Short-Term Outcome of Untreated Versus Treated Asymptomatic Bacteriuria in Renal Transplant Patients

Diagnosing and Managing Urinary Tract Infections in Kidney Transplant Recipients

In the article, the authors review antibiotic treatment options for both acute uncomplicated UTI and complicated UTI. In addition, they review alternative regimens which are needed in the setting of drug-resistant pathogens including vancomycin-resistant Enterococcus, -extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E), carbapenem-resistant Enterobacterales, and carbapenem-resistant Pseudomonas, which are encountered with more frequency.

Risk factors and outcomes of bloodstream infection from a urinary source in kidney transplant recipients

BACKGROUND

Bacteriuria is common among kidney transplant recipients (KTR). Risk factors and outcomes associated with bloodstream infection due to a urinary source (BSIU) in KTR are poorly understood.

METHODS

This single center case-control study from 2010 to 2022 compared KTR with BSIU to those with bacteria without bloodstream infection (BU). Multivariable logistic regression identified BSIU risk factors, and Cox models assessed its impact on graft failure.

RESULTS

Among 3435 patients, who underwent kidney transplantation at Emory Hospital, 757 (22%) developed bacteriuria, among whom 142 (18.8%) were BSIU. Male sex, presence of Escherichia coli, Klebsiella pneumoniae, or Pseudomonas species in urine culture, urethral stricture, neuromuscular bladder disorder, and history of diabetes-induced renal failure were independently associated with increased odds of BSIU (Male sex: aOR 2.29, 95% CI 1.52, 3.47, E. coli: aOR 5.14, 95% CI 3.02, 9.13; K. pneumoniae aOR 3.19, 95% CI 1.65, 6.27, Pseudomonas spp aOR 3.06, 95% CI 1.25, 7.18; urethral stricture: 4.10, 95% CI 1.63, 10.3, neuromuscular bladder disorder aOR 1.98, 95% CI 1.09, 3.53, diabetes: aOR 1.64, 95% CI 1.08, 2.49). BSIU was associated with increased hazard of graft failure (HR 1.52, 95% CI 1.05, 2.20).

CONCLUSION

Close monitoring is warranted for male KTR with bacteriuria, those with urine cultures positive for Pseudomonas spp, K. pneumoniae, or E. coli, as well as KTR with a history of diabetes-induced renal failure, urethral stricture, or neuromuscular bladder disorder due to their risk for developing BSIU. Future research should explore strategies to mitigate BSIU risk in these high-risk KTR and reduce the associated risk of long-term graft failure.

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.

Asymptomatic Bacteriuria in Kidney Transplant Recipients-A Narrative Review

Urinary tract infections (UTIs) are the most prevalent complications in kidney transplant (KTx) recipients. The most frequent finding in this group of patients is asymptomatic bacteriuria (ASB). Here, we provide an overview of the available evidence regarding ASB in KTx recipients, including its etiopathology, clinical impact and management. There is a growing body of evidence from clinical trials that screening for and treating ASB is not beneficial in most KTx recipients. However, there are insufficient data to recommend or discourage the use of a "screen-and-treat strategy" for ASB during the first 1-2 months post-transplant or in the case of an indwelling urinary catheter. Despite its frequency, ASB after KTx is still an understudied phenomenon.

Frequency of pre- and post-transplant infectious agents in kidney transplant patients

Purpose: Renal transplantation is the most important and successful treatment method for renal failure. In this study, it was aimed to investigate the frequency of Cytomegalovirus (CMV), BK virus (BKV) and bacterial agents in kidney transplant recipient (KTR)s before and in the first six months after transplantation. Materials and Methods: CMV and BKV were investigated by Real-time PCR in blood samples taken from patients who underwent kidney transplantation at the Organ Transplantation Center of our faculty, one week before the transplantation and in the first, third and sixth months after transplantation. Blood, urine, respiratory tract /wound (if necessary) cultures were performed. Decoy cells were evaluated in urine cytology. Results: The mean age of KTRs was 32.60±11.71 years, 28 (62.2%) were male. Donor origins were living related donors 39 (86.7%) and cadaveric 6 (13.3%). After transplantation, BKV was detected in 11/38 (28.9%) patients, CMV was found in 25/41 (60.9%) patients, and Decoy cell positivity was detected in 11/31 (35.4%) patients. While the highest rate of Real-time PCR positivities were in the third months and sixth months for BKV and first, month for CMV and gradually decreased towards the sixth month. Escherichia coli, Klebsiella pneumoniae, Candida nonalbicans, Enterococcus faecalis were most commonly grown in urine culture. Staphylococcus hominis, Streptecoccus epidermidis, were grown in blood culture. Acinetobacter baumannii, Klebsiella pneumoniae, Aspergillus fumigatus and Candida albicans grew in the culture of respiratory tract samples. Conclusion: Bacterial infections developed early in our KTRs. While the highest Real-time PCR positivity rate was in the third and sixth months for BKV, it was the first month for CMV and gradually decreased towards the sixth month. Decoy cell positivity may be also important for diagnosis of BKV infection in KTRs.

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.

Systematic review and meta-analysis of asymptomatic bacteriuria after renal transplantation: incidence, risk of complications, and treatment outcomes

BACKGROUND

Routine treatment for asymptomatic bacteriuria (ASB) after renal transplantation (RT) represents nowadays a controversial topic, being unknown its impact on the overall prognosis of the transplanted patient.

METHODS

Studies published during 1970-2019 that evaluated the benefit of treating ASB after RT regarding the risk of renal complications were included. The primary outcome was to assess whether the treatment is associated with a lower risk of symptomatic urinary tract infection (UTI) or an improved renal function at the end of the follow-up period. The secondary outcome was the risk of acute graft rejection (AGR). A meta-analysis with a random-effect model was performed. Heterogeneity was assessed with the I² measure.

RESULTS

Fifteen studies were included. The incidence of ASB in the first month and the first year after RT was 22% and 30%, respectively. ASB was not correlated to AGR (OR 1.18; 95% CI, 0.78-1.79). Eight studies compared the outcomes of ASB treatment, finding no benefit of treating regarding the risk of symptomatic UTI (OR 1.08; 95% CI, 0.63-1.84; I²  = 35%) or the change in renal function (mean difference in serum creatinine concentration-0.03 mg/dL,95% CI-0.15-0.10; I²  = 53%).

CONCLUSIONS

Asymptomatic bacteriuria represents a frequent finding after RT, highlighting the need for appropriate management of this condition. Considering that its treatment did not decrease the risk of the studied complications, antibiotic therapy should start to be questioned, as it has been related to higher rates of antimicrobial resistance and high economic costs.

Diagnosis and management of asymptomatic bacteriuria in kidney transplant recipients: a survey of current practice in Europe

Background

Asymptomatic bacteriuria is frequent in kidney transplant recipients (KTRs). However, there is no consensus on diagnosis or management. We conducted a European survey to explore current practice related to the diagnosis and management of asymptomatic bacteriuria in adult KTRs.

Methods

A panel of experts from the European Renal Association-European Dialysis Transplant Association/Developing Education Science and Care for Renal Transplantation in European States working group and the European Study Group for Infections in Compromised Hosts of the European Society of Clinical Microbiology and Infectious Diseases designed this cross-sectional, questionnaire-based, self-administered survey. Invitations to participate were e-mailed to European physicians involved in the care of KTRs.

Results

Two hundred and forty-four participants from 138 institutions in 25 countries answered the survey (response rate 30%). Most participants [72% (176/244)] said they always screen for asymptomatic bacteriuria in KTRs. Six per cent (15/240) reported never treating asymptomatic bacteriuria with antibiotics. When antimicrobial treatment was used, 24% of the participants (53/224) said they would start with empirical antibiotics. For an episode of asymptomatic bacteriuria caused by a fully susceptible microorganism and despite no contraindications, a majority of participants (121/223) said they would use a fluoroquinolone (n = 56), amoxicillin/clavulanic acid (n = 38) or oral cephalosporins (n = 27).

Conclusions

Screening for and treating asymptomatic bacteriuria are common in KTRs despite uncertainties around the benefits and harms. In an era of antimicrobial resistance, further studies are needed to address the diagnosis and management of asymptomatic bacteriuria in these patients.

Impact of asymptomatic bacteriuria incidence and management post-kidney transplantation

OBJECTIVE

Urinary tract infections (UTIs) are the most commonly occurring infectious complication following kidney transplantation. Questions remain regarding whether asymptomatic bacteriuria (ASB) should be treated. The aim was to evaluate the incidence and management of ASB in kidney transplant recipients at a large academic medical center.

METHODS

All subjects receiving an isolated kidney transplant between September 2012 and October 2016, and with at least one ASB episode were included. Demographics, symptomatology, and urine culture data were collected on subjects with bacteriuria in the first year post-transplant. Cultures were classified by symptoms, ASB treatment trends were analyzed, and ASB-to-UTI progression was compared between ASB treatment and non-treatment.

RESULTS

A total of 527 subjects were transplanted with 64 developing at least one ASB episode. The incidence of ASB was 12.1% and treated 74.6% of the time. Neither lack of ASB treatment (P = 0.463) nor ASB within the first month post-transplant (P = 0.303) were associated with ASB-to-UTI progression.

CONCLUSION

Despite high ASB treatment rate, this was not found to be protective against ASB-to-UTI progression. ASB within the first month post-transplant also did not correlate with increased progression risk. These results suggest minimization of ASB treatment in kidney transplant recipients remains an important antimicrobial stewardship target.

Urinary tract infections in solid organ transplant recipients: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of urinary tract infections (UTI) in solid organ transplantation, focusing on kidney transplant (KT) recipients. KT recipients have unique risk factors for UTI, including indwelling stents and surgical manipulation of the genitourinary tract. KT recipients experience multi-drug antibiotic-resistant infections-UTI prevention and management strategies must consider risks of antimicrobial resistance. Non-antimicrobial prevention strategies for UTI in KT recipients are reviewed. It is important to recognize that some renal transplant recipients with UTI may primarily present with fever, malaise, leukocytosis, or a non-specific sepsis syndrome without symptoms localized to the urinary tract. However, asymptomatic bacteriuria (AB) must be distinguished from UTI because AB is not necessarily a disease state. Accumulating data indicate that there are no benefits of antibiotics for treatment of AB in KT recipients more than 2 months after post-transplant. Further research is needed on management of AB in the early (<2 months) post-transplant period, prophylaxis for UTI in this era of antibiotic resistance, recurrent UTI, non-antimicrobial prevention of UTI, and uropathogens identified in donor urine and/or preservative fluid cultures.

Use of a subcutaneous ureteral bypass device for treatment of bilateral proximal ureteral injury in a 9-month-old cat

Case summary

A 9-month-old male domestic longhair cat presented following iatrogenic ureteral trauma after an attempted laparoscopic ovariectomy. Prior to identifying that the cat was male, both ureters were transected approximately 4 mm from the renal pelves. Initial management involved a left-sided Boari flap neoureterocystostomy, cystonephropexy and right ureteronephrectomy. Thirty-six hours later, the cat developed uroabdomen due to leakage from the neoureterocystostomy site. At a tertiary referral institution, the ureter was reconstructed via end-to-end anastomosis and a left-sided subcutaneous ureteral bypass (SUB) device was placed in the event the anastomosis failed. Five weeks after SUB placement, the cat was dysuric and stranguric. A urine culture was negative and clinical signs were attributed to sterile cystitis secondary to device placement. Blood urea nitrogen (BUN) was 22 mg/dl and creatinine was 1.2 mg/dl. Contrast pyelography confirmed device patency, but no contrast was identified through the ureteral anastomosis. At 12 months, BUN and creatinine were 1.5 mg/dl and 25 mg/dl, respectively, and a subclinical urinary tract infection was identified (Enterococcus faecalis). Antibiotic therapy was not prescribed in order to prevent multidrug resistance. At 42 months, BUN was 38 mg/dl and creatinine was 2.0 mg/dl. The cat had occasional and intermittent signs of pollakiuria and stranguria but was otherwise doing well.

Relevance and novel information

To our knowledge, this is the first case report to describe the use of a SUB device for management of traumatic proximal ureteral injury in a cat with one kidney. The case outcome provides valuable information about the direct effect of the SUB device and the presence of chronic Enterococcus species infection on long-term renal function.

Common Questions and Misconceptions in the Management of Renal Transplant Patients: A Guide for Health Care Providers in the Posttransplant Setting

Once renal transplant recipients are stabilized and require less frequent follow-up with their transplant team, health care providers outside of the transplant setting play an integral role in patients' ongoing medical care. Given renal transplant recipients' inherent complexity, these health care providers often seek consult regarding decisions that may affect transplant-related medications or outcomes. In this review, we discuss answers to 10 of the questions commonly posed to our renal transplant team by other health care providers.

The challenge of urinary tract infections in renal transplant recipients

Urinary tract infections (UTI) are an important cause of morbidity and mortality in renal transplant patients. These infections are quite common, and the goal of care is to identify and reduce risk factors while providing effective prophylaxis and treatment. Better understanding of long-term outcomes from these infections has led to the distinctions among UTI, recurrent UTI, and asymptomatic bacteriuria (ASB), and that each requires a different therapeutic approach. Specifically, new research has supported the perspective that asymptomatic bacteriuria should not be treated. Symptomatic UTI, on the other hand, requires intervention and remains an ongoing challenge for infectious disease clinicians. Many bacteria species are responsible for UTI in renal transplant patients, and in recent years there has been a global rise in infection caused by bacteria with newly acquired antibacterial resistance genes. Many renal transplant patients who experience UTI will also have multiple recurring episodes, which likely has a distinct pathophysiological mechanism leading to chronic colonization of the urinary tract. In these cases, long-term management includes bacterial suppression, which aims to reduce rather than eliminate bacteria to levels below the threshold for symptomatic infection. This review will address the current understanding of UTI epidemiology, pathogenesis, and risk factors in the renal transplant community, and also focus on current prevention and treatment strategies for patients who face an environment of increasingly antibiotic-resistant bacteria.