Asymptomatic Bacteriuria: Prevalence, Diagnosis, Management, and Current Antimicrobial Stewardship Implementations

Appropriate prescription of cytobacteriological urine examinations in older adults

Cytobacteriological urine examinations (CBEU) are frequently ordered for the older adults, sometimes without straightforward indication and with the risk of prescribing empirical antibiotics. The aim of this study was to evaluate the relevance of the CBEU prescription and empiric antibiotic therapy in our geriatric hospital. Among 129 patients (mean age 84 years, sex ratio 0.69), 229 CBEU were collected with 20.9% of inappropriate indication. Cultures were sterile in 43% (n = 99) of cases and positive in 57% (n = 130) cases. Gram-negative bacilli dominated the isolated bacteria (76.9%) followed by gram-positive cocci (17.6%). In 113 patients, probabilistic antibiotic therapy was prescribed of which 68 treatments were initiated before the CBEU. Ceftriaxone and amoxicillin plus clavulanic acid were the main therapeutic option used representing 70.8% of cases. Antibiotic therapy was re-evaluated after 3 days in 74.3% of patients. Efforts to reduce the number of useless ECBUs by training doctors to follow official guidelines are a priority.

Urine biomarkers individually and as a consensus model show high sensitivity and specificity for detecting UTIs

BACKGROUND

Current diagnoses of urinary tract infection (UTI) by standard urine culture (SUC) has significant limitations in sensitivity, especially for fastidious organisms, and the ability to identify organisms in polymicrobial infections. The significant rate of both SUC "negative" or "mixed flora/contamination" results in UTI cases and the high prevalence of asymptomatic bacteriuria indicate the need for an accurate diagnostic test to help identify true UTI cases. This study aimed to determine if infection-associated urinary biomarkers can differentiate definitive UTI cases from non-UTI controls.

METHODS

Midstream clean-catch voided urine samples were collected from asymptomatic volunteers and symptomatic subjects ≥ 60 years old diagnosed with a UTI in a urology specialty setting. Microbial identification and density were assessed using a multiplex PCR/pooled antibiotic susceptibility test (M-PCR/P-AST) and SUC. Three biomarkers [neutrophil gelatinase-associated lipocalin (NGAL), and Interleukins 8 and 1β (IL-8, and IL-1β)] were also measured via enzyme-linked immunosorbent assay (ELISA). Definitive UTI cases were defined as symptomatic subjects with a UTI diagnosis and positive microorganism detection by SUC and M-PCR, while definitive non-UTI cases were defined as asymptomatic volunteers.

RESULTS

We observed a strong positive correlation (R2 > 0.90; p < 0.0001) between microbial density and the biomarkers NGAL, IL-8, and IL-1β for symptomatic subjects. Biomarker consensus criteria of two or more positive biomarkers had sensitivity 84.0%, specificity 91.2%, positive predictive value 93.7%, negative predictive value 78.8%, accuracy 86.9%, positive likelihood ratio of 9.58, and negative likelihood ratio of 0.17 in differentiating definitive UTI from non-UTI cases, regardless of non-zero microbial density. NGAL, IL-8, and IL-1β showed a significant elevation in symptomatic cases with positive microbe identification compared to asymptomatic cases with or without microbe identification. Biomarker consensus exhibited high accuracy in distinguishing UTI from non-UTI cases.

CONCLUSION

We demonstrated that positive infection-associated urinary biomarkers NGAL, IL-8, and IL-1β, in symptomatic subjects with positive SUC and/or M-PCR results was associated with definitive UTI cases. A consensus criterion with ≥ 2 of the biomarkers meeting the positivity thresholds showed a good balance of sensitivity (84.0%), specificity (91.2%), and accuracy (86.9%). Therefore, this biomarker consensus is an excellent supportive diagnostic tool for resolving the presence of active UTI, particularly if SUC and M-PCR results disagree.

Lower Urinary Tract Inflammation and Infection: Key Microbiological and Immunological Aspects

The urinary system, primarily responsible for the filtration of blood and waste, is affected by several infectious and inflammatory conditions. Focusing on the lower tract, this review outlines the physiological and immune landscape of the urethra and bladder, addressing key immunological and microbiological aspects of important infectious/inflammatory conditions. The conditions addressed include urethritis, interstitial cystitis/bladder pain syndrome, urinary tract infections, and urosepsis. Key aspects of each condition are addressed, including epidemiology, pathophysiology, and clinical considerations. Finally, therapeutic options are outlined, highlighting gaps in the knowledge and novel therapeutic approaches.

Introduction of a New Protocol to Limit the Number of Cancelled Elective Orthopaedic Operations Due to Asymptomatic Bacteriuria

Background Asymptomatic bacteriuria (ASB) poses a significant diagnostic dilemma for medical professionals. Current hospital screening protocol determines the likelihood of a positive diagnosis of a urinary tract infection (UTI) based on the results of a bedside urinalysis. ASB, defined as a positive urine culture in the absence of symptoms, can contribute to unnecessary cancellations, poor utilisation of theatre time, and delayed patient care. We present a two-cycle audit proposing a new pathway to addressing ASB in patients awaiting elective orthopaedic surgery, aiming to optimise surgical yield. Our objectives are to identify areas for improvement in our departmental practices with respect to asymptomatic bacteria compared to the published literature. We propose a new protocol targeted to improve our current practices to minimise patient cancellations and optimise theatre utilisation. Methodology A total of 78 patients who had an elective orthopaedic procedure cancelled at a large district general hospital offering tertiary orthopaedic services, between two study periods spanning March 2018 to April 2019 and May 2019 to March 2020, were identified from electronic hospital records and theatre management systems. Demographics, procedure details, and reasons for cancellations, including the result of urinalysis and the presence of UTI symptoms were assessed. Our pathway was introduced after the first study period and, subsequently, re-audited to assess adherence to the new protocol and its effect on cancellations. Results We identified 78 patients, with a 50:50 male:female split and an average age of 63 (range = 9-90). Of the 33 patients in the first cohort, seven (21.2%) were cancelled due to UTI risk based on positive urinalysis. Of these seven cancellations, one (14.3%) patient reported symptoms of a UTI. The second cohort comprised 45 patients, two (4.4%) of whom were cancelled due to UTI risk based on symptom questionnaire results. These two symptomatic patients along with another two asymptomatic patients (8.8% in total) were found to have positive urinalyses; however, the two asymptomatic patients had their operations cancelled for unrelated reasons. Conclusions The study has shown that previously of all patients awaiting elective orthopaedic operations who had their procedures cancelled, 85.7% were cancelled due to ASB. After the introduction of a new protocol focussing on symptoms rather than urinalysis, we estimate that the number of cancelled elective orthopaedic operations has reduced by 71.4%, thereby greatly improving the utilisation of theatre time.

Antibiogram of uropathogens and associated risk factors among asymptomatic female college students in Dessie town, Northeast Ethiopia

BACKGROUND

Asymptomatic urinary tract infection (asymptomatic bacteriuria and asymptomatic candiduria) may not be routinely detected in sexually active non-pregnant female population at the initial and reversible stages. This is mainly due to the fact that most women may not feel compelled to seek medical attention.

OBJECTIVES

The aim of this study was to determine the prevalence, and factors associated with urinary tract infection (UTI), and antibiogram of the uropathogen isolates among asymptomatic female college students.

METHODS

An institutional-based cross-sectional study was conducted at selected colleges in Dessie from January 2021-March 2021. A total of 422 reproductive age (15 to 49 years) non-pregnant female students were included. Socio-demographic and clinical characteristics data were collected using structured questionnaires. Ten mLs of freshly voided mid-stream urine specimen was collected, transported and processed according to the standard operating procedures. Data were coded and entered for statistical analysis using SPSS version 22.0. Descriptive statistics, bivariate and multivariate logistic regression analysis were performed and p-values <0.05 with the corresponding 95% confidence interval (CI) were considered statistically significant.

RESULT

The overall prevalence of UTI was 24.6%. The prevalence of asymptomatic UTI bacteriuria and candiduria was 57 (13.5%) and 47 (11.1%), respectively. The predominant uropathogens were Staphylococcus saprophyticus 24 (23.1%), followed by Candida tropicalis 23 (22.1%), Candida albican 10 (9.6%), Candida krusei 9 (8.7%) and Escherichia coli 8 (7.7%). Gram negative bacterial isolates showed a higher level of resistance to amoxicillin-clavulanic acid 24 (92.3%). Gram positive bacterial uropathogens showed high level of resistance to penicillin 28 (96.6%) and trimethoprim-sulfamethoxazole 23 (79.3%). Gram positive bacterial isolates were sensitive to norfloxacin, clindamycin, and ciprofloxacin, accounting for 24 (82.7%), 20 (69.0%), and 19 (65.5%), respectively. Multidrug resistance was seen in 50 (87.7%) of bacterial uropathogens. Factors identified for acquisition of UTI were frequency of sexual intercourse (≥3 per week) (AOR = 7.91, 95% CI: (2.92, 21.42), and genital area washing habit (during defecation (AOR = 5.91, 95%CI: (1.86, 18.81) and every morning (AOR = 6.13, 95%CI: (1.60, 23.45)).

CONCLUSION

A significant prevalence of uropathogens, and high resistance of bacterial isolates to the commonly prescribed drugs were detected. Therefore, routine UTI screening, regular health education on the risk of asymptomatic infectious diseases for reproductive age group females, and antimicrobial susceptibility testing should be practiced to avoid the progression of an asymptomatic infection into a symptomatic UTI.

Urinary Tract Infections: The Current Scenario and Future Prospects

Urinary tract infections (UTIs) are among the most common bacterial infections worldwide, occurring in both community and healthcare settings. Although the clinical symptoms of UTIs are heterogeneous and range from uncomplicated (uUTIs) to complicated (cUTIs), most UTIs are usually treated empirically. Bacteria are the main causative agents of these infections, although more rarely, other microorganisms, such as fungi and some viruses, have been reported to be responsible for UTIs. Uropathogenic Escherichia coli (UPEC) is the most common causative agent for both uUTIs and cUTIs, followed by other pathogenic microorganisms, such as Klebsiella pneumoniae, Proteus mirabilis, Enterococcus faecalis, and Staphylococcus spp. In addition, the incidence of UTIs caused by multidrug resistance (MDR) is increasing, resulting in a significant increase in the spread of antibiotic resistance and the economic burden of these infections. Here, we discuss the various factors associated with UTIs, including the mechanisms of pathogenicity related to the bacteria that cause UTIs and the emergence of increasing resistance in UTI pathogens.

Diabetes Mellitus and the Kidneys

The pathomechanisms implicated in diabetic kidney disease in people are present in dogs and cats and, in theory, could lead to renal complications in companion animals with long-standing diabetes mellitus. However, these renal complications develop during a long period, and there is little to no clinical evidence that they could lead to chronic kidney disease in companion animals.

Impact of a Primary Care Antimicrobial Stewardship Program on Bacterial Resistance Control and Ecological Imprint in Urinary Tract Infections

Antimicrobial stewardship programs (ASPs) are a central component in reducing the overprescription of unnecessary antibiotics, with multiple studies showing benefits in the reduction of bacterial resistance. Less commonly, ASPs have been performed in outpatient settings, but there is a lack of available data in these settings. We implemented an ASP in a large regional outpatient setting to assess its feasibility and effectiveness. Over a 5-year post-implementation period, compared to the pre-intervention period, a significant reduction in antibiotic prescription occurred, with a reduction in resistance in E. coli urinary isolates. ASP activities also were found to be cost-effective, with a reduction in medication prescription.

Treatment of asymptomatic bacteriuria in the first 2 months after kidney transplant: A controlled clinical trial

BACKGROUND

The incidence of urinary tract infections (UTIs) in the first 2 months postrenal transplantation (pRT) is very high. We evaluate the efficacy of asymptomatic bacteriuria (AB) screening and treatment on the incidence of UTI in the first 2 months pRT METHODS: We conducted a randomized controlled clinical trial. A urine culture was obtained in all patients on the day of the bladder catheter removal, on week three, and before removal of the ureteral catheter. The intervention group received treatment for AB. The control group did not receive treatment. The primary outcomes were the cumulative incidence of UTI and/or graft pyelonephritis and the time to the first episode of UTI and/or graft pyelonephritis RESULTS: Eighty patients were randomized, 40 in each group, and the median follow-up was 63 days (IQR 54-70). The average age was 29.8 years and 33.7% (n = 27) were women. The incidences of UTI (n = 10, 25 % vs. n = 4, 10%, p = .07) and pyelonephritis (n = 6, 15% vs. n = 1, 2.5%, p = .04) were greater in the intervention group, as also shown in the survival analysis: UTI (HR2.8, 95% CI 0.8-9.1, p = .07) and pyelonephritis (HR 6.5, 95% CI 0.8-54.7, p = .08), respectively. The most commonly isolated bacterium was Escherichia coli (n = 28, 59.5%), and over half were E. coli with extended-spectrum beta-lactamases (n = 15). A major limitation was not obtaining the calculated sample size due to a delay in patient recruitment resulting from the COVID-19 pandemic CONCLUSION: Treatment of AB in the first 2 months pRT does not decrease the incidence of UTI or graft pyelonephritis and may actually increase their frequency. Routine treatment of AB during the first months after renal transplantation should not be a standard procedure.

The role of Dutch guidelines in the diagnostic outcomes and treatment decisions of hospitalised older adults with a suspected urinary tract infection: a retrospective cohort study

PURPOSE

Urinary tract infections (UTIs) are highly prevalent and difficult to diagnose in older adults. We aimed to evaluate the applicability of Dutch Association of Urology (NVU) and Dutch Association of Elderly Care Physicians (Verenso) guidelines in terms of diagnostic outcomes and treatment decisions in hospitalised older adults with suspected UTIs.

METHODS

A retrospective cohort study was conducted on 225 geriatric patients with a urine culture taken in 2019, to determine conformity of the studied population to NVU and Verenso.

RESULTS

Of 225 patients with suspected UTI (mean age 86 years; 56.4% female), 67.6% had urinary tract-related symptoms, of whom 96 received antibiotics, including those with a negative urine dipstick (n = 12) or urine culture (n = 28). Hundred seventy-seven and 147 patients were assessed and treated conforming to the NVU and Verenso guidelines, respectively. The 38 patients who were assessed and treated non-conforming to NVU, including patients with negative urine diagnostics, received antibiotics more often compared with 177 patients treated conforming to NVU (p < 0.001). A large number of patients with negative urine tests were treated conforming to Verenso and antibiotics were withheld in 75.5% of the patients. The non-conforming Verenso-treated patients with prescribed antibiotics had significantly more negative dipstick results (p = 0.05), fewer urinary tract-related symptoms (p < 0.001) and more often a different infectious focus (p < 0.001).

CONCLUSION

The common practice performed on the studied geriatric population was more in accordance with the NVU guideline than Verenso. The results indicated that compliance with the guidelines might lead to fewer antibiotic prescriptions in the study population.