Urine culture contamination: a College of American Pathologists Q-Probes study of 127 laboratories

Clinical Microbiome Testing for Urology

The urine culture is imperfect, and a series of alternative approaches are in development to assist in diagnosis, treatment, and prevention of urinary tract infection (UTI). Culture-independent approaches typically do not distinguish between viable and nonviable bacteria, and are generally not included in current clinical guidance. Next-generation sequencing may play an important future role in precise targeting of antibiotic treatment of asymptomatic bacteriuria prior to endourologic surgery or in pregnancy. Future studies are needed to determine whether microbiota modulation could prevent UTI. Possible modulation mechanisms may include fecal microbiota transplant, application of topical vaginal estrogen or probiotics, and bacteriophage therapy.

The impact of Boric Acid tubes on quantitative urinary bacterial cultures in hospitalized patients

INTRODUCTION

The accuracy of urine culture results can be affected by pre-analytical factors such as transport delays and storage conditions. The objectives of this study were to analyze urine collection practices and assess the impact of introducing boric acid tubes for urine collection on quantitative urinary bacterial cultures of hospitalized patients in medical wards.

METHODS

A quasi-experimental pre-post study conducted in an acute care facility. In the pre-intervention phase (2020-2021), urine samples were transported without preservatives at room temperature. In 2022 (post-intervention), we transitioned to boric acid transport tubes, evaluating its effect on significant bacterial growth (≥ 105 CFU/ml). Bivariate and multivariate analyses identified predictors of culture positivity.

RESULTS

Throughout the duration of the study, a total of 12,660 urine cultures were analyzed. Date and time documentation was complete for 38.3% of specimens. Culture positivity was higher with longer processing times: positivity was 21.3% (220/1034) when specimens were processed within 4 h, 28.4% (955/3364) when processed in 4-24 h, and 32.9% (137/417) when processed after 24 h (p < 0.0001). For 4-24-hour processing, positivity decreased from 30.4% (704/2317) pre-intervention to 24.0% (251/1047) post-intervention (p < 0.001), with no significant changes in < 4 or ≥ 24-hour specimens. Stratified analysis by processing time revealed that the intervention was associated with reduced positivity only in cultures processed within 4-24 h (OR 0.80, 95% CI 0.67-0.94; p = 0.008).

CONCLUSION

The introduction of boric acid transport tubes predominantly influenced cultures transported within a 4-24-hour window. This presents an opportunity to improve urine tract infection diagnostic practices in healthcare settings.

Preoperative urine culture with contaminants is not associated with increased risk for urinary tract infection after ureteroscopic stone treatment

PURPOSE

We aimed to assess whether the presence of contaminants in the pre-operative urine culture (preop-UC) predicts postoperative urinary tract infection (postop-UTI) in patients undergoing elective ureteroscopy with laser lithotripsy.

METHODS

A retrospective chart review was performed from 01/2019 to 12/2021 examining patients with unilateral stone burden ≤ 2 cm who underwent ureteroscopy with laser lithotripsy and had a preop-UC within 3 months. Positive, negative, contaminated, and polymicrobial definitions for UCs were established in accordance with current guidelines. Patients with positive and polymicrobial cultures were excluded. Postop-UTI was defined as the presence of urinary symptoms and a positive UC within 30 days of the procedure. Multivariable logistic regression models were utilized to evaluate risk factors for contamination in the preop-UC and the risk of postop-UTI.

RESULTS

A total of 201 patients met the inclusion-exclusion criteria. Preop-UC was negative in 153 patients and contaminated in 48 patients. Significant contaminant-related factors included female gender and increased BMI. Postop-UTI was diagnosed in 3.2% of patients with negative preop-UCs and 4.2% of patients with contaminants, with no difference between groups (p = 0.67). The regression model determined that the presence of contaminants in preop-UC failed to predict postop-UTI (OR 0.69, p = 0.64).

CONCLUSION

The presence of contaminants in preop-UCs is not associated with an increased risk of postop-UTIs after ureteroscopy. Our study supports that contaminants in the preop-UC can be interpreted as a negative UC in terms of postop-UTI risk stratification. Preoperative antibiotics should not be prescribed for patients undergoing uncomplicated ureteroscopy for stone surgery in the setting of a contaminated preop-UC.

Do external urine collection devices reduce contamination in urine samples for women with symptoms of urinary tract infection? A systematic review

INTRODUCTION

To evaluate the impact of external urine collection devices (UCD) on contamination of urine samples in women with symptoms of urinary tract infection.

METHODS

This review was conducted according to the Systematic Reviews of Diagnostic Test Accuracy guidelines (PROSPERO CRD42021241758). PubMed was searched for paired sample studies and controlled trials. Studies comparing UCDs with non-invasive urine collection procedures were considered.

RESULTS

Only two studies were found. Neither of the two studies found any difference regarding contamination between specimens collected with the UCDs compared and non-invasive techniques. In the largest study, including 1264 symptomatic women, 18.8% of those allocated to UCDs failed to collect urine samples successfully.

CONCLUSIONS

More studies involving women with symptoms of urinary tract infection are needed to produce more robust data on the impact of these devices on urine contamination rates.

Best methods for urine sample collection for diagnostic accuracy in women with urinary tract infection symptoms: a systematic review

BACKGROUND

Most guidelines recommend a midstream urine (MSU) or a midstream clean-catch (MSCC) sample for urinalysis. However, whether this sample is better than others is still controversial.

OBJECTIVES

To assess the most adequate non-invasive method to collect a urine specimen for diagnosing urinary tract infections (UTI) in symptomatic non-pregnant women.

METHODS

This review was conducted according to the Systematic Reviews of Diagnostic Test Accuracy guidelines (PROSPERO CRD42021241758). PubMed was searched paired sample studies and controlled trials. Studies comparing MSCC, MSU without cleaning, first-void urine, and random voiding samples were considered. Studies evaluating invasive methods were excluded. The main outcome was diagnostic accuracy of urine cultures. Contamination rates were evaluated. The risk of bias tool for systematic reviews on diagnostic accuracy (QUADAS-2) was assessed.

RESULTS

Six studies including 1,010 patients were evaluated. Only two studies used paired samples. No study was considered as having low risk of bias. There was no difference in contamination for MSU specimens collected with or without cleansing and between random void urine collection and MSCC. In one study comparing first-void urine with MSU samples, the contamination rate was lower in the latter, but the gold standard of urine culture was only used for one sampling collection.

CONCLUSIONS

To the best of our knowledge, this systematic review is the first to assess the evidence available from different exclusively non-invasive urine sampling. Despite being widely recommended, our review did not find consistent evidence that asking women to provide midstream samples with or without cleansing is better.

Prevalence and predictors of urine culture contamination in primary care: A cross-sectional study

BACKGROUND

Antimicrobial resistance is a global health threat. To slow resistance and preserve antibiotics, stewardship interventions are increasingly promoted and mandated. Urine cultures are the most common microbiological test in the outpatient setting. Contamination most likely occurs during urine collection from surrounding vaginal, perineal, and epidermal flora. Sample contamination can lead to incorrect diagnosis, unnecessary or inappropriate treatment, poor patient outcomes, and higher costs. Therefore, ensuring proper collection of urinary samples serves as a prime diagnostic stewardship target, one that international nursing societies increasingly endorse as an opportunity for nurse involvement.

OBJECTIVES

Determine the prevalence, predictors, and antibiotic prescribing associated with contaminated urine cultures in primary care clinics.

DESIGN

Cross-sectional study.

SETTING

Two adult safety-net clinics in Houston, Texas.

PARTICIPANTS

1265 clinical encounters among 1114 primary care patients.

METHODS

We reviewed charts from office visits among patients who had a urine culture ordered between November 2018 and March 2020. Patient demographics, culture results and prescription orders were captured for each visit. Culture results were defined as no growth, contaminated (i.e., mixed flora, non-uropathogens, or ≥3 bacterial species isolated), or low-count (102-105 colony forming units (CFU)/mL) or high-count (>105 CFU/mL) uropathogen-positive. We performed multinomial logistic regression to identify predictors independently associated with contaminated cultures.

RESULTS

Our study evaluated 1265 cultures from 1114 patients that were primarily female (84 %), of Hispanic/Latino (74.4 %) or Black/African American (18.9 %) race/ethnicity with a mean age of 43 years. Out of 1265 urine cultures, 264 (20.9 %) had no growth, 694 (54.9 %) were contaminated, 159 (12.6 %) were low-count positive, and 148 (11.7 %) were high-count positive. Female sex, pregnancy, and obesity were associated with contaminated cultures (multinomial adjusted odds ratios: 15.89, 14.34, 1.93, respectively; 95 % confidence intervals: 10.25-24.61, 8.03-25.61, 1.32-2.81, respectively). Antibiotic prescribing was significantly higher among symptomatic patients with contaminated cultures compared to those with no growth.

CONCLUSION

Urine culture contamination occurred frequently in our clinics, and obesity, female sex and pregnancy were independent risk factors for contamination. The association of pregnancy and contamination is particularly concerning as pregnant females are routinely screened and treated for asymptomatic bacteriuria in the United States. Culture contamination may obscure underlying uropathogens, leading to pyelonephritis or potential neonatal infection if untreated. Conversely, overtreatment of false positive bacteriuria could lead to adverse effects from antibiotics and increased risk for antibiotic resistance. As nurses play a prominent role in patient education, diagnostic stewardship interventions may want to utilize nurses' educational capabilities to improve urine culture collection.

TWEETABLE ABSTRACT

55 % of urine cultures collected in primary care clinics were contaminated, revealing a major opportunity for nurse-driven diagnostic stewardship interventions.

The diagnostic value of rapid urine test platform UF-5000 for suspected urinary tract infection at the emergency department

Background and objective

Urine culture is time consuming, which may take days to get the results and impede further timely treatment. Our objective is to evaluate whether the fast urinalysis and bacterial discrimination system called Sysmex UF-5000 may predict urinary tract infections (UTIs) (within minutes) compared with the clinical routine test in suspected UTI patients. In addition, we aimed to explore the accuracy of microbiologic information by UF-5000.

Materials and Methods

Consecutive patients who were admitted from the emergency department at Queen Mary Hospital (a tertiary hospital in Hong Kong) from June 2019 to February 2020 were enrolled in the present study. The dipstick test, manual microscopic test with culture, and Sysmex UF-5000 test were performed in the urine samples at admission.

Results

A total of 383 patients were finally included in the present study. UF-5000 urinalysis (area under the receiver operator characteristic curve, AUC=0.821, confidence interval, 95%CI: 0.767–0.874) outperformed the dipstick test (AUC=0.602, 95%CI: 0.550–0.654, P=1.32×10^-10) for predicting UTIs in patients without prior antibiotic treatment. A significant net benefit from UF-5000 was observed compared with the dipstick test (NRI=39.9%, 95%CI: 19.4–60.4, P=1.36 × 10^-4). The urine leukocyte tested by UF-5000 had similar performance (AUC) for predicting UTI compared with the manual microscopic test (P=0.27). In patients without a prior use of antibiotics, the concordance rates between UF-5000 and culture for predicting Gram-positive or -negative bacteriuria and a negative culture were 44.7% and 96.2%, respectively.

Conclusions

UF-5000 urinalysis had a significantly better predictive value than the dipstick urine test for predicting UTIs.

Urine Flow Cytometry Parameter Cannot Safely Predict Contamination of Urine—A Cohort Study of a Swiss Emergency Department Using Machine Learning Techniques

Background: Urine flow cytometry (UFC) analyses urine samples and determines parameter counts. We aimed to predict different types of urine culture growth, including mixed growth indicating urine culture contamination. Methods: A retrospective cohort study (07/2017–09/2020) was performed on pairs of urine samples and urine cultures obtained from adult emergency department patients. The dataset was split into a training (75%) and validation set (25%). Statistical analysis was performed using a machine learning approach with extreme gradient boosting to predict urine culture growth types (i.e., negative, positive, and mixed) using UFC parameters obtained by UF-4000, sex, and age. Results: In total, 3835 urine samples were included. Detection of squamous epithelial cells, bacteria, and leukocytes by UFC were associated with the different types of culture growth. We achieved a prediction accuracy of 80% in the three-class approach. Of the n = 126 mixed cultures in the validation set, 11.1% were correctly predicted; positive and negative cultures were correctly predicted in 74.0% and 96.3%. Conclusions: Significant bacterial growth can be safely ruled out using UFC parameters. However, positive urine culture growth (rule in) or even mixed culture growth (suggesting contamination) cannot be adequately predicted using UFC parameters alone. Squamous epithelial cells are associated with mixed culture growth.

Quantitative assessment of bladder wall vascularity index in children with acute cystitis using superb microvascular imaging

PURPOSE

The purpose of this study was to investigate the effectiveness of the vascularization index (VI) obtained using color superb microvascular imaging (cSMI) technique in assessment of the anterior urinary bladder wall in pediatric patients with acute cystitis (AC).

METHODS

The anterior bladder wall of 157 patients (age range 13-84 months, mean 43.62 ± 17.79 months) whose clinical and laboratory findings were proven of AC and 150 healthy asymptomatic participants (age range 13-84 months, mean 43.88 ± 18.11 months) with normal laboratory values were examined using cSMI. VI measurements were performed by manually drawing the contours of the anterior bladder wall using the free region of interest with 2-dimensional cSMI VI (2DcSMIVI) mode. The quantitative 2DcSMIVI values of the symptomatic group and the asymptomatic group were compared. The correlation between the 2DcSMIVI values and the anterior bladder wall thickness (BWT) were analyzed.

RESULTS

The mean 2DcSMIVI values of the BWT were significantly higher in symptomatic group when compared to the asymptomatic group (p<0.001). AC can be diagnosed with a 93% sensitivity, 92% specificity when 3.25% 2DcSMIVI designated as the cutoff value. There was a significant positive correlation between 2DcSMIVI values and BWT (p<0.001).

CONCLUSION

Two-dimensional cSMI VI can be used effectively in children as an imaging method in the diagnosis of AC.

Applying Diagnostic Stewardship to Proactively Optimize the Management of Urinary Tract Infections

A urinary tract infection is amongst the most common bacterial infections in the community and hospital setting and accounts for an estimated 1.6 to 2.14 billion in national healthcare expenditure. Despite its financial impact, the diagnosis is challenging with urine cultures and antibiotics often inappropriately ordered for non-specific symptoms or asymptomatic bacteriuria. In an attempt to limit unnecessary laboratory testing and antibiotic overutilization, several diagnostic stewardship initiatives have been described in the literature. We conducted a systematic review with a focus on the application of molecular and microbiological diagnostics, clinical decision support, and implementation of diagnostic stewardship initiatives for urinary tract infections. The most successful strategies utilized a bundled, multidisciplinary, and multimodal approach involving nursing and physician education and feedback, indication requirements for urine culture orders, reflex urine culture programs, cascade reporting, and urinary antibiograms. Implementation of antibiotic stewardship initiatives across the various phases of laboratory testing (i.e., pre-analytic, analytic, post-analytic) can effectively decrease the rate of inappropriate ordering of urine cultures and antibiotic prescribing in patients with clinically ambiguous symptoms that are unlikely to be a urinary tract infection.

The Five Ds of Outpatient Antibiotic Stewardship for Urinary Tract Infections

Urinary tract infections (UTI) are one of the most common indications for antibiotic prescriptions in the outpatient setting. Given rising rates of antibiotic resistance among uropathogens, antibiotic stewardship is critically needed to improve outpatient antibiotic use, including in outpatient clinics (primary care and specialty clinics) and emergency departments. Outpatient clinics are in general a neglected practice area in antibiotic stewardship programs, yet most antibiotic use in the United States is in the outpatient setting. This article provides a comprehensive review of antibiotic stewardship strategies for outpatient UTI in the adult population, with a focus on the "five Ds" of stewardship for UTI, including right diagnosis, right drug, right dose, right duration, and de-escalation. Stewardship interventions that have shown success for improving prescribing for outpatient UTI are discussed, including diagnostic stewardship strategies, such as reflex urine cultures, computerized decision support systems, and modified reporting of urine culture results. Among the many challenges to achieving stewardship for UTI in the outpatient setting, some of the most important are diagnostic uncertainty, increasing antibiotic resistance, limitations of guidelines, and time constraints of stewardship personnel and front-line providers. This article presents a stewardship framework, built on current evidence and expert opinion, that clinicians can use to guide their own outpatient management of UTI.

Fast and precise pathogen detection and identification of overlapping infection in patients with CUTI based on metagenomic next-generation sequencing: A case report

RATIONALE

The gold standard for pathogen detection and identification of complicated urinary tract infection (CUTI) remains quantitative urine culture, however, the diagnostic value of urine culture remains limited due to the time-consuming procedure and low detection rate. Here we report a case of successfully using Metagenomic next-generation sequencing (mNGS) provided fast and precise detection and identification of overlapping infection in patients with CUTI with no similar reports or studies published before to the best of our knowledge.

PATIENT CONCERNS

A 70-year-old male was admitted to hospital due to elevated serum creatinine for 2 weeks.

DIAGNOSES

Acute exacerbation of chronic renal failure and CUTI were the most critical diagnosis on admission.

INTERVENTIONS

Blood purification, bladder irrigation and aggressive anti-infective therapy were administered. But the empirical anti-infection therapy and the adjustment of treatment according to the evidence of urine culture drug sensitivity had no obvious effect. We further carried out urinary PMseq-DNA detection and the results showed overlapping infection with Enterococcus faecium, Enterococcus hirae, Pseudomonas aeruginosa, Pseudomonas denitrificans and Candida albicans. According to the genetic test results, linezolid, meropenem and fluconazole triple anti-infection treatment was given.

OUTCOMES

After adjusting the treatment, the infection was basically controlled in 10 days, and even the renal function was significantly improved, dialysis independence was achieved after 3 months.

LESSONS

Our case illustrated the potential application of mNGS in detecting pathogenic microorganisms in patients with CUTI especially when overlapping infections are present.

Significant bacteriuria among requested repeat urine samples and its clinical correlation

BACKGROUND AND OBJECTIVES

Urinary tract infections (UTI) are the most common bacterial infections in both outpatient and inpatient department received for routine bacterial culture and sensitivity. We looked for significant bacteriuria in requested repeat urine sample after primary urine culture yielded significant growth (>105 CFU/ml) of ≥3 types of colonies. Also studied, different isolates grown with their sensitivity pattern and contamination rates of urine samples from different departments.

MATERIALS AND METHODS

In routine, primary urine cultures yielding ≥3 types of colonies on Cystine Lactose Electrolyte Deficient (C.L.E.D) were requested for repeat samples, collected with aseptic precautions after proper instructions. Data was analyzed for the Microbiological profile and its clinical correlation.

RESULTS

Among 617 received requested urine samples, 292 (47.3%) yielded significant bacteriuria. Clinical details were available for 252 cases out of which 100 (39.7%) showed asymptomatic bacteriuria, 87 (34.5%) complicated UTI and 65 (25.7%) uncomplicated UTI. Null hypothesis was rejected as 292 (47.3%) of the received repeat samples showed significant bacteriuria and 325 (53%) showed normal flora/no growth i.e. there is a 50% chance of getting either a positive culture or normal flora/no growth in repeat urine samples after the primary urine culture showed ≥3 types of colonies. It indicates the importance of requesting repeat urine samples for an accurate urine culture report. Male patients were significantly associated with significant bacteriuria and complicated UTI (p= 0.001). Escherichia coli (n=112, 28%) was the most common followed by Klebsiella species (n=66, 16.4%) and Enterococcus species (n=69, 17.2%). 183 (45.6%) isolates were Multi-Drug Resistant (MDR) Gram Negative Bacilli (GNBs), Escherichia coli (50.3%) being most common. Vancomycin Resistant Enterococcus (VRE) (n=8, 2.0%) was also isolated.

CONCLUSION

Our study justifies the rationale for asking a repeat urine samples which helps in providing an appropriate microbiological report with antibiotic sensitivity pattern, hence preventing unwanted reporting of commensals/contaminants facilitating evidence based therapy.

Envisioning Future UTI Diagnostics

Urinary tract infections (UTIs) are among the most common bacterial infections in the United States and are a major driver of antibiotic use - both appropriate and inappropriate - across healthcare settings. UTI treatment has become complex due to antibacterial resistance; one quarter of urinary tract isolates of Escherichia coli in the United States in 2017 were resistant to fluoroquinolones and one third to trimethoprimsulfamethoxazole (1), agents with historically predictable activity against E. coli. As a result, more broad-spectrum antibiotics are being used to treat UTIs, contributing to selection of further antibiotic resistance.

Urine Trouble: Reducing Midstream Clean Catch Urine Contamination Among Children 3-17 Years Old

BACKGROUND

Children, caregivers, and clinicians often prefer midstream clean catch technique to urethral catheterization for obtaining urine cultures. However, contamination is common, potentially resulting in unnecessary medical intervention and cost. With this resident-led initiative, we aimed to reduce pediatric midstream clean catch urine culture contamination over 6 months.

METHODS

A bundled intervention was implemented in the emergency department, inpatient units, and outpatient clinics at our institution. Baseline contamination rates were collected April 2016 to September 2017; the intervention was introduced October 2017 to March 2018 and evaluated April 2018 to September 2018. Sustainability was measured October 2018 to September 2020. Balancing measures included rates of repeat urine cultures, positive cultures, and contaminated cultures by urethral catheterization.

RESULTS

Rates of midstream clean catch urine culture contamination were 45.3% preintervention and 30.9% postintervention, a 14.7% (95% confidence interval: 8.0% to 21.5%) absolute decrease. Before and after intervention, girls and patients 16 to 17 years old had the highest rates of midstream clean catch contamination. Six months postintervention, the rate of repeat urine culture decreased from 4.9% to 0.9% with no change in positive culture results or contaminated cultures by urethral catheterization. Over the subsequent 2 years, the impact of the intervention decreased (rate of contamination over 30 months postintervention: 38.4%, a 7.3% [95% confidence interval: 2.9% to 11.6%] absolute decrease; rate of repeat urine culture: 3.2%).

CONCLUSIONS

An intervention to improve midstream clean catch urine culture collection was associated with a clinically meaningful decrease in contamination. Impact of the resident-led intervention decreased over time.

Reducing contamination of midstream urine samples through standardized collection processes: a best practice implementation project

OBJECTIVE

The objective of this project is to decrease the rates of midstream urine sample contamination through standardization of evidence-based techniques among nurses.

INTRODUCTION

Urinary tract infection is a prevalent health problem worldwide. The diagnosis and treatment of urinary tract infection depend on a thorough physical examination and the results of an uncontaminated midstream specimen of urine. However, improper techniques used in the collection often cause sample contamination, leading to delayed diagnosis and the use of inappropriate antibiotics for treatment. As nurses are at the forefront of care delivery, they are involved in reducing the rates of midstream urine sample contamination. Thus, the use of an evidence-based approach to standardize collection of midstream urine culture is crucial for the provision of higher-quality patient care.

METHODS

Education sessions were delivered to the nurses and an evidence-informed standardized patient education leaflet was crafted by the project team for implementation. With a sample size of 30 nurses and patients, the project took place in a 21-bed adult surgical ward in a hospital in Singapore. The JBI Practical Application of Clinical Evidence System (JBI PACES) and Getting Research into Practice (GRiP) programs were used to implement the evidence-based project. The project was implemented in three phases from October 2018 to January 2019. A standardized audit tool devised from JBI PACES was used for the audits in this project. The rates of midstream urine specimen contamination and the knowledge of nurses were also monitored.

RESULTS

The baseline audit revealed that the nursing staff required educational sessions to improve their knowledge of midstream urine sample collection. Aside from criteria 1,3 and 4, the remaining criteria achieved compliance of more than 80%. The criteria below 80% compliance became the main focus of the project interventions. At follow-up cycle 1, all criteria achieved at least 80% compliance except criteria 4 and 5, which achieved 73% and 69% compliance, respectively. At the three-month post implementation audit, all criteria achieved a compliance rate of at least 80%. Fisher's exact test was carried out, and statistical significance of the results was achieved (p < 0.001) when compared to baseline audit. The rates of midstream urine specimen contamination also significantly decreased from 40% at the baseline audit to 20% at the third-month post implementation audit. Nurses' knowledge markedly improved as measured by the three-question quiz.

CONCLUSION

This evidence-based implementation project highlights the effectiveness of the JBI PACES and GRiP processes for initiating best practice within a nursing environment. The use of JBI best-practice recommendations to standardize methods for midstream urine specimen collection effectively reduced the rates of midstream urine contamination.

A New Gold Rush: A Review of Current and Developing Diagnostic Tools for Urinary Tract Infections

Urinary tract infections (UTIs) are one of the most common infections in the United States and consequently are responsible for significant healthcare expenditure. The standard urine culture is the current gold standard for diagnosing urinary tract infections, however there are limitations of the test that directly contribute to increased healthcare costs. As a result, new and innovative techniques have been developed to address the inefficiencies of the current standard-it remains to be seen whether these tests should be performed adjunctly to, or perhaps even replace the urine culture. This review aims to analyze the advantages and disadvantages of the newer and emerging diagnostic techniques such as PCR, expanded quantitative urine culture (EQUC), and next generation sequencing (NGS).

A performance comparison of the fully automated urine particle analyzer UF-5000 with UF-1000i and Gram staining in predicting bacterial growth patterns in women with uncomplicated urinary tract infections

Background

The aim of this study was to compare the performance of the new flow cytometer UF-5000 with the UF-1000i and Gram staining for determining bacterial patterns in urine samples.

Methods

Women who attended our clinic with symptoms suggestive of urinary tract infection were enrolled in the study. Mid-stream urine samples were collected for gram staining, urine analysis and urine cultures. Bacterial patterns were classified using the UF-1000i (none, cocci bacteria or rods/mixed growth), the UF-5000 (none, cocci, rods or mixed growth) and Gram staining.

Results

Among the 102 included samples, there were 10 g-positive cocci, 2 g-positive bacilli, 66 g-negative rods, and 24 mixed growth. The sensitivity/specificity of the UF-1000i was 81.8/91.1% for gram-negative rods and 23.5/96.9% for cocci/mixed. The sensitivity/specificity of the UF-5000 was 80.0/88.2% for gram negative rods and 70.0/86.5% for gram-positive cocci.

Conclusions

The UF-5000 demonstrated good sensitivity and specificity for Gram-negative bacilli and demonstrated an improved sensitivity for detecting Gram-positive cocci compared with the UF-1000i.

Clinical physiological parameters for the prediction of gram-negative bacterial infection in the emergency department

Background

Early detection and treatment of Gram-negative bacteria (GNB), major causative pathogens of sepsis (a potentially fatal condition caused by the body’s response to an infection), may benefit a patient’s outcome, since the mortality rate increases by 5–10% for each hour of delayed therapy. Unfortunately, GNB diagnosis is based on bacterial culture, which is time consuming. Therefore, an economic and effective GNB (defined as a positive blood, sputum, or urine culture) infection detection tool in the emergency department (ED) is warranted.

Methods

We conducted a retrospective cohort study in the ED of a university-affiliated medical center between January 01, 2014 and December 31, 2017. The inclusion criteria were as follows: (1) age ≥ 18; (2) clinical suspicion of bacterial infection; (3) bacterial culture from blood, sputum, or urine ordered and obtained in the ED. Descriptive statistics was performed on patient demographic characteristics, vital signs, laboratory data, infection sites, cultured microorganisms, and clinical outcomes. The accuracy of vital signs to predict GNB infection was identified via univariate logistic regression and receiver operating characteristic (ROC) curve analysis.

Results

A total of 797 patients were included in this study; the mean age was 71.8 years and 51.3% were male. The odds ratios of patients with body temperature ≥ 38.5 °C, heart rate ≥ 110 beats per minute, respiratory rate ≥ 20 breaths per minute, and Glasgow coma scale (GCS) < 14, in predicting GNB infection were found to be 2.3, 1.4, 1.9, and 1.6, respectively. The area under the curve values for ROC analysis of these measures were 0.70, 0.68, 0.69, and 0.67, respectively.

Conclusion

The four physiological parameters were rapid and reliable independent predictors for detection of GNB infection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-020-05758-1.

Microbiology testing and antibiotic treatment for urinary tract infections in general practice: a nationwide observational study

PURPOSE

Routine urine testing is recommended prior to antibiotic treatment for urinary tract infections (UTIs) among high-risk groups for complicated UTIs. This study aims to examine whether the proportion of UTI encounters where antibiotics are prescribed that have accompanying urine testing differs by patient groups.

METHODS

A retrospective analysis was conducted using records of general practice encounters for UTIs occurring between January 2013 and July 2018 in an Australian national database. We calculated the proportion of UTI encounters with antibiotics prescribed that had accompanying urine microbiology testing and the odds ratios for the likelihood of testing by patient groups using generalised estimating equations.

RESULTS

Of 132,688 UTI encounters with antibiotics prescribed, 95,800 (72.2%) were accompanied by urine testing. Among high-risk groups for complicated UTIs and expected to have a high likelihood of testing, we found pregnant women [82.6% vs. non-pregnant 72.3%, adjusted odds ratio (aOR) 1.82, 95% confidence intervals (CI) 1.55-2.12] and children aged 5-9 years (77.6% vs. 20-44 years 72.0%, aOR 1.33, 95% CI 1.22-1.45) had relatively high odds of testing. However, children aged < 5 years (68.7% vs. 20-44 years 72.0%, aOR 0.83, 95% CI 0.76-0.90), patients with recurrent UTIs (69.0% compared to first-onset UTIs 73.6%, aOR 0.81, 95% CI 0.79-0.83), and patients in residential aged care facilities (67.3% vs. not 72.3%, aOR 0.80, 95% CI 0.72-0.90) had relatively low odds of testing.

CONCLUSION

Our results suggest inconsistencies and potential underuse of urine testing when antibiotics were prescribed for high-risk groups in UTI management. Further antibiotic stewardship is needed to improve guideline-based antibiotic prescribing for UTIs.

The prevalence of positive urine dipstick testing and urine culture in the asymptomatic pregnant woman: A cross-sectional study

OBJECTIVE

Pregnancy induces unique physiological changes to the urinary tract, leaving pregnant women more susceptible to pyelonephritis. Urinary tract infections are generally diagnosed using urine sampling and testing with reagent sticks (dipstick) or laboratory culture. This study aimed to establish the prevalence of positive urine reagent strip and urine culture in asymptomatic pregnant women.

STUDY DESIGN

This was a cross-sectional study of 300 women attending routine antenatal clinics. Samples were analysed using an automated urine dipstick analyser for the presence of glucose, protein, leucocyte esterase, blood, and nitrites. All samples were cultured. Multinomial logistic regression was performed to investigate risk factors for urine contamination and infection. Sensitivities and specificities were calculated for common dipstick findings for positive and mixed urine culture.

RESULTS

One-in-three (37.0 % [111/300], 95 % CI 31.6-42.8 %) women had at least one positive finding on reagent strip testing. Ten per cent ([29/300], 95 % CI 6.7-13.7 %) of samples had a positive culture for a single organism, whereas 46.7 % ([140/300], 95 % CI 40.9-52.5 %) of samples were positive for multiple organisms (mixed culture). 43.7 % ([131/300], 95 % CI 38.0-49.5 %) of samples had a negative culture. Organisms cultured were similar to previous reports from high-income countries. BMI was identified on regression analysis as a risk factor for contamination.

CONCLUSIONS

There is a high prevalence of positive urine dipstick and contaminated culture in asymptomatic pregnant women. BMI is a risk factor for urine culture contamination and further research into this topic is essential given trends in obesity worldwide.

Management of Recurrent Urinary Tract Infections in Women: How Providers Can Improve the Patient Experience

OBJECTIVE

To provide guidance to providers on how to improve the patient experience for women with recurrent urinary tract infections (rUTIs).

METHODS

The recently updated 2019 American Urological Association (AUA) guidelines for recurrent uncomplicated acute cystitis and other contemporary publications pertaining to recurrent UTIs in women were reviewed. These data were used to summarize practice-based methodology to formulate recommendations with an emphasis on education to enhance the patient experience.

RESULTS

We summarize the guideline-based management of patients with rUTI and augment this with a patient-focused perspective to provide recommendations for how to best counsel patients regarding evaluation, treatment using antibiotic stewardship practices, and a comprehensive prevention plan. We focus on patient education as the foundation for successful provider-patient relationships as well as patient compliance with care pathways.

CONCLUSION

rUTIs are costly, time-consuming, and painful for patients. For providers, rUTIs represent a frustrating aspect of clinical care facing the balance of antibiotic stewardship with effective treatment and patient expectations with limited data supporting nonantibiotic therapies. Urologists have the skills and knowledge to provide this patient population with competent and compassionate care. By investing in these patients, being responsive to their concerns and offering education, patients will have a better overall experience with this chronic condition.

Contamination in Adult Midstream Clean-Catch Urine Cultures in the Emergency Department: A Randomized Controlled Trial

INTRODUCTION

A midstream clean-catch urine sample is recommended to obtain a urine culture in symptomatic adults with suspected urinary tract infection. The aim of this randomized controlled trial was to determine whether a novel funnel urine-collection system combined with a silver-colloidal cleaning wipe would decrease mixed flora contamination in midstream clean-catch urine cultures from ambulatory adults in the emergency department.

METHODS

In a 2x2 factorial trial, adult participants were randomized to 4 groups: (A) sterile screw-top urine collection container/cup paired with a castile-soap wipe (control group); (B) sterile screw-top urine collection container/cup paired with a colloidal silver-impregnated wipe; (C) sterile urine-collection funnel paired with a castile-soap wipe; (D) sterile urine-collection funnel paired with a colloidal silver-impregnated wipe.

RESULTS

The trial was stopped after interim analysis, as the contamination rate in the control group (30%) was markedly lower than the historical ED contamination rate (40%) at the study site. From 1,112 urinalysis results, 223 urine culture results were analyzed (190 female patients and 33 male patients). Urine contamination rates were as follows: Group A, n = 67 (29.9% contaminated); Group B, n = 69 (34.8% contaminated); Group C, n = 51 (23.5% contaminated); Group D, n = 36 (22.2% contaminated). The differences in contamination rates were not statistically different among any of the groups.

DISCUSSION

The use of a funnel urine-collection system and silver-impregnated wipe did not reduce urine-culture contamination in adult midstream clean-catch urine cultures in the emergency department.

Educational intervention does not reduce non-invasive urine contamination rates in children presenting to the emergency department

AIM

Urinary tract infection is common in children with high contamination rates with non-invasive urine sampling (NIU). Our aims were to evaluate an educational tool for decreasing contamination rates and find factors associated with contamination.

METHODS

This was a prospective cohort interventional study with a review of microbiology data and medical records of all NIU specimens collected at a large tertiary children's emergency department (ED) over a 1-year period. The intervention was the provision of a urine collection kit and educational pamphlet and education of staff. NIU contamination was calculated for 6 months pre-intervention and 6 months post-intervention. The association of factors with NIU contamination was evaluated for all cohorts (age, gender, presence of diarrhoea, season, time of day, time to incubation and activity of the ED).

RESULTS

A total of 2104 NIU samples were included (median age 3 years, 52% females). There was no difference between periods in contamination rates (29.2% and 31.2%, respectively, P = 0.322). Collectively, high monthly activity of the department, age and female gender were associated with contamination. The highest contamination rates were among children aged 0-3 months and 12 years and older (38.1 and 48.9%, respectively).

CONCLUSIONS

The urine collection kit and educational tool did not decrease NIU contamination rates in our ED. Contamination rates were correlated with the monthly activity of our department and female gender and were noticeably high among infants and adolescents. Given the high prevalence of urinary tract infection among these age groups, measures should be taken to reassess indications and methods for urine collection.

Is it Time to Say Goodbye to Culture and Sensitivity? The Case for Culture-independent Urology

Next-generation sequencing has highlighted the limitations of conventional culture methods in the role of urology while discovering the intricate details of the role of microbiota in urologic health and disease. This review article explores: the utility and limitations of conventional culture methods; how culture-independent technologies are revolutionizing medicine; and how the implementation of these technologies may lead to improved patient outcomes. Finally, this article discusses the barriers to widespread adoption of culture-independent technologies, with suggestions for how these hurdles may be overcome.

Advances and Challenges in the Diagnosis and Treatment of Urinary Tract Infections: the Need for Diagnostic Stewardship

PURPOSE OF REVIEW

Urinary tract infections (UTIs), including catheter-associated UTIs, are among the most common bacterial infections in both inpatient and outpatient settings. Diagnosis of true UTI remains a clinical challenge, and excessive antimicrobial treatment of asymptomatic bacteriuria (ASB) or contaminated urine cultures is common.

RECENT FINDINGS

Challenges with the appropriate diagnosis of UTIs include the lack of specific signs and symptoms, no definitive diagnostic criteria, high incidence of ASB, contamination of samples, and frequent lack of indications for ordering urine cultures. Promising interventions include education and feedback, indication requirements when ordering cultures, and use of reflex culture policies that limit urine cultures. Antimicrobial and diagnostic stewardship interventions can work synergistically to decrease ordering of urine cultures without clear indication and prevent excessive antimicrobial administration in patients without clearly defined UTI.

Promoting appropriate urine culture management to improve health care outcomes and the accuracy of catheter-associated urinary tract infections

Published literature indicates that the unjustified ordering or improper collection of urine for urinalysis or culture from either catheterized patients or those without indwelling devices, or misinterpretation of positive results, often leads to adverse health care events, including increased financial burdens, overreporting of mandated catheter-associated urinary tract infection events, overtreatment of patients with antimicrobial agents, selection of multidrug-resistant organisms, and Clostridium difficile infection. Moreover, national guidelines that provide evidence-based direction on core processes that form the basis for subsequent clinical therapy decisions or surveillance interpretations; that is, the appropriate ordering and collection of urine for laboratory testing and the treatment of patients with symptomatic urinary tract infection, are not widely known or lack adherence. This article provides published evidence on the influence of inappropriate ordering of urine specimens and subsequent treatment of asymptomatic bacteriuria and associated adverse effects; reviews research on bacterial contamination and preservation; and delineates best practices in the collection, handling, and testing of urine specimens for culture or for biochemical analysis in both catheterized and noncatheterized patients. The goal is to provide infection preventionists (IPs) with a cohesive evidence-based framework that will assist them in facilitating the implementation of a urine culture management program that reduces patient harms, enhances the accuracy of catheter-associated urinary tract infection surveillance, improves antibiotic stewardship, and reduces costs.

Use of a midstream clean catch mobile application did not lower urine contamination rates in an ED

OBJECTIVES

Urine microscopy is a common test performed in emergency departments (EDs). Urine specimens can easily become contaminated by different factors, including the collection method. The midstream clean-catch (MSCC) collection technique is commonly used to reduce urine contamination. The urine culture contamination rate from specimens collected in our ED is 30%. We developed an instructional application (app) to show ED patients how to provide a MSCC urine sample. We hypothesized that ED patients who viewed our instructional app would have significantly lower urine contamination rates compared to patients who did not.

METHODS

We prospectively enrolled 257 subjects with a urinalysis and/or urine culture test ordered in the ED and asked them to watch our MSCC instructional app. After prospective enrollment was complete, we retrospectively matched each enrolled subject to an ED patient who did not watch the instructional app. Controls were matched to cases based on gender, type of urine specimen provided, ED visit date and shift. Urinalysis and urine culture contamination results were compared between the matched pairs using McNemar's test.

RESULTS

The overall urine culture contamination rate of the 514 subjects was 38%. The majority of the matched pairs had a urinalysis (63%) or urinalysis plus urine culture (35%) test done. There were no significant differences in our urine contamination rates between the matched pairs overall or when stratified by gender, by prior knowledge of the clean catch process or by type of urine specimen.

CONCLUSION

We did not see a lower contamination rate for patients who viewed our instructional app compared to patients who did not. It is possible that MSCC is not effective for decreasing urine specimen contamination.

Nappy pad urine samples for investigation and treatment of UTI in young children: the 'DUTY' prospective diagnostic cohort study

BACKGROUND

The added diagnostic utility of nappy pad urine samples and the proportion that are contaminated is unknown.

AIM

To develop a clinical prediction rule for the diagnosis of urinary tract infection (UTI) based on sampling using the nappy pad method.

DESIGN AND SETTING

Acutely unwell children <5 years presenting to 233 UK primary care sites.

METHOD

Logistic regression to identify independent associations of symptoms, signs, and urine dipstick test results with UTI; diagnostic utility quantified as area under the receiver operator curves (AUROC). Nappy pad rule characteristics, AUROC, and contamination, compared with findings from clean-catch samples.

RESULTS

Nappy pad samples were obtained from 3205 children (82% aged <2 years; 48% female), culture results were available for 2277 (71.0%) and 30 (1.3%) had a UTI on culture. Female sex, smelly urine, darker urine, and the absence of nappy rash were independently associated with a UTI, with an internally-validated, coefficient model AUROC of 0.81 (0.87 for clean-catch), which increased to 0.87 (0.90 for clean-catch) with the addition of dipstick results. GPs' 'working diagnosis' had an AUROC 0.63 (95% confidence intervals [CI] = 0.53 to 0.72). A total of 12.2% of nappy pad and 1.8% of clean-catch samples were 'frankly contaminated' (risk ratio 6.66; 95% CI = 4.95 to 8.96; P<0.001).

CONCLUSION

Nappy pad urine culture results, with features that can be reported by parents and dipstick tests, can be clinically useful, but are less accurate and more often contaminated compared with clean-catch urine culture.

Rapid differentiation of cocci/mixed bacteria from rods in voided urine culture of women with uncomplicated urinary tract infections

OBJECTIVES

To evaluate the ability of laser flow cytometry to predict cocci/mixed growth in the pre-analytical phase of urine specimens.

METHODS

We retrospectively reviewed urine samples from women with uncomplicated urinary tract infections from urologic clinics for study. Urine analyses were performed with laser flow cytometry (UF1000i, Sysmex, Kobe, Japan) and then diagrams were generated (forward scatter vs. fluorescent light scatter). Each specimen (bacteria count >357 BACT/μL) was classified as either cocci bacteria or rods/mixed growth according to the diagrams. Standard urine cultures were performed, and the agreement between cultures and the UF1000i interpretations was analyzed with kappa statistics.

RESULTS

Finally, 491 specimens met the criteria for analysis. Among the 376 specimens with single bacteria growth, there were 26 gram-positive cocci (13 Streptococci spp., 7 Staphylococci spp., 6 Enterococci spp.), 1 gram-positive rods (Corynebacterium spp.), and 349 gram-negative rods (273 Escherichia coli, 33 Klebsiella spp., 29 Proteus spp., 6 Citrobacter spp., 4 Enterobacter spp., 3 Pseudomonas spp., and 1 Providencia spp.). There were 115 specimens with two bacteria species or more that were regarded as mixed growth. Agreement of rods or cocci/mixed growth between the laser flow cytometry and urine cultures yielded a kappa value of 0.58. The positive and negative predictive rate of the UF1000i for cocci/mixed growth in voided urine culture was 81.8% and 84.7%, respectively.

CONCLUSIONS

Through laser flow cytometry, we can predict growth of cocci/mixed growth in the pre-analytical phase of urine culture, thus avoiding unnecessary urine culture and waiting time.

The influence of contaminated urine cultures in inpatient and emergency department settings

We retrospectively evaluated 131 patients with contaminated urine cultures during a 12-month period. Sixty-four patients (48.8%) experienced 139 potential complications related to these specimens. The most common complication was inappropriate antibiotic administration (noted in 58 patients [44.3%]). Contaminated urine cultures led to additional diagnostic evaluation and unnecessary antibiotic use.

Urinary Squamous Epithelial Cells Do Not Accurately Predict Urine Culture Contamination, but May Predict Urinalysis Performance in Predicting Bacteriuria

OBJECTIVES

The presence of squamous epithelial cells (SECs) has been advocated to identify urinary contamination despite a paucity of evidence supporting this practice. We sought to determine the value of using quantitative SECs as a predictor of urinalysis contamination.

METHODS

Retrospective cross-sectional study of adults (≥18 years old) presenting to a tertiary academic medical center who had urinalysis with microscopy and urine culture performed. Patients with missing or implausible demographic data were excluded (2.5% of total sample). The primary analysis aimed to determine an SEC threshold that predicted urine culture contamination using receiver operating characteristics (ROC) curve analysis. The a priori secondary analysis explored how demographic variables (age, sex, body mass index) may modify the SEC test performance and whether SECs impacted traditional urinalysis indicators of bacteriuria.

RESULTS

A total of 19,328 records were included. ROC curve analysis demonstrated that SEC count was a poor predictor of urine culture contamination (area under the ROC curve = 0.680, 95% confidence interval [CI] = 0.671 to 0.689). In secondary analysis, the positive likelihood ratio (LR+) of predicting bacteriuria via urinalysis among noncontaminated specimens was 4.98 (95% CI = 4.59 to 5.40) in the absence of SECs, but the LR+ fell to 2.35 (95% CI = 2.17 to 2.54) for samples with more than 8 SECs/low-powered field (lpf). In an independent validation cohort, urinalysis samples with fewer than 8 SECs/lpf predicted bacteriuria better (sensitivity = 75%, specificity = 84%) than samples with more than 8 SECs/lpf (sensitivity = 86%, specificity = 70%; diagnostic odds ratio = 17.5 [14.9 to 20.7] vs. 8.7 [7.3 to 10.5]).

CONCLUSIONS

Squamous epithelial cells are a poor predictor of urine culture contamination, but may predict poor predictive performance of traditional urinalysis measures.

Effectiveness of Preanalytic Practices on Contamination and Diagnostic Accuracy of Urine Cultures: a Laboratory Medicine Best Practices Systematic Review and Meta-analysis

BACKGROUND

Urinary tract infection (UTI) in the United States is the most common bacterial infection, and urine cultures often make up the largest portion of workload for a hospital-based microbiology laboratory. Appropriately managing the factors affecting the preanalytic phase of urine culture contributes significantly to the generation of meaningful culture results that ultimately affect patient diagnosis and management. Urine culture contamination can be reduced with proper techniques for urine collection, preservation, storage, and transport, the major factors affecting the preanalytic phase of urine culture.

OBJECTIVES

The purposes of this review were to identify and evaluate preanalytic practices associated with urine specimens and to assess their impact on the accuracy of urine culture microbiology. Specific practices included collection methods for men, women, and children; preservation of urine samples in boric acid solutions; and the effect of refrigeration on stored urine. Practice efficacy and effectiveness were measured by two parameters: reduction of urine culture contamination and increased accuracy of patient diagnosis. The CDC Laboratory Medicine Best Practices (LMBP) initiative's systematic review method for assessment of quality improvement (QI) practices was employed. Results were then translated into evidence-based practice guidelines.

SEARCH STRATEGY

A search of three electronic bibliographic databases (PubMed, SCOPUS, and CINAHL), as well as hand searching of bibliographies from relevant information sources, for English-language articles published between 1965 and 2014 was conducted.

SELECTION CRITERIA

The search contained the following medical subject headings and key text words: urinary tract infections, UTI, urine/analysis, urine/microbiology, urinalysis, specimen handling, preservation, biological, preservation, boric acid, boric acid/borate, refrigeration, storage, time factors, transportation, transport time, time delay, time factor, timing, urine specimen collection, catheters, indwelling, urinary reservoirs, continent, urinary catheterization, intermittent urethral catheterization, clean voided, midstream, Foley, suprapubic, bacteriological techniques, and microbiological techniques.

MAIN RESULTS

Both boric acid and refrigeration adequately preserved urine specimens prior to their processing for up to 24 h. Urine held at room temperature for more than 4 h showed overgrowth of both clinically significant and contaminating microorganisms. The overall strength of this body of evidence, however, was rated as low. For urine specimens collected from women, there was no difference in rates of contamination for midstream urine specimens collected with or without cleansing. The overall strength of this evidence was rated as high. The levels of diagnostic accuracy of midstream urine collection with or without cleansing were similar, although the overall strength of this evidence was rated as low. For urine specimens collected from men, there was a reduction in contamination in favor of midstream clean-catch over first-void specimen collection. The strength of this evidence was rated as high. Only one study compared midstream collection with cleansing to midstream collection without cleansing. Results showed no difference in contamination between the two methods of collection. However, imprecision was due largely to the small event size. The diagnostic accuracy of midstream urine collection from men compared to straight catheterization or suprapubic aspiration was high. However, the overall strength of this body of evidence was rated as low. For urine specimens collected from children and infants, the evidence comparing contamination rates for midstream urine collection with cleansing, midstream collection without cleansing, sterile urine bag collection, and diaper collection pointed to larger reductions in the odds of contamination in favor of midstream collection with cleansing over the other methods of collection. This body of evidence was rated as high. The accuracy of diagnosis of urinary tract infection from midstream clean-catch urine specimens, sterile urine bag specimens, or diaper specimens compared to straight catheterization or suprapubic aspiration was varied.

AUTHORS' CONCLUSIONS

No recommendation for or against is made for delayed processing of urine stored at room temperature, refrigerated, or preserved in boric acid. This does not preclude the use of refrigeration or chemical preservatives in clinical practice. It does indicate, however, that more systematic studies evaluating the utility of these measures are needed. If noninvasive collection is being considered for women, midstream collection with cleansing is recommended, but no recommendation for or against is made for midstream collection without cleansing. If noninvasive collection is being considered for men, midstream collection with cleansing is recommended and collection of first-void urine is not recommended. No recommendation for or against is made for collection of midstream urine without cleansing. If noninvasive collection is being considered for children, midstream collection with cleansing is recommended and collection in sterile urine bags, from diapers, or midstream without cleansing is not recommended. Whether midstream collection with cleansing can be routinely used in place of catheterization or suprapubic aspiration is unclear. The data suggest that midstream collection with cleansing is accurate for the diagnosis of urinary tract infections in infants and children and has higher average accuracy than sterile urine bag collection (data for diaper collection were lacking); however, the overall strength of evidence was low, as multivariate modeling could not be performed, and thus no recommendation for or against can be made.

Overdiagnosis of Urinary Tract Infection and Underdiagnosis of Sexually Transmitted Infection in Adult Women Presenting to an Emergency Department

Urinary tract infections (UTIs) and sexually transmitted infections (STIs) are commonly diagnosed in emergency departments (EDs). Distinguishing between these syndromes can be challenging because of overlapping symptomatology and because both are associated with abnormalities on urinalysis (UA). We conducted a 2-month observational cohort study to determine the accuracy of clinical diagnoses of UTI and STI in adult women presenting with genitourinary (GU) symptoms or diagnosed with GU infections at an urban academic ED. For all urine specimens, UA, culture, and nucleic acid amplification testing for Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis were performed. Of 264 women studied, providers diagnosed 175 (66%) with UTIs, 100 (57%) of whom were treated without performing a urine culture during routine care. Combining routine care and study-performed urine cultures, only 84 (48%) of these women had a positive urine culture. Sixty (23%) of the 264 women studied had one or more positive STI tests, 22 (37%) of whom did not receive treatment for an STI within 7 days of the ED visit. Fourteen (64%) of these 22 women were diagnosed with a UTI instead of an STI. Ninety-two percent of the women studied had an abnormal UA finding (greater-than-trace leukocyte esterase level, positive nitrite test result, or pyuria). The positive and negative predictive values of an abnormal UA finding were 41 and 76%, respectively. In this population, empirical therapy for UTI without urine culture testing and overdiagnosis of UTI were common and associated with unnecessary antibiotic exposure and missed STI diagnoses. Abnormal UA findings were common and not predictive of positive urine cultures.

Twenty-five years of accomplishments of the College of American Pathologists Q-probes program for clinical pathology

CONTEXT

During the past 25 years, the College of American Pathologists' (CAP) Q-Probes program has been available as a subscription program to teach laboratorians how to improve the quality of clinical laboratory services.

OBJECTIVE

To determine the accomplishments of the CAP Q-Probes program.

DESIGN

We reviewed Q-Probes participant information, study data and conclusions, author information, and program accomplishments.

RESULTS

During this time 117 Q-Probes clinical pathology studies were conducted by 54 authors and coauthors, 42,899 laboratories enrolled from 24 countries, 98 peer-reviewed publications occurred and were cited more than 1600 times, and the studies were featured 59 times in CAP Today. The most frequent studies (19) focused on turnaround times for results or products at specific locations (emergency department, operating room, inpatients, outpatients), specific diseases (acute myocardial infarction, urinary tract), availability for specific events such as morning rounds or surgery, a specific result (positive blood cultures), and a method on how to use data for improvement (stat test outliers). Percentile ranking of study participants with better performance provided benchmarks for each study with attributes statistically defined that influenced improved performance. Other programs, such as an ongoing quality improvement program (Q-Tracks), a laboratory competency assessment program, a pathologist certification program, and an ongoing physician practice evaluation program (Evalumetrics), have been developed from Q-Probes studies.

CONCLUSIONS

The CAP's Q-Probes program has made significant contributions to the medical literature and has developed a worldwide reputation for improving the quality of clinical pathology services worldwide.

Antimicrobial treatment of asymptomatic bacteriuria in noncatheterized adults: a systematic review

Asymptomatic bacteriuria (ASB) is a common clinical finding characterized by the presence of bacteria in the urine of an individual without signs or symptoms suggestive of urinary tract infection. Despite available guidelines on the diagnosis and management of ASB, it is often managed inappropriately. We performed a systematic review of clinical trials evaluating antimicrobial therapy for ASB, identified translational barriers to evidence-based practice, and we offer strategies to optimize antimicrobial use for ASB. We conducted a systematic search of the PubMed, International Pharmaceutical Abstracts, Cumulative Index to Nursing and Allied Health databases, and the Cochrane Library. Randomized controlled trials, cohort trials, case-control studies, and meta-analyses published in the English language were included in this review if they addressed treatment of ASB with at least one antimicrobial agent in nonpregnant adults. Articles were excluded if they evaluated patients with indwelling urinary catheters or were not clinical trials. Of the 304 articles identified from the search, 287 were excluded; thus 17 articles met the inclusion criteria. Although treatment of ASB with antimicrobial therapy may improve short-term microbiologic outcomes, the clinical significance is diminished because the effect is not sustained, there is no measurable improvement in morbidity or mortality, and some data indicate that therapy is deleterious. Several translational barriers that preclude adoption of evidence-based practice are identified. Treatment guidelines may not achieve their desired effect and underscore the need for additional methods to translate clinical trial data into practice. Clinical pharmacists are a core member of the antimicrobial stewardship team and in an important position to participate in initiatives that promote appropriate antimicrobial use. We suggest a multifaceted approach consisting of education and frequent routine prospective audits with feedback coupled with appropriate process and outcome measures.

Evaluation of the BD Vacutainer Plus Urine C&S Preservative Tubes compared with nonpreservative urine samples stored at 4°C and room temperature

OBJECTIVES

The stability of urine specimens submitted for culture remains a challenge for many laboratories because of delays in specimen transport. We evaluated the usefulness of BD Vacutainer Plus Urine C&S Preservative Tube in ensuring specimen stability.

METHODS

Clinical urine specimens collected in sterile collection cups (n = 110) were plated onto sheep blood and MacConkey agar following standard laboratory procedures guidelines. Thereafter, specimens were divided into 3 storage conditions: nonpreservative, refrigerated; nonpreservative, room temperature (RT); BD Vacutainer Plus Urine C&S Preservative Tube, RT. For each sample type, additional cultures were set up at 2, 4, 24, and 48 hours.

RESULTS

Initially, 18 specimens had no growth, 32 showed mixed skin flora, and 60 yielded at least 1 uropathogen. Increased colony counts of uropathogens were observed for nonpreserved urine samples stored at RT; these changes were statistically significant. Minor differences between refrigerated urine samples and BD Vacutainer Plus Urine C&S Preservative Tube samples were seen but were not statistically significant.

CONCLUSIONS

The use of preservative-containing collection tubes is desirable to ensure specimen stability when prompt processing or refrigeration is not feasible.

Alterations of microbiota in urine from women with interstitial cystitis

Background

Interstitial Cystitis (IC) is a chronic inflammatory condition of the bladder with unknown etiology. The aim of this study was to characterize the microbial community present in the urine from IC female patients by 454 high throughput sequencing of the 16S variable regions V1V2 and V6. The taxonomical composition, richness and diversity of the IC microbiota were determined and compared to the microbial profile of asymptomatic healthy female (HF) urine.

Results

The composition and distribution of bacterial sequences differed between the urine microbiota of IC patients and HFs. Reduced sequence richness and diversity were found in IC patient urine, and a significant difference in the community structure of IC urine in relation to HF urine was observed. More than 90% of the IC sequence reads were identified as belonging to the bacterial genus Lactobacillus, a marked increase compared to 60% in HF urine.

Conclusion

The 16S rDNA sequence data demonstrates a shift in the composition of the bacterial community in IC urine. The reduced microbial diversity and richness is accompanied by a higher abundance of the bacterial genus Lactobacillus, compared to HF urine. This study demonstrates that high throughput sequencing analysis of urine microbiota in IC patients is a powerful tool towards a better understanding of this enigmatic disease.