Urinary tract infections following renal transplantation: a single-center experience

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.

Prevalence and Predictive Factors of Urinary Tract Infection in Kidney Transplant Recipients: A 10-Year Study

OBJECTIVES

Urinary tract infections are the main infectious complications among kidney transplant recipients and are considered as a potential risk factor for poor graft outcomes. However, the risk factors of urinary tract infections are controversial. The purpose of our study was to estimate the incidence and predisposing factors of urinary tract infections in patients undergoing kidney transplant in our teaching hospital of Sahloul, Tunisia.

MATERIALS AND METHODS

We retrospectively analyzed the charts of 141 consecutive adult kidney transplants that were performed at the Department of Nephrology, University Hospital of Sahloul, Tunisia, between January 2007 and April 2016.

RESULTS

Of 141 patients, 72 (51.1%) had urinary tract infections after kidney transplant. Mean age was 32.54 ± 12.1 years; 47.6% were male patients, and 52.4% were female patients. The average time between transplant and early urinary tract infections was 11 days (range, 1-30 days). Among our patient group, 87.8% of urinary tract infections occurred within the first 6 months posttransplant. We collected 205 episodes of urinary tract infections: 66.3% were asymptomatic bacteriuria, 10.2% acute cystitis, and 23.4% pyelonephritis. The estimated risk factors for urinary tract infection included only female sex (P < .05); older age (P = .32), longer duration of catheter (P = .34), and high body mass index (P = .46) were not correlated with urinary tract infection.

CONCLUSIONS

Despite preventive measures, urinary tract infections remain an important cause of morbidity among kidney transplant recipients. In fact, more than half of kidney transplant recipients had at least 1 urinary tract infection after surgery. Female sex was statistically associated with higher risk of urinary tract infection.

Prevalence and risk factors of urinary tract infection in kidney recipients: a meta-analysis study

BACKGROUND

A kidney recipient's urinary tract infection (UTI) can result in infectious problems and be a risk factor for less successful transplant outcomes. UTI risk factors are still controversial. The present study aimed to investigate the prevalence of UTI and its association with risk factors in kidney recipients.

METHOD

Twenty-six papers published between 2005 and 2022 were retrieved using keywords and searching Medlib, ScienceDirect, PubMed, and other databases. If possible, the pooled prevalence of UTI in kidney recipients and odds ratio (OR) with a 95% confidence interval for each risk factor were calculated. The data were analyzed using the random effects model in R and Stata 14.

RESULTS

The total sample size was 72,600, with an average age of 48.7 years. The pooled prevalence of UTI was 35% (95% CI, 30-40%). The estimated risk factors for UTI were female (OR = 3.13; 95%CI: 2.35-4.17), older age (OR = 1.03; 95%CI: 1-1.05), history of UTI (OR = 1.31; 95%CI) CI: 1.05-1.63), receiving a kidney from a deceased donor (OR = 1.59; 95%CI: 1.23-2.35), long-term use of an indwelling catheter (OR = 3.03; 95%CI: 1.59-6.59), a ureteral stent (OR = 1.54; 95%CI: 1.16-2.06), diabetes (OR = 1.17; 95%CI: 0.97-1.41), hypertension (OR = 1.6; 95%CI: 1.26-2.28), acute rejection process (OR = 2.22; 95%CI: 1.45-3.4), and abnormal urinary tract anatomy (OR = 2.87; 95%CI 1.44-5.74).

CONCLUSION

This meta-analysis revealed that UTIs are a significant problem in kidney recipients. Factors such as female sex, old age, history of UTIs, deceased donor, long-term use of an indwelling catheter, diabetes, acute rejection process, use of ureteral stent, abnormal urinary tract anatomy, and hypertension were related to an increased risk of UTIs in kidney recipients.

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.

Evaluation of the correlation between oral infections and systemic complications in kidney transplant patients: a retrospective pilot study

BACKGROUND

Data regarding the efficacy of the dental clearance required prior to kidney transplantation (KT) for preventing post-transplant complications is controversial. The aim of this retrospective study was to investigate a possible correlation between any untreated oral infectious foci and the onset of systemic complications in KT patients.

METHODS

Patients scheduled for regular check-ups during the post-transplant period were visited at the C.I.R. Dental School in Turin, Italy. Patients were asked to bring orthopantomography (OPT) acquired prior to transplantation to compare the possible presence of untreated infectious foci at the time of transplantation with the time of their post-transplant visit. Patients were then divided, according to the evaluation of the OPT obtained prior to the transplantation, into two groups according to their dental status prior to the transplant. "Group Infected" was comprised of patients with no dental clearance, and "Group Clear" included patients with dental clearance. The medical records were then retrospectively reviewed for the evaluation of any systemic complications that occurred after transplantation. The following medical complications were considered: fever, pneumonia, urinary tract infections, systemic infections, kidney rejection, and death. Complications were divided in two groups: early complications, which occurred within 100 days of transplantation, and late complications, which occurred more than 100 days after transplantation.

RESULTS

A total of 77 patients were enrolled in the study. Group Infected was composed of 19 subjects (25%), while Group Clear was composed of 58 patients (75%). In Group Infected, 13 (68%) patients developed complications within 100 days of transplantation, and 11 (58%) did so after 100 days. In Group Clear, 31 (53%) patients had complications within 100 days of the transplant, and 23 (40%) did after 100 days. Patients in Group Infected had a statistically significant increase in episodes of fever (p = 0.03), compared to Group Clear, with a higher relative risk (RR) of 3.66 in the first 100 days after transplantation.

CONCLUSION

Within the limitations of the present retrospective pilot study, and based on the results, a correlation between the absence of dental clearance prior to KT and a higher RR of developing a fever within the first 100 days post transplantation was highlighted. The present results encourage doctors to continue research on the topic, which remains controversial. Further prospective studies are required to confirm the results of the present study.

Acute kidney injury secondary to urinary tract infection in kidney transplant recipients

Acute kidney injury (AKI) in kidney transplant recipients (KTRs) is a common, yet poorly investigated, complication of urinary tract infections (UTI) and urosepsis. A retrospective comparative analysis was performed, recruiting 101 KTRs with urosepsis, 100 KTRs with UTI, and 100 KTRs without history of UTI or sepsis. The incidences of AKI in the urosepsis and UTI groups were 75.2% and 41%, respectively. The urosepsis group has also presented with a significantly higher prevalence of AKI stage 2 and 3 than the UTI group. The rates of recovery from AKI stages 1, 2 and 3, were 75,6%, 55% and 26.1%, respectively. Factors independently associated with renal recovery from AKI were: AKI severity grade (AKI stage 2 with OR = 0.25 and AKI stage 3 with OR = 0.1), transfusion of red blood cells (RBC) (OR = 0.22), and the use of steroid bolus in the acute phase of treatment (OR = 4). The septic status (urosepsis vs UTI) did not influence the rates of renal recovery from AKI after adjustment for the remaining variables. The dominant cause of RBC transfusions in the whole population was upper GI-bleeding. In multivariable analyses, the occurrence of AKI was also independently associated with a greater decline of eGFR at 1-year post-discharge and with a greater risk of graft loss. In KTRs with both urosepsis and UTI, the occurrence of AKI portends poor transplantation outcomes. The local transfusion policy, modulation of immunosuppression and stress ulcer prophylaxis (which is not routinely administered in KTRs) in the acute setting may be modifiable factors that significantly impact long-term transplantation outcomes.

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.

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.

Long-Term Infectious Complications of Kidney Transplantation

Infections remain a common complication of solid-organ transplantation. Most infections in the first month after transplant are typically health care-associated infections, whereas late infections, beyond 6-12 months, are community-acquired infections. Opportunistic infections most frequently present in the first 12 months post-transplant and can be modulated on prior exposures and use of prophylaxis. In this review, we summarize the current epidemiology of postkidney transplant infections with a focus on key viral (BK polyomavirus, cytomegalovirus, Epstein-Barr virus, and norovirus), bacterial (urinary tract infections and Clostridioides difficile colitis), and fungal infections. Current guidelines for safe living post-transplant are also summarized. Literature supporting prophylaxis and vaccination is also provided.

Urinary Tract Infections in the First 6 Months after Renal Transplantation

Purpose

Urinary tract infections (UTIs) are common in the first 6 months after renal transplantation, and there are only limited data about UTIs after transplantation in Saudi Arabia in general.

Methods

A retrospective study from January 2017 to May 2020 with 6-month follow-up.

Results

279 renal transplant recipients were included. Mean age was 43.4 ± 16.0 years, and114 (40.9%) were women. Urinary stents were inserted routinely during transplantation and were removed 35.3 ± 28 days postoperatively. Ninety-seven patients (35%) developed urinary tract infections (UTIs) in the first six months after renal transplantation. Of those who developed the first episode of UTI, the recurrence rates were 57%, 27%, and 14% for having one, two, or three recurrences, respectively. Late urinary stent removals, defined as more than 21 days postoperatively, tended to have more UTIs (OR: 1.43, P: 0.259, CI: 0.76–2.66). Age >40, female gender, history of neurogenic bladder, and transplantation abroad were statistically significant factors associated with UTIs and recurrence. Diabetes, level of immunosuppression, deceased donor renal transplantation, pretransplant residual urine volume, or history of vesicoureteral reflux (VUR) was not associated with a higher incidence of UTIs. UTIs were asymptomatic in 60% but complicated with bacteremia in 6% of the cases. Multidrug resistant organisms (MDROs) were the causative organisms in 42% of cases, and in-hospital treatment was required in about 50% of cases. Norfloxacin + Bactrim DD (160/800 mg) every other day was not associated with the lower risk of developing UTIs compared to the standard prophylaxis daily Bactrim SS (80/400 mg).

Conclusion

UTIs and recurrence are common in the first 6 months after renal transplantation. Age >40, female gender, neurogenic bladder, and transplantation abroad are associated with the increased risk of UTIs and recurrence. MDROs are common causative organisms, and hospitalization is frequently required. Dual prophylactic antibiotics did not seem to be advantageous over the standard daily Bactrim.

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

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

Poor oral health status and short-term outcome of kidney transplantation

AIMS

This study aims to know whether poor oral health increases the risk of acute rejection and hospitalization in kidney allograft recipients.

METHODS AND RESULTS

This is a prospective cohort study. The same dentist followed participants for 2 months after renal transplant for monitoring oral health (clinical evaluation, DTMF index, and CPITN index), signs of graft rejection, infection, and hospitalization. We compiled rates and reasons for hospital readmission or extended hospital stay. The CPITN had a mean score of 0.38 ± 0.71, increasing to 0.90 ± 0.84, 60 days after transplant (P < .001). No one rejected the graft in the period of study. Patients with older age (P = .009; OR: 1.07; CI 95% 1.01-1.12) were at higher risk of hospitalization at each year of age and patients presenting pretransplant dental focus (P = .001; OR: 7.23; CI 95% 2.13-24.56) had 7.23 times more chance to be hospitalized in the first 2 months after the transplant. One participant was hospitalized due to acute foci of dental infection.

CONCLUSION

There was an association between dental focus and hospital readmission/stay. However, our methods do not provide conclusive proof of causality. Hospitalization due to acute dental infection was rare.

Five compelling UTI questions after kidney transplant

PURPOSE

Urinary tract infection (UTI) is the most common bacterial infection among infectious complications in kidney transplant recipients (KTR). After transplantation, infections can result from surgical complications, donor-derived infections, pre-existing recipient infections, and nosocomial infections. Post-transplant infection is still a major cause of morbidity, mortality, graft dysfunction and rejection. In this paper, we aimed to review a few compelling questions in kidney transplantation (KTX).

METHODS

To identify relevant clinical questions regarding KTX and UTI a meeting was conducted among physicians involved in the KT program in our hospital. After discussion, several clinically relevant questions related to UTI after KTX. The 5 first rated in importance were judged generalizable to other clinical settings and selected for the purposes of this review.

RESULTS

Nearly half of the patients present in the first three months of transplant with UTI. The most common uropathogens in post-transplant UTIs are Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecalis. Risk factors for UTI include female sex, advanced age, recurrent UTI before transplant, prolonged urethral catheterization, delayed graft function, and cadaveric kidney transplant.

CONCLUSION

The incidence of post-transplant UTI is similar in both developed and developing countries. E.coli is the most common pathogen in most of studies. Cadaveric donor and post-dialysis transplantation are defined as independent risk factors for post-transplant UTI. Further studies are still required to identify risk factors after kidney transplantation and UTI's importance for graft function and patient outcome.

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

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

Safety and efficacy of methenamine hippurate for the prevention of recurrent urinary tract infections in adult renal transplant recipients: A single center, retrospective study

BACKGROUND

Recurrent urinary tract infections (UTI) are an important cause of morbidity and mortality in renal transplant recipients (RTR).

METHODS

In this retrospective study we gathered clinical data from patients prescribed methenamine hippurate to prevent recurrent UTI pre- and post-intervention. Thirty-eight RTR ≥18 years old at Northwestern Memorial Hospital from 2006-2017 were included in the final analysis.

RESULTS

The median and range for follow-up days were 365 (299-365) pre- vs 314 (105-365) post-methenamine. Total UTI frequency (9.16 vs 5.01/1000 patient follow-up days), days of antibiotic therapy to treat UTI (215 vs 132/1000 patient follow-up days), and hospitalization due to UTI (2.64 vs 1.07/1000 patient follow-up days) decreased while patients took methenamine. Escherichia coli and Klebsiella pneumoniae were the most commonly identified cause of UTI both pre- and post-intervention. Drug resistant bacteria (ESBL-producing or VRE) affected 3 patients pre- and recurred in 1 of those patients plus 3 new patients post-methenamine. Methenamine had few adverse side effects for patients. One patient had nausea and 1 was intolerant.

CONCLUSION

We found that methenamine is well tolerated and is useful in reducing UTI, antibiotic prescriptions, and hospitalization in RTR with recurrent UTI. Larger prospective studies are needed to confirm these findings.

Recurrent urinary tract infections in kidney transplant recipients during the first-year influence long-term graft function: a single-center retrospective cohort study

Urinary tract infections (UTIs) after kidney transplantation are associated with significant morbidity. However, data on the impact of UTI on graft survival are controversial. We conducted a retrospective cohort study of 380 kidney transplant patients. Recipients with symptomatic UTIs during the first year after transplantation were categorized into three groups: early (< 3 episodes from months 1st to 6th), late (< 3 episodes during months 7th to 12th) and recurrent (≥ 3 episodes throughout the whole first year). Graft function at three years was considered the primary outcome. Symptomatic UTIs occurred in 184 (48.4%) kidney transplant recipients during the first year; 83 (21.8%) patients developed early UTIs, 50 (13.2%) late UTIs and 51 (13.4%) recurrent UTIs. We observed a significant improvement in graft function after three years in all patients (P < 0.001) except those who had recurrent UTIs. A Kaplan-Meier analysis showed that recipients with recurrent UTIs had worse graft outcome (eGFR value < 60 mL/min/1.73 m²) (P = 0.01). Recurrent UTIs was an independent predictor of graft function at three years in a model adjusted for DGF and episodes of acute rejection (Hazard Ratio, 2.2; 95% CI, 1.3 to 3.5; P = 0.001). Recurrent symptomatic UTIs during the first year after transplantation have negative impact on long-term graft function.

Updates on urinary tract infections in kidney transplantation

Urinary tract infection (UTI) represents the most common infection after kidney transplantation; it is associated with an increased risk for acute kidney rejection and impaired graft function in the early post-transplant period. Kidney transplant recipients with UTIs are often clinically asymptomatic due to the immunosuppressive therapy; however, asymptomatic bacteriuria may progress to acute pyelonephritis, bacteremia and urosepsis, particularly in the early post-transplant period, that are independent risk factors for short and long-term graft and patient survival. This article reviews the definitions, incidence, risk factors and the management of UTI in kidney transplant recipients; furthermore, the main controversial and still unanswered questions, regarding the causes of recurrent UTIs, adequate use of antibiotics to avoid antibiotic resistance, dosing and timing for prophylaxis and treatment of symptomatic infections, are also discussed. The emerging definition of urinary microbiota introduces new concepts in understanding the complexity of the disease and might represent the future target for therapeutic interventions.

The challenge of urinary tract infections in renal transplant recipients

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

Review of Infectious Disease Prophylaxis in Solid Organ Transplantation

As immunosuppressive therapy has evolved over the years, rejection rates in solid organ transplant have declined, but infections remain a significant cause of morbidity and mortality in this population. Prophylaxis against bacterial, viral, and fungal infections is often used to prevent infection from common pathogens during high-risk periods. As an integral part of the multidisciplinary medical team, it is important that nurses caring for transplant recipients be familiar with methods to detect and prevent infectious diseases in this population. This article presents a review of risk factors for and prevalence of common infectious pathogens, as well as important considerations regarding prophylactic medications in solid organ transplant recipients.

Genitourinary Tract Infections

Similarly to the general population, genitourinary tract infections are common conditions in theimmunocompromised host. They can be furthermore divided into infections of the urinary tract and genital tract infections. Transplant recipients are more likely to have infections of the urinary tract infections while persons with human immunodeficiency virus (HIV) are at higher risk for the second group of infections, especially sexually transmitted infections (STIs). Manifestations of these diseases can be associated with more complications and can be more severe. We provide an overview of manifestations, diagnosis, and management of these disorders.

Urinary tract infections in kidney transplant recipients 1st year after transplantation

Background:

One of the main causes of adverse complications following kidney transplantation is urinary tract infection (UTI). This study was done to define the incidence rate, clinical profiles, causative microorganisms, and UTI risk factors among kidney transplant recipients in Mashhad city.

Materials and Methods:

In this retrospective study, we perused medical files of 247 kidney recipients who underwent transplant surgery at Mashhad University Montaserie Hospital, during 2012–2014. All patients were followed for UTI during the 1^st year after surgery.

Results:

75 episodes of UTI developed by 152 pathogens in 56 (22.7%) of patients during 1-year follow-up. 26.6% of total UTIs were diagnosed within the 1^st month after transplantation. The most frequently isolated uropathogens were Escherichia coli (55.3%, n = 84). The high rate of candiduria (8.5%) was observed, too.

Conclusion:

UTI is known as one of the hospitalization reasons in kidney transplantation recipients. Defining appropriate antibiotic prophylaxis against bacterial and fungal agents and early removal of urethral catheter are suggested to decrease posttransplantation complications.

The prevalence and predictive factors of urinary tract infection in patients undergoing renal transplantation: A meta-analysis

BACKGROUND

Urinary tract infections (UTIs) are the main cause of infectious complications in renal transplant (RTx) recipients and are considered as a potential risk factor for poorer graft outcomes. However, the risk factors of UTIs are controversial. We estimated the incidence and predisposing factors of UTIs in patients undergoing RTx.

METHODS

Seventeen studies (6,671 patients) evaluated the prevalence and the risk factors of UTIs in patients with RTx published January 2000-October 2014 were included. The data were pooled using the fixed effect model or DerSimonian-Laird random effect model according to I².

RESULTS

Thirteen eligible articles with a total of 3,364 patients were evaluated and the pooled prevalence of UTIs was 38.0% (95% confidence interval [CI], 29%-47%; P < .01). The estimated risk factors for UTI include female sex (odds ratio [OR], 3.11; 95% CI, 2.10-4.13), older age (OR, 1.032; 95% CI, 1.01-1.04), duration of catheter (OR, 1.52; 95% CI, 1.03-2.03), acute rejection episodes (OR, 1.64; 95% CI, 1.11-2.41), and receiving a kidney from a deceased donor (OR, 1.28; 95% CI, 1.09-1.52).

CONCLUSIONS

More than one-third of RTx patients had at least 1 UTI after surgery. Female sex, older age of the recipient, long duration of catheter, acute rejection episodes, and cadaveric donor were associated with higher risk of UTI.

Bacterial Infections in Renal Transplant Recipients

BACKGROUND

Patients after kidney transplantation are highly susceptible to infections owing to immunosuppression as well as other risk factors--extended hospitalization, Foley catheterization, and double J catheter insertion among others. Bacterial infections, especially shortly after operation, are a major threat to the graft function. The aims of this study were to identify risk factors of bacterial infections after kidney transplantation and to determine the impact of those infections on the subsequent renal function.

METHODS

One hundred twenty patients who underwent kidney transplantation in 2013 and 2014 were examined in our study for possible risk factors of bacterial infections and for possible outcome of such infections on their future condition.

RESULTS

Among 120 patients under observation, 50 (41.7%) had early infectious complications (during hospitalization), 41 (82%) of which were urinary tract infections (UTI). The second most common infectious complication was infection of the surgical wound. Statistically significant results were obtained only for patient's age and duration of hospital stay (P = .001 and P = .000004, respectively). Bacterial infection resulted in longer hospital stay, higher reoperation risk, and lower creatinine clearance in the 14 days after transplantation (P = .000004, P = .0142, and P = .0455, respectively).

CONCLUSION

Bacterial infections influence mainly the short-term condition of kidney transplant recipients: extended hospital stay, decreased early creatinine clearance, and enhanced risk of reoperation. The most common risk factors, such as Foley catheterization, double J catheter insertion, and diabetes, were not significant in our observation.

Recurrent Acute Kidney Injury in Renal Transplant Patients: A Single-Center Study

OBJECTIVE

Renal transplant patients may have recurrent episodes of acute kidney injury (AKI) during the posttransplant period. Determination and management of risk factors may help to prevent recurrence of AKI and allograft loss. In this study, we investigated the clinical features of renal transplant patients with recurrent AKI and evaluated etiologies and risk factors.

MATERIALS AND METHODS

A total of 19 patients with 79 AKI episodes were examined retrospectively. AKI classes, etiologies, and risk factors were investigated. Their features were compared with 38 renal transplant patients without AKI.

RESULTS

Distribution of AKI episodes according to the type of injury was as follows: 15 prerenal, 43 renal, 6 postrenal, and 15 mixed. Renal transplant patients with recurrent AKI had a greater duration of dialysis before transplantation (P < .05). Logistic regression analysis revealed no predictor for recurrent AKI after renal transplantation. Infections participated in the development of 45 AKI episodes. Chronic kidney disease developed in 16 patients.

CONCLUSION

Infections are the leading condition associated with recurrent AKI in renal transplant patients. Recurrent AKI may contribute to the development and progression of chronic kidney injury.

Study of the risk factors related to acquisition of urinary tract infections in patients submitted to renal transplant

INTRODUCTION

Urinary tract infections (UTI) among transplant recipients are usually caused by gram-negative microorganisms and can provoke a high incidence of morbidity and mortality. The aim of this study was to evaluate the risk factors associated with the acquisition of UTIs during the first year after renal transplantation.

METHODS

Here, we report a single-center retrospective cohort study of 99 renal transplant patients followed for the first year after surgery. The definition of a UTI episode was a urine culture showing bacterial growth and leucocyturia when patients presented with urinary symptoms. The absence of infection (asymptomatic bacteriuria) was defined as an absence of symptoms with negative urine culture or bacterial growth with any number of colonies.

RESULTS

Ninety-nine patients were included in the study. During the study, 1,847 urine cultures were collected, and 320 (17.3%) tested positive for bacterial growth. Twenty-six (26.2%) patients developed a UTI. The most frequent microorganisms isolated from patients with UTIs were Klebsiella pneumoniae (36%), with 33% of the strains resistant to carbapenems, followed by Escherichia coli (20%). There were no deaths or graft losses associated with UTI episodes.

CONCLUSIONS

Among the UTI risk factors studied, the only one that was associated with a higher incidence of infection was female sex. Moreover, the identification of drug-resistant strains is worrisome, as these infections have become widespread globally and represent a challenge in the control and management of infections, especially in solid organ transplantation.

Bacterial and fungal infections in the early post-transplant period after kidney transplantation: etiological agents and their susceptibility

BACKGROUND

Infections remain serious complications in solid-organ transplant recipients, despite professional medical care, the introduction of new immunosuppressive drugs, and treatment that decreases the risk of infections.

METHODS

The study covered 295 adult patients undergoing kidney transplantation (KTx) between September 2001 and December 2007. All the patients were followed prospectively for infections from the KTx date and during the first 4 weeks after surgery. Samples of clinical materials were investigated for microbiological cultures. The microorganisms were cultured and identified in accordance with standard bacteriological procedures. Susceptibility testing was carried out through the use of Clinical and Laboratory Standards Institute procedures.

RESULTS

From 295 KTx recipients, 1073 clinical samples were taken for microbiological examination. Positive cultures were 26.9% (n = 289) of all samples tested; 525 strains were collected. Gram-positive bacteria were isolated in 52.2% (n = 274), Gram-negative bacteria were isolated in 40.8% (n = 214), and fungal strains were isolated in 7% (n = 37). Urine specimens (n = 582) were obtained from 84.5% of 245 recipients during the first month after transplantation. Among the isolated bacterial strains (n = 291), the most common were Gram-negative bacteria (56.4%). Gram-positive bacteria comprised 35.7%; fungal strains were found in 23 cases (7.9%). In surgical site specimens (n = 309), Gram-positive bacteria (72.1%) were the most common. Gram-negative bacteria comprised 24.4%. In blood specimens (n = 138), Gram-positive bacteria (81.6%) were the most common. Gram-negative bacteria comprised 15.8%; fungi were isolated in 2.6%. In respiratory tract specimens (n = 13), among the isolated bacterial strains (n = 8), the most common were Gram-positive bacteria (57.1%). Gram-negative bacteria comprised 14.3%; fungi were isolated in 28.6%.

CONCLUSIONS

Urine samples were predominantly positive after KTx. Our study showed Gram-positive bacteria in 52.2% after kidney transplantation. The proportion of isolates of multi-drug-resistant bacterial strains (MRCNS, vancomycin-resistant strains, high-level aminoglycoside-resistant strains, extended-spectrum beta-lactamase producers, and high-level aminoglycoside-resistant strains) was increased. These data indicate the need for strict adherence to infection control procedures in these patients.

Management of urinary tract infection in solid organ transplant recipients: Consensus statement of the Group for the Study of Infection in Transplant Recipients (GESITRA) of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) and the Spanish Network for Research in Infectious Diseases (REIPI)

BACKGROUND

Urinary tract infections (UTIs) are one of the most common infections in solid organ transplant (SOT) recipients.

METHODS

Experienced SOT researchers and clinicians have developed and implemented this consensus document in support of the optimal management of these patients. A systematic review was conducted, and evidence levels based on the available literature are given for each recommendation. This article was written in accordance with international recommendations on consensus statements and the recommendations of the Appraisal of Guidelines for Research and Evaluation II (AGREE II).

RESULTS

Recommendations are provided on the management of asymptomatic bacteriuria, and prophylaxis and treatment of UTI in SOT recipients. The diagnostic-therapeutic management of recurrent UTI and the role of infection in kidney graft rejection or dysfunction are reviewed. Finally, recommendations on antimicrobials and immunosuppressant interactions are also included.

CONCLUSIONS

The latest scientific information on UTI in SOT is incorporated in this consensus document.

A Nationwide Assessment of the Burden of Urinary Tract Infection among Renal Transplant Recipients

Objective. Evaluate the prevalence and outcomes of urinary tract infection (UTI) among renal transplant recipients. Methods. A secondary analysis of the Nationwide Inpatient Sample 2009–2011 was conducted. Survey-weighted multivariable regression analyses were used to examine the impact of UTI on transplant complications, total charges, and length of stay. Results. A total of 1,044 renal transplant recipients, representing a population estimate of 49,862, were included in the study. UTI was most common in transplant recipients with hypertension (53%) and prevalence was noted to be 28.2 and 65.9 cases per 1,000 for men and women, respectively. UTI increased the likelihood of transplant complications (182% for men, 169% for women). Total charges were 28% higher among men as compared to 22% among women with UTI. Such infection also increased the length of stay by 87% among men and 74% among women. Discussion. UTI in renal transplant recipients was associated with prolonged length of stay, total charges, and increased odds of transplant complications. Interventions to prevent UTI among such patients should be a priority area for future research and practice.

Septicemia and Infection due to ESBL-producing K. pneumoniae Following Feline Renal Allograft Transplantation

A 12 yr old castrated male domestic longhair underwent renal transplantation for treatment of chronic interstitial nephritis. Full-thickness intestinal biopsies obtained prior to transplantation revealed mild enteritis. Twelve months following transplantation, the patient underwent surgery for resection of a mesenteric mass causing septic peritonitis. The mesenteric mass was resected and an intestinal resection and anastomosis was performed. Extended-spectrum-β-lactamase producing Klebsiella pneumoniae was cultured from the resected tissue and urinary tract. Bacterial rods were noted to be circulating in the bloodstream, causing septicemia. Despite aggressive treatment of the septic peritonitis and septicemia using surgical debridement, drain placement, aggressive antibiotic therapy with IV meropenem, and vasopressor support, the patient succumbed to persistent hypotension and suffered cardiopulmonary arrest. Extended-spectrum-β-lactamase-producing bacteria are of growing concern in human and veterinary medicine, maintaining susceptibility often only to carbapenem and aminoglycoside antibiotics. Resistance to even those antibiotics is emerging. Veterinary patients with a history of antibiotic therapy, central venous or urinary catheterization, immunosuppression, enteric surgery, and an extended stay in the intensive care unit may be predisposed.

Infections with blaKPC-2-producing Klebsiella pneumoniae in renal transplant patients: a retrospective study

In renal transplant recipients, the urinary tract is the most common site of infections that might be caused by pathogens while on immunosuppressive therapy. The spread of enterobacteria resistant to carbapenem is worrying, as it is generally used as this agent is the first-line therapy for infections caused by Enterobacteriaceae producing extended spectrum β-lactamases. The most frequently encountered class A carbapenemases are the Klebsiella pneumoniae carbapenemase (KPC) enzymes. We describe the treatment and outcomes of 6 renal transplant patients who had urinary tract infections (UTIs) with blaKPC-2-producing K pneumoniae, confirmed by polymerase chain reaction amplification, namely 13.33% of renal transplant patients in the study period. Four patients survived, including 1 with reinfections and relapse, and 2 patients died. The antibiotics used for treatment, alone or combined, were colistin (n = 6, 42.8%), tigecycline (n = 5, 35.7%), doxycycline (n = 3, 21.4%), meropenem (n = 3, 21.4%), and fosfomycyn (n = 1, 7%). UTIs caused by carbapenemase-producing K pneumoniae are life-threatening. In the cases presented, favorable results were achieved with monotherapies using colistin, doxycycline, or meropenem.

Impact of urinary tract infection on allograft function after kidney transplantation

OBJECTIVES

Urinary tract infection (UTI) is the most common infectious complication after kidney transplantation. We aim to determine its impact on allograft function as indicated by several measures such as iothalamate glomerular filtration rate (iGFR), estimated glomerular filtration rate (eGFR), and creatinine value.

METHODS

We performed a single-center retrospective cohort study to determine the impact of UTI on kidney allograft outcome.

RESULTS

The study population consisted of 301 kidney transplant recipients; 84% were living donor transplants. One hundred and one patients (34%) developed at least one episode of UTI and the incidence of UTI during the first year after transplantation was 25%. At the end of the follow-up, the iGFR was lower among patients who had developed at least one UTI (p = 0.044). However, eGFR and creatinine values were not significantly different between UTI and non-UTI groups.

CONCLUSION

When kidney function was measured by eGFR and creatinine, there was no significant difference in allograft function between kidney recipients with or without UTI. However, when kidney function was measured by nuclear studies, there was a tendency toward impairment in allograft function among patients who developed atleast one UTI after transplantation.

Nosocomial infections within the first month of solid organ transplantation

Infections remain a common complication of solid organ transplantation. Early postoperative infections remain a significant cause of morbidity and mortality in solid organ transplant (SOT) recipients. Although significant effort has been made to understand the epidemiology and risk factors for early nosocomial infections in other surgical populations, data in SOT recipients are limited. A literature review was performed to summarize the current understanding of pneumonia, urinary tract infection, surgical-site infection, bloodstream infection, and Clostridium difficult colitis, occurring within the first 30 days after transplantation.

Recurrent urinary tract infections in kidney transplant recipients

Urinary tract infections (UTIs) are the most common infectious complication after kidney transplantation (KT). Recurrent UTIs after KT can contribute to increased morbidity and may also be associated with graft loss and mortality. Though several risk factors like female gender, diabetes mellitus, presence of ureteric stents, native kidney disease with urological malformations and re-transplantation have been associated with recurrent UTIs after KT, vesicoureteric reflux appears to be a unique risk factor in this patient population. The emergence of drug-resistant pathogens as causative agents for post-transplant recurrent UTIs poses a significant therapeutic challenge. The use of pathogen-specific antibiotic therapy guided by culture and sensitivity data is warranted. The optimal duration of antimicrobial therapy for recurrent UTIs in renal transplant recipients remains uncertain.

Impact of Gram-negative bloodstream infection on long-term allograft survival after kidney transplantation

BACKGROUND

Gram-negative bloodstream infections (BSI) are common complications after kidney transplantation. In this cohort study, we evaluated the long-term effect of Gram-negative BSI on allograft survival in kidney transplant recipients.

METHODS

Among a cohort of 1820 kidney recipients who were prospectively followed at the Mayo Clinic (Rochester, MN) from January 1, 1996, to December 31, 2007, we identified 120 patients with initial episodes of Gram-negative BSI before allograft failure. Multivariable Cox proportional hazard regression was used to examine the association between Gram-negative BSI, as a time-dependent covariate, and allograft and patient survival.

RESULTS

The median age of kidney recipients was 51 years (interquartile range, 39-61 years) and 58% were men. Among patients with Gram-negative BSI, 75% had a urinary tract source of infection and Escherichia coli was the most common microorganism (50%). Gram-negative BSI after transplantation was independently associated with allograft loss due to allograft failure or death (hazard ratio [HR], 2.52; 95% confidence intervals [CI], 1.83-3.47; P<0.001), allograft failure with death-censored (HR, 3.17; 95% CI, 2.11-4.76; P<0.001) and all-cause mortality (HR, 2.25; 95% CI, 1.55-3.26; P<0.001).

CONCLUSIONS

Prevention and proper management of urinary tract infections in kidney recipients is essential to reduce the risk of more serious complications, including Gram-negative BSI, that are associated with reduced allograft and patient survival.

Lower risk of urinary tract infection with low-dose trimethoprim/sulfamethoxazole compared to dapsone prophylaxis in older renal transplant patients on a rapid steroid-withdrawal immunosuppression regimen

BACKGROUND

Urinary tract infections (UTI) are common in renal transplant recipients. Trimethoprim/sulfamethoxazole (TMP/SMZ) in moderate to high daily doses prevents Pneumocystis jiroveci (PCP) and reduces the risk of UTI in renal transplant patients. Low-dose TMP/SMZ also reduces the risk of PCP, although its ability to reduce the risk of UTI is uncertain.

DESIGN

Retrospective review of 158 patients who received a renal transplant without corticosteroids for maintenance immunosuppression.

RESULTS

Forty percent of patients initially prescribed TMP/SMZ ultimately stopped this medication early because of an adverse reaction. Urinary infection occurred in 16% without a significant difference in the risk of UTI between those treated with dapsone vs. those treated with TMP/SMZ (HR [95%CI]: 1.7 [0.75, 3.9], p = 0.2). In the subset of patients who were older than age 47 yr (mean age for this cohort, SD ± 6.2 yr), those treated with dapsone originally or who switched from TMP/SMZ to dapsone had a greater risk of UTI compared to patients who remained on TMP/SMZ (HR [95%CI]: 4.3 [1.2, 15.5], p = 0.024).

CONCLUSIONS

For renal transplant recipients over the age of 47 yr, treated without long-term glucocorticoids, our retrospective data suggest that low-dose TMP/SMZ is associated with a lower risk of UTI compared to dapsone prophylaxis.

Prospective study of urinary tract infection surveillance after kidney transplantation

Background

Urinary tract infection (UTI) remains one of the main complications after kidney transplantation and it has serious consequences.

Methods

Fifty-two patients with kidney transplantation were evaluated for UTI at 3-145 days (mean 40.0 days) after surgery.. Forty-two received a graft from a live donor and 10 from a deceased donor. There were 22 female and 30 male patients, aged 11-47 years. Microscopic examinations, leukocyte esterase stick, and urinary culture were performed every third day and weekly after hospitalization. A positive culture was consider when patients presented bacterial counts up to 10⁵ counts.

Results

UTI developed in 19/52 (37%) patients at 3-75 days (mean 19.5 days after transplantation. Recurrent infection was observed in 7/52 (13.4%) patients at days 17-65. UTI was more frequent in patients who received deceased grafts compared with live grafts (7/10, 70% vs. 12/42, 28%; p < 0.007). Female patients were more susceptible than male (11/22, 50% vs. 8/22, 36.35%; p < 0.042). Five-year survival rate was 94.5% (49/52 patients). Kidney Graft exit update is 47/52 (90.2%), and there were no significant differences between graft rejection and UTI (p = 0.2518). Isolated bacteria were Escherichia coli (31.5%), Candida albicans (21.0%) and Enterococcus spp. (10.5%), followed by Pseudomonas aeruginosa, Klebsiella pneumoniae, Morganella morganii, Enterobacter cloacae and Micrococcus spp. Secondary infections were produced by (7/19, 36.8%). Enterococcus spp. (57%), E. coli (28%) and Micrococcus spp. (14.2%). Antibiotic resistance was 22% for ciprofloxacin and 33% for ampicillin. Therapeutic alternatives were aztreonam, trimethoprim-sulfamethoxazole, netilmicin and fosfomycin.

Conclusions

Surveillance of UTI for the first 3 months is a good option for improving quality of life of kidney transplantation patients and the exit of graft function especially for female patients and those receiving deceased grafts. Antibiograms provided a good therapeutic alternative to patients who presented with UTIs after receiving a kidney allograft.

Lipopolysaccharide directly alters renal tubule transport through distinct TLR4-dependent pathways in basolateral and apical membranes

Bacterial infection of the kidney is associated with renal tubule dysfunction and dysregulation of systemic electrolyte balance. Whether bacterial molecules directly affect renal tubule transport is unknown. We examined the effects of LPS on HCO3(-) absorption in the isolated rat and mouse medullary thick ascending limb (MTAL). LPS decreased HCO3(-) absorption when added to bath or lumen. The MEK/ERK inhibitor U0126 eliminated inhibition by bath LPS but had no effect on inhibition by lumen LPS. Conversely, the mammalian target of rapamycin (mTOR) inhibitor rapamycin eliminated inhibition by lumen LPS but had no effect on inhibition by bath LPS. Inhibiting basolateral Na(+)/H(+) exchange with amiloride eliminated inhibition of HCO3(-) absorption by lumen but not bath LPS. Confocal immunofluorescence showed expression of TLR4 in basolateral and apical membrane domains. Inhibition of HCO3(-) absorption by bath and lumen LPS was eliminated in MTALs from TLR4(-/-) mice. Thus LPS inhibits HCO3(-) absorption through distinct TLR4-dependent pathways in basolateral and apical membranes. These results establish that bacterial molecules can directly impair the transport function of renal tubules, identifying a new mechanism contributing to tubule dysfunction during bacterial infection. The LPS-induced reduction in luminal acidification may contribute to Gram-negative pathogenicity by promoting bacterial adherence and growth and impairing correction of infection-induced systemic acid-base disorders.

Urological complications and their impact on survival after kidney transplantation from deceased cardiac death donors

Urological complications after kidney transplantation may result in significant morbidity and mortality. However, the incidence of such complications after deceased cardiac death (DCD) donor kidney transplantation and their effect on survival is unknown. Purpose of this study was to estimate the incidence of urological complications after DCD kidney transplantation, and to estimate their impact on survival. Patient records of all 76 DCD kidney transplantations in the period 1997-2004 were reviewed for (urological) complications during the initial hospitalization until 30 days after discharge, and graft survival until the last hospital visit. Urological complications occurred in 32 patients (42.1%), with leakage and/or obstruction occurring in seven patients (9.2%). The latter seems to be comparable with the incidence reported in the literature for deceased heart-beating (DHB) transplantations (range 2.5-10%). Overall graft survival was 92% at 1 year and 88% at 3 years, comparable to the rates reported in the literature for kidneys from DHB donors, and was not affected by urological complications (chi(2) = 0.27, P = 0.61). Only a first warm-ischaemia time of 30 min or more reduced graft survival (chi(2) = 4.38, P < 0.05). We conclude that urological complications occur frequently after DCD kidney transplantation, but do not influence graft survival. The only risk factor for reduced graft survival in DCD transplant recipients was the first warm-ischaemia time.