Reliability of Symptoms and Dipstick for Postoperative Catheter-Associated Urinary Tract Infections.

OBJECTIVE: The aim of the study was to determine the diagnostic reliability of patient symptoms and urine dipstick results, including blood, leukocyte esterase, and nitrite, in diagnosing postoperative catheter-associated urinary tract infections (CAUTIs) after gynecologic surgery. METHODS: A prospective cohort study of patients undergoing gynecologic surgeries who required short-term (>24 hours) postoperative catheterization was conducted. Patients completed a questionnaire regarding symptoms. Urine dipstick analysis was completed on catheterized urine samples and urine was sent for culture for all patients. Positive likelihood ratios (LRs) were used to examine diagnostic reliability of patient symptoms and urine dipstick results in diagnosing postoperative CAUTIs. RESULTS: Fifty-seven patients with postoperative short-term indwelling catheterization were recruited, 25 (44%) of whom had CAUTIs diagnosed by urine culture at recruitment and 32 (56%) of whom did not have CAUTIs. Urine dipstick parameters were found to successfully diagnose CAUTIs, with positive LRs of 1.44 (95% confidence interval [CI], 1.04-1.99), 6.77 (95% CI, 2.23-20.52), and 9.47 (95% CI, 1.23-72.69) for blood, leukocyte esterase, and nitrite, respectively. The combination of leukocyte esterase and nitrite yielded a positive LR of 9.48 (95% CI, 2.62-34.25). Individual symptoms, alone or in combination, did not successfully diagnose positive urine culture (positive LRs <1.8). CONCLUSIONS: Urine dipstick parameters are reliable diagnostic tests for diagnosing postoperative CAUTIs after gynecologic surgery, particularly when in combination. Patient symptoms have little diagnostic value for positive urine cultures in catheterized patients after gynecologic surgery.

Using Proteomics to Identify Inflammation During Urinary Tract Infection.

Urinary tract infections (UTIs) are one of the most common bacterial infections. Conventional approaches to diagnose these infections rely on microbial urine culture, urine sediment microscopy and basic molecular urinalysis tests, in combination with assessments of patient symptoms that are indicative of UTI. The last decade has seen a more widespread clinical use of standardized MALDI-TOF methods to identify UTI-causing microbial agents. Shotgun proteomics methods to determine the extent of inflammation and types of immune cell effectors in urine have not become part of routine clinical tests. However, such methods are useful to investigate UTI pathogenesis, identify difficult-to-culture pathogens and understand antimicrobial effector mechanisms. The present chapter describes these approaches in order to gain quantitative and qualitative insights into inflammation and immune responses in patients with UTI and simultaneously profile the causative agents. The methods are also applicable to examine catheter-associated UTIs and vaginal infections from urine samples. Protocols provided here pertain to direct analyses of clinical specimens including urine sediments and urethral catheter biofilms.

(p)ppGpp and CodY Promote Enterococcus faecalis Virulence in a Murine Model of Catheter-Associated Urinary Tract Infection.

In Firmicutes, the nutrient-sensing regulators (p)ppGpp, the effector molecule of the stringent response, and CodY work in tandem to maintain bacterial fitness during infection. Here, we tested (p)ppGpp and codY mutant strains of Enterococcus faecalis in a catheter-associated urinary tract infection (CAUTI) mouse model and used global transcriptional analysis to investigate the relationship of (p)ppGpp and CodY. The absence of (p)ppGpp or single inactivation of codY led to lower bacterial loads in catheterized bladders and diminished biofilm formation on fibrinogen-coated surfaces under in vitro and in vivo conditions. Single inactivation of the bifunctional (p)ppGpp synthetase/hydrolase rel did not affect virulence, supporting previous evidence that the association of (p)ppGpp with enterococcal virulence is not dependent on the activation of the stringent response. Inactivation of codY in the (p)ppGpp0 strain restored E. faecalis virulence in the CAUTI model as well as the ability to form biofilms in vitro Transcriptome analysis revealed that inactivation of codY restores, for the most part, the dysregulated metabolism of (p)ppGpp0 cells. While a clear linkage between (p)ppGpp and CodY with expression of virulence factors could not be established, targeted transcriptional analysis indicates that a possible association between (p)ppGpp and c-di-AMP signaling pathways in response to the conditions found in the bladder may play a role in enterococcal CAUTI. Collectively, data from this study identify the (p)ppGpp-CodY network as an important contributor to enterococcal virulence in catheterized mouse bladder and support that basal (p)ppGpp pools and CodY promote virulence through maintenance of a balanced metabolism under adverse conditions.IMPORTANCE Catheter-associated urinary tract infections (CAUTIs) are one of the most frequent types of infection found in the hospital setting that can develop into serious and potentially fatal bloodstream infections. One of the infectious agents that frequently causes complicated CAUTI is the bacterium Enterococcus faecalis, a leading cause of hospital-acquired infections that are often difficult to treat due to the exceptional multidrug resistance of some isolates. Understanding the mechanisms by which E. faecalis causes CAUTI will aid in the discovery of new druggable targets to treat these infections. In this study, we report the importance of two nutrient-sensing bacterial regulators, named (p)ppGpp and CodY, for the ability of E. faecalis to infect the catheterized bladder of mice.

Purple urine bag syndrome, a travel companion. / Síndrome de la orina morada en bolsa, un compañero de viaje.

OBJECTIVE: Purple urine bag syndrome is a rare entity that appears in elderly patients with long-term urinary catheters with chronic diseases. METHOD: We describe the cases of two patients admitted to our service, who serve as example to illustrate this pathology and which process should be followed in its diagnosis and treatment. CONCLUSION: Purple urine bag syndrome is a rare entity that occurs more frequently in elderly patients, women, with long-term urinary catheters, whose main factors are debilitating diseases, prolonged immobility and chronic constipation. It should be treated by avoiding the triggering factors, adequate hydration of the patient, antibiotics directly antibiogram therapy and the change of urinary catheter can be evaluated.

Síndrome de la orina morada en bolsa, un compañero de viaje / Purple urine bag syndrome, a travel companion

OBJETIVO: El síndrome de la orina morada en bolsa, es una entidad poco frecuente, que aparece en pacientes de edad avanzada, portadores de sonda urinaria de largo tiempo de evolución, con enfermedades crónicas. MÉTODO: Describimos los casos de dos pacientes ingresados en nuestro servicio, que sirven de ejemplo para ilustrar esta patología y que proceso se debe seguir en su diagnóstico y tratamiento. CONCLUSIÓN: El síndrome de la orina morada en bolsa es una entidad rara, que se presenta con más frecuencia en pacientes de edad avanzada, mujeres, portadoras de sonda urinaria de largo tiempo de evolución, y cuyos factores asociados principalmente son enfermedades debilitantes, inmovilidad prolongada y estreñimiento crónico. Se debe tratar evitando los factores desencadenantes, adecuada hidratación del paciente, antibioterapia dirigida según antibiograma y puede valorarse el cambio de sondaje urinario

OBJECTIVE: Purple urine bag syndrome is a rare entity that appears in elderly patients with long-term urinary catheters with chronic diseases. METHOD: We describe the cases of two patients admitted to our service, who serve as example to illustrate this pathology and which process should be followed in its diagnosis and treatment. CONCLUSION: Purple urine bag syndrome is a rare entity that occurs more frequently in elderly patients, women, with long-term urinary catheters, whose main factors are debilitating diseases, prolonged immobility and chronic constipation. It should be treated by avoiding the triggering factors, adequate hydration of the patient, antibiotics directly antibiogram therapy and the change of urinary catheter can be evaluated

Predictive ability of NGAL in identifying urinary tract infection in children with neurogenic bladders.

BACKGROUND: Distinguishing between urinary tract infection (UTI) and colonization (UTC) in patients with neurogenic bladders who require clean intermittent catheterization (CIC) is difficult. Urinary neutrophil gelatinase-associated lipocalin concentrations (uNGAL) are increased in UTIs. Our objective was to determine the predictive accuracy of uNGAL for UTI in CIC-dependent children. METHODS: Cross-sectional study of CIC-dependent patients from August, 2015 to November, 2016. UTI was defined as (1) growth of ≥ 50,000 cfu/mL of a uropathogen, (2) > 10 urinary white blood cells/hpf, and (3) ≥ 2 of the following: temperature > 38 °C, abdominal pain, back pain, worsened incontinence, pain with catheterization, or malodorous/cloudy urine. Positive urine cultures that did not meet these criteria were grouped as UTC, and negative cultures were grouped as no growth. RESULTS: Two hundred one patients were included (no growth = 100, UTC = 77, UTI = 24). Median (interquartile range) uNGAL was higher in the UTI group (UTI 1361 (931, 2516) µg/g creatinine, UTC 246 (106, 548) µg/g creatinine, no growth 36 (11, 179) µg/g creatinine, p < 0.01 for all comparisons). The area under the ROC curve for uNGAL for UTI versus no UTI was 0.89, 95% CI (0.80-0.98). CONCLUSION: uNGAL is elevated in CIC-dependent children with UTI compared to those with negative cultures and those with UTC.

Frequency of Multidrug-Resistant Organisms Cultured From Urine of Children Undergoing Clean Intermittent Catheterization.

BACKGROUND: Children undergoing CIC frequently have positive urine culture results and receive many antimicrobial agents. Subsequently, this population is at high risk for infections caused by antimicrobial-resistant bacteria. Resistant pathogens, such as vancomycin-resistant Enterococcus (VRE), carbapenem-resistant Enterobacteriaceae (CRE), and organisms that produce extended-spectrum ß-lactamases (ESBLs), which are third-generation cephalosporin resistant (3GCR), are of particular concern. METHODS: In this retrospective study, all urine culture results and antimicrobial-susceptibility testing results were obtained between January 2008 and December 2014 from the electronic health record of children ≤18 years of age who were undergoing CIC (n = 14 832). Isolates were identified as VRE, CRE, or 3GCR. Organisms of the same type that were obtained in the same year and with identical antibiotic susceptibilities from the same patient were excluded. Simple linear regression was used to determine the association between year and rates of resistance. RESULTS: A total of 3997 positive culture results were included in this analysis. Of all Enterococcus isolates for which susceptibility results were available, 4.6% were VRE, 11.1% of all isolates that belonged to the Enterobacteriaceae family were 3GCR, and 0.4% of eligible isolates were CRE. There were significantly higher rates of resistance to third-generation cephalosporins and CRE in 2014 than in 2008 (P < .01). Simple linear regression revealed a significant association between year and rate for resistance to third-generation cephalosporins but not for CRE or VRE. The rate of increase in resistance to third-generation cephalosporins in patients who required CIC was higher than that in patients who did not need CIC. CONCLUSIONS: The rate of resistance to third-generation cephalosporins has increased significantly in the past 7 years in children undergoing CIC, which indicates that careful monitoring is warranted for continued increases in antimicrobial-resistant organisms in this unique patient population.

Candiduria: Evidence-based approach to management, are we there yet?

Candiduria is considered one of the most controversial issues in patient management. Neither the diagnosis nor the optimal treatment options are standardized. This is further complicated by lack of defined laboratory criteria for diagnosis as most of the studies were set for bacterial rather than fungal urinary tract infection (UTI). Furthermore, since Candida species is a known commensal of the genitourinary tract its presence in the urine sample adds ambiguity to making a definitive diagnosis of candidal UTI. Guidelines for diagnosis and management of candiduria have changed considerably over the past decades. In 1960s, the condition was believed to be benign with no intervention required. However, over the years new dimensions were added to address the issues associated with candiduria until the latest Infectious Diseases Association of America (IDSA) guidelines were published in 2009, which indicated that there was an increase in the incidence of candiduria caused by more resistant non-Candida albicans species. Further complicating the issue is the observation that candiduria may be the only indicator of a more serious invasive candidiasis, especially in immunocompromised patients. Long-term urinary catheterization is considered to be the most significant risk factor for candiduria followed by antibiotic use and diabetes. Strategies for management are based on the evaluation of candiduria in the context of the clinical setting to determine its relevance and make an appropriate decision about the need for antifungal therapy. Fluconazole is the main drug used for its efficacy and least complications. Other options include bladder irrigation with amphotericin B, flucytosine or parenteral amphotericin B. Since azoles other than fluconazole and all echinocandins are poorly excreted in urine they have been found to be less effective in candiduric patients.

Incidence and risk factors of urinary tract infection in very low birth weight infants.

OBJECTIVES: To describe the incidence and associated risk factors of urinary tract infection (UTI) in very low birth weight (VLBW) infants and to determine the value of diagnostic imaging studies after the first UTI episode before discharge from the neonatal intensive care unit (NICU). METHODS: VLBW infants born during 2003-2012 were reviewed for UTI. In a nested case-control study, potential risk factors of UTI were compared between infants with UTI (cases) versus birth weight and gestational age matched controls. Renal ultrasonography (USG) and voiding cystourethrography (VCUG) results were reviewed in cases. RESULTS: During the study period, 54.7% of urine culture specimens were collected by sterile methods. 3% (45/1,495) of VLBW infants met the study definition for UTI. UTI was diagnosed at mean postnatal age of 33.1±22.9 days. There was no significant difference in gender, ethnicity, antenatal steroid exposure, blood culture positive sepsis, ionotropic support, respiratory support and enteral feeding practices between cases and controls. Cases had a significantly higher cholestasis compared to controls (22% vs. 9% ; p = 0.03). However, cholestasis was not a significant predictor of UTI in the adjusted analysis [adjusted OR 2.38 (95% CI 0.84 to 6.80), p = 0.11]. Cases had higher central line days, parenteral nutrition days, total mechanical ventilation days, chronic lung disease, and length of stay compared to controls. Renal USG was abnormal in 37% and VCUG was abnormal in 17% of cases. CONCLUSIONS: The incidence of UTI in contemporary VLBW infants is relatively low compared to previous decades. Since no significant UTI predictors could be identified, urine culture by sterile methods is the only reliable way to exclude UTI. The majority of infants with UTI have normal renal anatomy. UTI in VLBW infants is associated with increased morbidity and length of stay.

How and when nurses collect urine cultures on catheterized patients: A survey of 5 hospitals.

BACKGROUND: Obtaining a specimen for urine culture is a key element in evaluating for catheter-associated urinary tract infections (CAUTIs). Evaluating nurses' knowledge regarding appropriate reasons and methods to obtain urine culture specimens are the first steps to improving practice. METHODS: Nurses at 5 hospitals completed a 40-question survey regarding their knowledge, training, and practices of appropriate reasons for obtaining urine cultures. The survey included different scenarios of patients with urinary catheters and when they would expect to obtain urine cultures. A 12-point scoring system calculated responses regarding urine collection appropriateness. RESULTS: There were 394 nurses who responded to the survey. Of them, 76.1% reported receiving education on CAUTI risk reduction within the last 12 months. Although 327 (83%) of all nurses surveyed reported that they never collect urine samples by draining directly from the drainage bag, only 58.4% viewed others to be fully compliant with that standard (P < .001). Nurses who considered their knowledge to be above average to excellent had similar knowledge assessment scores (out of 12 points) for triggers to obtain urine cultures (mean score, 4.9 ± 1.72) compared with those that reported average to poor knowledge (mean score, 4.64 ± 1.78; P = .15). CONCLUSIONS: Important opportunities exist for nurses to optimize the decisions to obtain urine cultures and the process for obtaining them. Addressing nurses' knowledge and practice may lead to more appropriate use of urine cultures.

Catheter-associated urinary tract infection in a surgical intensive care unit.

BACKGROUND/AIM: Because patients in intensive care units usully have an urinary catheter, the risk of urinary tract infection for these patients is higher than in other patients. The aim of this study was to identify risk factors and causative microrganisms in patients with catheter-associated urinary tract infection (CAUTI) in the Surgical Intensive Care Unit (SICU) during a 6-year period. METHODS: All data were collected during prospective surveillance conducted from 2006 to 2011 in the SICU, Military Medical Academy, Belgrade, Serbia. This case control study was performed in patients with nosocomial infections recorded during surveillance. The cases with CAUTIs were identified using the definition of the Center for Disease Control and Prevention. The control group consisted of patients with other nosocomial infections who did not fulfill criteria for CAUTIs according to case definition. Results. We surveyed 1,369 patients representing 13,761 patient days. There were a total of 226 patients with nosocomial infections in the SICU. Of these patients, 64 had CAUTIs as defined in this study, and 162 met the criteria for the control group. Multivariate logistic regression analysis identified two risk factors independently associated to CAUTIs: the duration of having an indwelling catheter (OR = 1.014; 95% CI 1.005-1.024; p = 0.003) and female gender (OR = 2.377; 95% CI 1.278-4.421; p = 0.006). Overall 71 pathogens were isolated from the urine culture of 64 patients with CAUTIs. Candida spp. (28.2%), Pseudomonas aeruginosa (18.3%) and Klebsiella spp. (15.5%) were the most frequently isolated microorganisms. CONCLUSIONS: The risk factors and causative microrganisms considering CAUTIs in the SICU must be considered in of planning CAUTIs prevention in this setting.

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.

A negative urinalysis rules out catheter-associated urinary tract infection in trauma patients in the intensive care unit.

BACKGROUND: Urinary tract infection (UTI) in trauma patients is associated with increased mortality. Whether the urinalysis (UA) is an adequate test for a urinary source of fever in the ICU trauma patient has not been demonstrated. We hypothesized that the UA is a valuable screen for UTI in the febrile, critically ill trauma patient. STUDY DESIGN: All trauma ICU patients in our surgical ICU who had a fever (temperature >38.0°C), urinary catheter, UA, and a urine culture between January 1, 2011 and December 13, 2011 were reviewed. A positive UA was defined as positive leukocyte esterase, positive nitrite, WBC > 10/high power field, or presence of bacteria. A positive urine culture was defined as growth of ≥10(5) colony forming units (cfu) of an organism irrespective of the UA result or ≥10(3) cfu in the setting of a positive UA. A UTI was defined as positive urine culture without an alternative cause of the fever. RESULTS: There were 232 UAs from 112 patients that met criteria. The majority (75%) of patients were men; the mean age was 40 (±16) years. Of the 232 UAs, 90 (38.7%) were positive. There were 14 UTIs. The sensitivity, specificity, positive predictive value, and negative predictive value of the UA for UTI were 100%, 65.1%, 15.5%, and 100%, respectively. CONCLUSIONS: A negative UA reliably excludes a catheter-associated UTI in the febrile, trauma ICU patient with a 100% negative predictive value, and it can rapidly direct the clinician toward more likely sources of fever and reduce unnecessary urine cultures.

Inhibition of the adhesion to catheters of uropathogenic Escherichia coli by sub-inhibitory concentrations of cefotaxime.

OBJECTIVE: To investigate the effect of sub-inhibitory concentrations of cefotaxime on adherence to siliconized latex urinary catheters of uropathogenic Escherichia coli strains from pregnant and non pregnant patients. STUDY DESIGN: Using random sampling, 30 E. coli strains were selected from hospitalized patients with catheter associated urinary tract infection, 12 from pregnant women and 18 from men and non-pregnant women. The strains were categorized on the basis of cefotaxime susceptibility, adhesion and biofilm production capacity, cell surface hydrophobicity and expression of adhesins and fimbriae in vitro. RESULTS: The overall results indicated that sub-inhibitory concentrations of cefotaxime could reduce the adhesiveness, the biofilm production and hence, potentially, the infection rate associated with indwelling urinary catheters. CONCLUSION: Based on our results, we propose that this reduction is due to decreasing exopolysaccharide production and increasing cell surface hydrophobicity of E.coli strains.