The Role of Asymptomatic Bacteriuria in Young Women With Recurrent Urinary Tract Infections: To Treat or Not to Treat?

Asymptomatic bacteriuria, to screen or not to screen - and when to treat?

PURPOSE OF REVIEW

Asymptomatic bacteriuria (ABU) is a common clinical condition that often leads to unnecessary treatment. The purpose of this review is to outline and evaluate the most recent literature on the management of ABU.

RECENT FINDINGS

The role of ABU management has been evaluated in several patient subgroups: healthy patients without identified risk factors, pregnant women, postmenopausal women, women with recurrent UTI, patients with diabetes, elderly institutionalized patients, patients with renal transplants, patients with indwelling catheters and prior to surgery. Available evidence only supports the need for screening and treatment of ABU in pregnant women and prior to urological procedures breaching the mucosa. In all the other conditions the treatment of ABU is not only useless but also harmful. A short course treatment in pregnant women is recommended; in patients with ABU prior to urological procedures breaching the mucosa the treatment should be given in line with antibiogram and in line with the recommendations of European Association of Urology guidelines.

SUMMARY

The approach to patients with ABU has changed completely during recent years. Today, screening and treatment of ABU is recommended only in pregnant women and in all patients who are candidates for urological procedures breaching the mucosa.

Management of Bacteriuria in Veterans Affairs Hospitals

Background

Bacteriuria contributes to antibiotic overuse through treatment of asymptomatic bacteriuria (ASB) and long durations of therapy for symptomatic urinary tract infections (UTIs), yet large-scale evaluations of bacteriuria management among inpatients are lacking.

Methods

Inpatients with bacteriuria were classified as asymptomatic or symptomatic based on established criteria applied to data collected by manual chart review. We examined frequency of treatment of ASB, factors associated with treatment of ASB, durations of therapy, and frequency of complications including Clostridium difficile infection, readmission, and all-cause mortality within 28 days of discharge.

Results

Among 2225 episodes of bacteriuria, 64% were classified as ASB. After excluding patients with non-UTI indications for antibiotics, 72% of patients with ASB received antibiotics. When evaluating only patients not meeting SIRS criteria, 68% of patients with ASB received antibiotics. The mean (±SD) days of antibiotic therapy for ASB, cystitis, CA-UTI and pyelonephritis were 10.0 (4.5), 11.4 (4.7), 12.0 (6.1), and 13.6 (5.3), respectively. In sum, 14% of patients with ASB were treated for greater than 14 days, and fluoroquinolones were the most commonly used empiric antibiotic for ASB [245/691 (35%)]. Complications were rare but more common among patients with ASB treated with antibiotics.

Conclusions

The majority of bacteriuria among inpatient veterans is due to ASB with high rates of treatment of ASB and prolonged durations of therapy for ASB and symptomatic UTIs.

Antibiotics for asymptomatic bacteriuria in kidney transplant recipients

BACKGROUND

Asymptomatic bacteriuria, defined as bacteriuria without signs or symptoms of urinary tract infection (UTI), occurs in 17% to 51% of kidney transplant recipients and is thought to increase the risk for a subsequent UTI. No consensus exists on the role of antibiotics for asymptomatic bacteriuria in kidney transplantation.

OBJECTIVES

To assess the benefits and harms of treating asymptomatic bacteriuria in kidney transplant recipients with antimicrobial agents to prevent symptomatic UTI, all-cause mortality and the indirect effects of UTI (acute rejection, graft loss, worsening of graft function).

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 1 September 2017 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 (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs) and quasi-RCTs in any language assessing treatment of asymptomatic bacteriuria in kidney transplant recipients at any time-point after transplantation.

DATA COLLECTION AND ANALYSIS

Two authors independently determined study eligibility, assessed quality and extracted data. Primary outcomes were incidence of symptomatic UTI and incidence of antimicrobial resistance. Other outcomes included incidences of all-cause mortality, graft loss, graft rejection, graft function, hospitalisation for UTI, adverse reactions to antimicrobial agents and relapse or persistence of asymptomatic bacteriuria. We expressed dichotomous outcomes as absolute risk difference (RD) or risk ratio (RR) with 95% confidence intervals (CI) and continuous data as mean differences (MD) with 95% CI. Data were pooled using the random effects model.

MAIN RESULTS

We included two studies (212 participants) comparing antibiotics versus no treatment, and identified three on-going studies. Overall, incidence of symptomatic UTI varied between 19% and 31% in the groups not treated for asymptomatic bacteriuria. Antibiotic treatment had uncertain effects on preventing symptomatic UTI (2 studies, 200 participants: RR 0.86, 95% CI 0.51 to 1.45). Risk for selecting multidrug-resistant organisms was uncertain with antibiotic treatment (1 study, 112 participants: RR 1.21, 95% CI 0.60 to 2.41). Persistence of asymptomatic bacteriuria was high regardless of treatment. Antibiotics also have uncertain effects on other important patient and graft outcomes, for instance on all-cause mortality (1 study, 112 participants: RR 2.23, 95% CI 0.21 to 23.86), graft loss (1 study, 112 participants: RR 1.11, 95% CI 0.07 to 17.36), acute rejection (1 study, 112 participants: RR 0.93, 95% CI 0.44 to 1.97), hospitalisation for UTI (1 study, 112 participants: RR 0.74, 95% CI 0.13 to 4.27), graft function (2 studies, 200 participants, MD in serum creatinine concentration -0.06 mg/dL, 95% CI -0.19 to 0.08) and adverse reactions (1 study, 112 participants: no severe adverse event attributable to the antibiotic treatment). Evidence quality was low for all outcomes.

AUTHORS' CONCLUSIONS

Currently, there is insufficient evidence to support routinely treating kidney transplant recipients with antibiotics in case of asymptomatic bacteriuria after transplantation, but data are scarce. Further studies assessing routine antibiotic treatment would inform practice and we await the results of three ongoing randomised studies, which may help resolve existing uncertainties.

Antimicrobial Stewardship in the Post-Acute Long-Term Care Setting: Case Discussion and Updates

Improving the use of antimicrobial medications in the post-acute long-term care setting is critical for combating resistance and reducing adverse events in older adults. Antimicrobial stewardship refers to a set of commitments and actions designed to optimize the treatment of infectious diseases while minimizing the adverse effects associated with antimicrobial medication use. The Centers for Disease Control and Prevention recommend all nursing homes take steps to improve antimicrobial prescribing practices and reduce inappropriate use. The current article highlights initiatives and clinical considerations through a case discussion. [Journal of Gerontological Nursing, 42 (7), 10-14.].

Whole-Genome Draft Sequences of Nine Asymptomatic Escherichia coli Bacteriuria Isolates from Diabetic Patients

Escherichia coli can colonize the urinary bladder without causing a disease response in the host. This asymptomatic bacteriuria (ABU) can protect against recurrent symptomatic urinary tract infection by virulent bacteria. Here, we report the whole-genome sequences of nine E. coli ABU isolates from diabetic patients.

Sociodemographic correlates of urine culture test utilization in Calgary, Alberta

BACKGROUND

Many clinical practice guidelines encourage diagnosis and empiric treatment of lower urinary tract infection without laboratory investigation; however, urine culture testing remains one of the largest volume tests in the clinical microbiology laboratory. In this study, we sought to determine if there were specific patient groups to which increased testing was directed. To do so, we combined laboratory data on testing rates with Census Canada sociodemographic data.

METHODS

Urine culture testing data was obtained from the Calgary Laboratory Services information system for 2011. We examined all census dissemination areas within the city of Calgary and, for each area, testing rates were determined for age and gender cohorts. We then compared these testing rates to sociodemographic factors obtained from Census Canada and used Poisson regression and generalized estimating equations to test associations between testing rates and sociodemographic variables.

RESULTS

Per capita urine culture testing is increasing in Calgary. For 2011, 100,901 individuals (9.2% of all people) received urine cultures and were included in this analysis. The majority of cultures were received from the community (67.9%). Substantial differences in rate of testing were observed across the city. Most notably, urine culture testing was drastically lower in areas of high (≥ $100000) household income (RR = 0.07, p < 0.0001) and higher employment rate (RR = 0.36, p < 0.0001). Aboriginal - First Nations status (RR = 0.29, p = 0.0008) and Chinese visible minority (RR = 0.67, p = 0.0005) were also associated with decreased testing. Recent immigration and visible minority status of South Asian, Filipino or Black were not significant predictors of urine culture testing. Females were more likely to be tested than males (RR = 2.58, p < 0.0001) and individuals aged 15-39 were the most likely to be tested (RR = 1.69, p < 0.0001).

CONCLUSIONS

Considerable differences exist in urine culture testing across Calgary and these are associated with a number of sociodemographic factors. In particular, areas of lower socioeconomic standing had significantly increased rates of testing. These observations highlight specific groups that should be targeted to improve healthcare delivery and, in turn, enhance laboratory utilization.

Clinical Practice Guidelines for the Antibiotic Treatment of Community-Acquired Urinary Tract Infections

Urinary tract infections (UTIs) are infectious diseases that commonly occur in communities. Although several international guidelines for the management of UTIs have been available, clinical characteristics, etiology and antimicrobial susceptibility patterns may differ from country to country. This work represents an update of the 2011 Korean guideline for UTIs. The current guideline was developed by the update and adaptation method. This clinical practice guideline provides recommendations for the diagnosis and management of UTIs, including asymptomatic bacteriuria, acute uncomplicated cystitis, acute uncomplicated pyelonephritis, complicated pyelonephritis related to urinary tract obstruction, and acute bacterial prostatitis. This guideline targets community-acquired UTIs occurring among adult patients. Healthcare-associated UTIs, catheter-associated UTIs, and infections in immunocompromised patients were not included in this guideline.

Asymptomatic bacteriuria in recurrent UTI - to treat or not to treat

Asymptomatic bacteriuria (ABU) is a common clinical condition that often leads to unnecessary antimicrobial use. The reduction of antibiotic overuse for ABU is consequently an important issue for antimicrobial stewardship to reduce the emergence of multidrug resistant strains. In the clinical setting we have an important issue that requires special attention: the role of ABU in women affected by recurrent urinary tract infections (rUTIs). In everyday clinical practice, young women affected by rUTI show after antibiotic treatment asymptomatic periods associated sometimes with or without bacteriuria. Although it is not recommended, the majority of women with ABU is treated with poor results and occasionally a selection of multidrug-resistant bacteria can be observed. Recent studies demonstrated that ABU should not be treated in young women affected by rUTI, because it may play even a protective role in preventing symptomatic episodes, particularly when Enterococcus faecalis has been isolated. Moreover, ABU treatment is associated with a higher occurrence of antibiotic-resistant bacteria, indicating that ABU treatment in women with rUTIs is even potentially dangerous.

Rate and association of lower urinary tract infection with recurrence after transurethral resection of bladder tumor

Purpose

To evaluate the rate of pyuria and bacteriuria after transurethral resection of bladder tumor (TURBT).

Materials and Methods

We retrospectively evaluated data obtained from 363 patients who underwent TURBT between October 2012 and December 2013 at Seoul National University Hospital. Urinalysis and urine culture were assessed at 3, 6, 12, and 24 months postoperatively. Primary endpoint was the rate of bacteriuria (≥10⁵/mL in a midstream) and pyuria (white blood cells ≥5/high-power field).

Results

We analyzed 306 patients who were eligible for the study. Pyuria was present in 23.5% of patients in the 3rd postoperative month and in 31.7% of patients in the 24th postoperative month. Bacteriuria was present in 1.3% of patients in the 3rd postoperative month and in 2.6% of patients in the 24th postoperative month. Among urothelial carcinoma patients (n=220), 24.1% showed pyuria and 1.8% showed bacteriuria at the 3rd postoperative month. We found that 31.8% showed pyuria and 3.2% showed bacteriuria at the 24th postoperative month. There was no significant difference in the rate of pyuria and bacteriuria between the intravesical treatment group and the no-treatment group. Multivariate analysis demonstrated that pyuria in the 3rd postoperative month (odd ratio [OR], 2.254; p=0.039), tumor multiplicity (OR, 3.331; p=0.001), and the absence of intravesical treatment (OR, 4.927; p=0.001) increases the risk of tumor recurrence.

Conclusions

A significant proportion of patients showed pyuria after TURBT during the follow-up period. Additionally, presence of pyuria in the short-term follow-up period after TURBT constitutes a risk factor for recurrence of bladder cancer.

Asymptomatic bacteriuria and urinary tract infection in pregnant women with and without diabetes: Cohort study

OBJECTIVE

To compare the prevalence of asymptomatic bacteriuria (ASB) and the incidence of urinary tract infection (UTI) in pregnant women with and without diabetes mellitus (DM) or gestational DM (GDM).

STUDY DESIGN

We performed a cohort study in five hospitals and two midwifery clinics in the Netherlands. Pregnant women with and without DM or GDM were screened for the presence of ASB around 12 and 32 weeks' gestation. Characteristics of participants as well as outcome data were collected from questionnaires and medical records. ASB was defined as the growth of at least 10e5 cfu/ml isolated from the urine of a woman without UTI complaints. UTI was considered to be present when a treating physician had diagnosed UTI and prescribed antibiotics.

RESULTS

We studied 202 women with and 272 women without DM or GDM. Of all women 31.7% with and 94.9% without DM or GDM provided a week 12 sample. The prevalence of ASB was comparable in women with and without DM or GDM (12 weeks' n = 322; 4.7% and 2.3%; relative risk (RR) 2.02; 95% confidence interval (CI) 0.52-7.84; 32 weeks' n = 422; 3.2% and 3.0%; RR 1.06; 95% CI 0.36-3.09), as was the incidence of UTI (16.8% and 12.9%; RR 1.31; 95% CI 0.85-2.02). Neither ASB nor UTI were associated with preterm birth or babies being small for gestational age.

CONCLUSION

In pregnant women with and women without DM or GDM, the overall prevalence of ASB was low. Neither ASB nor UTI did differ significantly between the groups. Our data discourage a routine ASB screen and treat policy in pregnant women with DM or GDM.

Inappropriate Management of Asymptomatic Patients With Positive Urine Cultures: A Systematic Review and Meta-analysis

BACKGROUND

Mismanagement of asymptomatic patients with positive urine cultures (referred to as asymptomatic bacteriuria [ASB] in the literature) promotes antimicrobial resistance and results in unnecessary antimicrobial-related adverse events and increased health care costs.

METHODS

We conducted a systematic review and meta-analysis of studies that reported on the rate of inappropriate ASB treatment published from 2004 to August 2016. The appropriateness of antimicrobial administration was based on guidelines published by the Infectious Diseases Society of America.

RESULTS

A total of 2142 nonduplicate articles were identified, and among them 30 fulfilled our inclusion criteria. The pooled prevalence of antimicrobial treatment among 4129 cases who did not require treatment was 45% (95% CI, 39-50). Isolation of gram-negative pathogens (odds ratio [OR], 3.58; 95% CI, 2.12-6.06), pyuria (OR, 2.83; 95% CI, 1.9-4.22), nitrite positivity (OR, 3.83; 95% CI, 2.24-6.54), and female sex (OR, 2.11; 95% CI, 1.46-3.06) increased the odds of receiving treatment. The rates of treatment were higher in studies with ≥100 000 cfu/mL cutoff values compared with <10 000 cfu/mL for bacterial growth (P, .011). The implementation of educational and organizational interventions designed to eliminate the overtreatment of ASB resulted in a median absolute risk reduction of 33% (rangeARR, 16-36%, medianRRR, 53%; rangeRRR, 25-80%).

CONCLUSION

The mismanagement of ASB remains extremely frequent. Female sex and the overinterpretation of certain laboratory data (positive nitrites, pyuria, isolation of gram-negative bacteria and cultures with higher microbial count) are associated with overtreatment. Even simple stewardship interventions can be particularly effective, and antimicrobial stewardship programs should focus on the challenge of differentiating true urinary tract infection from ASB.

Significance of Asymptomatic Bacteriuria

Since the recognition of asymptomatic bacteriuria (ABU), several studies have questioned its significance. It is a very common condition, observed in many healthy individuals. Current guidelines mandate that ABU should not be treated in all cases, as it does not seem to improve the outcome. Conditional restrictions for treatment of ABU can be relaxed in certain situations, with minimal exceptions to the rule.

Diagnosis, Treatment, and Prevention of Urinary Tract Infection

UTI may involve the lower or upper urinary tract and may be uncomplicated or complicated. The emphasis of this chapter is uncomplicated UTI. The diagnosis of uncomplicated cystitis (bladder infection) and pyelonephritis (kidney infection) is usually easily made based on the clinical presentation, whereas the diagnosis in patients with complicated UTI is often more complex. Thus uncomplicated cystitis is usually manifested by dysuria, frequency and/or urgency without fever, and pyelonephritis is usually manifested by fever and back pain/costovertebral angle tenderness. However, pyuria is usually present with UTI, regardless of location, and its absence suggests that another condition may be causing the patient's symptoms. Treatment of cystitis is usually straightforward with one of several effective short-course antimicrobial regimens, although antimicrobial resistance continues to increase and can complicate treatment choices in certain areas. Likewise, antimicrobial resistance has complicated our management of uncomplicated pyelonephritis since resistance of uropathogens to the fluoroquinolone class, the mainstay of oral treatment for pyelonephritis, is increasing worldwide, and some of the other agents used for cystitis are not recommended for pyelonephritis due to low tissue levels. The goal of prevention of recurrent cystitis is to minimize the use of antimicrobials and there are several research efforts in progress to develop effective and safe antimicrobial-sparing preventive approaches for this common condition.

Pathoadaptive Mutations in Uropathogenic Escherichia coli

Uropathogenic Escherichia coli (UPEC) are opportunistic human pathogens that primarily circulate as part of commensal intestinal microbiota. Though they have the ability to survive and proliferate in various urinary tract compartments, the urinary tract is a transient, occasional habitat for UPEC. Because of this, most of the UPEC traits have originally evolved to serve in intestinal colonization and transmission. Some of these bacterial traits serve as virulence factors - they are critical to or assist in survival of UPEC as pathogens, and the structure and/or function may be specialized for the infection. Other traits could serve as anti-virulence factors - they represent liability in the urinary tract and are under selection to be lost or inactivated during the infection. Inactivation, variation, or other changes of the bacterial genes that increase the pathogen's fitness during the infection are called pathoadaptive mutations. This chapter describes examples of pathoadaptive mutations in UPEC and provides rationale for their further in-depth study.

"Urinary Tract Infection"-Requiem for a Heavyweight

"Urinary tract infection" ("UTI") is an ambiguous, expansive, overused diagnosis that can lead to marked, harmful antibiotic overtreatment. "Significant bacteriuria," central to most definitions of "UTI," has little significance in identifying individuals who will benefit from treatment. "Urinary symptoms" are similarly uninformative. Neither criterion is well defined. Bacteriuria and symptoms remit and recur spontaneously. Treatment is standard for acute uncomplicated cystitis and common for asymptomatic bacteriuria, but definite benefits are few. Treatment for "UTI" in older adults with delirium and bacteriuria is widespread but no evidence supports the practice, and expert opinion opposes it. Sensitive diagnostic tests now demonstrate that healthy urinary tracts host a ubiquitous, complex microbial community. Recognition of this microbiome, largely undetectable using standard agar-based cultures, offers a new perspective on "UTI." Everyone is bacteriuric. From this perspective, most people who are treated for a "UTI" would probably be better off without treatment. Elderly adults, little studied in this regard, face particular risk. Invasive bacterial diseases such as pyelonephritis and bacteremic bacteriuria are also "UTIs." Mindful decisions about antibiotic use will require a far better understanding of how pathogenicity arises within microbial communities. It is likely that public education and meaningful informed-consent discussions about antibiotic treatment of bacteriuria, emphasizing potential harms and uncertain benefits, would reduce overtreatment. Emphasizing the microbiome's significance and using the term "urinary tract dysbiosis" instead of "UTI" might also help and might encourage mindful study of the relationships among host, aging, microbiome, disease, and antibiotic treatment.

The Acute Cystitis Symptom Score for Patient-Reported Outcome Assessment

OBJECTIVES

The Acute Cystitis Symptom Score (ACSS) was developed as a self-reporting questionnaire for clinical diagnosis of acute uncomplicated cystitis (AUC) and symptomatic changes in female patients. The aim of the present study was to assess the utility of the different domains of ACSS including the 'dynamics' domain after therapy. The applicability of these domains in assessing changes in symptoms, as a function of time, in this population was investigated.

MATERIALS AND METHODS

During the validation process of the ACSS in Uzbek and Russian languages, a subgroup of patients (n = 63) returned after therapy and filled in part B of ACSS. Descriptive statistics were used, where suitable.

RESULTS

The reduction of typical symptoms and quality of life (QoL) assessment between first and follow-up visit correlated significantly with answers in the 'dynamics' domain. Success/cure and non-success/failure could be clearly differentiated by the scores obtained in 'typical' and 'QoL' domains.

CONCLUSION

The ACSS has proven to be a useful instrument to clinically diagnose AUC in women. It is also a suitable instrument for patient-reported outcome assessment, with applicability in both daily practice and in clinical studies. Slight modifications in the 'dynamics' domain will even increase the applicability.

Deliberate Establishment of Asymptomatic Bacteriuria-A Novel Strategy to Prevent Recurrent UTI

We have established a novel strategy to reduce the risk for recurrent urinary tract infection (UTI), where rapidly increasing antibiotic resistance poses a major threat. Epidemiologic studies have demonstrated that asymptomatic bacteriuria (ABU) protects the host against symptomatic infections with more virulent strains. To mimic this protective effect, we deliberately establish ABU in UTI-prone patients, who are refractory to conventional therapy. The patients are inoculated with Escherichia coli (E. coli) 83972, now widely used as a prototype ABU strain. Therapeutic efficacy has been demonstrated in a placebo-controlled trial, supporting the feasibility of using E. coli 83972 as a tool to prevent recurrent UTI and, potentially, to outcompete antibiotic-resistant strains from the human urinary tract. In addition, the human inoculation protocol offers unique opportunities to study host-parasite interaction in vivo in the human urinary tract. Here, we review the clinical evidence for protection using this approach as well as some molecular insights into the pathogenesis of UTI that have been gained during these studies.

Practice variation in treatment of suspected asymptomatic bacteriuria prior to cardiac surgery: are there differences in postoperative outcome? A retrospective cohort study

OBJECTIVES

It is unclear whether postoperative infections can be prevented by treating asymptomatic bacteriuria, or whether, on the other hand, such treatment will increase the risk of more serious infection by pathogenic bacteria different from the ones causing bacteriuria. This study aimed to support future treatment decisions for preoperative cardiothoracic surgery patients with asymptomatic bacteriuria, by examining current preoperative practice, in relation to postoperative outcome.

METHODS

A retrospective cohort study was conducted. All patients who underwent cardiothoracic surgery in 2011-2013 using extracorporeal circulation in St. Antonius Hospital Nieuwegein, and who preoperatively had nitrituria and/or leucocyturia were included. Exclusion criteria were C-reactive protein level higher than 10 mg/l, emergency surgery, critical preoperative state and/or antibiotic treatment because of other infections. Outcomes were postoperative infections and length of stay. Furthermore, we compared culture results of preoperative urine with postoperative infection sites in order to study the hypothesis of haematogenous spread.

RESULTS

One thousand and two patients with leucocyturia or nitrituria were eligible, of whom 3.9% had been treated with antibiotics preoperatively (AB+). Of the 96.1% of patients who had not been treated (AB-), 8.3% had an infection postoperatively, compared with 5.1% in the treatment (AB+) group. This was not statistically significant {odds ratio, corrected for EuroSCORE, 0.53 [95% confidence interval (CI) 0.12-2.24, P = 0.39]}. Length of stay, corrected for EuroSCORE, between the treated (AB+) and the non-treated (AB-) group did not differ, with a hazard ratio of 1.05 (95% CI 0.63-1.75, P = 0.85). As regards bacterial culture results, none of patients not treated with antibiotics preoperatively (AB-) seemed to have a postoperative infection due to haematogenous spread of bacteria from the urinary tract present preoperatively.

CONCLUSIONS

The risk of haematogenous spread of bacteria seems to be non-existent in this large cohort of non-treated patients, under our local clinical practice. Based on this current, best available evidence, it seems therefore safe not to treat patients with asymptomatic bacteriuria prior to cardiothoracic surgery. This could also imply that it is safe not to perform routine preoperative urine testing.

The Paradigm Shift to Non-Treatment of Asymptomatic Bacteriuria

Asymptomatic bacteriuria, also called asymptomatic urinary infection, is a common finding in healthy women, and in women and men with abnormalities of the genitourinary tract. The characterization and introduction of the quantitative urine culture in the 1950s first allowed the reliable recognition of asymptomatic bacteriuria. The observations that a substantial proportion of patients with chronic pyelonephritis at autopsy had no history of symptomatic urinary infection, and the high frequency of pyelonephritis observed in pregnant women with untreated asymptomatic bacteriuria, supported a conclusion that asymptomatic bacteriuria was harmful. Subsequent screening and long term follow-up programs for asymptomatic bacteriuria in schoolgirls and women reported an increased frequency of symptomatic urinary tract infection for subjects with asymptomatic bacteriuria, but no increased morbidity from renal failure or hypertension, or increased mortality. Treatment of asymptomatic bacteriuria did not decrease the frequency of symptomatic infection. Prospective, randomized, comparative trials enrolling premenopausal women, children, elderly populations, patients with long term catheters, and diabetic patients consistently report no benefits with antimicrobial treatment of asymptomatic bacteriuria, and some evidence of harm. Several studies have also reported that antimicrobial treatment of asymptomatic bacteriuria increases the short term risk of pyelonephritis. Current investigations are exploring the potential therapeutic intervention of establishing asymptomatic bacteriuria with an avirulent Escherichia coli strain to prevent symptomatic urinary tract infection for selected patients.

Top Ten Myths Regarding the Diagnosis and Treatment of Urinary Tract Infections

BACKGROUND

Urinary tract infections (UTI) are the most common type of infection in the United States. A Centers for Disease Control and Prevention report in March 2014 regarding antibiotic use in hospitals reported "UTI" treatment was avoidable at least 39% of the time. The accurate diagnosis and treatment of UTI plays an important role in cost-effective medical care and appropriate antimicrobial utilization.

OBJECTIVE

We summarize the most common misperceptions of UTI that result in extraneous testing and excessive antimicrobial treatment. We present 10 myths associated with the diagnosis and treatment of UTI and succinctly review the literature pertaining to each myth. We explore the myths associated with pyuria, asymptomatic bacteriuria, candiduria, and the elderly and catheterized patients. We attempt to give guidance for clinicians facing these clinical scenarios.

DISCUSSION

From our ambulatory, emergency department, and hospital experiences, patients often have urine cultures ordered without an appropriate indication, or receive unnecessary antibiotic therapy due to over-interpretation of the urinalysis.

CONCLUSIONS

Asymptomatic bacteriuria is common in all age groups and is frequently over-treated. A UTI diagnosis should be based on a combination of clinical symptoms with supportive laboratory information. This review will assist providers in navigating common pitfalls in the diagnosis of UTI.

Letter to the Editor: Diagnostic Criteria in Urological Diseases do not Always Match with Findings by Extended Culture Techniques and Metagenomic Sequencing of 16S rDNA

Some diseases of the urinary tract are defined by the presence of microorganisms while others are defined by their absence. The underlying idea has always been that urine from healthy subjects is sterile and a negative urine culture has usually been taken as discriminative for an infection to be absent. Several disorders with symptoms that resemble infections are regarded as separate entities based on the exclusion of bacterial growth such as overactive neurogenic bladder and pelvic pain syndromes. During the recent years two paradigmata related to the role of bacteria in urological disease classification have changed completely. Firstly, bacteriuria does not necessarily mean an infection, and secondly, if extended sets of culture media for identification of fastidious and anaerobic bacteria or culture-independent metagenomic sequencing (MGS) is applied, a broad range of even non-culturable bacteria has been detected in the ”sterile” bladder urine in healthy individuals. The aim of this editorial is to initiate a discussion to redefine the criteria for urinary tract infections and non-infectious urological disorders with similar symptoms. Clinical studies, in which extended sets of culture media and MGS are integrated, are needed to clarify the pathogenesis of urological disorders where bacteria may play a role. The pure detection of bacteria in the urine does not by itself prove an infectious etiology of a specific disorder. It is important to avoid that results of new technologies lead to unnecessary antibiotic consumption with unwanted collateral damage and adverse events.

Urological infections due to multidrug-resistant bacteria: what we need to know?

PURPOSE

Recent epidemiological data have confirmed the increasing problem of antimicrobial resistance not only for hospitalized, healthcare-associated patients, but also for outpatients. In particular, the progressive increase in resistance to broad-spectrum antibiotics, such as third-generation cephalosporins, fluoroquinolones or carbapenems in Enterobacteriaceae, is an alarming situation for all urologists and general practitioners. Here, we aimed to review the epidemiological data of multidrug-resistant bacteria in the urological setting, in order to summarize all diagnostic and therapeutic recommendations to use in everyday clinical practice.

METHODS

We collected all recent publications from Medline and Cochrane Library from January 2000 to December 2013. Moreover, data from the abstracts presented at the EAU and AUA Congresses during the last 5 years have also been analyzed. All papers were evaluated by an expert panel on urological infections on behalf of the Italian Urological Association (SIU).

RESULTS

Fluoroquinolone and other antibiotic-resistant bacteria prevalence is normally very high in the lower urinary tract infection patients. In particular, multidrug-resistant bacteria prevalence in urological practice contributes to infectious morbidity increasing the financial costs to healthcare system. The expert panel on urological infections on behalf of the Italian Urological Association formulated new diagnostic pathway and therapeutic protocol in patients affected by urological tract infections due to multidrug-resistant bacteria.

CONCLUSIONS

The recent emergence of multidrug-resistant pathogens is an alarming public health issue also in urological practice with socioeconomic importance. Our practice should be revised on the basis of these new acquisitions.

Asymptomatic Bacteriuria in Clinical Urological Practice: Preoperative Control of Bacteriuria and Management of Recurrent UTI

Asymptomatic bacteriuria (ABU) is a common clinical condition that often leads to unnecessary antimicrobial use. The reduction of antibiotic overuse for ABU is consequently an important issue for antimicrobial stewardship and to reduce the emergence of multidrug resistant strains. There are two issues in everyday urological practice that require special attention: the role of ABU in pre-operative prophylaxis and in women affected by recurrent urinary tract infections (rUTIs). Nowadays, this is the time to think over our practice and change our way of thinking. Here, we aimed to summarize the current literature knowledge in terms of ABU management in patients undergoing urological surgery and in patients with rUTIs. In the last years, the approach to patient with ABU has changed totally. Prior to all surgical procedures that do not enter the urinary tract, ABU is generally not considered as a risk factor, and screening and treatment are not considered necessary. On the other hand, in the case of all procedures entering the urinary tract, ABU should be treated in line with the results of a urine culture obtained before the procedure. In patients affected by rUTIs, ABU can even have a protective role in preventing symptomatic recurrence, particularly when Enterococcus faecalis (E. faecalis) has been isolated.

Ibuprofen versus fosfomycin for uncomplicated urinary tract infection in women: randomised controlled trial

STUDY QUESTION

Can treatment of the symptoms of uncomplicated urinary tract infection (UTI) with ibuprofen reduce the rate of antibiotic prescriptions without a significant increase in symptoms, recurrences, or complications?

METHODS

Women aged 18-65 with typical symptoms of UTI and without risk factors or complications were recruited in 42 German general practices and randomly assigned to treatment with a single dose of fosfomycin 3 g (n=246; 243 analysed) or ibuprofen 3 × 400 mg (n=248; 241 analysed) for three days (and the respective placebo dummies in both groups). In both groups additional antibiotic treatment was subsequently prescribed as necessary for persistent, worsening, or recurrent symptoms. The primary endpoints were the number of all courses of antibiotic treatment on days 0-28 (for UTI or other conditions) and burden of symptoms on days 0-7. The symptom score included dysuria, frequency/urgency, and low abdominal pain.

STUDY ANSWER AND LIMITATIONS

The 248 women in the ibuprofen group received significantly fewer course of antibiotics, had a significantly higher total burden of symptoms, and more had pyelonephritis. Four serious adverse events occurred that lead to hospital referrals; one of these was potentially related to the trial drug. Results have to be interpreted carefully as they might apply to women with mild to moderate symptoms rather than to all those with an uncomplicated UTI.

WHAT THIS PAPER ADDS

Two thirds of women with uncomplicated UTI treated symptomatically with ibuprofen recovered without any antibiotics. Initial symptomatic treatment is a possible approach to be discussed with women willing to avoid immediate antibiotics and to accept a somewhat higher burden of symptoms.

FUNDING, COMPETING INTERESTS, DATA SHARING

German Federal Ministry of Education and Research (BMBF) No 01KG1105. Patient level data are available from the corresponding author. Patient consent was not obtained but the data are anonymised and risk of identification is low.Trial registration No ClinicalTrialGov Identifier NCT01488955.

An open label, non-controlled, multicentre, interventional trial to investigate the safety and efficacy of Canephron® N in the management of uncomplicated urinary tract infections (uUTIs)

Background

Despite of increasing prevalence of bacterial resistance to antibiotics and possible adverse drug reactions (ADRs), uncomplicated lower urinary tract infections (uUTIs) are usually treated with antibiotics. Canephron® N, a herbal medicinal product, was now investigated for safety and efficacy in women suffering from uUTI.

Methods

In an open-label, non-randomized, multicentre clinical trial 125 Caucasian female patients suffering from uUTI with a sum score of at least 6 for the symptoms dysuria, frequency and urgency (each rated 0–4) were enrolled. Patients were treated with 3x2 tablets Canephron® N for seven days. Symptom assessment was performed by the patient on a daily basis and by the investigator at Day 0, Day 7, Day 37. Primary endpoint was the incidence of ADRs during the treatment. Secondary endpoints were clinical cure (none of the main symptoms scored as worse than mild (“1”)) on Day 7, severity of uUTI symptoms on Day 7 and Day 37, patients requiring antibiotic treatment until Day 7, duration of uUTI symptoms and patients with early recurrence. Changes in safety data (dipstick analysis of urine; analysis of blood and urine in a central laboratory) were analysed descriptively. Further post hoc analyses were performed.

Results

None of 19 adverse events within the study period was considered as drug-related or serious. The responder rate was 71.2 % on Day 7 and 85.6 % on Day 37 (FAS, N = 125) with a significant improvement of all symptoms (all: p < 0.001). Only 2.4 % of patients required antibiotics during the treatment period and none of the patients met the definition of recurrence until Day 37. The mean changes of the main symptoms on Day 7 and Day 37 compared to Day 0 were: −1.9/-2.3 (dysuria); −1.8/-2.4 (frequency); −1.6/-1.9 (urgency). Symptomatic improvement was accompanied by decreased nitrite, leukocytes as well as erythrocyte levels from Day 0 to Day 7 and Day 37.

Conclusions

This trial emphasises the safe usage and efficacious opportunity of a non-antibiotic therapy approach with Canephron® N and fully justifies a large-scale controlled clinical trial.

Trial registration

Eudra CT nr. 2011-000838-11. ClinicalTrials.gov Identifier NCT01478620

Asymptomatic bacteriuria treatment is associated with a higher prevalence of antibiotic resistant strains in women with urinary tract infections

BACKGROUND

Women suffering from recurrent urinary tract infections (rUTIs) are routinely treated for asymptomatic bacteriuria (AB), but the consequences of this procedure on antibiotic resistance are not fully known. The aim of this study was to evaluate the impact of AB treatment on antibiotic resistance among women with rUTIs.

METHODS

The study population consisted of 2 groups of women who had previously been enrolled in a randomized clinical trial: group A was not treated, and group B was treated. All women were scheduled for follow-up visits every 6 months, or more frequently if symptoms arose. Microbiological evaluation was performed only in symptomatic women. All women were followed up for a mean of 38.8 months to analyze data from urine cultures and antibiograms.

RESULTS

The previous study population consisted of 673 women, but 123 did not attend the entire follow-up period. For the final analysis, 257 of the remaining 550 patients were assigned to group A, and 293 to group B. At the end of follow-up, the difference in recurrence rates was statistically significant (P < .001): 97 (37.7%) in group A versus 204 (69.6%) in group B. Isolated Escherichia coli from group B showed higher resistance to amoxicillin-clavulanic acid (P = .03), trimethoprim-sulfamethoxazole (P = .01), and ciprofloxacin (P = .03) than that from group A.

CONCLUSIONS

This study shows that AB treatment is associated with a higher occurrence of antibiotic-resistant bacteria, indicating that AB treatment in women with rUTIs is potentially dangerous.

A Controlled Quasi-Experimental Study of an Educational Intervention to Reduce the Unnecessary Use of Antimicrobials For Asymptomatic Bacteriuria

Background

Asymptomatic bacteriuria (ABU) should only be treated in cases of pregnancy or in-patients undergoing urologic procedures; however, unnecessary treatment of ABU is common in clinical practice.

Objective

To identify risk factors for unnecessary treatment and to assess the impact of an educational intervention focused on these risk factors on treatment of ABU.

Design

Quasi-experimental study with a control group.

Setting

Two tertiary teaching adult care hospitals.

Participants

Consecutive patients with positive urine cultures between January 30^th and April 17^th, 2012 (baseline) and January 30^th and April 30^th, 2013 (intervention).

Intervention

In January 2013, a multifaceted educational intervention based on risk factors identified during the baseline period was provided to medical residents (monthly) on one clinical teaching unit (CTU) at one hospital site, with the CTU of the other hospital serving as the control.

Results

During the baseline period, 160/341 (46.9%) positive urine cultures were obtained from asymptomatic patients at the two hospitals, and 94/160 (58.8%) were inappropriately treated with antibiotics. Risk factors for inappropriate use included: female gender (OR 2.1, 95% CI 1.1-4.3), absence of a catheter (OR 2.5, 1.2-5), bacteriuria versus candiduria (OR 10.6, 3.8-29.4), pyuria (OR 2.0, 1.1-3.8), and positive nitrites (OR 2.2, 1.1-4.5). In 2013, only 2/24 (8%) of ABU patients were inappropriately treated on the intervention CTU as compared to 14/29 (52%) on the control CTU (OR 0.10; 95% CI 0.02-0.49). A reduction was also observed as compared to baseline on the intervention CTU (OR 0.1, 0.02-0.7) with no significant change noted on the control CTU (OR 0.47, 0.13-1.7).

Conclusions

A multifaceted educational intervention geared towards medical residents with a focus on identified risk factors for inappropriate management of ABU was effective in reducing unnecessary antibiotic use.

Decreased microbiota diversity associated with urinary tract infection in a trial of bacterial interference

BACKGROUND

Patients with long-term indwelling catheters are at high risk of catheter-associated urinary tract infection (CAUTI). We hypothesized that colonizing the bladder with a benign Escherichia coli strain (E. coli HU2117, a derivative of E. coli 83972) would prevent CAUTI in older, catheterized adults.

MATERIALS AND METHODS

Adults with chronic, indwelling urinary catheters received study catheters that had been pre-coated with E. coli HU2117. We monitored the cultivatable organisms in the bladder for 28 days or until loss of E. coli HU2117. Urine from 4 subjects was collected longitudinally for 16S rRNA gene profiling.

RESULTS

Eight of the ten subjects (average age 70.9 years) became colonized with E. coli HU2117, with a mean duration of 57.7 days (median: 28.5, range 0-266). All subjects also remained colonized by uropathogens. Five subjects suffered invasive UTI, 3 febrile UTI and 2 urosepsis/bacteremia, all associated with overgrowth of a urinary pathogen. Colonization with E. coli HU2117 did not impact bacterial bladder diversity, but subjects who developed infections had less diverse bladder microbiota.

CONCLUSIONS

Colonization with E. coli HU2117 did not prevent bladder colonization or subsequent invasive disease by uropathogens. Microbial diversity may play a protective role against invasive infection of the catheterized bladder.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00554996 http://clinicaltrials.gov/ct2/show/NCT00554996.

A comparison of monomicrobial versus polymicrobial Enterococcus faecalis bacteriuria in a French University Hospital

Enterococci are of considerable relevance in the hospital setting. Their most common location is the urinary tract, where they may be responsible for both colonization and infections. They are often associated with the presence of other microorganisms. The aim was to compare monomicrobial and polymicrobial Enterococcus faecalis bacteriuria. A retrospective study was performed on the demographic, clinical, and laboratory data of 299 patients who had presented with E. faecalis bacteriuria in 2012 at a University Hospital. The bacteriuria was polymicrobial in 46.1 % of cases and in 36.4 % of cases was responsible for a urinary tract infection. Infections appeared to be more prevalent in the polymicrobial than the monomicrobial group (42 % vs 32 %, p = 0.06). Half of the patients who presented with urinary tract colonization received antibiotic treatment (54/ out of 10). A multivariate analysis adjusted for age (adjusted odds ratio [AOR] = 1.02 per year, p = 0.006), gender (AOR = 2.2, p = 0.007), and clinical classification (colonization or infection, AOR = 1.6, p = 0.091), showed that diabetes mellitus (AOR = 2.0, p = 0.04), hospital length of stay exceeding 28 days (AOR = 2.0, p = 0.03), and presence of a urinary catheter (AOR = 2.4, p = 0.001) were all factors associated with polymicrobial E. faecalis bacteriuria. A reduction in the length of hospital stay and the use of urinary catheters would appear to be required to decrease the incidence of urinary tract colonization and infections by polymicrobial E. faecalis. Improper use of antibiotics to treat urinary tract colonization remains a major concern.

Procalcitonin and pyuria-based algorithm reduces antibiotic use in urinary tract infections: a randomized controlled trial

BACKGROUND

Urinary tract infections (UTIs) are common drivers of antibiotic use. The minimal effective duration of antibiotic therapy for UTIs is unknown, but any reduction is important to diminish selection pressure for antibiotic resistance, costs, and drug-related side-effects. The aim of this study was to investigate whether an algorithm based on procalcitonin (PCT) and quantitative pyuria reduces antibiotic exposure.

METHODS

From April 2012 to March 2014, we conducted a factorial design randomized controlled open-label trial. Immunocompetent adults with community-acquired non-catheter-related UTI were enrolled in the emergency department of a tertiary-care 600-bed hospital in northwestern Switzerland. Clinical presentation was used to guide initiation and duration of antibiotic therapy according to current guidelines (control group) or with a PCT-pyuria-based algorithm (PCT-pyuria group). The primary endpoint was overall antibiotic exposure within 90 days. Secondary endpoints included duration of the initial antibiotic therapy, persistent infection 7 days after end of therapy and 30 days after enrollment, recurrence and rehospitalizations within 90 days.

RESULTS

Overall, 394 patients were screened, 228 met predefined exclusion criteria, 30 declined to participate, and 11 were not eligible. Of these, 125 (76% women) were enrolled in the intention-to-treat (ITT) analysis and 96 patients with microbiologically confirmed UTI constituted the per protocol group; 84 of 125 (67%) patients had a febrile UTI, 28 (22%) had bacteremia, 5 (4%) died, and 3 (2%) were lost to follow-up. Overall antibiotic exposure within 90 days was shorter in the PCT-pyuria group than in the control group (median 7.0 [IQR, 5.0-14.0] vs. 10.0 [IQR, 7.0-16.0] days, P = 0.011) in the ITT analysis. Mortality, rates of persistent infections, recurrences, and rehospitalizations were not different.

CONCLUSIONS

A PCT-pyuria-based algorithm reduced antibiotic exposure by 30% when compared to current guidelines without apparent negative effects on clinical outcomes.

Antibiotics for asymptomatic bacteriuria

BACKGROUND

Asymptomatic bacteriuria is commonly detected in women aged up to 60 years, patients with diabetes, and the elderly. The benefit of antibiotic treatment for this condition is controversial.

OBJECTIVES

To assess the effectiveness and safety of antibiotics treatment for asymptomatic bacteriuria in adults. Specific objectives were to assess 1) the effectiveness of antibiotics for preventing development of symptomatic UTI, UTI-related complications, overall mortality, UTI-related mortality, and resolution of bacteriuria; 2) the development of resistance to antibiotic treatment by comparing resistance of grown bacteria in urine before and after therapy; and 3) the frequency of adverse events.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register up to 24 February 2015 through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs comparing antibiotics to placebo or no treatment for asymptomatic bacteriuria in adults were included. The outcomes of interest were the development of symptomatic urinary tract infection (UTI), complications, death, any adverse event, development of antibiotic resistance, bacteriological cure, and decline in kidney function.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data and assessed study quality. Statistical analyses were performed using the random effects model and the results expressed as risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

We included nine studies (1614 participants) in this review. Symptomatic UTI (RR 1.11, 95% CI 0.51 to 2.43), complications (RR 0.78, 95% CI 0. 35 to 1.74), and death (RR 0.99, 95% CI 0.70 to 1.41) were similar between the antibiotic and placebo or no treatment arms. Antibiotics were more effective for bacteriological cure (RR 2.32, 95% CI 1.11 to 4.83) but also more adverse events developed in this group (RR 3.77, 95% CI 1.40 to 10.15). No decline in the kidney function was observed across the studies; minimal data were available on the emergence of resistant strains after antimicrobial treatment.The included studies were of medium and high quality, used different treatments for different durations of treatment and follow-up, different populations, but this did not appear to influence the results of review.

AUTHORS' CONCLUSIONS

No differences were observed between antibiotics versus no treatment of asymptomatic bacteriuria for the development of symptomatic UTI, complications or death. Antibiotics were superior to no treatment for the bacteriological cure but with significantly more adverse events. There was no clinical benefit from treating asymptomatic bacteriuria in the studies included in this review.

Prevalence and clinical outcome of subclinical bacteriuria in female dogs

OBJECTIVE

To determine the prevalence of subclinical bacteriuria and its natural clinical course over a 3-month period in healthy female dogs.

DESIGN

Observational, prospective, cross-sectional study.

ANIMALS

101 healthy client-owned female dogs.

PROCEDURES

In all dogs, screening clinicopathologic tests and bacteriologic culture of urine were performed. In culture-positive dogs, subclinical bacteriuria was confirmed by 2 positive culture results within 2 weeks and dogs were reevaluated at 3 months.

RESULTS

The prevalence of subclinical bacteriuria in healthy female dogs was 9 of 101 (8.9%). Three-month follow-up data were available for 8 of 9 dogs with subclinical bacteriuria. Four dogs had persistent bacteriuria, and 4 had transient bacteriuria. No dogs with subclinical bacteriuria developed clinical signs during the 3-month observation period. Subclinical bacteriuria was diagnosed in 6 of 51 (12%) young and middle-aged dogs and 3 of 50 (6.0%) senior and geriatric dogs. No significant difference was found in the prevalence of subclinical bacteriuria with age.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that subclinical bacteriuria is a nonprogressive condition in healthy female dogs and can be persistent or transient. No significant difference in the prevalence of subclinical bacteriuria in young and middle-aged dogs versus senior and geriatric dogs was detected. No dogs with subclinical bacteriuria developed clinical signs requiring antimicrobial treatment during the 3-month observation period. Healthy female dogs with subclinical bacteriuria may be a population of dogs in which antimicrobial treatment is unnecessary.

ACVIM consensus statement on therapeutic antimicrobial use in animals and antimicrobial resistance

The epidemic of antimicrobial resistant infections continues to challenge, compromising animal care, complicating food animal production and posing zoonotic disease risks. While the overall role of therapeutic antimicrobial use in animals in the development AMR in animal and human pathogens is poorly defined, veterinarians must consider the impacts of antimicrobial use in animal and take steps to optimize antimicrobial use, so as to maximize the health benefits to animals while minimizing the likelihood of antimicrobial resistance and other adverse effects. This consensus statement aims to provide guidance on the therapeutic use of antimicrobials in animals, balancing the need for effective therapy with minimizing development of antimicrobial resistance in bacteria from animals and humans.

Human urine is not sterile - shift of paradigm

OBJECTIVE

Until recently the generally accepted paradigm implied that urine of healthy people is sterile. In the present study, urine of healthy subjects was investigated by extended bacteriological methods.

MATERIAL AND METHODS

Three midstream urine samples from 52 healthy subjects each (24 females, 28 males; 18-25 years of age) were investigated by an extended set of culture media for identification of facultative aerobic (FAB) and nonclostridial anaerobic bacteria (NCAB). Ward's method (Euclidean distance) was used for similarity analysis.

RESULTS

The bacterial count of FAB in urine was usually low (≤ 10(2) colony-forming units/ml) in both groups. In contrast, the bacterial count of NCAB was higher (≥ 10(3) colony-forming units/ml), at least in some species, with significant differences between genders. The average number of bacterial species found was 5.8 in female and 7.1 in male urine. Half of the females were assigned to a specific 'female' microbial spectrum, different from that of males. In the mixed-gender clusters, the males showed a greater similarity among themselves.

CONCLUSIONS

As also shown by other investigators, urine of healthy people is normally not sterile. The role of the routinely not cultivated bacteria in healthy and diseased subjects needs to be established. It may alter the diagnostics of infectious and inflammatory diseases of the urogenital tract.

A Randomized, Double-Blind, Parallel-Group, Multicenter Clinical Study of Escherichia coli-Lyophilized Lysate for the Prophylaxis of Recurrent Uncomplicated Urinary Tract Infections

BACKGROUND

One strategy for managing recurrent uncomplicated urinary tract infections (UTIs) is prevention. This study tested OM-89S, a lyophilized lysate of 18 Escherichia coli strains manufactured using a modified lytic process.

METHODS

This was a randomized, double-blind trial in 451 female subjects with recurrent uncomplicated UTIs. Period 1 of the study tested 6 mg of OM-89S versus placebo (3 months), plus a 3-month observation. Period 2 of the study was a 3-month treatment period (each monthly cycle consisted of 6 mg of OM-89S daily for 10 days and placebo for 20 days, vs. 50 mg nitrofurantoin daily for 30 days), plus a 3-month observation.

RESULTS

There was no difference in the mean rate of UTI episodes between the OM-89S (0.66 ± 0.93) and placebo groups (0.63 ± 0.86; p = 0.95) in period 1. Similar findings were obtained for period 2. OM-89S was well-tolerated.

CONCLUSIONS

Our results did not demonstrate a preventive effect of OM-89S compared to placebo. This may be due to the low number of UTIs that occurred during the study, the high number of protocol violations, and/or the modified manufacturing process used for OM-89S.