% of women within their lifetimes. Studies in mice and humans have revealed that UPEC strains undergo a complex pathogenesis cycle that involves both the formation of intracellular bacterial communities (IBC) and the colonization of extracellular niches. Despite the commonality of the UPEC pathogenesis cycle, no specific urovirulence genetic profile has been determined; this is likely due to the fluid nature of the UPEC genome as the result of horizontal gene transfer and numerous genes of unknown function. UTI89 has a large extrachromosomal element termed pUTI89 with many characteristics of UPEC pathogenicity islands and that likely arose due to horizontal gene transfer. The pUTI89 plasmid has characteristics of both F plasmids and other known virulence plasmids. We sought to determine whether pUTI89 is important for virulence. Both in vitro and in vivo assays were used to examine the function of pUTI89 using plasmid-cured UTI89. No differences were observed between UTI89 and plasmid-cured UTI89 based on growth, type 1 pilus expression, or biofilm formation. However, in a mouse model of UTI, a significant decrease in bacterial invasion, CFU and IBC formation of the pUTI89-cured strain was observed at early time points postinfection compared to the wild type. Through directed deletions of specific operons on pUTI89, the cjr operon was partially implicated in this observed defect. Our findings implicate pUTI89 in the early aspects of infection.

TLR4-mediated expulsion of bacteria from infected bladder epithelial cells

Uropathogenic Escherichia coli invade bladder epithelial cells (BECs) by direct entry into specialized cAMP regulated exocytic compartments. Remarkably, a significant number of these intracellular bacteria are subsequently expelled in a nonlytic and piecemeal fashion by infected BECs. Here, we report that expulsion of intracellular E. coli by infected BECs is initiated by the pattern recognition receptor, Toll-like receptor (TLR)4, after activation by LPS. Also, we reveal that caveolin-1, Rab27b, PKA, and MyRIP are components of the exocytic compartment, and that they form a complex involved in the exocytosis of bacteria. This capacity of TLR4 to mediate the expulsion of intracellular bacteria from infected cells represents a previously unrecognized function for this innate immune receptor.

Cranberries for preventing urinary tract infections

BACKGROUND

Cranberries have been used widely for several decades for the prevention and treatment of urinary tract infections (UTIs).

OBJECTIVES

To assess the effectiveness of cranberry products in preventing UTIs in susceptible populations.

SEARCH STRATEGY

We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL in The Cochrane Library) and the Internet. We contacted companies involved with the promotion and distribution of cranberry preparations and checked reference lists of review articles and relevant studies. Date of last search: January 2007.

SELECTION CRITERIA

All randomised controlled trials (RCTs) or quasi-RCTs of cranberry products for the prevention of UTIs in all populations.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed and extracted information. Information was collected on methods, participants, interventions and outcomes (UTIs - symptomatic and asymptomatic, side effects, adherence to therapy). Relative risk (RR) were calculated where appropriate, otherwise a narrative synthesis was undertaken. Quality was assessed using the Cochrane criteria.

MAIN RESULTS

Ten studies (n = 1049, five cross-over, five parallel group) were included. Cranberry/cranberry-lingonberry juice versus placebo, juice or water was evaluated in seven studies, and cranberries tablets versus placebo in four studies (one study evaluated both juice and tablets). Cranberry products significantly reduced the incidence of UTIs at 12 months (RR 0.65, 95% CI 0.46 to 0.90) compared with placebo/control. Cranberry products were more effective reducing the incidence of UTIs in women with recurrent UTIs, than elderly men and women or people requiring catheterisation. Six studies were not included in the meta-analyses due to methodological issues or lack of available data. However, only one reported a significant result for the outcome of symptomatic UTIs. Side effects were common in all studies, and dropouts/withdrawals in several of the studies were high.

AUTHORS' CONCLUSIONS

There is some evidence that cranberry juice may decrease the number of symptomatic UTIs over a 12 month period, particularly for women with recurrent UTIs. It's effectiveness for other groups is less certain. The large number of dropouts/withdrawals indicates that cranberry juice may not be acceptable over long periods of time. It is not clear what is the optimum dosage or method of administration (e.g. juice, tablets or capsules). Further properly designed studies with relevant outcomes are needed.

Clinical significance of bacteriuria with low colony counts of Enterococcus species

The clinical significance of low counts of enterococci in urine cultures remains unclear. The goal of this study was to investigate the clinical significance of enterococci growing in numbers lower than 100,000 colony-forming units per milliliter (cfu/ml) in urine samples. Clinical parameters were collected from patients whose midstream clean-catch urine samples grew Enterococcus spp. in amounts between >or=10,000 and 100,000 cfu/ml and who were not previously treated with antibiotics. Only those patients who had leukocyturia in addition to positive culture were considered to have true urinary tract infection (UTI). Of the 208 patients included in the study, 54% were diagnosed with true UTI. Patients with true UTI were older by 6 years (p=0.03), were more likely to be hospitalized (p=0.016), had higher rates of dysuria (p=0.0001), urgency (p=0.0001), and frequency (p=0.0001), and had more solid tumors (p=0.03). By multivariate analysis, urgency (OR=7.1) and hospitalization (OR=4.4) were identified as independent risk factors for true UTI with enterococci in low counts. Enterococcal counts in patients with true UTI were randomly distributed all along the scale between 10,000 and 100,000 cfu/ml, and no differential cutoff could be determined. In conclusion, more than half of the patients whose urine cultures grow Enterococcus spp. in counts lower than 100,000 cfu/ml may have true UTI, especially if they are hospitalized and have symptoms of dysuria, urgency, or frequency. Microbiology laboratories should perform a complete work-up on samples containing low counts of enterococci, and the final interpretation should be done by physicians, using additional clinical information.

Actin-gated intracellular growth and resurgence of uropathogenic Escherichia coli

Strains of uropathogenic Escherichia coli (UPEC) can invade terminally differentiated superficial bladder epithelial cells and subsequently multiply, forming large biofilm-like inclusions referred to as pods. In contrast, within immature bladder cells UPEC enter a more quiescent state and often fail to replicate appreciably. As immature bladder epithelial cells undergo terminal differentiation the actin cytoskeleton is radically diminished, a phenomenon that we reasoned could influence the intracellular fate of UPEC. Here we show that UPEC within undifferentiated bladder cells is trafficked into acidic compartments having key features of late endosomes and lysosomes. These UPEC-containing vacuoles are often enmeshed within a network of actin filaments, the disruption of which stimulates intravacuolar growth and efflux of UPEC in cell culture-based studies. In this in vitro model system, release of UPEC into the host cytosol further stimulates intracellular bacterial growth and the rapid development of pod-like inclusions. These inclusions, as well as those observed using an in vivo mouse model, develop in association with cytokeratin intermediate filaments that may act as scaffolding for intracellular biofilm formation. Our data suggest an aetiological basis for recurrent urinary tract infections, linking bladder cell differentiation and the accompanying redistribution of actin microfilaments with the resurgence of UPEC from quiescent intravacuolar reservoirs within the bladder epithelium.

Treatment of Bacterial Urinary Tract Infections: Presence and Future

Bacterial urinary tract infections (UTIs) are frequent infections in the outpatient as well as in the nosocomial setting. The stratification into uncomplicated and complicated UTIs has proven to be clinically useful. Bacterial virulence factors on the one side and the integrity of the host defense mechanisms on the other side determine the course of the infection. In uncomplicated UTIs Escherichia coli is the leading organism, whereas in complicated UTIs the bacterial spectrum is much broader including Gram-negative and Gram-positive and often multiresistant organisms. The therapy of uncomplicated UTIs is almost exclusively antibacterial, whereas in complicated UTIs the complicating factors have to be treated as well. There are two predominant aims in the antimicrobial treatment of both uncomplicated and complicated UTIs: (i) rapid and effective response to therapy and prevention of recurrence of the individual patient treated; (ii) prevention of emergence of resistance to antimicrobial chemotherapy in the microbial environment. The main drawback of current antibiotic therapies is the emergence and rapid increase of antibiotic resistance. To combat this development several strategies can be followed. Decrease the amount of antibiotics administered, optimal dosing, prevention of infection and development of new antibiotic substances. The aim of this review is to highlight the current and to describe future treatment options for UTIs.

Current challenges in the treatment of complicated urinary tract infections and prostatitis

Serious urinary tract infections (UTIs) and acute bacterial prostatitis in adults cause significant morbidity and economic burden. Chronic bacterial prostatitis is a rather rare condition seen in urological practice, however, in certain occasions difficult to treat. In this paper, we review the bacterial etiologies and the resistance patterns found in adults with serious UTIs and bacterial prostatitis, and discuss considerations for selecting optimal antimicrobial therapy. The role of fluoroquinolones as targeted therapy for serious UTIs is highlighted. The use of effective antimicrobial therapy is the foundation of management of serious UTIs and bacterial prostatitis. Selection of the optimal antimicrobial agent must take into account patient-specific factors; infection characteristics (e.g., severity, community- vs. institutional- or hospital-acquired, need for IV agent, UTI, prostatitis); local resistance pattern; pharmacokinetic and pharmacodynamic principles; and cost. Fluoroquinolones are among the alternatives for empirical antibiotic treatment of serious UTIs and acute bacterial prostatitis. In serious UTIs activity of the antimicrobial agent against Pseudomonas aeruginosa needs to be taken into account. In chronic bacterial prostatitis fluoroquinolones are the first choice because of their favourable pharmacokinetic properties at the site of infection. Targeted antimicrobial therapy--emphasising the correct antibacterial spectrum and correct dosage--is likely to provide important benefits, such as reduced morbidity and associated costs, reduced emergence of resistance and maintenance of class efficacy.

Bedside Ultrasonography in the ICU

This is the second of a two-part review on the application of bedside ultrasonography in the ICU. In this part, the following procedures will be covered: (1) echocardiography and cardiovascular diagnostics (second part); (2) the use of bedside ultrasound to facilitate central-line placement and to aid in the care of patients with pleural effusions and intra-abdominal fluid collections; (3) the role of hand-carried ultrasound in the ICU; and (4) the performance of bedside ultrasound by the intensivist. The safety and utility of bedside ultrasonography performed by adequately trained intensivists has now been well demonstrated. This technology, as a powerful adjunct to the physical examination, will become an indispensable tool in the management of critically ill patients.

Managing Urinary Tract Infections in Nursing Homes: A Qualitative Assessment

OBJECTIVE

To elucidate the steps in the management of urinary tract infections (UTIs) in elderly nursing home residents, in order to derive data which would assist in an economic evaluation of such infections.

METHOD

Maximum variation sampling was used to recruit General Practitioners (GPs) and nurses (who worked in nursing homes), into the study. Using semi-structured interviews, a topic guide was used to explore diagnosis, treatment and the role of GPs and nurses in the management of UTIs in nursing home residents. Thematic analysis was employed to identify the main themes.

MAIN OUTCOME MEASURES

A comprehensive description of the management of UTIs in nursing home residents that will be used in a future economic evaluation of the costs of this prevalent infection in this setting.

RESULTS

Ten GPs and nurses respectively took part in the interviews. Three overarching themes emerged from the interviews: information, processes and decision-making. Health care professionals described the key symptoms for diagnosis (information), testing procedures to confirm the presence of an infection (processes); many variations in management pathways were described. The nurse was central to decision-making in treatment i.e. prescribing of an antibiotic. Most GPs reported that they accepted the nursing staff's assessment of the resident and seldom visited a patient in a nursing home for a UTI.

CONCLUSIONS

The management approach to UTIs varied greatly and was a more complex process than anticipated. Identification of the component steps will be used to perform an economic evaluation of UTIs in nursing homes.

Emerging drugs for bacterial urinary tract infections

Bacterial urinary tract infections (UTIs) are frequent infections in the outpatient as well as in the nosocomial setting. The stratification into uncomplicated and complicated UTIs has proven to be clinically useful. Bacterial virulence factors on the one side and the integrity of the host defence mechanisms on the other side determine the course of the infection. In uncomplicated UTIs, Escherichia coli is the leading organism, whereas in complicated UTIs, the bacterial spectrum is much broader, including Gram-negative, Gram-positive and often multiresistant organisms. The therapy of uncomplicated UTIs is almost exclusively antibacterial, whereas in complicated UTIs the complicating factors also have to be treated. There are two predominant aims in the antimicrobial treatment of both uncomplicated and complicated UTIs: i) rapid and effective response to therapy and prevention of recurrence of the individual patient treated; and ii) prevention of emergence of resistance to chemotherapy in the microbial environment. The aim of this review is to highlight the existing, and to describe emerging, treatment options for UTIs.

Virulence genotype and phylogenetic origin in relation to antibiotic resistance profile among Escherichia coli urine sample isolates from Israeli women with acute uncomplicated cystitis

To clarify the virulence and phylogenetic implications of antimicrobial agent resistance in Escherichia coli, 100 E. coli isolates from urine samples of Israeli women with acute uncomplicated cystitis were analyzed by molecular phylotyping and virulence genotyping for comparison with resistance phenotypes. The differences between the isolates that were resistant and susceptible to trimethoprim-sulfamethoxazole and ampicillin were minimal. In contrast, ciprofloxacin resistance was associated with greatly reduced inferred virulence and categorical shifts away from the highly virulent phylogenetic group B2, which explained much of the virulence effect. The results of amplification fingerprinting suggested that most ciprofloxacin-resistant isolates represented unique clonal groups and were not derived from clonal groups with more highly virulent susceptible isolates. These findings suggest that virulence and antimicrobial resistance are not mutually exclusive in E. coli clinical isolates. Instead, the relationship between virulence and antimicrobial resistance varies according to the particular resistance phenotype; for ciprofloxacin resistance, the relationship is strongly influenced by phylogenetic background. The basis for the concentration of ciprofloxacin resistance in non-B2 phylogenetic groups remains unknown.

Antibody responses and protection from pyelonephritis following vaccination with purified Escherichia coli PapDG protein

PURPOSE

A critical early step in the establishment of Escherichia coli pyelonephritis is bacterial attachment via the tip protein of P fimbriae. This adhesin, PapG, binds to glycolipid receptors present on vaginal and kidney epithelial surfaces. In this study we investigated the efficacy of vaccination with purified PapDG protein complex in preventing pyelonephritis caused by E. coli.

MATERIALS AND METHODS

Mature cynomolgus monkeys were intraperitoneally vaccinated with 100 microg purified PapDG protein. Following 3 identical boosters serum antibody titers to PapDG were measured by enzyme-linked immunosorbent assay. Vaccinated and unvaccinated animals were urethrally inoculated with 1 x 10 cfu of E. coli strain DS17, which was isolated from a child with acute pyelonephritis. The infection course was monitored by catheterized urine cultures, and by histological examination of the kidneys, bladder and kidney tissue culture 28 days after infection.

RESULTS

Intraperitoneal administration of purified PapDG vaccine resulted in the development of specific antibody responses in cynomolgus monkeys. In contrast to control monkeys, vaccinated monkeys did not show histological evidence of pyelonephritis after subsequent urethral challenge with pyelonephritogenic E. coli expressing P fimbriae.

CONCLUSIONS

Purified PapDG is a tractable vaccine candidate that in our small study demonstrated the ability to elicit adequate serum antibody levels to prevent E. coli mediated pyelonephritis.

All dysuria is local. A cost-effectiveness model for designing site-specific management algorithms

OBJECTIVE

To determine the cost-effectiveness of management strategies for dysuria in different office settings.

DESIGN

Decision and cost-effectiveness analyses, assuming the payer's perspective. Data on disease prevalence, test characteristics, treatment efficacy, and adverse effects were drawn from the English language literature using medline searches and bibliographies.

SETTING

Hypothetical primary care practice.

PATIENTS

Otherwise healthy, nonpregnant women with symptoms of dysuria, urgency, and frequency.

INTERVENTIONS

All reasonable combinations of urinalysis, urine culture, pelvic examination, chlamydia and gonorrhea cultures, and empiric treatment with trimethoprim-sulfamethoxazole.

RESULTS

The cost-effectiveness of strategies varied substantially among different patient settings. In all settings, empiric trimethoprim-sulfamethoxazole for all patients was least expensive and least effective. Most testing increased both cost and effectiveness. Compared to empiric antibiotics, performing pelvic examination and urine culture for women with normal urinalyses had a marginal cost-effectiveness ratio of $4 to $32 per symptom-day avoided (SDA). Adding urine culture for patients with pyuria had a marginal cost of $34 to $107 per SDA, which fell to $40/SDA when the prevalence of resistance to trimethoprim-sulfamethoxazole exceeded 40%. Pelvic examination and urine culture for all patients regardless of urinalysis results achieved the greatest benefit but at the highest cost (>$300 per SDA).

CONCLUSIONS

In otherwise healthy women with symptoms of dysuria and no vaginal complaints, performing pelvic exam and urine culture based on urinalysis offers a reasonable alternative to empiric therapy. Other testing may be warranted, depending on antibiotic resistance and the value of avoiding a day of dysuria.

Cranberries for preventing urinary tract infections

BACKGROUND

Cranberries (particularly in the form of cranberry juice) have been used widely for several decades for the prevention and treatment of urinary tract infections (UTIs). The aim of this review is to assess the effectiveness of cranberries in preventing such infections.

OBJECTIVES

To assess the effectiveness of cranberry juice and other cranberry products in preventing UTIs in susceptible populations.

SEARCH STRATEGY

Electronic databases and the Internet were searched using English and non English language terms; companies involved with the promotion and distribution of cranberry preparations were contacted; reference lists of review articles and relevant trials were searched. Cochrane Central Register of Controlled Trials (CENTRAL - the Cochrane Library, issue 1, 2003) was searched in February 2003.

SELECTION CRITERIA

All randomised or quasi randomised controlled trials of cranberry juice/products for the prevention of urinary tract infections in susceptible populations. Trials of men, women or children were included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed and extracted information. Information was collected on methods, participants, interventions and outcomes (urinary tract infections (symptomatic and asymptomatic), side effects and adherence to therapy). RR were calculated where appropriate, otherwise a narrative synthesis was undertaken. Quality was assessed using the Cochrane criteria.

MAIN RESULTS

Seven trials met the inclusion criteria (four cross-over, three parallel group). The effectiveness of cranberry juice (or cranberry-lingonberry juice) versus placebo juice or water was evaluated in six trials, and the effectiveness of cranberries tablets versus placebo was evaluated in two trials (one study evaluated both juice and tablets). In two good quality RCTs, cranberry products significantly reduced the incidence of UTIs at twelve months (RR 0.61 95% CI:0.40 to 0.91) compared with placebo/control in women. One trial gave 7.5 g cranberry concentrate daily (in 50 ml), the other gave 1:30 concentrate given either in 250 ml juice or in tablet form. There was no significant difference in the incidence of UTIs between cranberry juice versus cranberry capsules (RR 1.11 95% CI:0.49 to 2.50). Five trials were not included in the meta-analyses due to methodological flaws or lack of available data. However, only one reported a significant result for the outcome of symptomatic UTIs. Side effects were common in all trials, and dropouts/withdrawals in several of the trials were high.

REVIEWERS' CONCLUSIONS

There is some evidence from two good quality RCTs that cranberry juice may decrease the number of symptomatic UTIs over a 12 month period in women. If it is effective for other groups such as children and elderly men and women is not clear. The large number of dropouts/withdrawals from some of the trials indicates that cranberry juice may not be acceptable over long periods of time. In addition it is not clear what is the optimum dosage or method of administration (e.g. juice or tablets). Further properly designed trials with relevant outcomes are needed.

Managing complicated urinary tract infections: the urologic view

Patients with complicated UTIs are a diverse group. These patients have upper UTIs and structural or functional abnormalities that reduce the efficacy of antimicrobial therapy. They are at increased risk for morbidity such as bacteremia and sepsis, perinephric abscess, renal deterioration, and emphysematous pyelonephritis. Appropriate urinary tract imaging, antimicrobials, medical and surgical therapies, and follow-up are required to avoid potentially devastating outcomes.

Urinary tract infections

Urinary tract infections (UTIs) are a common infectious disease in primary care practice. This article reviews topics highlighting recent research, including UTIs in pregnancy and pediatric UTIs. The authors also discuss catheter-associated UTIs, given the large number of hospitalized patients undergoing catheterization and residents of long-term care facilities, in whom catheters are used frequently, and complicated UTIs.

The relationship between treatment objectives and practice patterns in the management of urinary tract infections

OBJECTIVE

To describe physicians' goals when treating uncomplicated urinary tract infections (UTIs) and the relationship between goals and practice patterns.

STUDY DESIGN

Analysis of survey results.

POPULATION

Primary care physicians.

OUTCOMES MEASURED

Self-reported treatment objectives and practice patterns.

RESULTS

Most physicians reported their UTI management was convenient for the patient (81.3%). Fewer stated they minimized patients' costs (53.4%), made an accurate diagnosis (56.7%), or avoided unnecessary antibiotics (40.9%). Physicians who stressed convenience or minimizing patient expenses were less likely to use many resources (urine culture, microscopic urinalysis, followup visits and tests, and prolonged antibiotic treatment) and more likely to use telephone treatment. Physicians who stressed accurate diagnoses or avoiding unnecessary antibiotics were more likely to use the same resources and less likely to use telephone treatment.

CONCLUSION

UTI management goals vary across physicians and are associated with different clinical approaches. Differences in treatment objectives may help explain variations in practice patterns.

Norfloxacin-releasing urethral catheter for long-term catheterization

Norfloxacin-releasing urethral catheters were prepared for the purpose of preventing urinary tract infections during long-term catheterization. The outer and inner surfaces of the catheters were coated with poly(ethylene-co-vinyl acetate) (EVA) and an amphiphilic multiblock co-polymer (PEO2kPDMS), composed of poly(ethylene oxide) and poly(dimethyl siloxane). Norfloxacin, a fluoroquinolone synthetic antibiotic, was impregnated into a coating layer. The in vitro drug release behavior was monitored for 30 days, the surface topography was investigated using scanning electron microscopy (SEM) and the antibacterial activity against different bacteria implicated in urinary tract infection was evaluated by the in vitro inhibition zone test. All the coated catheters showed continuous delivery of norfloxacin for up to 30 days owing to hydrophobic natures of norfloxacin and EVA. PEO2kPDMS incorporated in a coating layer produced a smooth and uniform surface. The coated catheters created considerable inhibition zones for 10 days against Escherichia coli. Klebsiella pneumoniae and Proteus vulgaris, indicating the continuous release of norfloxacin. Overall, it was evident that the catheters coated with EVA/PEO2kPDMS blends containing norfloxacin have a promising potential for the clinical use in patients undergoing long-term catheterization.

Diabetes and the risk of acute urinary tract infection among postmenopausal women

OBJECTIVE

To examine whether the presence of diabetes alters the risk of acute urinary tract infection (UTI) in postmenopausal women.

RESEARCH DESIGN AND METHODS

A case-control study of the Group Health Cooperative of Puget Sound (GHC), a staff-model nonprofit health maintenance organization in Washington State, was conducted. Subjects were women aged 55-75 years who had been members of GHC for at least 1 year and who had had an acute symptomatic UTI within the preceding month. Laboratory files were used to identify women with a urine culture that grew > or =10(5) colonies of a urinary pathogen. Medical records were reviewed to confirm the presence of acute, clinically symptomatic UTI. Control subjects were randomly selected from the GHC enrollment file, screened to remove women with recent UTI, and frequency matched to cases by age within 2 years. An interviewer ascertained self-reported clinician-diagnosed diabetes. Diagnosis of diabetes was confirmed by the GHC diabetes registry. A subsample of women underwent measurement of postvoid residual bladder volume (n = 748) and culture of vaginal flora (n = 454).

RESULTS

Of the 901 case and 913 control subjects, diabetes was reported in 13.1 and 6.8%, respectively. The health plan diabetes registry confirmed the diagnosis in 92% of women who self-reported the condition. The age-adjusted odds ratio (OR) for UTI in relation to self-reported clinician-diagnosed diabetes was 2.2 (95% CI 1.6-3.0). Adjustment for frequency of sexual intercourse and history of UTI had little effect on this estimate. Compared with nondiabetic women, higher UTI odds were seen in subjects who used oral hypoglycemic agents (OR 2.9 [95% CI 1.7-5.1]) and insulin (2.6 [1.5-4.6]) but not in subjects with untreated diabetes or diabetes treated by lifestyle changes (1.3 [0.7-2.3]). No significant difference was seen in the OR for UTI in diabetic women with disease of shorter duration (<10 years, OR 1.9) or longer duration (> or =10 years, OR 2.6) or in relation to HbA(1c) level. Similar microbiologic pathogens were seen in diabetic and nondiabetic women. No significant differences were seen by diabetes status in mean postvoid residual bladder volume or vaginal flora.

CONCLUSIONS

Diabetes under pharmacologic treatment is associated with increased risk of clinically apparent UTI in postmenopausal women.

Tubular cell-Escherichia coli interaction products modulate migration of monocytes through generation of transforming growth factor-beta and macrophage-monocyte chemoattractant protein-1

BACKGROUND

Urinary tract infection is a common occurrence often associated with renal interstitial inflammation in the form of accumulation of mononuclear cells. We hypothesized that bacteria activate tubular cells to secrete cytokines, which may promote migration of mononuclear cells at the site of interaction.

MATERIALS AND METHODS

We evaluated the migration of monocytes in response to tubular cell products (TC-S) and interaction products of E. coli with proximal tubular cells (TC-EC-S; concentrations of 5%, 10%, and 25%) using a modified Boyden chamber. To determine the molecular mechanism, we evaluated the effect of antibodies against macrophage-monocyte chemoattractant protein-1 (MCP-1) and transforming growth factor-beta (TGF-beta) on E. coli-tubular cell interaction product-induced migration of monocytes. In addition, we studied the effect of free-radical scavengers on activation of tubular cells.

RESULTS

The TC-EC-S enhanced (p < 0.0001) migration of monocytes compared with TC-S. Both anti-TGF-beta and anti-MCP-1 antibodies partly inhibited (p < 0.0001) TC-EC-S-induced monocyte migration. The modified TC-EC-S (produced in the presence of superoxide dismutase [SOD], dimethyl thiourea [DMTU], or catalase, all scavengers of free radicals) induced lesser monocyte migration than did TC-EC-S alone.

CONCLUSIONS

These results suggest that E. coli activates tubular cells to generate cytokines such as MCP-1 and TGF-beta that promote migration of monocytes. Free radicals such as superoxide and hydrogen peroxide may be acting as second messengers in E. coli-induced tubular cell activation.

A prospective, multicenter, randomized, double-blind study comparing ertapenem and ceftriaxone followed by appropriate oral therapy for complicated urinary tract infections in adults

OBJECTIVES

To compare the efficacy and safety of ertapenem, a new once-daily parenteral beta-lactam, with that of ceftriaxone for the initial empiric treatment of adults with complicated urinary tract infections (cUTIs).

METHODS

In a multicenter, prospective, double-blind study, patients with cUTIs were stratified as to whether they had acute pyelonephritis or other cUTIs (without pyelonephritis) and randomized to receive ertapenem, 1 g once a day, or ceftriaxone, 1 g once a day. After 3 days, patients with a satisfactory clinical response could be switched to an oral antimicrobial agent.

RESULTS

Of 258 randomized patients, 97 (55.4%) in the ertapenem group and 53 (63.9%) in the ceftriaxone group were evaluated microbiologically. Almost all patients in each treatment group were switched to oral therapy. The mean duration of therapy was similar in both treatment groups: parenteral, approximately 4 days; total, approximately 13 days. The most common pathogen was Escherichia coli. At the primary efficacy endpoint, 5 to 9 days after treatment, 85.6% of patients who received ertapenem and 84.9% who received ceftriaxone had a favorable microbiologic response, indicating that the two treatment groups were equivalent. The frequency and severity of drug-related adverse events were generally similar in both treatment groups.

CONCLUSIONS

In this study, ertapenem was as effective as ceftriaxone for the initial treatment of cUTI in adults, was generally well tolerated, and had a similar safety profile.

Extraintestinal pathogenic Escherichia coli: "the other bad E coli"

Extraintestinal pathogenic Escherichia coli (ExPEC), the specialized strains of E coli that cause most extraintestinal E coli infections, represent a major but little-appreciated health threat. Although the reasons for their evolution remain mysterious, by virtue of their numerous virulence traits ExPEC clearly possess a unique ability to cause disease outside the host intestinal tract. Broader appreciation of the existence and importance of ExPEC and better understandings of their distinctive virulence mechanisms, reservoirs, and transmission pathways may lead to effective preventive interventions against the morbid and costly infections ExPEC cause.

Diagnostic Investigation of Pyelonephritis

Urinary tract infections are common, especially among women, and cause significant morbidity. While prognosis is probably more dependent on whether or not an episode of urinary tract infection is complicated (ie, associated with functional, metabolic, or anatomic abnormalities of the urinary tract) or uncomplicated, anatomic localization of infection has important implications for therapy. Pyelonephritis is difficult to diagnose with a high degree of accuracy based on clinical findings alone. Radiologic imaging plays an important role in the diagnosis and management of selected patients. Noninvasive and inexpensive methods to allow accurate localization of infection are needed.

Nosocomial infections in pediatric intensive care units

Nosocomial infections are a significant problem in pediatric intensive care units. While Indian estimates are not available, western PICUs report incidence of 6-8%. The common nosocomial infections in PICU are bloodstream infections (20-30% of all infections), lower respiratory tract infections (20-35%), and urinary tract infections (15-20%); there may be some differences in their incidence in different PICUs. The risk of nosocomial infections depends on the host characteristics, the number of interventions, invasive procedures, asepsis of techniques, the duration of stay in the PICU and inappropriate use of antimicrobials. Most often the child had endogenous flora, which may be altered because of hospitalization, are responsible for the infections. The common pathogens involved are Staphylococcus aureus, coagulase negative staphylococci, E. coli Pseudomonas aeruginosa, Klebsiella, enterococci, and candida. Nosocomial pneumonias predominantly occur in mechanically ventilated children. There is no consensus on the optimal approach for their diagnosis. Bloodstream infections are usually attributable to the use of central venous lines; use of TPN and use of femoral site for insertion increase the risk. Urinary tract infections occur mostly after catheterization and can lead to secondary bacteremia. The diagnostic criteria have been discussed in the review. With proper preventive strategies, the nosocomial infection rates can be reduced by up to 50%; handwashing, judicious use of interventions, and proper asepsis during procedures remain the most important practices.