Catheter-associated Bacteriuria Research Articles

Inter-rater agreement of CAUTI (catheter-associated urinary tract infections) diagnosis among Infectious disease physicians

Background: CAUTIs constitute forty percent of nosocomial infections, yet their direct link with mortality remains debated. In 2009, NHSN estimated the economic burden of CAUTIs in the U.S. to be over $340 million. Limited data exist on inter-physician concordance in diagnosing CAUTIs, especially in patients with abnormal genitourinary (GU) anatomy. Our study assessed inter-provider variability in diagnosing CAUTI in 50 such patients, including those meeting NHSN(National healthcare safety network) criteria. Methods: We included a random set of 50 adults (18+) with abnormal GU anatomy admitted to the University of Miami hospitals from January 2018 to November 2021 who had a urinary foley catheter and at least one positive urine culture during their hospitalization. Three Infectious disease fellows and three board-certified Infectious disease physicians independently reviewed each patient’s chart, classifying them as having or not having a CAUTI. Inter-physician reliability was assessed using kappa statistics. Results: Our findings highlight substantial variation in clinician-determined CAUTI incidence among the 50 patients with abnormal GU anatomy, ranging from 8% to 32% (Figures 2,3). Inter-rater agreement on CAUTI diagnosis was generally poor (Kappa Hollenbeak CS, et al. The attributable cost of catheter-associated urinary tract infections in the United States: A systematic review. Am J Infect Control. 2018 Jul;46(7):751-757. Trautner BW, et al. Development and validation of an algorithm to recalibrate mental models and reduce diagnostic errors associated with catheter-associated bacteriuria. BMC Med Inform Decis Mak. 2013 Apr 15;13:48. Gafary M, et al. Catheter Associated Urinary Tract Infections (CAUTI) in Bladder Cancer Patients Post Cystectomy With a Neobladder, Open Forum Infectious Diseases, Volume 2, Issue suppl_1, December 2015, 293.

119. Performance of Infectious Diseases Specialists, Hospitalists, and Generalists in Case-Based Scenarios Illustrating Antimicrobial Stewardship Principles at 16 VA Medical Centers

BackgroundAs part of a project to implement and evaluate antimicrobial dashboards at selected VA facilities nationwide, we assessed provider attitudes and knowledge related to antibiotic prescribing among physicians working in inpatient settings at 16 VA facilities.MethodsThe online survey explored attitudes toward antimicrobial use and assessed respondents’ management of four clinical scenarios: cellulitis, community-acquired pneumonia (CAP), non-catheter-associated asymptomatic bacteriuria (NC-ASB), and catheter-associated asymptomatic bacteriuria (C-ASB). Responses were scored by assigning +1 for an answer most consistent with guidelines, 0 for a less-guideline-concordant but acceptable answer and -1 for an incorrect answer. Scores were normalized to 100% correct to 100% incorrect across all questions within a scenario, and mean scores were calculated across respondents by specialty; differences in mean score per scenario were tested using ANOVA.ResultsOne-hundred-thirty-nine physicians completed the survey (n=19 ID physicians, 62 hospitalists, 58 generalists). Attitudes were similar across the three specialties. There was a significant difference in cellulitis scenario scores (correct responses: ID=67.4%, hospitalists=51.2%, generalists=41.8% correct, p=0.0087). Scores were not significantly different across specialties for CAP (correct responses: ID 76.2%, hospitalists 63%, generalists 56.5%, p=0.0914) and NC-ASB (correct responses; ID 63%, hospitalists 55%, generalists 36.2%, p=0.322), though ID trended higher. Lowest scores were observed for C-ASB (ID 39.5% correct, hospitalists 4% incorrect, generalists 8.5% incorrect, p=0.12).ConclusionSignificant differences in performance on management of cellulitis and low overall scores on C-ASB management point to these conditions as being potentially high-yield targets for antimicrobial stewardship interventions.Disclosures Matthew B. Goetz, MD, Nothing to disclose Peter A. Glassman, MBBS, US Pharmacopeia (formerly), PAG; Kaiser Permanente (current employee, spouse) (Advisor or Review Panel member, The above refers to USP (ended in 2020).)

Prospective assessment of catheter-associated bacteriuria clinical presentation, epidemiology, and colonization dynamics in nursing home residents

BACKGROUNDCatheterization facilitates continuous bacteriuria, for which the clinical significance remains unclear. This study aimed to determine the clinical presentation, epidemiology, and dynamics of bacteriuria in a cohort of long-term catheterized nursing home residents.METHODSProspective urine culture, urinalysis, chart review, and assessment of signs and symptoms of infection were performed weekly for 19 study participants over 7 months. All bacteria ≥ 1 × 103 cfu/mL were cultured, isolated, identified, and tested for susceptibility to select antimicrobials.RESULTSIn total, 226 of the 234 urine samples were polymicrobial (97%), with an average of 4.7 isolates per weekly specimen. A total of 228 urine samples (97%) exhibited ≥ 1 × 106 CFU/mL, 220 (94%) exhibited abnormal urinalysis, 126 (54%) were associated with at least 1 possible sign or symptom of infection, and 82 (35%) would potentially meet a standardized definition of catheter-associated urinary tract infection (CAUTI), but only 3 had a caregiver diagnosis of CAUTI. Bacterial isolates (286; 30%) were resistant to a tested antimicrobial agent, and bacteriuria composition was remarkably stable despite a combined total of 54 catheter changes and 23 weeks of antimicrobial use.CONCLUSIONBacteriuria composition was largely polymicrobial, including persistent colonization by organisms previously considered to be urine culture contaminants. Neither antimicrobial use nor catheter changes sterilized the urine, at most resulting in transient reductions in bacterial burden followed by new acquisition of resistant isolates. Thus, this patient population exhibits a high prevalence of bacteriuria coupled with potential indicators of infection, necessitating further exploration to identify sensitive markers of true infection.FUNDINGThis work was supported by the NIH (R00 DK105205, R01 DK123158, UL1 TR001412).

A prospective study on the pathogenesis of catheter-associated bacteriuria in critically ill patients

BackgroundUpdating the pathogenesis of catheter-associated bacteriuria (CA-bacteriuria) in the intensive care unit (ICU) is needed to adapt prevention strategies. Our aim was to determine whether the main pathway of CA-bacteriuria in ICU patients was endoluminal or exoluminal.In a prospective study, quantitative urine cultures were sampled from catheter sampling sites, collector bags and the catheter outer surface near the meatus from days 1 to 15 after catheterization. The endoluminal pathway was CA-bacteriuria (defined as 102 CFU/mL) first in collector bags and then in catheters. The exoluminal pathway was CA-bacteriuria first in catheters, on day 1 in early cases and after day 1 in late cases.ResultsOf 64 included patients, 20 had CA-bacteriuria. Means of catheterization days and incidence density were 6.81 days and 55.2/1000 catheter-days. Of 26 microorganisms identified, 12 (46.2%) were Gram positive cocci, 8 (30.8%) Gram negative bacilli and 6 yeasts. Three (11.5%) CA-bacteriuria were endoluminal and 23 (88.5%) exoluminal, of which 10 (38.5%) were early and 13 (50%) late. Molecular comparison confirmed culture findings. A quality audit showed good compliance with guidelines.ConclusionThe exoluminal pathway of CA-bacteriuria in ICU patients predominated and surprisingly occurred early despite good implementation of guidelines. This finding should be considered in guidelines for prevention of CA-bacteriuria.

A comparison of the efficacy of normal saline and Savlon solutions in periurethral cleaning to reduce catheter-associated bacteriuria: A randomized control trial

ObjectiveCatheter-associated urinary tract infection (CAUTI) is a common nosocomial infection. However, there has been no randomized control trial (RCT) comparing the efficacy of periurethral cleaning solutions for reducing CAUTI. This study aimed to compare the efficacy of normal saline solution (NSS) and Savlon solution. MethodsA non-inferiority cross-over RCT was conducted to compare the 2 solutions by the incidence of significant bacteriuria (SB) on day 5 after Foley catheterization. Patients admitted to a tertiary referral hospital from June 2018 to August 2019 participated in the study. The acceptable prespecified non-inferiority margin was 10%. ResultsThere were 265 and 275 patients in the NSS and Savlon groups, respectively. The incidence of CAUTI was 2.65/1000 catheter-days, and the median duration of catheterization was 5 days (IQR 4, 7). There was no significant difference between the incidence of SB in the NSS and Savlon groups, as indicated by the adjusted difference of 0.6 (95% CI: -3.1-4.2). ConclusionThis study was the first RCT in patients from multiple hospital units to compare the efficacy of the 2 solutions in the periurethral cleaning process. The study demonstrated non-inferiority of NSS to Savlon solution. Thai Clinical Trials Registry Study IDTCTR20180518001.

Comparison of catheter-associated bacteriuria and urinary tract infections between designed sheathed urethral catheters versus other methods of urinary drainage

Introduction: One of the most common nosocomial infections is urinary tract infection (UTI) which more commonly occurs in patients with urethral catheter. Objectives: The aim of this study is to compare the incidence rate of catheter-associated bacteriuria (CRB) and UTI between sheathed designed catheters versus other methods of urinary drainage. Patients and Methods: In this randomized double-blind controlled trial, 150 male patients, who needed urethral catheter, were randomly assigned into three groups; condom bag, designed sheath catheter and traditional Foley catheter. The midstream urine samples were sent to laboratory to evaluate bacteriuria immediately after catheter insertion, upon catheter removal and after two weeks consequently. Results: The mean age of patients was 51.28 ± 14.12 years. The frequency of bacteriuria in patients was 19 (38%), 10 (20%) and 10 (20%) in the traditional catheter, condom bag and sheathed designed catheter, respectively, which was strongly significant (P<0.001). Conclusion: The frequency of bacteriuria in the patients with designed sheathed catheter was significantly less than the traditional catheter. Therefore, using the designed catheter in short-term may be safer in the patients. Trial registration: The trial was registered in the Thai Clinical Trials Registry (identifier: TCTR20200703002; http://www.clinicaltrials.in.th/index.php?tp=regtrials & menu=trialsear ch & smenu=fulltext & task=search & task2=view1& id=6443).

1151. A Comparison of Periurethral Cleaning Between Normal Saline and Savlon Solutions Before Indwelling Urinary Catheterization in Reducing Catheter-Associated Bacteriuria: A Randomized Controlled Study

BackgroundCatheter-associated urinary tract infection (CAUTI) is one of the most common nosocomial infections. To date, there have been no randomized controlled studies to recommend the most appropriate antiseptic solution for periurethral cleaning before indwelling urinary catheterization. This study was aimed to compare normal saline solution (NSS) and Savlon solution for periurethral cleaning before indwelling urinary catheterization in reducing catheter-associated bacteriuria.MethodsA randomized controlled, noninferiority, cross-over study to determine the incidence of significant bacteriuria (SB) on day 5 after Foley catheterization, using 2 different solutions for periurethral cleaning (NSS and Savlon solutions), was carried out in all adult patients admitted in the 2 medical intensive care units (ICUs), 1 surgical ICU, 2 neurosurgical ICUs, 4 medical wards, 4 surgical wards and 1 emergency room (ER) of King Chulalongkorn Memorial Hospital, Thailand, from June 2018 to March 2019. The acceptable prespecified noninferiority margin was set to be 10%. Each solution was used alternately every 3 months in each unit. Urine culture was collected on day 1, 3, and 5 of Foley catheter.ResultsDuring the study period, there were 207 and 160 patients in the NSS and Savlon groups, respectively. 202 (55%) patients had received Foley catheterization in the emergency room. There were no significant differences in the indication, the current illness, and preexisting condition between the 2 groups. The overall incidence of SB on day 3 and 5 after catheterization was 4% and 8.2%. The incidence of CAUTI was 3.43/1,000 catheter-day. The median duration of catheterization was 5 (IQR 3, 7) days. On day 5 after catheterization, noninferiority was demonstrated for the incidence of SB with an adjusted difference of 4 (95% CI of the difference: −2.1% to 8.9%, P = 0.05). Regarding the incidence of CAUTI, there was no significant difference between the 2 groups.ConclusionTo the best of our knowledge, our study was the first randomized controlled study to compare the 2 solutions for periurethral cleaning before indwelling urinary catheterization in different departments. This study demonstrates the noninferiority of NSS to Savlon solution in reducing the incidence of SB.Disclosures All authors: No reported disclosures.

The evolution of catheter-associated urinary tract infection (CAUTI): Is it time for more inclusive metrics?

Catheter-associated urinary tract infection (CAUTI) has long been considered a preventable healthcare-associated infection. Many federal agencies, the Centers for Medicare and Medicaid Services (CMS), and public and private healthcare organizations have implemented strategies aimed at preventing CAUTIs. To monitor progress in CAUTI prevention, the National Healthcare Safety Network (NHSN) CAUTI metric has been adopted nationally as the primary outcome measure and has been refined over the past decades. However, this surveillance metric may underestimate infectious and noninfectious catheter harm. We suggest evolving to more inclusive performance metrics to better reflect quality improvement efforts underway in hospitals. The standardized device utilization ratio (SUR) provides a good surrogate for preventable catheter harm. On the other hand, a population-based metric that combines both standardized infection ratio (SIR) and SUR would address both infectious and noninfectious harm, while adjusting for population risk. Finally, electronically captured catheter-associated bacteriuria may contribute essential information on local testing stewardship.

Spectrum and antibiotic resistance of catheter-associated urinary tract infections.

Catheter associated urinary tract infections (CAUTIs) are amongst the most common nosocomial infections and are also considered among the most common complications associated with indwelling urinary catheters. Most catheter associated infections are derived from the patient’s own perineal flora, however the presence of a catheter increases the chance of being colonised by cross transmission of nosocomial bacteria as well. Most episodes of short-term catheter-associated bacteriuria are asymptomatic and are caused by single organisms, while long-term catheterisation promotes multibacterial infections and colonization. With prolonged duration of catheterization bacteriuria is considered universal because of the formation of biofilms on the surface of the catheter. Chronic indwelling catheters are an important reservoir of different multiresistant gram-negative organisms, therefore they are frequently isolated from CAUTIs. Treatment of catheter associated asymptomatic bacteriuria is not recommended because it will only promote the emergence of resistant organisms without effectively clearing the urine of catheterised patients.

Reducing catheter-associated urinary tract infections in the ICU.

Patients in the ICU are at higher risk for catheter-associated urinary tract infection (CAUTI) due to more frequent use of catheters and lower threshold for obtaining urine cultures. This review provides a summary of CAUTI reduction strategies that are specific to the intensive care setting. The surveillance definition for CAUTI is imprecise and measures catheter-associated bacteriuria rather than true infection. Alternatives have been proposed, but CAUTI rates measured by this definition are currently required to be reported to the Centers for Medicare and Medicaid Services and high CAUTI rates can result in financial penalties. Although CAUTI may not directly result in significant patient harm, it has several indirect patient safety implications and CAUTI reduction has several benefits. Various bundles have been successful at reducing CAUTI both in individual institutions and on larger scales such as healthcare networks and entire states. CAUTI reduction is possible in the ICU through a combination of reduced catheter usage, improved catheter care and stewardship of urine cultures.

Poster 23: Measuring the Effect of Patient and Caregiver Education on Preventing UTI and the Inappropriate Treatment of Catheter-Associated Bacteriuria in the Outpatient Spinal Cord Injury Population

Poster 23: Measuring the Effect of Patient and Caregiver Education on Preventing UTI and the Inappropriate Treatment of Catheter-Associated Bacteriuria in the Outpatient Spinal Cord Injury Population

A fast and frugal algorithm to strengthen diagnosis and treatment decisions for catheter-associated bacteriuria.

ObjectivesGuidelines for managing catheter-associated urinary tract infection (CAUTI) and asymptomatic bacteria (ASB) are poorly translated into routine care due in part to cognitive diagnostic errors. This study determines if the accuracy for CAUTI and ASB diagnosis and treatment improves after implementation of a fast and frugal algorithm compared with traditional education methods.Materials and methodsA pre and post-intervention with contemporaneous comparison site involving inpatient and long term care wards at two regional Veterans Affairs Systems in United States. Participants included 216 internal medicine residents and 16 primary care clinicians. Intervention clinicians received training with a fast and frugal algorithm. Comparison site clinicians received guidelines education. Diagnosis and treatment accuracy compared with a criterion standard was assessed during similar three-month, pre- and post-intervention periods. Sensitivity, specificity, and likelihood ratios were compared for both periods at each site.ResultsBacteriuria management was evaluated against criterion standard in 196 cases pre-implementation and 117 cases post-implementation. Accuracy of bacteriuria management among intervention participants was significantly higher, post-implementation, than those at the comparison site (Intervention: positive likelihood ratio (LR+) = 8.5, specificity = 0.89, 95% confidence interval (CI) = 0.78−1.00; comparison: LR+ = 4.62, specificity (95%CI) = 0.79 (0.63−0.95). Further, improvements at the intervention site were statistically significant (pre-implementation: LR+ = 2.1, specificity (95%CI) = 0.60 (0.50−0.71); post-implementation: LR+ = 8.5, specificity (95%CI) = 0.89 (0.78−1.00). At both sites, there were similar improvements in negative LR from pre- to post-implementation: [Intervention site = 0.28 to 0.08; comparison site = 0.13 to 0.04]. Inappropriate management of ASB declined markedly from 32 (40%) to 3 (11%) cases at the intervention site.ConclusionsA fast and frugal algorithm improves diagnosis and treatment accuracy for CAUTI and reduces inappropriate treatment of ASB. Fast and frugal algorithms that realign diagnostic intuitions and treatment norms can enhance translation of evidence into practice.

Risk Factors for Bacteremia in Patients With Urinary Catheter-Associated Bacteriuria.

Catheter-associated bacteriuria is complicated by secondary bacteremia in 0.4% to 4.0% of cases. The directly attributable mortality rate is 12.7%. To identify risk factors for bacteremia associated with catheter-associated bacteriuria. Data were acquired from a large electronic clinical and administrative database of consecutive adult inpatient admissions to 2 acute care hospitals during a 7-year period. Data on patients with catheter-associated bacteriuria and bacteremia were compared with data on control patients with catheter-associated bacteriuria and no bacteremia, matched for date of admission plus or minus 30 days. Urine and blood cultures positive for the same pathogen within 7 days were used to define catheter-associated bacteriuria and bacteremia. Multivariable conditional logistic regression was used to determine independent risk factors for bacteremia. The sample consisted of 158 cases and 474 controls. Independent predictors of bacteremia were male sex (odds ratio, 2.76), treatment with immunosuppressants (odds ratio, 1.68), urinary tract procedure (odds ratio, 2.70), and catheter that remained in place after bacteriuria developed (odds ratio, 2.75). Patients with enterococcal bacteriuria were half as likely to become bacteremic as were patients with other urinary pathogens (odds ratio, 0.46). Odds of secondary bacteremia increased 2% per additional day of hospital stay (95% CI, 1.01-1.04) and decreased 1% with each additional year of age (95% CI, 0.97-0.99). The results add new information about increased risk for bacteremia among patients with catheters remaining in place after catheter-associated bacteriuria and confirm evidence for previously identified risk factors.

Role of interspecies interactions in dual-species biofilms developed in vitro by uropathogens isolated from polymicrobial urinary catheter-associated bacteriuria

Most catheter-associated urinary tract infections are polymicrobial. Here, uropathogen interactions in dual-species biofilms were studied. The dual-species associations selected based on their prevalence in clinical settings were Klebsiella pneumoniae–Escherichia coli, E. coli–Enterococcus faecalis, K. pneumoniae–E. faecalis, and K. pneumoniae–Proteus mirabilis. All species developed single-species biofilms in artificial urine. The ability of K. pneumoniae to form biofilms was not affected by E. coli or E. faecalis co-inoculation, but was impaired by P. mirabilis. Conversely, P. mirabilis established a biofilm when co-inoculated with K. pneumoniae. Additionally, E. coli persistence in biofilms was hampered by K. pneumoniae but not by E. faecalis. Interestingly, E. coli, but not K. pneumoniae, partially inhibited E. faecalis attachment to the surface and retarded biofilm development. The findings reveal bacterial interactions between uropathogens in dual-species biofilms ranged from affecting initial adhesion to outcompeting one bacterial species, depending on the identity of the partners involved.

Diagnosis and Management of Catheter-Associated Urinary Tract Infection

The widespread use of urinary catheters is associated with a rising number of catheter-associated infections (CA-UTI) and the approach to these infections presents a diagnostic challenge due to difficulty in differentiating this entity from catheter-associated asymptomatic bacteriuria (CA-ASB). This article reviews the current literature regarding diagnosis, microbiology, treatment, and prevention of CA-UTIs. Misconceptions surrounding diagnostic technique and indications for testing result in unneeded antimicrobial administration. Due to the substantial burden of CA-UTIs, much emphasis has been placed on prevention and the most successful prevention strategies are aimed at behavioral changes to minimize unnecessary catheterizations. There are significant clinical sequelae of CA-UTIs and they pose a substantial burden on the healthcare system. Clinicians must accurately diagnose and manage CA-UTIs to prevent unnecessary antibiotic use which often leads to increasing antimicrobial resistance. In an effort to prevent CA-UTIs, healthcare systems should focus on prevention of unnecessary urinary catheterizations or prompt removal of urinary catheters once they are no longer indicated.

What is the role of catheter antibiotic prophylaxis for patients undergoing joint arthroplasty?

Antimicrobial prophylaxis at the time of urinary catheter insertion and removal is commonly administered in patients undergoing joint arthroplasty, despite the lack of evidence to support this practice. The rationale is the theoretical risk of prosthetic joint infection arising from bacterial seeding from the urinary tract at the time of catheterization. In an era of antimicrobial stewardship, further assessment is warranted. This study aimed to investigate the incidence of catheter-associated (CA) bacteriuria and bacteraemia in patients undergoing total joint arthroplasty and to assess the antimicrobial susceptibility of any isolated microorganisms. This prospective observational study undertaken over a 6-month period (May to October 2014) included 99 patients undergoing elective primary hip and knee arthroplasty at St Vincent's Hospital, Melbourne. Urine specimens were collected at insertion and removal of urinary catheters along with blood cultures upon urinary catheter removal. Overall 98% of the cohort received catheter antimicrobial prophylaxis for urinary catheter insertion and removal; the majority of patients received gentamicin (94%). Bacteriuria on catheter insertion had an incidence of 4.4%. The incidence of CA bacteriuria was 1.3%. All cultured organisms were sensitive to commonly used antibiotics including cephazolin. There were no cases of bacteraemia with urinary catheter removal. Increasing age, American Society of Anesthesiologists status and female gender were associated with the development of bacteriuria. The incidence of CA bacteriuria and bacteraemia with antimicrobial prophylaxis is low. This study provokes discussion about the requirement of catheter prophylaxis in this surgical context and the utility of preoperative urine screening.

Predictors of ertapenem therapeutic efficacy in the treatment of urinary tract infections (UTIs) in hospitalized adults: the importance of renal insufficiency and urinary pH.

In hospitalized adults acute uncomplicated cystitis (AUC) and catheter associated bacteriuria (CAB) may be treated with oral antibiotics. With AUC or CAB due to extended spectrum ß-lactamase (ESBL) + Gram negative bacilli (GNB) physicians often use intravenous therapy, e.g., ertapenem. We reviewed our recent experience in hospitalized adults with AUC and CAB treated with ertapenem. Therapeutic efficacy of ertapenem was assessed by decreased pyuria/bacteriuria, and elimination of the uropathogen. The effectiveness of ertapenem in the presence of renal insufficiency (CrCl < 50ml/min) and acid and alkaline urinary pH were evaluated. In addition, rapidity of eradication of bacteriuria was assessed by time to negative urine cultures (TTNC). In those with an acid urinary pH ertapenem was highly effective in eliminating bacteriuria (TTNC < 3days). TTNC was prolonged ( >3days) in patients with decreased renal function and alkaline urinary pH. We reviewed 45 hospitalized adults with AUC or CAB to determine if renal insufficiency and or alkaline urinary pH affected ertapenem efficacy. In the 33 adult hospitalized patients with AUC and 12 with CAB, we found that ertapenem was consistently effective in eliminating the GNB bacteriuria. In hospitalized adults, the presence of renal insufficiency and acid urine, bacteriuria was eliminated in < 3days. However, in those with renal insufficiency and an alkaline urine pH, the rapidity of cure, i.e., time to negative cultures (TTNC) was prolonged, i.e., > 3days which has not been previously reported.

A Metaproteomics Approach to Elucidate Host and Pathogen Protein Expression during Catheter-Associated Urinary Tract Infections (CAUTIs)

Long-term catheterization inevitably leads to a catheter-associated bacteriuria caused by multispecies bacterial biofilms growing on and in the catheters. The overall goal of the presented study was (1) to unravel bacterial community structure and function of such a uropathogenic biofilm and (2) to elucidate the interplay between bacterial virulence and the human immune system within the urine. To this end, a metaproteomics approach combined with in vitro proteomics analyses was employed to investigate both, the pro- and eukaryotic protein inventory. Our proteome analyses demonstrated that the biofilm of the investigated catheter is dominated by three bacterial species, that is, Pseudomonas aeruginosa, Morganella morganii, and Bacteroides sp., and identified iron limitation as one of the major challenges in the bladder environment. In vitro proteome analysis of P. aeruginosa and M. morganii isolated from the biofilm revealed that these opportunistic pathogens are able to overcome iron restriction via the production of siderophores and high expression of corresponding receptors. Notably, a comparison of in vivo and in vitro protein profiles of P. aeruginosa and M. morganii also indicated that the bacteria employ different strategies to adapt to the urinary tract. Although P. aeruginosa seems to express secreted and surface-exposed proteases to escape the human innate immune system and metabolizes amino acids, M. morganii is able to take up sugars and to degrade urea. Most interestingly, a comparison of urine protein profiles of three long-term catheterized patients and three healthy control persons demonstrated the elevated level of proteins associated with neutrophils, macrophages, and the complement system in the patient's urine, which might point to a specific activation of the innate immune system in response to biofilm-associated urinary tract infections. We thus hypothesize that the often asymptomatic nature of catheter-associated urinary tract infections might be based on a fine-tuned balance between the expression of bacterial virulence factors and the human immune system.

Safety and efficacy of a novel silver-impregnated urinary catheter system for preventing catheter-associated bacteriuria: A pilot randomized clinical trial

The purpose of this study was to evaluate the safety of a novel silver-impregnated Foley catheter system designed to prevent catheter-associated bacteriuria and funguria, assess recruitment feasibility for a future pivotal trial, and preliminarily assess efficacy. This single-center, randomized controlled trial at a university hospital involved adult neurosurgical patients expected to have a urinary catheter for ≥24 hours. Subjects were randomized to a novel silver-impregnated (test) Foley catheter system or a control system. They were followed for 30 days (or until discharge) while catheterized and for up to 48 hours after catheter removal, with daily bacteriuria testing and assessment for symptoms of infection and catheter intolerance. Ninety-five subjects were randomized (intention-to-treat [ITT] population). Of these, 61 subjects (64%) had a catheter for ≥24 hours without perioperative antibiotics beyond 24 hours (evaluable population). In the ITT population, 11 of 95 (12%) subjects had an asymptomatic bacteriuria (ABU) event. Compared with controls, test system recipients had a trend toward longer time to ABU in the ITT population (P = .08, log-rank test) and a longer time to ABU in the evaluable population (P = .03). All 6 ABU events caused by gram-negative bacilli occurred in the control group. In this pilot randomized trial the test system was well tolerated and seemingly effective in preventing catheter-associated bacteriuria, especially with gram-negative bacilli. A pivotal study is warranted.

Risk Factors for Nosocomial Bacteremia Secondary to Urinary Catheter-Associated Bacteriuria: A Systematic Review

A systematic appraisal of evidence suggests that male patients in hospital may be at higher risk for bacteremia following urinary catheter-associated bacteriuria than females. Other risk factors include immunosuppressant medication, red blood cell transfusion, neutropenia, malignancy, and liver disease.