Impact of asymptomatic bacteriuria incidence and management post-kidney transplantation

Systematic Review and Meta-Analysis Provide no Guidance on Management of Asymptomatic Bacteriuria within the First Year after Kidney Transplantation

(1) Background: Urinary tract infections (UTIs) are among the most frequent complications in kidney transplant (KT) recipients. Asymptomatic bacteriuria (ASB) may be a risk factor for UTIs and graft rejection. We aimed to evaluate available evidence regarding the benefit of screening and treatment of ASB within the first year after KT. (2) Evidence acquisition: A systematic literature search was conducted in MEDLINE, the Cochrane Library CENTRAL and Embase. Inclusion criteria were manuscripts in English addressing the management of ASB after KT. The PICO questions concerned Patients (adults receiving a KT), Intervention (screening, diagnosis and treatment of ASB), Control (screening and no antibiotic treatment) and Outcome (UTIs, sepsis, kidney failure and death). (3) Evidence synthesis: The systematic review identified 151 studies, and 16 full-text articles were evaluated. Seven were excluded because they did not evaluate the effect of treatment of ASB. There was no evidence for a higher incidence of lower UTIs, acute pyelonephritis, graft loss, or mortality in patients not treated with antibiotics for ASB. Analysis of comparative non-randomized and observational studies did not provide supplementary evidence to guide clinical recommendations. We believe this lack of evidence is due to confounding risk factors that are not being considered in the stratification of study patients.

Profile, Risk Factors, and Outcomes of Asymptomatic Bacteriuria in Kidney Transplant Recipients with Normal Pretransplant Genitourinary Tract: A Single-Center Experience

Introduction

There is a paucity of studies on asymptomatic bacteriuria (ASB) among kidney transplant recipients (KTR) in developing countries. This study assessed the clinical profile, risk factors, outcomes, and impact of treatment of ASB in KTRs with a normal genitourinary tract.

Methods

Consecutive KTRs from 2009 to 2018 with no clinical or radiological evidence of obstructive uropathy were included. Urinary tract infection (UTI) after ASB was defined as occurrence of cystitis, pyelonephritis, or urosepsis, with ASB being the first bacteriuric episode.

Results

Seven hundred ten out of 794 patients with median follow up of 47 months were included. The mean age was 35.5 ± 12 years. Eighty-one patients (11.4%) developed ASB at a median of 25 days (IQR 10, 134.5). Fifty-three percent and 4.9% of ASB episodes were extended-spectrum beta-lactamase (ESBL) positive and carbapenem-resistant organisms, respectively. Eighteen patients (32.1%) with early ASB (<3 months) and 5 (20%) with late ASB developed UTI on follow-up. Fifty-five percent of early and 16% of late ASB episodes were treated, with no significant difference observed in the risk of development of UTI when compared to untreated ASB episodes.

Conclusion

The incidence of ASB as first bacteriuric episode in our cohort was 11.4%, with there being significant antimicrobial resistance. Female gender, pretransplant UTI, and delayed graft function were independently associated with development of ASB. Treatment of ASB episodes either early or late did not decrease the risk of development of UTI.

Opportunities for Antimicrobial Stewardship Interventions Among Solid Organ Transplant Recipients

Although antimicrobial stewardship programs have excelled over the past decade, uptake and application of these programs to special populations such as solid organ transplant recipients have lagged. Here, we review the value of antimicrobial stewardship for transplant centers and highlight data supporting interventions that are ripe for adoption. In addition, we review the design of antimicrobial stewardship initiatives, targets for both syndromic and system-based interventions.

A work in progress: antimicrobial stewardship in solid organ transplant patient populations

PURPOSE OF REVIEW

To review recent medical literature addressing antimicrobial stewardship in solid organ transplant (SOT) recipients.

RECENT FINDINGS

Few studies with a strict focus on SOT patients have been published to date. Team-based antimicrobial stewardship interventions in SOT populations do have beneficial impacts on antimicrobial stewardship-relevant outcomes. Several studies have compared SOT-specific antibiograms to widely accepted hospital antibiograms; these studies all have found important differences in resistance rates among bacterial pathogens. Novel biomarkers like virome monitoring for assessing the net state of immunosuppression hold promise for individualized antimicrobial stewardship interventions.

SUMMARY

SOT patients are an understudied population with respect to antimicrobial stewardship interventions. Current antimicrobial stewardship interventions for SOT patients are largely extrapolated from studies in general patient populations and may not accurately reflect SOT-specific infection risks or outcomes. Antimicrobial stewardship interventions do impact SOT-relevant care goals but require significantly more research to achieve the depth and reach of antimicrobial stewardship interventions developed for general populations.

Urinary Tract Infections in Kidney Transplant Recipients-Is There a Need for Antibiotic Stewardship?

(1) Background: Urinary tract infections (UTI) are the most common infections after kidney transplantation. Given the risk of urosepsis and the potential threat to the graft, the threshold for treating UTI and asymptomatic bacteriuria with broad spectrum antibiotics is low. Historically fluoroquinolones were prescription favorites for patients that underwent kidney transplantation (KT). After the recent recommendation to avoid them in these patients, however, alternative treatment strategies need to be investigated (2) Methods: We retrospectively analyzed the charts of 207 consecutive adult kidney transplantations that were performed at the department of General, Visceral and Transplantation Surgery of the University Hospital of Tuebingen between January 2015 and August 2020. All charts were screened for the diagnosis and treatment of asymptomatic bacteriuria (ASB) and urinary tract infections (UTI) and the patients' clinical characteristics and outcomes were evaluated. (3) Results: Of the 207 patients, 68 patients suffered from urinary tract infections. Patients who developed UTI had worse graft function at discharge (p = 0.024) and at the 12 months follow-up (p < 0.001). The most commonly prescribed antibiotics were Ciprofloxacin and Piperacillin/Tazobactam. To both, bacterial resistance was more common in the study cohort than in the control group. (4) Conclusions: Urinary tract infections appear to be linked to worse graft functions. Thus, prevention and treatment should be accompanied by antibiotic stewardship teams.

A Current Review of the Etiology, Clinical Features, and Diagnosis of Urinary Tract Infection in Renal Transplant Patients

Urinary tract infection (UTI) represents the most common infection after kidney transplantation and remains a major cause of morbidity and mortality in kidney transplant (KT) recipients, with a potential impact on graft survival. UTIs after KT are usually caused by Gram-negative microorganisms. Other pathogens which are uncommon in the general population should be considered in KT patients, especially BK virus since an early diagnosis is necessary to improve the prognosis. UTIs following kidney transplantation are classified into acute simple cystitis, acute pyelonephritis/complicated UTI, and recurrent UTI, due to their different clinical presentation, prognosis, and management. Asymptomatic bacteriuria (ASB) represents a frequent finding after kidney transplantation, but ASB is considered to be a separate entity apart from UTI since it is not necessarily a disease state. In fact, current guidelines do not recommend routine screening and treatment of ASB in KT patients, since a beneficial effect has not been shown. Harmful effects such as the development of multidrug-resistant (MDR) bacteria and a higher incidence of Clostridium difficile diarrhea have been associated with the antibiotic treatment of ASB.

Asymptomatic Bacteriuria in Post Renal Transplant Patients: To Treat or Not?

Urinary tract infections (UTIs) can commonly occur within the first few weeks following kidney transplantation procedures. Although the management of asymptomatic bacteriuria and acute graft pyelonephritis is important to reduce the risk of graft rejections following kidney transplantation, the efficacy of antibiotics administration remains controversial among studies in the literature. The aim of this review is to elaborate more on asymptomatic bacteriuria following kidney transplantation and try to formulate proper evidence about the efficacy of antibiotics administration on eliminating the frequency of infections and enhancing the quality of care for patients. Most studies in the literature are observational, which are usually biased in the interventions. However, the current evidence regarding the management and screening of asymptomatic bacteriuria seems to discourage such an approach. Almost all of the included studies reported that antibiotic administration did not significantly lower the rates of secondary symptomatic UTIs or enhance the functions of the graft. In addition, there is no significant impact on mortality and other clinical outcomes. Lastly, the frequent administration of antibiotics can significantly increase the risk of recurrence due to the emergence of novel strains of bacteria that are resistant to the currently administered antibiotics making it unfavorable.

Predictive factors and management of urinary tract infections after kidney transplantation: a retrospective cohort study

BACKGROUND

Urinary tract infection (UTI) is one of the most common infectious complications in kidney transplant recipients. The aims of our study were to identify possible predictive factors for UTI and advocate for the management of UTI after kidney transplantation (KT).

METHODS

Between January 2013 and December 2018, 182 adult patients with end-stage kidney disease who underwent KT were retrospectively analyzed. Patients who had urinary symptoms and positive urine culture were diagnosed with UTI. The types of urinary bacteria causing UTIs were also examined.

RESULTS

UTIs occurred in forty-one patients (25.1%), and the median time to UTI onset (UTI-free survival) after KT was 189 days. The Cox hazard regression analysis showed that the predictive factors for UTI onset were as follows: posttransplant urinary catheterization, including indwelling urinary catheterization and clean intermittent catheterization; a maximum bladder capacity before KT of less than 150 ml; and a low serum albumin level at 1 month after KT. The most common causative agent was Escherichia coli (56.6%), followed by Enterococcus spp. (15.6%) and Klebsiella spp.

CONCLUSIONS

Kidney transplant recipients with prolonged postoperative malnutrition, posttransplant voiding dysfunction and/or urinary storage disorder had an increased risk of UTI. Bladder function tests, such as uroflowmetry, postvoid residual urine tests, and urodynamic tests, were needed to predict UTI. For patients with malnutrition, care should be taken to ensure sufficient calorie intake. Kidney transplant recipients who develop UTI should be treated as complicated UTI patients.