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

A new technique for the treatment of ureteric stricture after kidney transplantation

OBJECTIVE

To evaluate the safety and effectiveness of endoscopic treatments with Allium® metal ureteric stent (AMUS) for ureteric strictures after kidney transplantation (KT).

PATIENTS AND METHODS

In a prospective manner, we gathered clinical data from 68 patients who underwent endoscopic treatments with AMUS for ureteric strictures after KT between January 2019 and March 2022. The definition of surgical success was the unobstructed drainage of the AMUS, or in cases where there was AMUS migration, occlusion or encrustation and subsequently removed, there is no worsening of renal hydronephrosis in the patient during the follow-up period.

RESULTS

Based on the specific circumstances of the ureteric strictures, three distinct types of surgery were selected for treatment. The overall success rate of endoscopic treatments for ureteric strictures following KT was 90% (61/68) during a follow-up period of 1 year. Surgical complications included haematuria (18%), pain (10%), urinary tract infections (7.4%), and lower urinary tract symptoms (7.4%). The incidences of stent migration, occlusion, and encrustation were 10%, 2.9%, and 1.5%, respectively. Postoperatively, significant improvements were observed in various parameters. At 1 month after surgery, there was a notable decrease in blood creatinine levels (105.5 vs 90.4 mol/L), urea nitrogen levels (6.6 vs 5.4 mmol/L), and hydronephrosis volume (64.4 vs 43.9 mL). Additionally, the serum estimated glomerular filtration rate increased from 49.5 to 64.4 mL/min/1.73 m2. The follow-up results of patients at 1 year after surgery were similar to those observed at 1 month after surgery.

CONCLUSIONS

Systemic endoscopic treatments with AMUS were found to be safe and effective for ureteric strictures after KT with short-term follow-ups. This technique offers a novel option for the treatment of post-KT strictures.

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.

The phenomenon of urinary tract infection experienced by women with a kidney transplant

BACKGROUND

Urinary tract infection is the most common infection among people with a kidney transplant and increases the risk of graft rejection. Women have a higher risk. A literature search did not identify any description of the phenomenon of urinary tract infection experienced by women with a kidney transplant.

OBJECTIVE

To examine how women with a kidney transplant experienced the phenomenon of a urinary tract infection.

DESIGN

A qualitative study with a phenomenological approach.

APPROACH

Eight individual semistructured interviews based on van Manen's four lifeworld existentials and analysed using systematic text condensation.

PARTICIPANTS

Women with a kidney transplant and recently been admitted to the hospital due to a urinary tract infection.

FINDINGS

We identified four themes: (1) Feeling both typical and atypical symptoms; (2) Becoming aware of the body and trying her best to prevent urinary tract infection; (3) Having a urinary tract infection is a dual experience, both good and bad; (4) Support from relatives.

CONCLUSION

The urinary tract infection symptoms pathway varied between participants but also between individual episodes of incidents among each participant. Participants felt secure when they experienced a common symptom pattern, but a new symptom pattern made them insecure. Together with their relatives, they experienced a urinary tract infection as a disruption of their everyday life and it decreased their experiences of happiness. They experienced to be supported by relatives but also by healthcare professionals, but needed more information on how to prevent, observe and react to a urinary tract infection in the future.

Different profiles of acute graft pyelonephritis among kidney recipients from standard or elderly donors

Background

Acute graft pyelonephritis (AGPN) is a relatively common complication in kidney transplants (KTs); however, the effects on allograft function, diagnostic criteria, and risk factors are not well established.

Methods

Retrospective analysis of all consecutive adult KTs was performed between 01 January 2011 and 31 December 2018 (follow-up ended on 31 December 2019) to examine the association between the diagnosis of AGPN (confirmed with magnetic resonance imaging [MRI]) during the first post-transplantation year and graft outcomes.

Results

Among the 939 consecutive KTs (≈50% with donors ≥60 years), we identified 130 MRI-confirmed AGPN episodes, with a documented association with recurrent and multidrug-resistant bacterial urinary tract infections (UTIs) (p < 0.005). Ureteral stenosis was the only risk factor associated with AGPN (OR 2.9 [95% CI, 1.6 to 5.2]). KTs with AGPN had a decreased allograft function at the first year (ΔeGFR 6 mL/min/1.73 m2 [-2-15] in non-AGPN vs. -0.2 [-6.5-8.5] in AGPN, p < 0.001), with similar and negative profiles in KTs from standard or elderly donors. However, only KTs with AGPN and a donor <60 years showed reduced death-censored graft survival (p = 0.015); most of this subgroup received anti-thymocyte globulin (ATG) induction (40.4% vs. 17.7%), and their MRI presented either a multifocal AGPN pattern (73.9% vs. 56.7%) or abscedation (28.3% vs. 11.7%). No difference was noted in death-censored graft survival between early (<3 months post-KT) or late (3-12 months) AGPN, solitary/recurrent forms, or types of multidrug-resistant pathogens. Linear regression confirmed the independent role of multifocal pattern, abscedation, ATG induction, and donor age on the eGFR at the first year.

Conclusion

AGPN, influenced by multifocal presentation, ATG induction, donor age, and abscedation, affects kidney function and significantly impacts allograft survival in KTs with donors <60 years.

Toward an optimization of empirical antibiotic therapy in acute graft pyelonephritis: A retrospective multicenter study

OBJECTIVE

Acute graft pyelonephritis (AGPN) is the most frequent infectious complication in kidney transplant recipients (KTR). The treatment of acute community-acquired (CA) pyelonephritis is based on third-generation cephalosporins (3GC) and fluoroquinolones. Cefepime or a piperacillin-tazobactam combination are more often used in healthcare-associated (HCA) infections. However, these recommendations do not consider the resistance observed in KTRs. The objective of our study was to define the most appropriate empirical antibiotherapy for AGPN in KTRs according to the CA and HCA settings. To answer this question, we assessed the prevalence of resistance to different antibiotics usually recommended for urinary tract infections (UTIs) in the general population.

METHODS

Observational, retrospective, multicenter study covering all episodes of AGPN occurring in hospitalized KTRs in 2019.

RESULTS

A total of 210 patients were included in 7 centers and 244 episodes of AGPN were analyzed (158 CA-AGPN and 86 HCA-AGPN). The prevalence of 3GC and fluoroquinolone resistance was 23 % (n = 36) and 30 % (n = 50) in CA infections (n = 158), and 47 % (n = 40) and 31 % (n = 27) in HCA infections (n = 86), respectively. Cefepime resistance rate was 19 % (n = 30) in CA-AGPN and 29 % (n = 25) in HCA-AGPN. Piperacillin-tazobactam combination had resistance rates > 15 % in both CA and HCA infections. The only antimicrobials with resistance rates < 10 % were aminoglycosides and carbapenems.

CONCLUSION

None of the antibiotics recommended in empirical treatment in UTIs has shown a resistance rate of less than 10% with regard to AGPN. Therefore, none of them should be used as monotherapy. A combination therapy including amikacin could be an appropriate strategy in this setting.

Effect of increasing age and ureteral stent implantation on urinary tract infections after kidney transplantation - update of recent literature

PURPOSE OF REVIEW

This review aims to present the recent literature regarding effects of aging and ureteral stent implantation (UrS) on the risk of urinary tract infections (UTIs) in kidney transplant (KTX) recipients.

RECENT FINDINGS

UTIs in kidney transplant recipients remain a clinical challenge and represent a leading cause of morbidity, hospitalization rates, and mortality. Higher age was described as a significant risk factor for UTIs in several studies including a recent Brazilian analysis, indicating a 3.6%/years of age increase in UTI risk. Subsequently, a large meta-analysis, published in 2023, confirmed the correlation between older age and elevated UTI risk. The Swiss Transplant Cohort Study in 2022, largest of its kind, similarly confirmed a link between advanced age and heightened risk of recurrent UTIs in KTX. A recent prospective study highlighted UrS placement as a modifiable risk factor, emphasizing the need for careful consideration and antibiotic prophylaxis. Additionally, the type of stents played a crucial role, with external stents associated with a 1.69 times higher UTI risk. The challenge of determining optimal UrS removal timing further complicates posttransplant care, with insufficient evidence to guide practices.

SUMMARY

The aging population of KTX recipients requires a personalized approach to effectively reduce and manage UTIs as one of the most important complications following KTX. Prophylactic stent implantation is successful in lowering ureteral complications, however, is associated with an increased incidence of UTIs. To reduce the increased risk of UTIs, the length of stent insertion requires strict supervision and maintenance.

Chronic E. Coli Drug-Resistant Cystitis Treated with a Sequence of Modulated Extremely Low-Frequency Electromagnetic Fields: A Randomized Study of 148 Cases

(1) Background: This study investigated the effects of sequenced electromagnetic fields, modulated at extremely low frequencies and intensities, in the treatment of drug-resistant Escherichia coli (E. coli)-induced chronic bacterial cystitis. (2) Methods: A total of 148 female participants, aged 18 to 80 years diagnosed with chronic bacterial cystitis caused by drug-resistant E. coli, were recruited for this study. Participants were randomly assigned to two groups: an experimental group (n = 74) with osteopathic palpation and assessment treated with a sequence of electromagnetic fields, and a control group (n = 74) receiving a placebo treatment. Both groups were assessed at this study's outset, 4 weeks after eight applications, and at 12 weeks for symptomatic presentation and laboratory parameters. (3) Results: After 4 weeks of treatment, a significant difference was observed between the two groups regarding D-DIMER levels, IL-6 levels, erythrocyte levels, leukocyte levels, and E. coli levels (p < 0.001). By the 12th week, the experimental group continued to exhibit a significant reduction in the examined parameters compared to the control group (p < 0.001). Additionally, the treatment did not induce any side effects in the patients in the experimental group. (4) Conclusions: Treatment with coherently sequenced electromagnetic fields, modulated at an extremely low frequency and intensity, not only appears to provide an effective alternative for the symptoms of chronic bacterial cystitis caused by drug-resistant E. coli but also demonstrates a potent antibacterial effect.

Randomized clinical trial of non-antibiotic prophylaxis with d-Mannose plus Proanthocyanidins vs. Proanthocyanidins alone for urinary tract infections and asymptomatic bacteriuria in de novo kidney transplant recipients: The Manotras study

BACKGROUND

Studies analyzing non-antibiotic alternatives in kidney transplant UTI's are lacking. d-Mannose, a simple sugar, inhibits bacterial attachment to the urothelium, as does Proanthocyanidins; both could act as a synergic strategy preventing UTI; nonetheless their efficacy and safety have not been evaluated in kidney transplant population yet.

METHODS

This is a pilot prospective, double-blind randomized trial. Sixty de novo kidney transplant recipients were randomized (1:1) to receive a prophylactic strategy based on a 24-h prolonged release formulation of d-Mannose plus Proanthocyanidins vs. Proanthocyanidins (PAC) alone. The supplements were taken for the first 3 months after kidney transplant and then followed up for 3 months as well. The main objective of the study was to search if the addition of Mannose to PAC alone reduced the incidence of UTI and/or asymptomatic bacteriuria in the first 6 months post-transplantation.

RESULTS

27% of patients experienced one UTI episode (cystitis or pyelonephritis) while asymptomatic bacteriuria was very common (57%). Incidences according UTI type or AB were: 7% vs. 4% for cystitis episode (p 0.3), 4% vs. 5% for pyelonephritis (p 0.5) and 17% vs. 14% for asymptomatic bacteriuria (p 0.4) for patients in the Mannose+PAC group vs. PAC group respectively. The most frequent bacteria isolated in both groups was Escherichia coli (28% of all episodes), UTI or AB due to E. coli was not different according to study group (30% vs. 23% for Mannose+PAC vs. PAC alone p 0.37).

CONCLUSIONS

Non-antibiotic therapy is an unmet need to prevent UTI after kidney transplantation; however, the use of d-Mannose plus PAC does not seem capable to prevent it.

Bacterial infections in solid organ transplant recipients

PURPOSE OF REVIEW

Bacteria are the leading cause of infections in solid organ transplant (SOT) recipients, significantly impacting patient outcome. Recently detailed and comprehensive epidemiological data have been published.

RECENT FINDING

This literature review aims to provide an overview of bacterial infections affecting different types of SOT recipients, emphasizing underlying risk factors and pathophysiological mechanisms.

SUMMARY

Lung transplantation connects two microbiotas: one derived from the donor's lower respiratory tract with one from the recipient's upper respiratory tract. Similarly, liver transplantation involves a connection to the digestive tract and its microbiota through the bile ducts. For heart transplant recipients, specific factors are related to the management strategies for end-stage heart failure based with different circulatory support tools. Kidney and kidney-pancreas transplant recipients commonly experience asymptomatic bacteriuria, but recent studies have suggested the absence of benefice of routine treatment. Bloodstream infections (BSI) are frequent and affect all SOT recipients. Nonorgan-related risk factors as age, comorbidity index score, and leukopenia contribute to BSI development. Bacterial opportunistic infections have become rare in the presence of efficient prophylaxis. Understanding the epidemiology, risk factors, and pathophysiology of bacterial infections in SOT recipients is crucial for effective management and improved patient outcomes.

Outcomes of Bladder Washout for the Treatment of Recurrent Urinary Tract Infections After Renal Transplantation

Background Current literature suggests that anywhere from 2.9-27% of renal transplant recipients (RTR) will develop recurrent urinary tract infections (UTIs) (≥2 UTIs over six months or ≥3 UTIs over 12 months). Recurrent UTIs are of particular importance to RTR given its increased risk for allograft fibrosis and overall patient survival. Alternative solutions are needed for the management of recurrent UTIs, especially given the vulnerability of RTR to UTIs. We hypothesize that bladder washout (BW) reduces the incidence and recurrence of UTIs in RTR. Methods This is a retrospective study evaluating the utility of BW procedures on RTR diagnosed with recurrent UTIs between December 2013 and July 2021 at a single center. Results A total of 106 patients were included in the study with a total of 118 BW performed. 69% of patients were successfully treated with BW, meaning they no longer met the criteria for recurrent UTIs (<1 UTI) in the six-month post-BW period. The mean number of UTIs was 2.76 (range 2-7) before the BW and 1.16 (range 0-5) after the BW. On average, there were 1.60 fewer UTIs in the post-BW period compared to the pre-BW period (p<0.0001). There is no statistically significant difference in success rates stratified by bacterial class (p=1) or antimicrobial resistance class (p=0.6937). Conclusion BW decreased the incidence of UTIs in the six-month post-operative period as nearly 70% of patients did not have UTI recurrence. This data provides evidence that BW may have utility in transplant recipients with recurrent UTIs. We hope this will stimulate further prospective randomized studies in this area.

The global burden of antimicrobial resistance - urinary tract infections

Antimicrobial resistance (AMR) has emerged as a significant global healthcare problem. Antibiotic use has accelerated the physiologic process of AMR, particularly in Gram-negative pathogens. Urinary tract infections (UTIs) are predominantly of a Gram-negative nature. Uropathogens are evolutionarily highly adapted and selected strains with specific virulence factors, suggesting common mechanisms in how bacterial cells acquire virulence and AMR factors. The simultaneous increase in resistance and virulence is a complex and context-dependent phenomenon. Among known AMR mechanisms, the plenitude of different β-lactamases is especially prominent. The risk for AMR in UTIs varies in different patient populations. A history of antibiotic consumption and the physiology of urinary flow are major factors that shape AMR prevalence. The urinary tract is in close crosstalk with the microbiome of other compartments, including the gut and genital tracts. In addition, pharmacokinetic properties and the physiochemical composition of urinary compartments can contribute to the emergence of AMR. Alternatives to antibiotic treatment and a broader approach to address bacterial infections are needed. Among the various alternatives studied, antimicrobial peptides and bacteriophage treatment appear to be highly promising approaches. We herein summarize the present knowledge of clinical and microbiological AMR in UTIs and discuss innovative approaches, namely new risk prediction tools and the use of non-antibiotic approaches to defend against uropathogenic microbes.

Management of kidney transplant recipients for primary care practitioners

Patients with kidney transplants have a significant co-morbidity index, due to a high number of pre-existing conditions and use of immunosuppression medications. These patients are at higher risk of developing conditions such as hypertension, dyslipidemia, post-transplant diabetes, cardiovascular events, and anemia. Moreover, they are particularly susceptible to infections such as urinary tract infections or pyelonephritis, cancers, and gastrointestinal complications such as diarrhea, which in turn may be attributed to medication adverse effects or infectious causes. Along with these concerns, meticulous management of electrolytes and allograft function is essential. Prior to prescribing any new medications, it is imperative to exercise caution in identifying potential interactions with immunosuppression drugs. This review aims to equip primary care practitioners to address these complex issues and appropriate methods of delivering care to this rapidly growing highly susceptible group.

"Electronic Phenotyping" Antimicrobials to Facilitate Outpatient Stewardship for Asymptomatic Bacteriuria and Urinary Tract Infection in Renal Transplant

Asymptomatic bacteriuria and urinary tract infection in renal transplant are important antimicrobial stewardship targets but are difficult to identify within electronic medical records. We validated an "electronic phenotype" of antibacterials prescribed for these indications. This may be more useful than billing data in assessing antibiotic indication in this outpatient setting.

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.

Clinical Characteristics of Uncomplicated Acute Pyelonephritis Caused by Escherichia coli and Klebsiella pneumoniae

INTRODUCTION

This study compared the clinical characteristics and antimicrobial susceptibility of uncomplicated acute pyelonephritis (APN) caused by Escherichia coli and Klebsiella pneumoniae.

METHODS

We retrospectively reviewed the medical records of patients with uncomplicated APNs caused by E. coli and K. pneumoniae admitted to Keimyung University Dongsan Hospital between February 2014 and December 2021.

RESULTS

We enrolled 497 patients (372 with E. coli infection, 125 with K. pneumoniae infection). Male, healthcare-associated infection, solid tumors, liver cirrhosis, chronic renal disease, solid organ transplantation, and antibiotic usage within the last 3 months were more strongly associated with K. pneumoniae uncomplicated APNs than with E. coli. Bacteremia and fever occurred more frequently in E. coli uncomplicated APNs. Antimicrobial resistance rates to piperacillin/tazobactam and carbapenem were higher in K. pneumoniae. Antimicrobial resistance rates to aztreonam and ciprofloxacin were lower in K. pneumoniae. Thirty-day mortality was more observed in K. pneumoniae group in univariate analysis, but this difference was not observed after adjustment. Male sex, ultimately fatal disease in McCabe, and prior antibiotic use within 3 months were more associated with K. pneumoniae.

CONCLUSIONS

Male, underlying diseases, and prior antibiotic use was more associated with K. pneumoniae. Further study will be needed that microbiome of each situation and the related with the distribution of the strains.

The Burden and Impact of Early Post-transplant Multidrug-Resistant Organism Detection Among Renal Transplant Recipients, 2005-2021

Background

Reducing the burden of multidrug-resistant organism (MDRO) colonization and infection among renal transplant recipients (RTRs) may improve patient outcomes. We aimed to assess whether the detection of an MDRO or a comparable antibiotic-susceptible organism (CSO) during the early post-transplant (EPT) period was associated with graft loss and mortality among RTRs.

Methods

We conducted a retrospective cohort study of RTRs transplanted between 2005 and 2021. EPT positivity was defined as a positive bacterial culture within 30 days of transplant. The incidence and prevalence of EPT MDRO detection were calculated. The primary outcome was a composite of 1-year allograft loss or mortality following transplant. Multivariable Cox hazard regression, competing risk, propensity score-weighted sensitivity, and subgroup analyses were performed.

Results

Among 3507 RTRs, the prevalence of EPT MDRO detection was 1.3% (95% CI, 0.91%-1.69%) with an incidence rate per 1000 EPT-days at risk of 0.42 (95% CI, 0.31-0.57). Among RTRs who met survival analysis inclusion criteria (n = 3432), 91% (3138/3432) had no positive EPT cultures and were designated as negative controls, 8% (263/3432) had a CSO detected, and 1% (31/3432) had an MDRO detected in the EPT period. EPT MDRO detection was associated with the composite outcome (adjusted hazard ratio [aHR], 3.29; 95% CI, 1.21-8.92) and death-censored allograft loss (cause-specific aHR, 7.15; 95% CI, 0.92-55.5; subdistribution aHR, 7.15; 95% CI, 0.95-53.7). A similar trend was seen in the subgroup and sensitivity analyses.

Conclusions

MDRO detection during the EPT period was associated with allograft loss, suggesting the need for increased strategies to optimize prevention of MDRO colonization and infection.

Bring it on again: antimicrobial stewardship in transplant infectious diseases: updates and new challenges

Advancement in solid organ transplantation and hematopoietic stem cell transplant continues to improve the health outcomes of patients and widens the number of eligible patients who can benefit from the medical progress. Preserving the effectiveness of antimicrobials remains crucial, as otherwise transplant surgeries would be unsafe due to surgical site infections, and the risk of sepsis with neutropenia would preclude stem cell transplant. In this review, we provide updates on three previously discussed stewardship challenges: febrile neutropenia, Clostridioides difficile infection, and asymptomatic bacteriuria. We also offer insight into four new stewardship challenges: the applicability of the "shorter is better" paradigm shift to antimicrobial duration; antibiotic allergy delabeling and desensitization; colonization with multidrug-resistant gram-negative organisms; and management of cytomegalovirus infections. Specifically, data are accumulating for "shorter is better" and antibiotic allergy delabeling in transplant patients, following successes in the general population. Unique to transplant patients are the impact of multidrug-resistant organism colonization on clinical decision-making of antibiotic prophylaxis in transplant procedure and the need for antiviral stewardship in cytomegalovirus. We highlighted the expansion of antimicrobial stewardship interventions as potential solutions for these challenges, as well as gaps in knowledge and opportunities for further research.

Natural history and prognostic factors of candidemia in kidney transplant recipients: A retrospective, multinational study

BACKGROUND

The natural history of candidemia in kidney transplant recipients (KTR) remains poorly understood. This study aimed to evaluate mortality, prognostic factors and overall graft loss after candidemia in KTRs.

METHODS

This is a retrospective multicentre study enrolling all KTRs ≥15 years old with candidemia diagnosed at hospitals in Brazil, Spain and Italy from 2010 to 2020. Primary endpoints were mortality rates at 14 and 30 days. Secondary endpoints were prognostic factors of 14-day mortality and overall graft loss.

RESULTS

We enrolled 93 KTRs of which 75 were from Brazil. The mean time interval from transplantation to the onset of candidemia was 45.2 ± 61.5 months. 42% of all patients were on haemodialysis, 31.3% had an episode of sepsis and 39% underwent surgery within 30 days before fungemia. European patients were more likely to receive echinocandin (32 vs. 72%, p < .001). 22.7% of Brazilian patients did not receive any antifungal before death. All-cause mortality at 14 days was higher in Brazil (41.3 vs. 11.1%, p = .016). Candida colonisation (OR 6.91 [95% CI: 1.08-44.3], p = .042) and hypotension (OR 4.87 [95% CI: 1.62-14.66], p = .005) were associated with 14-day mortality. Echinocandin treatment had a protective effect (OR 0.19 [95% CI: 0.05-0.73], p = .015). Graft loss at 90 days occurred in 48% of patients (70.7 in Brazil vs. 22.2% in Europe, p < .01).

CONCLUSIONS

Candidemia in KTR is usually documented late after engraftment in patients requiring HD, surgical procedures and dysbiosis secondary to antibiotic use. Mortality was higher in Brazil. Echinocandin therapy was associated with improved survival.

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.

Antimicrobial Stewardship in Immunocompromised Patients: Current State and Future Opportunities

Immunocompromised (IC) patients are high risk for complications due to a high rate of antibiotic exposure. Antimicrobial stewardship interventions targeted to IC patients can be challenging due to limited data in this population and a high risk of severe infection-related outcomes. Here, the authors review immunocompromised antimicrobial stewardship barriers, metrics, and opportunities for antimicrobial use and testing optimization. Last, the authors highlight future steps in the field.

Outcomes of asymptomatic histologic pyelonephritis of kidney transplant

BACKGROUND

Urinary Tract Infections are the most common post-transplant infection and can have varied presentations. This study aimed to describe the outcomes of kidney transplant recipients with asymptomatic histologic pyelonephritis on allograft biopsy. Histologic Pyelonephritis was defined as neutrophil cast or neutrophilic tubulitis, interstitial infiltrates with predominant neutrophils, and no evidence of rejection or glomerulonephritis on biopsy.

METHODS

The study included 123 kidney transplant recipients, of whom 95 underwent protocol biopsies, and 28 had biopsies for elevated creatinine within the first 2 years of a kidney transplant.

RESULTS

The mean age of the cohort was 55.3 years, with 52% females and 78% deceased donor transplants. The risk factors for asymptomatic histologic pyelonephritis were recipient female sex (OR 1.89, 1.3-2.7, diabetes mellitus (OR 2.479, 1.687-3.645), and deceased donation (OR 1.69, 1.098-2.63). The incidence of asymptomatic pyelonephritis on protocol biopsy was 1.7%, with 52% having positive urine cultures and Escherichia coli being the most common bacteria. Subjects with asymptomatic pyelonephritis had inferior graft survival compared to the matched cohort HR 1.88 (1.06-3.35), p = .0281. In addition, of these 123 subjects, 68 (55%) subsequently developed pyelonephritis, and 34 subjects had pyelonephritis within 6 months after this episode. Subjects with recurrent infections exhibited lower survival HR 2.86 (1.36-6.02) and a trend toward higher rejection risk.

CONCLUSION

Asymptomatic histologic pyelonephritis can occur in kidney transplant recipients and is associated with inferior graft survival.

Treatment of Asymptomatic Bacteriuria after Kidney Transplantation: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background and Objectives: Asymptomatic bacteriuria (ASB) is prevalent in kidney transplant recipients (KTRs) and is hypothesized to heighten the risk of subsequent urinary tract infections (UTIs). Whether antibiotic treatment of ASB in KTRs is beneficial has not been elucidated. Materials and Methods: We carried out a systematic review and meta-analysis of all randomized controlled trials (RCTs) and quasi-RCTs that examined the merits of managing asymptomatic bacteriuria in KTRs. The primary outcomes were rates of symptomatic urinary tract infections (UTIs) and antimicrobial resistance. Results: Five studies encompassing 566 patients were included. No significant difference in symptomatic UTI rates was found between antibiotics and no treatment groups (relative risk (RR) 1.05, 95% confidence interval (CI) = 0.78-1.41), with moderate heterogeneity (I2 = 36%). Antibiotic treatment was found to present an uncertain risk for the development of drug-resistant strains (RR = 1.51, 95% CI = 0.95-2.40, I2 = 0%). In all trials, no significant difference between study arms was demonstrated regarding patient and graft outcomes, such as graft function, graft loss, hospitalization due to UTI, all-cause mortality, or acute rejection. Conclusions: The practice of screening and treating kidney transplant patients for asymptomatic bacteriuria does not curtail the incidence of future symptomatic UTIs, increase antimicrobial resistance, or affect graft outcomes. Whether early treatment of ASB after kidney transplantation (<2 months) is beneficial requires more RCTs.

Diagnosis, Prevention, and Treatment of Infections in Kidney Transplantation

Kidney transplant often is complicated by infections in the recipient from therapy-related and patient-related risk factors. Infections in kidney transplant recipients are associated with increased morbidity, mortality, and allograft dysfunction. There is a predictable timeline after kidney transplant regarding the types of pathogens causing infections, reflecting the net state of immunosuppression. In the early post-transplant period, bacterial infections comprise two thirds of all infections, followed by viral and fungal infections. Infections occurring early after kidney transplantation are generally the result of postoperative complications. In most cases, opportunistic infections occur within 6 months after kidney transplantation. They may be caused by a new infection, a donor-derived infection, or reactivation of a latent infection. Community-acquired pneumonia, upper respiratory tract infections, urinary tract infections, and gastrointestinal infections are the most common infections in the late period after transplantation when the net immunosuppression is minimal. It is crucial to seek information on the time after transplant, reflecting the net state of immunosuppression, previous history of exposure/infections, geography, and seasonal outbreaks. It is imperative that we develop regionally specific guidelines on screening, prevention, and management of infections after kidney transplantation.

Early versus late removal of urinary catheter after kidney transplantation

BACKGROUND

The optimal treatment for end-stage kidney disease is kidney transplantation. During the operation, a catheter is introduced into the bladder and remains in place postoperatively to allow the bladder to drain. This decreases tension from the cysto-ureteric anastomosis and promotes healing. Unfortunately, urinary catheters can pose an infection risk to patients as they allow bacteria into the bladder, potentially resulting in a urinary tract infection (UTI). The longer the catheter remains in place, the greater the risk of developing a UTI. There is no consensus approach to the time a catheter should remain in place post-transplant. Furthermore, the different timings of catheter removal are thought to be associated with different incidences of UTI and postoperative complications, such as anastomotic breakdown.

OBJECTIVES

This review aimed to compare patients who had their catheter removed < 5 days post-transplant surgery to those patients who had their catheter removed ≥ 5 days following their kidney transplant. Primary outcome measures between the two groups included: the incidence of symptomatic UTIs, the incidence of asymptomatic bacteriuria and the incidence of major urological complications requiring intervention and treatment.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 13 April 2023 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs) and quasi-RCTs comparing timing of catheter removal post-transplantation were eligible for inclusion. All donor types were included, and all recipients were included regardless of age, demographics or type of urinary catheter used.

DATA COLLECTION AND ANALYSIS

Results from the literature search were screened by two authors to identify if they met our inclusion criteria. We designated removal of a urinary catheter before five days (120 hours) as an 'early removal' and anything later than this as a 'late removal.' The studies were assessed for quality using the risk of bias tool. The primary outcome of interest was the incidence of asymptomatic bacteriuria. Statistical analyses were performed using the random effects model, and results were expressed as relative risk (RR) with 95% confidence intervals (CI). Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Two studies (197 patients) were included in our analysis. One study comprised a full-text article, and the other was a conference abstract with very limited information. The risk of bias in the included studies was generally either high or unclear. It is uncertain whether early versus late removal of the urinary catheter made any difference to the incidence of asymptomatic bacteriuria (RR 0.89, 95% Cl 0.17 to 4.57; participants = 197; I2 = 88%; very low certainty evidence). Data on other outcomes, such as the incidence of UTI and the incidence of major urological complications, were lacking. Furthermore, the follow-up of patients across the studies was short, with no patients being followed beyond one month.

AUTHORS' CONCLUSIONS

A high-quality, well-designed RCT is required to compare the effectiveness of early catheter removal versus late catheter removal in patients following a kidney transplant. At the present time, there is insufficient evidence to suggest any difference between early and late catheter removal post-transplant, and the studies investigating this were generally of poor quality.

Pathological Approach to Kidney Allograft Infection

Infectious agents can pose a significant challenge in kidney transplantation, as they have the potential to cause direct infections in the transplanted kidney. These infections can lead to a decline in kidney function and reduce the longevity of the transplanted kidney. Common post-transplant allograft infections include bacterial pyelonephritis and the BK virus infection, while adenovirus, JC virus, and cytomegalovirus are less frequent but can also lead to significant allograft dysfunctions. The histopathological features of these infections are characterized by the infiltration of inflammatory cells in the kidney interstitial area and the presence of viral nuclear inclusions or cytopathic changes in the renal tubular epithelial cells. The confirmation of causative organisms can be achieved by immunohistochemical staining or the visualization of viral particles using electron microscopic examination. However, these methods typically require a longer turnaround time and are not readily available in developing countries, unlike standard hematoxylin-eosin staining. Notably, the differential diagnosis of interstitial inflammation in kidney allografts almost always includes T cell-mediated rejection, which has a different treatment approach than allograft infections. The aim of this review was to prompt clinicians to identify diverse pathological alterations as observed in kidney allograft biopsies, thereby facilitating further investigations and the management of suspected kidney allograft infections.

Urinary Tract Infection 1 Year After Kidney Transplant: Effect on Kidney Transplant Outcomes

OBJECTIVES

Transplant is the gold standard treatment for end-stage renal disease, and yet infectious complications frequently arise in kidney recipients in the context of immunosuppression therapy, with urinary tract infection being the most common. We aimed to assess the prevalence of posttransplant urinary tract infections in kidney transplant recipients and assess the effects on kidney allograft and overall patient outcomes.

MATERIAL AND METHODS

We performed a retrospective analysis of data from State University of New York Upstate University Hospital from January 2016 to November 2022 to assess transplant outcomes in patients who underwent a kidney transplant at our center and met the inclusion criteria.

RESULTS

There were 507 renal allograft recipients who met our inclusion criteria and were assessed for the incidence of urinary tract infection within the first year after transplant. Urinary tract infection was recurrent in 113 transplant recipients (55.6%) within the first year, and 118 (58.1%) were on prophylactic antibiotics at urinary tract infection diagnosis. We observed no relation between recurrence of urinary tract infection and use of prophylactic antibiotics (P = .21). Overall allograft survival rate was 92.1% in the urinary tract infection group and 96.7% in the group without urinary tract infection, which was significantly different (P = .02). Urinary tract infection significantly affected allograft survival (hazard ratio, 3.51; 95% CI, 1.49-8.23; P = .004). Overall patient survival rates were 86.7% and 91.4% in the groups with and without urinary tract infection, respectively (P = .08).

CONCLUSIONS

We determined that allograft survival was significantly greater in the group without urinary tract infection versus the urinary tract infection group. We found no relation between urinary tract infection recurrence and prophylactic antibiotics. We also found that overall patient survival was not significantly different in the group with urinary tract infection versus the group without urinary tract infection.

Case Commentary: Unlocking the Potential of Bacteriophage to Prevent Recurrent Urinary Tract Infections after Kidney Transplantation

Recurrent urinary tract infections (UTIs) are common in kidney transplant recipients, and novel prevention approaches are needed. The case presented by Le et al. (Antimicrob Agents Chemother, in press) describes a patient with recurrent UTIs due to extended-spectrum β-lactamase-producing Klebsiella pneumoniae who was successfully treated with bacteriophage therapy. This commentary highlights the potential for bacteriophage therapy to prevent recurrent UTIs, as well as outstanding questions that require further investigation.

Successful eradication of renal allograft abscess by CT-guided percutaneous pigtail drainage: A case report

RATIONALE

Renal allograft abscess is an infrequent complication in kidney transplant recipients. The mainstay of treatment is adequate drainage and optimal antibiotic administration.

PATIENT CONCERNS

A 25-year-old female who presented with dysuria, frequency, chills, fever, and allograft pain was initially diagnosed with a urinary tract infection complicated by septic shock 15 months after kidney transplantation. Ultrasound depicted a hypoechoic mass and contrast-enhanced computed tomography (CT) revealed a lesion with no enhancement in the renal allograft. CT-guided percutaneous pigtail drainage placement was implemented.

DIAGNOSES

Blood-stained pus was aspirated from the lesion in the renal allograft. The aspirate culture revealed Escherichia coli and Proteus mirabilis with an antibiogram consistent to urine culture. The diagnosis of renal allograft abscess originated from urinary tract infection was confirmed.

INTERVENTIONS

The patient underwent CT-guided percutaneous pigtail drainage and conducted culture of the aspirate.

OUTCOMES

The patient's symptoms immediately abated after drainage and renal allograft function recovered normally. Ultrasound and CT showed total regression of the renal allograft abscess at the 1-month outpatient follow-up.

LESSONS

Heightened alertness should be attached to that severe urinary tract infections presenting with sepsis shock and antibiotic treatment non responders are likely to progress to renal allograft abscess in kidney transplant recipients. CT-guided percutaneous pigtail drainage was a safe and effective minimally invasive treatment.

Infections after organ transplantation and immune response

Organ transplantation has provided another chance of survival for end-stage organ failure patients. Yet, transplant rejection is still a main challenging factor. Immunosuppressive drugs have been used to avoid rejection and suppress the immune response against allografts. Thus, immunosuppressants increase the risk of infection in immunocompromised organ transplant recipients. The infection risk reflects the relationship between the nature and severity of immunosuppression and infectious diseases. Furthermore, immunosuppressants show an immunological impact on the genetics of innate and adaptive immune responses. This effect usually reactivates the post-transplant infection in the donor and recipient tissues since T-cell activation has a substantial role in allograft rejection. Meanwhile, different infections have been found to activate the T-cells into CD₄⁺ helper T-cell subset and CD₈⁺ cytotoxic T-lymphocyte that affect the infection and the allograft. Therefore, the best management and preventive strategies of immunosuppression, antimicrobial prophylaxis, and intensive medical care are required for successful organ transplantation. This review addresses the activation of immune responses against different infections in immunocompromised individuals after organ transplantation.

[Do we need to treat asymptomatic bacteriuria in immunocompromised patients? : A rapid review]

BACKGROUND

Antimicrobial resistance (AMR), especially multidrug resistant Escherichia coli strains, is a problem even in Europe. That is why inadequate usage of antibiotic therapy should be avoided, especially in the treatment of asymptomatic bacteriuria (ASB).

OBJECTIVES

Should ASB be treated with antibiotics in immunocompromized patients, namely solid organ transplant, especially kidney transplant or stem cell transplant recipients?

MATERIALS AND METHODS

A rapid review based on a systematic literature search in MEDLINE between 1980 and 2022 was performed. For evidence synthesis, only randomized controlled trials (RCTs) or quasi-RCTs were considered.

RESULTS

No studies were identified for the search term solid organ and stem cell transplantation. Three RCTs (antibiotic therapy versus no therapy) were included for adult kidney transplantation. None of the studies showed a benefit for antibiotic therapy of ASB in reduction of symptomatic urinary tract infections, especially in the late transplantation phase two months after kidney transplantation; furthermore, this therapy may promote AMR development. In addition, there are numerous gaps of evidence, e.g., in pediatric transplantation or regarding the influence of special immunosuppressants.

CONCLUSION

There is no evidence for antibiotic therapy of ASB in adult kidney transplantation two months after the surgery. Further studies addressing the identified evidence gaps are essential for the prevention of further AMR development.

Duration of antibiotic treatment for acute graft pyelonephritis: What's the standard of care?

BACKGROUND

Limited evidence is available to inform the duration of antibiotic treatment in kidney transplant recipients with bacterial acute graft pyelonephritis. Guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation suggest a 14-21 day duration.

METHODS

A four-question survey was constructed to determine the current standard of practice for the duration of treatment for acute graft pyelonephritis. The survey was distributed among members of the Infectious Diseases and the Kidney Pancreas Communities of Practice of the American Society of Transplantation.

RESULTS

Among 144 survey respondents, 87 (60%) were infectious disease physicians, and 36 (25%) were transplant nephrologists. Although most (55%) respondents preferred a 14-day duration, a spread between 7 and 28 days was observed. Goals of treatment and drivers for longer duration differed between infectious disease physicians and transplant nephrologists.

CONCLUSIONS

Although most respondents prefer a 14-day duration of treatment for acute graft pyelonephritis, a wide range of responses was seen between 7 and 28 days. More evidence is needed to inform optimal treatment duration in this common infectious complication after transplantation.

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.

Pediatric Infectious Diseases Related to Transplantation: Insights From Japan

Infectious diseases after transplantation account for significant morbidity and mortality in children undergoing transplantation; the importance of pediatric transplant infectious disease (TID) specialists has therefore been recognized. Although tremendous advancement continues in transplantation medicine, pediatric-specific data and evidence are limited. In Japan, the majority of TIDs had not been managed by infectious disease specialists because pediatric infectious diseases have not been recognized as a solo subspecialty until recently in Japan. However, in the last decade, there was a new movement for pediatric TID in Japan; some pediatric infectious disease specialists trained outside Japan have been playing an important role in managing pediatric TID in a few academic and pediatric institutions. In this review article, we introduce the current status of infectious complications related to pediatric hematopoietic cell and solid organ transplantation, highlighting currently available local evidence, common practice and issues in the field of pediatric TID in Japan.

Bacterial Urinary Tract Infection and Early Asymptomatic Bacteriuria in Kidney Transplantation Still Negatively Affect Kidney Transplant Outcomes in the Era of Modern Immunosuppression and Cotrimoxazole Prophylaxis

Risk factors and consequences of urinary tract infection (UTI) post-kidney transplant have been variously reported by studies that were heterogenous in immunosuppressants and prophylactic protocols. We aimed to clarify the risks and consequences of UTI in kidney transplant recipients with post-transplantation cotrimoxazole prophylaxis in the context of modern immunosuppression. This retrospective cohort included kidney transplant recipients receiving tacrolimus, mycophenolate, prednisolone, and cotrimoxazole for bacterial UTI prophylaxis. Recipients were categorized into non-UTI and UTI groups. Asymptomatic bacteriuria (ASB) was screened in the first 3 months and was evaluated for association with UTI. Of 348 kidney transplant recipients, 129 were in the UTI group and 219 in the non-UTI group. UTI risk factors were female sex, body mass index ≥ 25 kg/m², human leukocyte antigen mismatch, and panel reactive antibody ≥ 50%. Recipients with recurrent UTI had inferior allograft function compared with non-UTI recipients. Patient survival was significantly lower in recipients with UTI in the first post-transplant month. Higher degree of immunosuppressions was associated with recurrent UTI and drug-resistant organisms. In conclusion, UTI continues to negatively affect graft function and survival of kidney transplant recipients. Treating ASB in the first 3 months did not reduce the UTI incidence in the first transplantation year.

Diabetes Mellitus as a Predictive Factor for Urinary Tract Infection for Patients Treated with Kidney Transplantation

Background and Objectives: We aimed to investigate the rate of incidence and risk factors of post-transplant urinary tract infection (UTI) in patients receiving kidney transplantation (KT) at our institution. Materials and Methods: A retrospective cohort study was carried out on patients who underwent KT for end-stage kidney disease (ESKD) from January 2008 to December 2021 at Gifu University Hospital. UTI was defined as the existence of bacterial and/or fungal infection in urine with ≥105 colony-forming units/mL, with or without urinary and/or systemic symptoms of UTI. Patients were divided into two groups: those with UTI after KT (UTI group) and those without UTI (non-UTI group). The primary endpoint of this study was the relationship between covariates and UTI after KT. Results: Two hundred and forty patients with ESKD received KT at Gifu University Hospital. Thirty-four participants developed UTI after surgery, and the most common pathogen was Escherichia coli. At the end of the follow-up, graft loss was observed in six patients (2.5%), independent of UTI episodes. In the multivariate analysis, diabetes mellitus (DM) was statistically associated with post-transplant UTI in kidney transplant recipients. Conclusions: Preoperative serum glucose control in patients with DM may have a crucial role in preventing UTI and preserving renal function after KT.

Beta-lactam allergies, surgical site infections, and prophylaxis in solid organ transplant recipients at a single center: A retrospective cohort study

BACKGROUND

Beta-lactam allergies (BLAs) are common in hospitalized patients, including transplant recipients. BLA is associated with decreased use of preferred surgical site infection (SSI) prophylaxis and increased SSIs, but this has not been studied in the transplant population.

METHODS

We reviewed adult heart, kidney, and liver transplant recipients between January 1, 2016 and December 31, 2019 to characterize reported BLA and collect SSI prophylaxis regimens at time of transplant. We compared the use of preferred SSI prophylaxis and SSI incidence based on reported BLA status. Post hoc we collected antibiotic days of therapy (DOT) (excluding pneumocystis prophylaxis) in the 30-day period posttransplant for patients without SSI. We utilized descriptive statistics for comparisons.

RESULTS

Of 691 patients included (116 heart, 400 kidney, and 175 liver transplant recipients), 118 (17%) reported BLA. Rash and hives were the two most reported BLA reactions (36% and 24%), categorized as potential T-cell mediated and IgE mediated, respectively. Preferred SSI prophylaxis was prescribed in 13 (11%) patients with BLA and 573 (92%) without BLA (p < .001). No difference could be detected in SSI incidence between BLA and non-BLA patients (4.2 vs. 4.3%, p = 1.0). Of 659 without SSI, 169 (25.6%) received antibiotics within 30 days of transplant; mean antibiotic DOT for BLA and non-BLA patients were 3.5 ± 8.0 versus 2.3 ± 5.8, p = .12.

CONCLUSION

BLA transplant recipients received nonpreferred SSI prophylaxis more frequently than non-BLA recipients, but there was no difference in 30-day SSIs between the groups. One-fourth of solid organ transplant recipients received systemic antibiotics within 30 days of transplant.

Outpatient and peri-operative antibiotic stewardship in solid organ transplantation

BACKGROUND

The consequences of inappropriate antimicrobial use including resistance are increasingly recognized as a global public health threat and many steps have been taken over the last few decades to advance antimicrobial stewardship initiatives with most organ transplant centers currently part of institutions with active antimicrobial stewardship programs.

METHODS

A review of the literature was conducted and articles were categorized according to the topic and relevance in the judgment of the two authors.

RESULTS

A summary review of the currently available literature was created with a focus on periprocedural and outpatient antimicrobial stewardship. Limitations in the data were significant and discussed in the review.

CONCLUSION

The principles of antimicrobial stewardship remain important throughout all phases starting with periprocedural prophylactic antimicrobial selection all the way through to discharge and subsequent healthcare encounters. Despite the broad advances in stewardship initiatives and the rapidly progressing supportive data overall there continue to be significant opportunities for additional research within various special patient populations including recipients of solid organ transplantation (SOT). The recent white paper published in the American Journal of Transplantation called to action the transplant and stewardship communities to have an increased focus and awareness of the issues that antimicrobial overuse can present in the SOT patient population. This is an important step that will hopefully generate more data in this group of patients that arguably faces the greatest vulnerability to the consequences of increased antimicrobial resistance.

Shorter durations of antibiotic therapy in organ transplant

PURPOSE OF REVIEW

Recent evidence supports shorter courses of antibiotics for several common infections and prophylactic indications. Unfortunately, solid organ transplant patients are often underrepresented or excluded from these studies. As a result, prolonged antibiotic durations are often used in clinical practice despite a lack of demonstrable benefit. This paper reviews recent publications addressing antibiotic duration of therapy in SOT recipients.

RECENT FINDINGS

Although largely limited to observational studies, longer courses of antibiotics for surgical prophylaxis, urinary tract infections, and bloodstream infections have not demonstrated benefit compared to shorter courses. In some instances, longer courses of therapy have been associated with harm (i.e., adverse drug events and development of resistance).

SUMMARY

Although the data remains limited, findings from retrospective studies evaluating shorter courses of antibiotics in SOT patients is encouraging. More robust research is desperately needed to define the optimal duration of antibiotics for common infections in SOT patients.

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

Asymptomatic bacteriuria is a common clinical condition that often leads to unnecessary treatment. It has been shown that incidence of asymptomatic bacteriuria increases with age and are more prominent in women than men. In older women, the incidence of asymptomatic bacteriuria is recorded to be more than 15%. This number increased up to 50% for those who reside in long-term care facilities. In most scenarios, asymptomatic bacteriuria does not lead to urinary tract infections, and therefore, antibiotic treatment of asymptomatic bacteriuria has not been shown to improve patient outcomes. In 2019, the Infectious Disease Society of America (IDSA) updated its asymptomatic bacteriuria management guidelines, which emphasized on the risks and benefits of treating the condition. Women who are pregnant should be screened for asymptomatic bacteriuria in the first trimester and treated, if positive. Individuals who are undergoing endoscopic urologic procedures should be screened and treated appropriately for asymptomatic bacteriuria as well. Treating asymptomatic bacteriuria in individuals with diabetes, neutropenia, spinal cord injuries, indwelling urinary catheters, and so on has not been found to improve clinical outcomes. Furthermore, unnecessary treatment is often associated with unwanted consequences including but not limited to increased antimicrobial resistance, Clostridioides difficile infection, and increased health care cost. As a result, multiple antibiotic stewardship programs around the US have implemented protocols to appropriately reduce unnecessary treatment of asymptomatic bacteriuria. It is important to appropriately screen and treat asymptomatic bacteriuria only when there is evidence of potential benefit.

Impact of Carbapenem Peri-Transplant Prophylaxis and Risk of Extended-Spectrum Cephalosporin-Resistant Enterobacterales Early Urinary Tract Infection in Kidney Transplant Recipients: A Propensity Score-Matched Analysis

Background

Urinary tract infection (UTI) is the most common bacterial infection after kidney transplantation (KT), leading to unfavorable clinical and allograft outcomes. Gram-negative uropathogenic bacteria are frequently encountered especially extended-spectrum cephalosporin-resistant (ESC-R) Enterobacterales (EB), causing UTI early after KT.

Methods

A retrospective single transplant study was conducted between January 2016 and December 2019. We performed 1:1 nearest-neighbor propensity score matching without replacement using recipient age, recipient sex, induction, transplant year, human leukocyte antigen, cold ischemia time, and panel-reactive antibody before analyses. Cumulative incidence of ESC-R EB early (within 14 days after KT) UTI was estimated by the Kaplan–Meier method. Risk factors for ESC-R EB early UTI were analyzed by a Cox proportional hazards model. Variables measured after transplantation were considered time-dependent covariates.

Results

We included 620 KT recipients (37% women; mean age ± SD, 43 ± 11 years). Overall, 64% and 76% received deceased-donor allograft and induction therapy. Sixty-five (10%) and 555 (90%) received carbapenems and cefuroxime peri-transplant prophylaxis, respectively. Early UTI occurred in 183 (30%) patients, 52% caused by ESC-R EB. Propensity score matching produced 65 well-balanced pairs. During a 14-day follow-up, the cumulative incidence of ESC-R EB early UTI was 5 and 28% in the carbapenems and cefuroxime groups, respectively (log-rank test = 0.003). Peri-transplant carbapenems prophylaxis was a protective factor against ESC-R EB after KT (hazard ratio, 0.19; 95% confidence interval, 0.05–0.64; p = 0.008). Clinical and allograft outcomes did not differ significantly between the groups.

Conclusions

In the setting where ESC-R EB UTI is common among KT recipients, carbapenems peri-transplant prophylaxis could protect against the occurrence of early ESC-R EB UTI after KT. Further prospective studies should focus on this specific infection prevention strategy.

Contemporary risk factors for ureteral stricture following renal transplantation

INTRODUCTION

Allograft ureteral strictures after renal transplantation impact graft function and increase patient morbidity. They can be challenging to treat and may require complex surgical repair. Therefore, the objective of this study was to identify contemporary risk factors for the development of post-renal transplant ureteral strictures.

METHODS

A retrospective analysis was performed on all renal transplant patients at Vancouver General Hospital from 2008-2019. Demographics, clinical parameters, and outcomes were compared between patients who did and did not develop ureteral strictures. Putative risk factors for ureteral stricture were analyzed using logistic regression.

RESULTS

A total of 1167 patients were included with a mean followup of 61.9±40.8 months. Ureteral strictures occurred in 25 patients (2.1%). Stricture patients had no demographic differences compared to non-stricture patients but had significantly higher rates of postoperative complications, longer hospital stays, and decreased renal function one year post-transplant (all p<0.05). On multivariable analysis, cold ischemia time >435 minutes (odds ratio [OR] 43.9, confidence interval [CI] 1.6-1238.8, p=0.027), acute rejection (OR 3.0, CI 1.1-7.4, p=0.027), and postoperative complications (OR 112.4, CI 2.4-5332.6, p=0.016) were risk factors for stricture.

CONCLUSIONS

Renal transplant patients with ureteral stricture experience greater morbidity and reduced post-transplant renal function compared to non-stricture patients. Our findings support attempts to reduce cold ischemia time, acute rejection, and postoperative complications to mitigate this potential complication. Our study is limited by the low incidence of ureteral stricture resulting in a small sample of stricture patients. Future research in a larger, multicenter setting is warranted.

Sodium-glucose cotransporter 2 inhibitors for treatment of diabetes mellitus after kidney transplantation

INTRODUCTION

Diabetes mellitus in kidney transplant recipients is a risk factor for cardiovascular events and premature death. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are increasingly used in nontransplant populations to improve diabetes control and cardiovascular and renal benefits. Limited literature exists regarding the safety and efficacy of these agents in renal transplant recipients.

METHODS

We retrospectively reviewed all kidney transplant recipients within our health system who were prescribed a SGLT2i after transplantation for diabetes. The safety, tolerability, and effectiveness of SGLT2i were analyzed.

RESULTS

Thirty-nine kidney transplant recipients were initiated on SGLT2i therapy, twenty-seven of which remained on therapy for at least 1 year. Ten (25%) patients experienced an adverse event while on a SGLT2i, with urinary tract infections (UTI) being the most common. Seventeen patients (43%) discontinued the SGLT2i at the time of chart review, most commonly due to cost and kidney function decline. The median [IQR] hemoglobin A1c (HbA1c) at SGLT2i initiation of 8.4% [7.8-9.2] decreased to 7.5% [6.8-8.0%] after 3 months and 7.5% [6.5-7.9] after 12 months. No meaningful change in kidney function or tacrolimus exposure was observed.

CONCLUSION

SGLT2i may be a safe and effective treatment for diabetes in kidney transplant recipients. Cost is a barrier to SGLT2i therapy, and UTIs were the most frequently encountered adverse events in this cohort. More studies are needed to understand the safety profile and determine the effect of SGLT2i on diabetes-related comorbidities among kidney transplant recipients.

Incidences of infectious events in a renal transplant cohort of the German Center of Infectious Diseases (DZIF)

Background

Infectious complications are a major cause of morbidity and mortality after kidney transplantation.

Methods

In this transplant cohort study at the German Center of Infectious Diseases (DZIF), we evaluated all infections occurring during the first year after renal transplantation. We assessed microbial etiology, incidence rates, and temporal occurrence of these infections.

Results

Of 804 renal transplant recipients (65.2% male, 51 ± 14 years), 439 (54.6%) had 972 infections within the first year after transplantation. Almost half of these infections (47.8%) occurred within the first three months. Bacteria were responsible for 66.4% (645/972) of all infections, followed by viral (28.9%[281/972]) and fungal (4.7%[46/972]) pathogens. The urinary tract was the most common site of infection (42.4%). Enterococcus was most frequently isolated bacteria (20.9%), followed by E.coli (17.6%) and Klebsiella (12.5%). E.coli was the leading pathogen in recipients &lt;50 years of age, whereas Enterococcus predominated in older recipients. Resistant bacteria were responsible for at least one infection in 9.5% (76/804) of all recipients. Viral infections occurred in 201 recipients (25.0%). Of these, herpes viruses predominated (140/281[49.8%]) and cytomegalovirus had the highest incidence rate (12.3%). In the 46 fungal infections, Candida albicans (40.8%) was most commonly isolated. Other fungal opportunistic pathogens, including Aspergillus fumigatus and Pneumocystis, were rare.

Conclusions

Renal allograft recipients in Germany experience a high burden of infectious complications in the first year after transplantation. Bacteria were the predominating pathogen, followed by opportunistic infections such as cytomegalovirus. Microbial etiology varied between age groups and resistant bacteria were identified in 10% of recipients.

Retrospective Analysis of the Risk Factors of Perioperative Bacterial Infection and Correlation with Clinical Prognosis in Kidney Transplant Recipients

Background

Infection remains a leading cause of morbidity and mortality in kidney transplant patients. This study aimed to investigate the risk factors of bacterial infection during the perioperative period of transplantation and the effects of infection on long-term clinical outcomes.

Methods

In total, 295 kidney transplantation recipients were included in this retrospective study and assigned to two groups: non-infected and infected. The tacrolimus concentration, pharmacogenomics, laboratory parameters, and clinical outcomes of both groups were evaluated.

Results

A relatively low incidence of urinary tract infection was observed in our cohort, and lung was identified as the most frequent site of infection. Gram-negative bacteria, such as Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae, were the most common infecting strains in kidney transplant recipients. Patients with diabetes showed greater susceptibility to infection. Compared with the non-infected group, tacrolimus concentration was significantly lower on day 7 and 14 in the infected group. White blood cell count, neutrophil count, and C-reactive protein (CRP) in the infected group were markedly higher post-transplantation, while albumin levels were lower relative to the non-infected group. ABCB1 (rs2032582) genotype showed clear associations with infection. Furthermore, the incidence of delayed graft function (DGF) and early acute rejection (AR) before infection was significantly greater in the infected group. Finally, early post-transplant infection was associated with a marked increase in the incidence of AR, post-transplant diabetes mellitus (PTDM), and secondary infection.

Conclusion

Pre-diabetes, longer duration of catheterization, lower albumin, higher CRP, tacrolimus concentration on the day 7 and 14, early AR before infection, and DGF were closely related to postoperative infection in kidney transplantation recipients. Moreover, bacterial infection during the perioperative period was closely associated with AR, PTDM and secondary infection.

Bring it on: Top five antimicrobial stewardship challenges in transplant infectious diseases and practical strategies to address them

Antimicrobial therapies are essential tools for transplant recipients who are at high risk for infectious complications. However, judicious use of antimicrobials is critical to preventing the development of antimicrobial resistance. Treatment of multidrug-resistant organisms is challenging and potentially leads to therapies with higher toxicities, intravenous access, and intensive drug monitoring for interactions. Antimicrobial stewardship programs are crucial in the prevention of antimicrobial resistance, though balancing these strategies with the need for early and frequent antibiotic therapy in these immunocompromised patients can be challenging. In this review, we summarize 5 frequently encountered transplant infectious disease stewardship challenges, and we suggest strategies to improve practices for each clinical syndrome. These 5 challenging areas are: asymptomatic bacteriuria in kidney transplant recipients, febrile neutropenia in hematopoietic stem cell transplantation, antifungal prophylaxis in liver and lung transplantation, treatment of left-ventricular assist device infections, and Clostridioides difficile infection in solid-organ and hematopoietic stem-cell transplant recipients. Common themes contributing to these challenges include limited data specific to transplant patients, shortcomings in diagnostic testing, and uncertainties in pharmacotherapy.

Urinary Tract Infections Caused by K. pneumoniae in Kidney Transplant Recipients – Epidemiology, Virulence and Antibiotic Resistance

Urinary tract infections are the most common complication in kidney transplant recipients, possibly resulting in the deterioration of a long-term kidney allograft function and an increased risk of recipient’s death. K. pneumoniae has emerged as one of the most prevalent etiologic agents in the context of recurrent urinary tract infections, especially with multidrug resistant strains. This paper discusses the epidemiology and risk factors associated with urinary tract infections in kidney transplant recipients, multi-drug resistance of K. pneumoniae (ESBL, KPC, NDM), treatment and pathogenesis of K. pneumoniae infections, and possible causes of recurrent UTIs. It also addresses the issue of colonization/becoming a carrier of K. pneumoniae in the gastrointestinal tract and asymptomatic bacteriuria in relation to a symptomatic UTI development and epidemiology.