Urinary Tract Infection and Kidney Transplantation: A Review of Diagnosis, Causes, and Current Clinical Approach

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.

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.

Molecular characterization of ESBL-producing uropathogenic Escherichia coli isolates among kidney transplant patients: Emergence and spread of B2-ST131 clone type

This study was conducted to identify the distribution of virulence determinants in uropathogenic Escherichia coli (UPEC) isolates obtained from kidney transplant (KTP) and non-transplant patients (non-KTP) with urinary tract infections (UTI). Additionally, the (GTG)5 fingerprinting technique was used to investigate the genetic diversity of Extended-Spectrum B-Lactamase (ESBL)-positive isolates. In this case-control study, 111 urine isolates were obtained from non-KTPs and KTPs, respectively. The presence of genetic markers encoding adhesion proteins, toxins and major E. coli phylogroups was assessed through PCR amplification. Molecular typing of ESBL-positive UPEC strains was performed using (GTG)5 fingerprinting and Multilocus sequence typing (MLST) techniques. Overall, 65 and 46 UPEC isolates were obtained from non-KTPs and KTPs, respectively. Among the studied isolates, traT (85.6%) gene was the most frequently observed virulence gene, followed by kpsMT (49.5%). Using the 80% cut-off point, all the 35 UPEC isolates were classified into four major clusters, namely A, B, C, and D. The majority of the Sequence Type (ST) 131 isolates belonged to cluster A. Additionally, three ST1193 isolates belonged to cluster A and phylogroup B2. Moreover, ST38, ST131 and ST10 were in different cluster. In general, we observed significant differences in the papA, ompT, sat, and vat genes between KTPs and non-KTPs. Furthermore, since all the isolates carried one or more virulence factors (VFs), these findings are concerning in the context of managing UTIs caused by the UPEC strain. Additionally, the distribution of ST and Clonal Complex (CC) among isolates in the main clusters revealed significant differences between MLST and (GTG)5 fingerprinting analysis.

Regulation of gut microbiota: a novel pretreatment for complications in patients who have undergone kidney transplantation

Kidney transplantation is an effective method to improve the condition of patients with end-stage renal disease. The gut microbiota significantly affects the immune system and can be used as an influencing factor to change the prognoses of patients who have undergone kidney transplantation. Recipients after kidney transplantation showed a lower abundance of Firmicutes and Faecalibacterium prausnitzii and a higher proportion of Bacteroidetes and Proteobacteria. After using prebiotics, synbiotics, and fecal microbiota transplantation to regulate the microbial community, the prognoses of patients who underwent kidney transplantation evidently improved. We aimed to determine the relationship between gut microbiota and various postoperative complications inpatients who have undergone kidney transplantation in recent years and to explore how gut microecology affects post-transplant complications. An in-depth understanding of the specific functions of gut microbiota and identification of the actual pathogenic flora during complications in patients undergoing kidney transplantation can help physicians develop strategies to restore the normal intestinal microbiome of transplant patients to maximize their survival and improve their quality of life.

Detection of microbial biofilms inside the lumen of ureteral stents: two case reports

BACKGROUND

We report large biofilm structures that covered almost the entirety of the lumen and surface of double-J stents in two postrenal transplant patients, with no development of urinary tract infection. Biofilm bacteria of one patient were integrated by coccus in a net structure, whereas overlapping cells of bacilli were present in the other patient. To the best of our knowledge, this is the first time that high-quality images of the architecture of noncrystalline biofilms have been found inside double-J stents from long-term stenting in renal transplant recipients.

CASE PRESENTATION

Two renal transplant recipients, a 34-year-old male and a 39-year-old female of Mexican-Mestizo origin, who underwent a first renal transplant and lost it due to allograft failure, had a second transplant. Two months after the surgical procedure, double-J stents were removed and analyzed using scanning electron microscopy (SEM). None of the patients had an antecedent of UTI, and none developed UTI after urinary device removal. There were no reports of injuries, encrustation, or discomfort caused by these devices.

CONCLUSION

The bacterial biofilm inside the J stent from long-term stenting in renal transplant recipients was mainly concentrated on unique bacteria. Biofilm structures from the outside and inside of stents do not have crystalline phases. Internal biofilms may represent a high number of bacteria in the double-J stent, in the absence of crystals.

Adrenal Insufficiency Associated With Empty Sella Syndrome and Steroid Malabsorption Complicated With Septic Shock Due to Post-transplant Pyelonephritis: A Case Report

Renal transplant recipients are immunocompromised and predisposed to develop hyponatremia because they are exposed to immunological, infectious, pharmacological, and oncologic disorders. A 61-year-old female renal transplant recipient was admitted with diarrhea, anorexia, and headache for about a week during the tapering of oral methylprednisolone for chronic renal allograft rejection. She also presented hyponatremia and was suspected to have secondary adrenal insufficiency based on a low plasma cortisol level of 1.9 μg/dL and a low adrenocorticotropic hormone level of 2.6 pg/mL. Brain magnetic resonance imaging to assess the hypothalamic-pituitary-adrenal axis revealed an empty sella. She also developed septic shock and disseminated intravascular coagulation due to post-transplant pyelonephritis. She had reduced urine output and underwent hemodialysis. Both plasma cortisol and adrenocorticotropic hormone levels were relatively low (5.2 μg/dL and 13.5 pg/mL, respectively), which also suggested adrenal insufficiency. She was treated with hormone replacement therapy and antibiotics, successfully recovered from septic shock, and was withdrawn from dialysis. In empty sella syndrome, the somatotropic and gonadotropic axis are the most affected, followed by the thyrotropic and corticotropic axis. She did not present these abnormalities, which may suggest that empty sella syndrome is a separate pathology, and the axis suppression had occurred due to long-term steroid treatment. Diarrhea due to cytomegalovirus colitis might have induced steroid malabsorption and manifested adrenal insufficiency. Secondary adrenal insufficiency should be investigated as a cause of hyponatremia. It should always be borne in mind that diarrhea during oral steroid treatment may cause adrenal insufficiency associated with steroid malabsorption.

The Prevalence and Risk Factors for Urinary Tract Infection in Kidney Transplant Recipients in the First Year After Transplantation

Background: End-stage renal disease (ESRD) needs replacement therapy and most often, kidney transplantation is the best therapeutic option. Urinary tract infection (UTI) is one of the most important complications after renal transplantation that affects transplantation outcomes. Objectives: This study aimed to define the incidence rate, UTI risk factors among kidney transplant recipients, and causative organism of UTI and their antibiotic susceptibility. Methods: In this cross-sectional study, we collected clinical, demographic, and laboratory data from 268 transplant recipients in Ali-Asghar Hospital from 2011 - 2018. Data collected from patients were analyzed with SPSS software version 25. Results: According to the results, 50 (18.7%) had UTI in the first year after renal transplantation. Female gender and underlying cause of renal failure were predisposing factors for UTI. The most common causative organism was Escherichia coli (58.4%). The antibiotic susceptibility results showed nitrofurantoin and meropenem as the most effective antibiotics for Escherichia coli. Conclusions: The UTI was more common in women and patients with analgesic nephropathy and lupus nephritis. The most common causative organism was E. coli and meropenem and nitrofurantoin were the most effective drug choices.

Caracterización de la infección urinaria y resistencia antimicrobiana en receptores de trasplante renal de un centro colombiano

La infección del tracto urinario (ITU) es una de las principales complicaciones postrasplante renal, los datos a nivel nacional en ese grupo poblacional son limitados.

Objetivos caracterizar la microbiología de las ITU presentadas en receptores de trasplante renal (TxR) en un centro colombiano durante el periodo 2017–2019, los factores relacionados con la resistencia antimicrobiana y el impacto de la ITU en la función del injerto renal.

Métodos estudio de corte transversal ejecutado mediante el análisis de la base de datos de ingresos hospitalarios por urgencias de pacientes receptores de TxR con sospecha clínica de ITU en una institución de cuarto nivel en Bogotá, Colombia. El análisis de datos se ejecutó en STATA 13.0.

Resultados La ITU causó 12,69% de visitas a urgencias en pacientes trasplantados. Los microorganismos aislados fueron: Escherichia coli 52,22%, Klebsiella pneumoniae 16,67%, Pseudomonas aeruginosa 4,44%, Salmonella spp 4,44%, Proteus mirabilis 3,33%, Serratia marcescens 2,22%, Klebsiella oxytoca 2,22%, Citrobacter koseri 1,11%, Enterobacter cloacae 1,11%, otros 2,22%; El urocultivo fue negativo en 10% de los casos. El 28,39% (n:23) de gérmenes aislados fue multisensible mientras que el 71,60% (n:58) expresó algún tipo de patrón de resistencia distribuido así: 68,96% productor de betalactamasa de espectro extendido (BLEE), 15,52% productor de carbapenemasas, 12,06% productor de betalactamasa tipo IRT, 3,45% fue catalogado como multirresistente. 17,78% de los pacientes presentó criterios de urosepsis, no se registró ningún caso de mortalidad asociada a la ITU. La creatinina sérica tuvo un incremento promedio de 0,46 mg/dl durante el episodio de ITU (p: <0,0001) y el antecedente de diabetes mellitus se relacionó con la ITU causada por gérmenes resistentes (p: 0,008).

Conclusiones La ITU es una causa frecuente de atención en urgencias para pacientes receptores de TxR; la Escherichia coli es el microorganismo causal más frecuente y cerca del 70% de los gérmenes aislados presentó algún patrón de resistencia antimicrobiana.

Urinary tract infections in renal transplant recipients at a quaternary care centre in Australia

Background

Urinary tract infections (UTI) are the most common of infections after renal transplantation. The consequences of UTIs in this population are serious, with increased morbidity and hospitalisation rates as well as acute allograft dysfunction. UTIs may impair overall graft and patient survival. We aimed to identify the prevalence and risk factors for post-transplant UTIs and assess UTIs’ effect on renal function during a UTI episode and if they result in declining allograft function at 2 years post-transplant. Additionally, the causative organism, the class of antibacterial drug employed for each UTI episode and utilisation rates of trimethoprim/sulfamethoxazole (TMP/SMX) prophylaxis were also quantified.

Methods

This was a retrospective study of 72 renal transplant patients over a 5-year period who were managed at the Royal Brisbane and Women’s Hospital. Patient charts, pathology records and dispensing histories were reviewed as part of this study and all UTIs from 2 years post transplantation were captured.

Results

Of these patients, 20 (27.8%) had at least one UTI. Older age (p = 0.015), female gender (p < 0.001), hyperglycaemia (p = 0.037) and acute rejection episodes (p = 0.046) were risk factors for developing a UTI on unadjusted analysis. Female gender (OR 4.93) and age (OR 1.03) were statistically significant risk factors for a UTI on adjusted analysis. On average, there was a 14.4% (SEM 5.20) increase in serum creatinine during a UTI episode, which was statistically significant (p = 0.027), and a 9.1% (SEM 6.23) reduction in serum creatinine after the UTI episode trending toward statistical significance.

(p = 0.076). Common organisms (Escherichia coli and Klebsiella pneumoniae) accounted for 82% of UTI episodes with 70% of UTI cases requiring only a single course of antibiotic treatment. Furthermore, the antibiotic class used was either a penicillin (49%) or cephalosporin (36%) in the majority of UTIs. The use of TMP/SMX prophylaxis for Pneumocystis carinii pneumonia prophylaxis did not influence the rate of UTI, with > 90% of the cohort using this treatment.

Conclusions

There was no significant change in serum creatinine and estimated glomerular filtrate rate from baseline to 2 years post-transplant between those with and without a UTI.

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.

Prevalence of Sexually Transmitted Diseases in Asymptomatic Renal Transplant Recipients

OBJECTIVES

Sexually transmitted diseases, which may be asymptomatic, have the potential to cause serious health problems in renal transplant recipients. The aim of this study was to determine the prevalence of sexually transmitted diseases in sexually active asymptomatic renal transplant patients by using real-time multiplex polymerase chain reaction assays.

MATERIALS AND METHODS

This prospective controlled study was conducted between November 2016 and January 2017 in our hospital. Our study group included 80 consecutive, sexually active asymptomatic patients (40 men and 40 women) who had undergone renal transplant in our hospital and who presented to our outpatient clinic for routine follow-up. We also included a control group of 80 consecutive, sexually active nontransplant patients (40 men and 40 women). All patient samples were tested for Gardnerella vaginalis and obligate anaerobes (Prevotella bivia, Porphyromonas species), Candida species, Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma species, Trichomonas vaginalis, Neisseria gonorrhoeae, Chlamydia trachomatis, herpes simplex virus 1 and 2, and Cytomegalovirus by real-time multiplex polymerase chain reaction.

RESULTS

The prevalences of infection with Gardnerella vaginalis and obligate anaerobes (P = .043), Ureaplasma species (P = .02), and Cytomegalovirus (P = .016) were found to be significantly higher in the study group versus the control group. However, there was no difference between the 2 groups regarding the prevalence of Mycoplasma infection (P = .70).

CONCLUSIONS

Sexually transmitted diseases may occur more frequently in sexually active asymptomatic renal transplant recipients than in nontransplanted individuals. Real-time multiplex polymerase chain reaction analysis may be a suitable method for determining these pathogens.

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.

Surgical management of vesicoureteral reflux with recurrent urinary tract infection after renal transplantation in a dog

CASE DESCRIPTION A 3-year-old male Cocker Spaniel renal transplant recipient was readmitted 39 weeks after transplantation because of acute clinical signs of pollakiuria, intermittent vomiting, decreased appetite, lethargy, and mild fever. CLINICAL FINDINGS Hydronephrosis and hydroureter were observed with ultrasonography and contrast cystography, and a diagnosis of vesicoureteral reflux (VUR) was made. Urinary tract infection (UTI) caused by Escherichia coli was also diagnosed on the basis of results of urine culture. TREATMENT AND OUTCOME Despite treatment of the UTI with an appropriate antimicrobial for 6 weeks, the VUR persisted and the UTI recurred 9 weeks after cessation of antimicrobial treatment. Therefore, surgical correction by means of revision extravesicular ureteroneocytostomy was performed. Both VUR and hydronephrosis resolved after surgery. No recurrences of clinical signs of urinary tract complications were observed during the subsequent 22-month follow-up period. CLINICAL RELEVANCE Results suggested that ureteral reimplantation with an extravesicular technique incorporating a long submucosal tunnel may be an effective treatment for VUR when medical management fails in canine renal transplant recipients with recurrent UTIs.

Early Infections in Renal Transplant Recipients: Incidence, Risk Factors, and Causative Microorganisms

OBJECTIVES

This study aimed to compare renal transplant recipients with and without infection with respect to demographic and clinical characteristics as well as risk factors; to determine the incidence of posttransplant infections; and to study the antibiotic resistance patterns of bacterial species identified as the causative organisms in posttransplant infections.

MATERIALS AND METHODS

This study included a total of 136 patients undergoing renal transplant in a 4-year period. The patients were categorized into 2 groups. The 2 groups were compared with each other with respect to general clinical and demographic variables and the number and frequency of infectious attacks within a 1-year follow-up, infection type, and antibiotic resistance patterns.

RESULTS

Ninety-two (67.6%) of the subjects were male and 44 (32.4%) were female. A total of 57 (41.9%) patients developed 128 infectious attacks. Urinary tract infections were the most common infections (42.1%). There was a significant correlation between a clinically relevant urinary culture proliferation and postoperative infection rate (P = .002). There was a significant correlation between antimicrobial resistance and the number of infectious attacks (P = .023). There was a significant correlation between the proliferation of Extended Spectrum Beta Lactamase-positive Enterobactericeae species and the number of infectious attacks (P = .000).

CONCLUSIONS

Presence of a clinically relevant proliferation in the preoperative urinary culture, which was identified as a risk factor for infection, increased the number of infectious attacks. Moreover, Extended Spectrum Beta Lactamase-positive Enterobactericeae species increased the number of infections. These 2 principle results should be taken into account in patient management.

BK Virus Nephropathy in Kidney Transplantation: An Approach Proposal and Update on Risk Factors, Diagnosis, and Treatment

BK virus belongs to Polyomaviridae family; it causes 95% of nephropathy cases related to polyomavirus, with the other 5% caused by JC virus. Nephropathy jeopardizes graft function, causing a premature failure of the graft in 1%-10% of patients with kidney transplants. Nowadays, antiviral effective treatment is unknown, which is why blood and urine screening of renal transplantation patients has become the most important recommendation to guide the decrease of immunosuppression, and the only proven method to decrease poor outcomes. Different interventions, such as cidofovir, leflunomide, fluoroquinolones, and intravenous immunoglobulin, have been attempted with no improvement at all. This review aims to summarize the most relevant features of BK virus, historical issues, transmission mechanisms, risk factors, and therapeutic interventions.

Acute pyelonephritis in transplanted kidneys: can diffusion-weighted magnetic resonance imaging be useful for diagnosis and follow-up?

PURPOSE

To assess reliability of diffusion-weighted magnetic resonance imaging (DW-MRI) in the management of acute pyelonephritis (APN) foci in transplanted kidneys.

MATERIALS AND METHODS

In the 2012-2014 period, 24 kidney-transplanted patients underwent MR screening for clinical suspicion of APN. Two readers independently analyzed all images, establishing presence and location of APN foci. The 22 patients who were positive at the MR exam constituted the study population. For each patient the apparent diffusion coefficient (ADC) was measured in the APN foci and in three sites of the healthy parenchyma (case-control comparison). The data were matched to the laboratory measurements for white blood cell, C-reactive protein, and serum creatinine.

RESULTS

Forty-six APN foci were found in 22/24 patients. At the acute stage, the difference in ADC between healthy parenchyma and APN foci was significant (2.06 ± 0.16 vs. 1.43 ± 0.32 × 10(-3) mm(2)/s; p < 0.0001). The performance of ADC as APN indicator was tested by the receiving operating characteristics (ROC) curve: the area under curve AUC = 0.99 witnessed an excellent discriminatory ability, with threshold APN/normal parenchyma 1.9 × 10(-3) mm(2)/s. At the 1-month follow-up 43/46 APN foci were no longer visible, with ADC values significantly higher than at the acute stage; all laboratory data were physiological, with WBC significantly reduced from the acute phase (5.2 ± 1.6 × 10(9)/L vs. 10.6 ± 4.8 × 10(9)/L; p < 0.0001). The other 3 patients underwent further therapy and exams, including a third MR.

CONCLUSIONS

DW-MRI with ADC measurement seems to be a reliable tool in diagnosing and monitoring APN foci in transplanted kidneys, with clinical impact on patient management.

Antibiotic selective pressure and development of bacterial resistance detected in bacteriuria following kidney transplantation

INTRODUCTION

Bacteriuria (symptomatic and asymptomatic) is the most common infectious complication after kidney transplantation. This study aimed to determine its prevalence among kidney transplant recipients hospitalized after transplantation, respective risk factors, and frequency of isolates and antibacterial susceptibility.

METHODS

Retrospectively, we divided hospitalized patients into 3 groups. Groups 1 and 2 included 78 and 152 recipients with and without bacteriuria, respectively, and the potential risk factors were compared. Cefixime was prescribed as early postsurgical prophylaxis. Group 3 patients were 116 randomly selected nontransplantation patients with urinary tract infection. Frequency of uropathogens and their antibiotic susceptibility were compared in groups 1 and 3.

RESULTS

In total, 103 bacteriuria episodes were detected in 15.2% of the patients. The frequency of risk factors in groups 1 and 2 was similar. Escherichia coli was the most common isolate in groups 1 (40.8%) and 3 (68.1%; P = .03). Streptococcus faecalis was the most common gram-positive isolate in groups 1 (17.5%) and 3 (6.9%; P = .03). Sensitivity rates in group 1 were 9% to trimethoprim-sulfamethoxazole, 20% to ciprofloxacin, and 38.4% to gentamicin, which was not significantly different from group 3. However, the sensitivity rates of gram-negative isolates to ceftriaxone were 9.5% and 28.4% (P = .004) in groups 1 and 3, respectively, and to cefixime 4.5% and 22% (P = .01).

DISCUSSION

High antibacterial resistance of uropathogens isolated from kidney transplantation and nontransplantation patients is alarming. The higher resistance to third-generation cephalosporins in transplant recipients may be due to antibiotic selection pressure secondary to postsurgical prophylaxis with cefixime.

[Management of urological complications after renal transplantation]

Urological complications after kidney transplantation can cause a major reduction in renal function. Surgical complications like urinary leakage and ureteral obstruction need to be solved by a specialist in the field of endourological procedures and open surgical interventions. The article summarizes this and other common urological problems after kidney transplantation.

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.

Vitamin D deficiency is an independent risk factor for urinary tract infections after renal transplants

Vitamin D deficiency is frequently found in patients with renal transplants (RTxs). Because vitamin D plays indispensable roles in the immune system, there may be an association between vitamin D deficiency and infection in these patients, but this has not been fully elucidated. Therefore, this study investigated the impact of pre-RTx vitamin D deficiency on urinary tract infection (UTI) development after RTx.We measured 25-hydroxyvitamin D3 (25(OH)D3) levels in 410 patients 2 weeks before they underwent RTx. Vitamin D deficiency was defined as 25(OH)D3 <10 ng/mL. The primary outcome was UTI occurrence after RTx. Cox proportional hazard analysis determined whether vitamin D deficiency was independently associated with UTI.The mean 25(OH)D3 level was 12.8 ± 6.9 ng/mL, and 171 patients (41.7%) were vitamin D deficient. During a median follow-up duration of 7.3 years, the UTI incidence was significantly higher in vitamin D-deficient patients (52 patients, 30.4%) compared with vitamin D-nondeficient patients (40 patients, 16.7%) (P = 0.001). Moreover, multivariate Cox proportional hazard analysis showed that vitamin D deficiency was an independent predictor of UTI after RTx (hazard ratio 1.81, 95% confidence interval 1.11-2.97, P = 0.02).Vitamin D deficiency was an independent risk factor for UTI after RTx; hence, determining 25(OH)D3 levels might help to predict infectious complications after RTx.

Predictive factors of infection in the first year after kidney transplantation

BACKGROUND

Infectious disease, a complication favored by immunosuppression, is the main cause of 1st-year mortality in solid organ transplantation. In renal transplant recipients (RTRs), urinary tract infection (UTI) is the most common, and the microorganisms that are isolated depend on chronology.

METHODS

We present an observational study comprising 129 RTRs from January 2010 to December 2011 who were followed during the 1st year after transplantation. We analyzed occurrence of infections, predisposing factors, timing, severity, site of infection, and microorganisms.

RESULTS

The patients had a total of 424 infectious episodes during the 1st year (3.29 episodes/patient/year). The predominant focus was the urinary tract, with at least 1 episode in 69.8% of patients. Bacteremia was recorded in 25.6% of patients and surgical wound infection in 20.9%. Cytomegalovirus infection or disease was diagnosed in 46.5%. Severe infections occurred in 30.2%. The predominant pathogen was E. coli. There was a significant correlation between hospital stay and the number of infections (P = .000; r = 0.407) and between body mass index and hospital stay (P = .001; r = 0.282). Severe infections were more frequent in diabetics, patients with a double-J stent, and those treated with basiliximab. Patients with cytomegalovirus replication had a higher number of infections (4.1 ± 1.2 vs 2.5 ± 5; P = .000) and significantly higher annual serum creatinine (1.65 ± 5.7 vs 1.31 ± 1.3 mg/dL; P = .003).

CONCLUSIONS

The prevalence of infections in the 1st year after kidney transplantation is very high, occurring mainly in the early period, in the urinary tract, and due to E. coli. Cytomegalovirus replication is associated with a higher number of infections and higher serum creatinine at 1 year. Body mass index is a predictor of early infection and of bacteremia in the post-transplantation period. Basiliximab induction and having a double-J stent were predictors of severe infections.