Recurrence of urinary tract infections and development of urinary-specific antibiogram for kidney transplant recipients

Association between phenotypic characteristics of Escherichia coli and UTI recurrence in immunocompromised patients: A case-control study

BACKGROUND

Urinary tract infection (UTI) recurrence is important in immunocompromised patients. There is a trend to study genotypically and phenotypically the role of certain virulence factors of Escherichia coli in the diagnosis of recurrent UTI. The main objective of this study was to determine if there is an association between phenotypic characteristics of E coli and UTI recurrence in immunocompromised patients.

METHODS

A case-control study was performed on immunocompromised patients from Hospital Regional de Alta Especialidad del Bajío, Mexico. E coli strains isolated from these patients were identificated and antimicrobial susceptibility test were performed. Strains with filamented cell morphology, mucoid colonial phenotype, or biofilm production were considered cases. Strains without the characteristics were considered controls. UTI recurrence was identified based on clinical records. The odds ratio (OR) was calculated to quantify the magnitude of the association.

RESULTS

An association between filamented cell morphology and UTI recurrence was found (OR = 2.19 95% CI 1.06-4.51; P = .031). No association was found between mucoid colony morphology (P>.05) or biofilm production (P>.05) and UTI recurrence. An association between mucoid colony morphology and extended-spectrum β-lactamase production was found (OR = 3.09 95% 1.59-5.99; P<.001).

CONCLUSIONS

Filamented cell morphology and mucoid colonial phenotype may have a possible diagnostic value for the detection of UTI recurrence and antimicrobial resistance. Further diagnostic test studies are needed to fully assess their clinical utility.

Therapeutic Potential of Intravenous Phage as Standalone Therapy for Recurrent Drug-Resistant Urinary Tract Infections

Recurrent urinary tract infections (rUTI) are common in kidney transplant recipients (KTR) and are associated with multidrug resistance and increased morbidity/mortality. Novel antibiotic alternatives to reduce UTI recurrence are critically needed. We describe a case of rUTI due to extended spectrum beta lactamase (ESBL) Klebsiella pneumoniae in a KTR that was treated successfully with 4 weeks of adjunctive intravenous bacteriophage therapy alone, without concomitant antibiotics, and with no recurrence in a year of follow-up.

Antimicrobial stewardship in solid organ transplant recipients: Current challenges and proposed metrics

BACKGROUND

Solid organ transplant (SOT) recipients are challenging populations for antimicrobial stewardship interventions due to a variety of reasons, including immunosuppression, consequent risk of opportunistic and donor-derived infections, high rates of infection with multi-drug resistant organisms (MDROs), Clostridioides difficile, and need for prolonged antimicrobial prophylaxis. Despite this, data on stewardship interventions and metrics that address the distinct needs of these patients are limited.

METHODS

We performed a narrative review of the current state of antimicrobial stewardship in SOT recipients, existing interventions and metrics in this population, and considerations for implementation of transplant-specific stewardship programs.

RESULTS

Antimicrobial stewardship metrics are evolving even in the general patient population. Data on metrics applicable to the SOT population are even more limited. Standard process, outcomes, and balancing metrics may not always apply to the SOT population. A successful stewardship program for SOT recipients requires reviewing existing data, applying general stewardship principles, and understanding the nuances of SOT patients.

CONCLUSION

As antimicrobial stewardship interventions are being implemented in SOT recipients; new metrics are needed to assess their impact. In conclusion, SOT patients present a challenging but important opportunity for antimicrobial stewards.

ABBREVIATIONS

SOT, antimicrobial stewardship program, MDRO, Clostridioides difficile infection, Centers for Disease Control and Prevention, Infectious Diseases Society of America, prospective audit and feedback, hematopoietic cell transplant, cytomegalovirus, trimethoprim-sulfamethoxazole, surgical site infections, nucleic acid amplification testing, days of therapy, defined daily dose, and length of stay.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

The time is now: antimicrobial stewardship in solid organ transplantation

PURPOSE OF REVIEW

To provide a summary of complications of antimicrobials and opportunities for antimicrobial stewardship (AS) in solid organ transplant (SOT) patient care.

RECENT FINDINGS

Personalized, precision antimicrobial prescribing in SOT aiming to avoid negative consequences of antimicrobials is essential to improving patient outcomes. The positive impact AS efforts in transplant care has been recognized and bespoke activities tailored to special interests of transplant patients and providers are evolving. Strategies to optimize stewardship interventions targeting antibacterial, antiviral, and antifungal drug selection and dosing in the transplant population have been recently published though clinical integration using a 'handshake' stewardship model is an optimal starting point in transplant care. Other recent studies involving transplant recipients have identified opportunities to shorten duration or avoid antimicrobials for certain commonly encountered clinical syndromes. This literature, informing recent consensus clinical practice guidelines, may help support institutional practice guidelines and protocols. Proposals to track and report stewardship process and outcome measures as a routine facet of programmatic transplant quality reporting have been published. However, developing novel metrics accounting for nuances of transplant patients and programs is critical. Important studies are needed to evaluate organizational transplant prescribing cultures and optimal behavioral science-based interventions relevant to antimicrobial use in this population.

SUMMARY

Consequences of antimicrobial use, such as drug toxicities, and Clostridiodes difficile (CDI) and multidrug-resistant organisms colonization and infection disproportionately affect SOT recipients and are associated with poor allograft and patient outcomes. Stewardship programs encompassing transplant patients aim to personalize antimicrobial prescribing and optimize outcomes. Further studies are needed to better understand optimal intervention strategies in SOT.

Solid organ transplant-specific antibiogram in a tertiary pediatric hospital in Canada

SOT recipients are more vulnerable to infections with antimicrobial-resistant organisms, and therefore, it may be useful for transplant centers to create transplant-specific antibiograms to direct empirical antimicrobial regimens and monitor trends in antimicrobial resistance. SOT-specific antibiograms were created using antimicrobial susceptibility data on isolates from 2012 to 2018 at The Hospital for Sick Children, Toronto, Ontario, Canada. The CLSI guidelines were followed to generate the antibiograms except that results from 2 years of data were pooled on a rolling basis to achieve larger sample sizes. The 3 most frequent organisms in one analysis period of the SOT antibiogram were Escherichia coli (average sample size ±standard deviation; n = 28.7 ± 3.8), Staphylococcus aureus (n = 27.8 ± 5.0), and Pseudomonas aeruginosa (non-CF) (n = 19.8 ± 8.8). For E.coli, susceptibilities in the SOT antibiogram were significantly lower than those in the hospital-wide antibiogram in 2017-2018 for ampicillin (27% vs 47%; p = .014), piperacillin/tazobactam (55% vs 88%; p < .001), cefotaxime (59% vs 89%; p < .001), ciprofloxacin (71% vs 88%; p = .007), and trimethoprim-sulfamethoxazole (41% vs 69%; p = .001), but not significantly different for aminoglycosides and meropenem. In the SOT antibiogram of E. coli, decreased susceptibility trend was confirmed in some antibiotics, including piperacillin/tazobactam (83% in 2012-2013 vs 55% in 2017-2018). At our center, the solid organ transplant-specific antibiogram revealed important differences in E. coli susceptibilities and trends in antimicrobial resistance. Developing a SOT antibiogram will assist in revising and improving empiric treatment guidelines as well as monitoring antimicrobial resistance in this population.

Institutional protocol adherence in the incidence of recurrent urinary tract infection after kidney transplantation

OBJECTIVES

Recurrent urinary tract infections (rUTIs) occur frequently after kidney transplantation (KT), however their optimal management remains undefined. This study aimed to identify risk factors for rUTI and to validate a protocol for UTI and rUTI treatment after KT.

METHODS

This retrospective cohort study involved patients undergoing KT between January 2013 and July 2016. Patients were followed-up from day of KT until graft loss, death or end of follow-up (31 December 2018). We analysed all episodes of symptomatic UTI. The main outcome measure was rUTI after KT. Analysis was done per episode in a multilevel approach; patient features were considered in the distal level and UTI features in the proximal level. Univariate and multivariate analyses were performed by Cox regression. A propensity score was used to adjust the risk of patients with carbapenem-resistant Enterobacteriaceae.

RESULTS

During the study period, 787 patients underwent KT, of whom 152 (19.3%) developed 356 UTI episodes. The most common micro-organisms wereEscherichia coli (165/356; 46.3%) and Klebsiella pneumoniae (101/356; 28.4%). Multidrug-resistant micro-organisms were isolated in 161 UTIs (45.2%). Risk factors for rUTI were diabetic nephropathy as the cause of end-stage renal disease (P = 0.02), UTI in first 180 days after KT (P = 0.04), anatomic alteration of the urinary tract at UTI diagnosis (P = 0.004) and length of time to effective therapy (P = 0.002); UTI treatment duration according to institutional protocol (P = 0.04) was the only protective factor identified.

CONCLUSION

Appropriate therapy duration has an impact on rUTI prevention after KT.

Antimicrobial stewardship in transplant patients

PURPOSE OF REVIEW

To provide an update on the current landscape of antimicrobial stewardship in solid organ transplant (SOT) recipients.

RECENT FINDINGS

Constructing personalized antimicrobial prescribing approaches to avoid untoward consequences of antimicrobials while improving outcomes is an emerging and critical aspect of transplant medicine. Stewardship activities encompassing the specialized interests of transplant patients and programs are evolving. New literature evaluating strategies to optimize antimicrobial agent selection, dosing, and duration have been published. Additionally, consensus guidance for certain infectious clinical syndromes is available and should inform institutional clinical practice guidelines. Novel metrics for stewardship-related outcomes in transplantation are desperately needed. Though exciting new molecular diagnostic technologies will likely be pivotal in the care of immunocompromised patients, optimal clinical adaptation and appropriate integration remains unclear. Important studies understanding the behaviors influencing antimicrobial prescribing in organizational transplant cultures are needed to optimize interventions.

SUMMARY

Consequences of antimicrobial use, such as Clostridiodes difficile and infections with multidrug-resistant organisms disproportionately affect SOT recipients and are associated with poor allograft and patient outcomes. Application of ASP interventions tailored to SOT recipients is recommended though further studies are needed to provide guidance for best practice.

Phenotypic and Genotypic Characterization of Escherichia coli Causing Urinary Tract Infections in Kidney-Transplanted Patients

Urinary tract infection (UTI), frequently caused by uropathogenic Escherichia coli (UPEC), is the most common infection after kidney transplantation (KTx). Untreated, it can lead to urosepsis and impairment of the graft function. We questioned whether the UPEC isolated from KTx patients differed from the UPEC of non-KTx patients. Therefore, we determined the genome sequences of 182 UPEC isolates from KTx and control patients in a large German university clinic and pheno- and genotypically compared these two isolated groups. Resistance to the β-lactams, trimethoprim or trimethoprim/sulfamethoxazole was significantly higher among UPEC from KTx than from control patients, whereas both the isolated groups were highly susceptible to fosfomycin. Accordingly, the gene content conferring resistance to β-lactams or trimethoprim, but also to aminoglycosides, was significantly higher in KTx than in control UPEC isolates. E. coli isolates from KTx patients more frequently presented with uncommon UPEC phylogroups expressing higher numbers of plasmid replicons, but interestingly, less UPEC virulence-associated genes than the control group. We conclude that there is no defining subset of virulence traits for UPEC from KTx patients. The clinical history and immunocompromised status of KTx patients enables E. coli strains with low uropathogenic potential, but with increased antibiotic resistance to cause UTIs.

Strategies for Antimicrobial Stewardship in Solid Organ Transplant Recipients

Complications of antimicrobial therapy, such as multidrug-resistant organisms and Clostridium difficile, commonly affect solid-organ transplant recipients and have been associated with graft loss and mortality. Although opportunities are abundant, antimicrobial stewardship practices guiding appropriate therapy have been infrequently reported in transplant patients. A patient-centered, multidisciplinary structure, using established antimicrobial optimization principles, is needed to create nuanced approaches to protect patients and antimicrobials and improve outcomes.

Impact of Urinary Tract Infections in Kidney Transplant Recipients: A 4-Year Single-Center Experience

BACKGROUND

Urinary tract infection (UTI) is the most frequent bacterial infection in kidney transplant recipients (KTRs), yet little is known about the impact of severe UTIs. We aimed to explore the burden of severe UTIs post renal transplant on both graft function and health care resources.

METHODS

We conducted a retrospective review of KTRs with severe UTI warranting hospital admission at our center between January 1, 2012, and December 31, 2015.

RESULTS

We identified 198 UTI-related hospital admissions in 83 KTRs representing 7.4% of transplant admissions; 44.6% were men and 45 (54.2%) had recurrent admissions. The most commonly isolated pathogens were E coli (47.5%) and Klebsiella (16.2%): extended-spectrum β-lactamase-producing organisms were detected in 31.3% of Klebsiella and in 25.5% of E coli. During UTI, the median serum creatinine increased from 126 to 196.5 μmol/L, then decreased to 149 and 161 μmol/L 3 months and 1 year after UTI, respectively. Acute kidney injury complicated 40.9% of UTIs (23.7% stage 1, 12.1% stage 2, 5.1% stage 3), with no significant difference between single and recurrent admission groups (χ² = 0.36, P = .5). The 1-year mortality and death-censored graft loss were 1.2% and 3.6%, respectively. The median length of hospital stay was 4 days (286 days per annum) and the estimated annual cost was £87,665 ($117,347).

CONCLUSIONS

UTI post renal transplant represents a substantial burden on health care resources and patient morbidity in terms of acute kidney injury and deterioration in graft function. Thus, applying proper preventative and management strategies is paramount.

Managing recurrent urinary tract infections in kidney transplant patients

INTRODUCTION

Recurrent urinary tract infections (UTI) are a common clinical problem in kidney transplant recipients. Due to the complex urological anatomy derived from the implantation of the kidney graft, the spectrum of the disease and the broad underlying pathophysiological mechanisms. Recurrent UTI worsen the quality of life, decrease the graft survival and increase the costs of kidney transplantation. Areas covered: In this review, we describe the definitions, clinical characteristics, pathophysiological mechanisms and microbiology of recurrent urinary tract infections in kidney transplantations. The actual published literature on the management of recurrent urinary tract infections is based on case series, observational cohorts and very few clinical trials. In this review, the available evidence is compiled to propose evidence-based strategies to manage these complex cases. Expert commentary: The management of recurrent urinary tract infections in kidney transplant patients requires a proper diagnosis of the underlying mechanism. Early identification of structural or functional urological abnormalities, potentially amenable for surgical correction, is crucial for a successful management. The use of antibiotics to prevent recurrent infections should be carefully evaluated to avoid side effects and emergence of antibiotic-resistant microorganisms.