Bacterial urinary tract infection after solid organ transplantation in the RESITRA cohort

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.

Host and microbial factors in kidney transplant recipients with Escherichia coli acute pyelonephritis or asymptomatic bacteriuria: a prospective study using whole-genome sequencing

BACKGROUND

Urinary tract infection is the most common infection among kidney transplant recipients (KTRs). Many transplant physicians fear that host compromise will allow low-virulence strains to cause pyelonephritis in KTRs, so they often treat asymptomatic bacteriuria with antibiotics. Identification of the host/microbe factors that determine the clinical presentation (i.e. pyelonephritis versus asymptomatic bacteriuria) once an Escherichia coli strain enters a KTRs bladder could inform management decisions.

METHODS

We prospectively collected all E. coli isolates causing either pyelonephritis or asymptomatic bacteriuria in KTRs at our institution (December 2012-June 2015). Whole-genome sequencing was used to assess bacterial characteristics (carriage of 48 virulence genes and phylogenetic and clonal background). Host parameters were also collected.

RESULTS

We analysed 72 bacteriuria episodes in 54 KTRs (53 pyelonephritis, 19 asymptomatic bacteriuria). The pyelonephritis and asymptomatic bacteriuria isolates exhibited a similar total virulence gene count per isolate [median 18 (range 5-33) and 18 (5-30), respectively; P = 0.57] and for individual virulence genes differed significantly only for the prevalence of the pap operon (pyelonephritis 39%,versus asymptomatic bacteriuria 0%; P = 0.002). No other significant between-group differences were apparent for 86 other bacterial and host variables.

CONCLUSIONS

Our findings suggest that bacterial adherence plays a role in the pathogenesis of pyelonephritis in KTRs despite significantly altered host urinary tract anatomy and weakened immunity. Whether KTRs might benefit from targeted therapies (e.g. vaccination or inhibitors of fimbrial adhesion) has yet to be studied.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Preventing sepsis development in complicated urinary tract infections

Introduction: Urinary tract infections (UTIs) are the most prevalent infections in the community and the most common reason for antimicrobial prescribing in ambulatory care. A UTI is defined as complicated when urinary tract anatomical abnormalities or urinary devices are present, when it is recurrent and when associated with immunodeficiency. Complicated UTIs (cUTIs) have a higher risk of treatment failure and often require longer antimicrobial treatment courses. cUTIs, especially those which are healthcare-associated, are often due to multidrug resistant organisms (MDROs).Areas covered: This article will review the available evidence in relation to prevention of sepsis in cUTI, evaluating the risk factors associated with sepsis development. Published articles from January 2005 to September 2019 on UTIs and sepsis prevention in complicated UTIs were identified by using MEDLINE (National Library of Medicine Bethesda MD) and by reviewing the references of retrieved articles.Expert opinion: Prevention of sepsis relies on prompt and timely diagnosis of cUTI, early identification of the causative organism, removal of obstructions and source control, proper and adequate empirical/targeted antimicrobial treatment. In particular, source control, i.e. removal of urinary obstructions, infected stents, urinary catheters, nephrostomies, and drainage of hydronephrosis/abscess, is essential for preventing the development and progression of sepsis.

Prevalence of asymptomatic bacteriuria among kidney transplant recipients beyond two months post-transplant: A multicenter, prospective, cross-sectional study

BACKGROUND

During routine post-kidney transplant care, most European transplant physicians screen patients for asymptomatic bacteriuria. The usefulness of this strategy is debated. To make screening cost-effective, asymptomatic bacteriuria should be prevalent enough to justify the expense, and antibiotics should improve patient outcomes significantly if asymptomatic bacteriuria is detected. Regrettably, the prevalence of asymptomatic bacteriuria among kidney transplant recipients is not well defined.

METHODS

To determine the prevalence of asymptomatic bacteriuria among kidney transplant recipients, we did a cross-sectional study among kidney transplant recipients undergoing routine surveillance in three outpatient transplant clinics in Belgium and France. We excluded patients who were in the first two months post-transplantation and/or had a urinary catheter. Asymptomatic participants who had a urine culture with one organism isolated at ≥ 105 CFU/mL were asked to provide a confirmatory urine specimen. Asymptomatic bacteriuria was defined per Infectious Diseases Society of America guidelines.

RESULTS

We screened 500 consecutive kidney transplant recipients. Overall, the prevalence of asymptomatic bacteriuria was 3.4% (17/500 patients). It was similarly low among kidney transplant recipients who were between 2 and 12 months after transplantation (1.3%, 1/76 patients) and those who were farther after transplantation (3.8%, 16/424 patients: p = 0.49). Asymptomatic bacteriuria was significantly associated with female gender (risk ratio 3.7, 95% CI 1.3-10.3, p = 0.007) and older age (mean age: 61 ± 12 years [bacteriuric participants], versus 53 ± 15 years [non-bacteriuric participants], p = 0.03). One participant's colistin-resistant Escherichia coli isolate carried the globally disseminated mcr-1 gene.

CONCLUSIONS

Among kidney transplant recipients who are beyond the second month post-transplant, the prevalence of asymptomatic bacteriuria is low. Further studies are needed to ascertain the cost-effectiveness of a screen-and-treat strategy for asymptomatic bacteriuria in this population.

Bacterial urinary tract infection among adult renal transplant recipients at St. Paul's hospital millennium medical college, Addis Ababa, Ethiopia

BACKGROUND

Despite significant advances in surgical techniques, immunosuppression protocols, follow up periods and antimicrobial stewardship in modern medicine; post-renal transplantation urinary tract infection remained a major public health problem globally. This multiple serious squeals includes asymptomatic bacteriuria, cystitis and pyelonephritis. Among these, the bacterial origin of infection complications accounts for the most significant clinical, socio-economic impacts in many countries of the world. Therefore, the aim of the study was to investigate the prevalence of bacterial isolates that cause urinary tract infections, assess antibiotic susceptibility pattern among symptomatic and asymptomatic renal transplant recipients attending at St. Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia.

METHODS

A hospital-based cross-sectional study was conducted from December 2017 to August 2018 among 74 renal transplant recipients St. Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia. A first morning voided clean-catch mid-stream urine specimens were collected and 0.001 ml inoculated onto blood and MacConkey agar plates following the standard bacteriological protocols. It was incubated aerobically at 35-37 °C for 24-48 h. Cultural characteristics and series of biochemical tests were used for the identification of isolates to species level based on the standard bacteriological protocols.

RESULTS

A hospital-based cross-sectional study has shown that significant bacteriuria was found in 11/74 (14.9, 95% CI =8.2-24.7) patients. The prevalence among females 6/32 (18.75%) was higher among males 5/42 (11.9%) without significant association (COR = 2.09, 95% CI = 1.04-8.45, P = 0.253). Urinary tract infection was higher in the age group of 35-49 years old (19.3%). Age was statistically significant and stronger independent associated risk factor with crude odds ratio = 3.67, 95% CI = 2.89-20.07 and P = 0.003, respectively. The most prevalent bacteria isolates were Escherichia coli 2(18.2%), Staphylococcus aureus 2(18.2%), Acinetobacter spp. 2(18.2%), Enterococcus spp. 2(18.2%), Coagulase-negative Staphylococci 2(18.2%) followed by Porteus mirabilis 1(9.1%). The majority (80%) of Gram-negative bacteria were resistant to ciprofloxacin, chloramphenicol, and trimethoprim/sulfamethoxazole. Simultaneously, the multidrug-resistant bacterial isolates accounts for 82% among tested kidney allograft recipients.

CONCLUSIONS

In conclusion, the overall prevalence of urinary tract infection in the study participants was relatively low with a prevalence of 14.9%. Majority of the study participants were asymptomatic and a higher percentage of females were involved. The multidrug-resistant bacterial isolates in the present study account for 82%.

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.

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.

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.

Calcineurin inhibitor Tacrolimus impairs host immune response against urinary tract infection

Calcineurin inhibitor Tacrolimus, is a potent immunosuppressive drug widely used in order to prevent acute graft rejection. Urinary tract infection (UTI) is the most frequent infectious complication in renal transplant patients and long-term use of Tacrolimus might be involved in higher susceptibility to bacterial infections. It remains largely unknown how Tacrolimus affects the host innate immune response against lower and upper UTI. To address this issue, we used experimental UTI model by intravesical inoculation of uropathogenic E.coli in female wild-type mice pre-treated with Tacrolimus or solvent (CTR). We found that Tacrolimus pre-treated mice displayed higher bacterial loads (cystitis, pyelonephritis and bacteremia) than CTR mice. Granulocytes from Tacrolimus pre-treated mice phagocytized less E. coli, released less MPO and expressed decreased levels of CXCR2 receptor upon infection. Moreover, Tacrolimus reduced TLR5 expression in bladder macrophages during UTI. This immunosuppressive state can be explained by the upregulation of TLR-signaling negative regulators (A20, ATF3, IRAK-M and SOCS1) and parallel downregulation of TLR5 as observed in Tacrolimus treated granulocytes and macrophages. We conclude that Tacrolimus impairs host innate immune responses against UTI.

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.

INFECÇÕES RELACIONADAS À ASSISTÊNCIA À SAÚDE E FATORES ASSOCIADOS NO PÓS-OPERATÓRIO DE TRANSPLANTE HEPÁTICO

RESUMO Objetivo: identificar a incidência das infecções relacionadas à assistência à saúde e seus fatores associados, durante o primeiro mês do pós-operatório de pacientes adultos submetidos ao transplante hepático em um hospital público de Fortaleza. Método: estudo retrospectivo, descritivo com abordagem quantitativa, realizado com 53 receptores de fígado no primeiro semestre do ano de 2015. Os dados foram coletados através dos prontuários, fichas ambulatoriais e de notificação de infecções. Resultados: dos pacientes avaliados, 15 (28,3%) apresentaram infecção durante o primeiro mês, em que o mais prevalente foi a sepse clínica (n=6; 37,4%), seguida de infecção do trato respiratório (n=3; 18,8%), trato urinário (n=3;18,8%), sítio cirúrgico (n=3; 18,8%) e por último, infecção de corrente sanguínea (n=1; 6,2%). Os que apresentaram associação estatística em relação a não ocorrência de infecções foram o grupo dos pacientes casados e a indicação de cirrose por hepatite C. A média dos dias de internação no pós-operatório, o uso do imunossupressor micofenolato de mofetil e a média do uso de alguns dispositivos invasivos, foram identificados como os fatores associados à ocorrência de infecções, sendo estatisticamente significativos para p=<0,05. Conclusão: a identificação da incidência das infecções relacionadas à assistência à saúde e seus fatores associados em pacientes submetidos ao transplante hepático, poderá subsidiar o direcionamento das ações de saúde, com a finalidade de diminuir a morbimortalidade associada às infecções e otimizando a recuperação desses pacientes.

Using the Asseco Medical Management Solutions Program to Monitor Patients After Kidney Transplantation

INTRODUCTION

In Poland there is an average of 2.31 doctors per 1000 population (according to the Organization of Economic Cooperation and Development 2016), which is one of the lowest results in all of the European Union countries. With the persistent low number of specialists, the quantity of patients and their medical records keep increasing. In order to facilitate the work of doctors and to improve monitoring of the patients, most medical institutions decided to implement IT systems. At the Department of General and Transplant Surgery of Pomeranian Medical University in Szczecin, we have been using the Asseco Medical Management Solutions (AMMS) system for 5 years. The aim of this study was to evaluate the usefulness of the AMMS system in monitoring and early detection of disorders in renal transplant recipients.

MATERIALS AND METHODS

The retrospective study included 100 patients who underwent surgical treatments between 2012 and 2017. By analyzing the results of laboratory tests (ie, complete blood count), the concentration of creatinine and urea, potassium, and the doses of immunosuppressive drugs, we evaluated the usefulness of the AMMS system.

RESULTS

The clinical usefulness of the AMMS system related to the evaluation of predictors of early graft dysfunction has been confirmed. We have saved time in the analysis of medical records.

CONCLUSIONS

The AMMS system improved the management of medical records of patients after surgeries and allowed for the retrospective evaluation of the treatment and its immediate modification. The unification of medical IT systems in Poland would increase the availability of patients' data and support information transfer among all medical institutions. It would enable multifacility scientific meta-analysis.

Does the urinary tract infection caused by carbapenem-resistant Gram-negative bacilli impact the outcome of kidney transplant recipients?

The incidence of urinary tract infection (UTI) after kidney transplantation (KT) caused by multidrug-resistant (MDR) bacteria is growing. The aim of this study was to analyze the impact of UTI caused by carbapenem-resistant Gram-negative bacteria (CR-GNB) in the survival of graft and recipients following KT. This was a retrospective cohort study involving patients who underwent KT between 2013 and 2016. Patients were followed since the day of the KT until loss of graft, death or end of the follow-up period (31th December 2016). The outcomes measured were UTI by MDR following KT and graft and patient survival. Analyses were performed using Cox regression; for the graft and patient survival analysis, we used a propensity score for UTI by CR-GNB to matching a control group. UTI was diagnosed in 178 (23.9%) of 781 patients, who developed 352 UTI episodes. 44.6% of the UTI cases were caused by MDR bacteria. Identified risk factors for UTI by MDR bacteria were DM, urologic disease as the cause of end-stage renal failure, insertion of ureteral stent, carbapenem use, and delayed graft function (DGF). Risk factors for death during the follow-up period were female gender, patients over 60 years old at the time of KT, DM, body mass index over 31.8, UTI caused by CR-GNB. In conclusion, UTIs caused by CR-GNB have great impact on patients' survival after KT.

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.

Infection-related hospitalizations after kidney transplantation in children: incidence, risk factors, and cost

BACKGROUND

Infection is the leading cause of death and hospitalization in renal transplant recipients. We describe posttransplant infections requiring hospitalization, their risk factors and cost in a national pediatric kidney transplantation cohort.

METHODS

Data on renal transplant recipients <20 years were extracted from the French National Medicoadministrative Hospital Discharge database between 2008 and 2013 and matched with the Renal Transplant Database. We used Cox regression to study risk factors of hospitalization and calculated the instantaneous risk of hospitalization per month for all infections and by infection type.

RESULTS

Five hundred and ninety-three patients were included, and 660 infection-related hospitalizations were identified in 260 patients. The leading cause of hospitalization was urinary tract infection (UTI), followed by viral infection (16.6 and 15.6 per 100 person-years, respectively). Risk factors were younger age at transplantation, high number of HLA mismatches, and use cyclosporine rather than tacrolimus as first anticalcineurin treatment. Risk factors varied by infection type. Female gender, uropathy, cold ischemia time, and cyclosporine were associated with increased risk of UTI, while only age at transplantation inversely correlated with virus-related hospitalizations. Instantaneous risk of all infections decreased with time, except for cytomegalovirus (CMV) infection that displayed a peak at 6 months posttransplantation after prophylaxis withdrawal. Total cost of infection-related hospitalizations was 1600 kilo-euro (k€) (933 €/person-years).

CONCLUSIONS

This study highlights the high burden of infection in transplanted pediatric patients, especially the youngest. This should be considered both for pretransplantation information and designing procedures aiming to decrease hospitalization rate and duration.

Risk factors for health care-associated infection in hospitalized adults: Systematic review and meta-analysis

BACKGROUND

Health care-associated infections (HAIs) are a public health problem that increase health care costs. This article aimed to systematically review the literature and meta-analyze studies investigating risk factors (RFs) independently associated with HAIs in hospitalized adults.

METHODS

Electronic databases (MEDLINE, Embase, and LILACS) were searched to identify studies from 2009-2016. Pooled risk ratios (RRs) or odds ratios (ORs) or mean differences (MDs) and 95% confidence intervals (CIs) were calculated and compared across the groups. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.

RESULTS

Of 867 studies, 65 met the criteria for review, and the data of 18 were summarized in the meta-analysis. The major RFs independently associated with HAIs were diabetes mellitus (RR, 1.76; 95% CI, 1.27-2.44), immunosuppression (RR, 1.24; 95% CI, 1.04-1.47), body temperature (MD, 0.62; 95% CI, 0.41-0.83), surgery time in minutes (MD, 34.53; 95% CI, 22.17-46.89), reoperation (RR, 7.94; 95% CI, 5.49-11.48), cephalosporin exposure (RR, 1.77; 95% CI, 1.30-2.42), days of exposure to central venous catheter (MD, 5.20; 95% CI, 4.91-5.48), intensive care unit (ICU) admission (RR, 3.76; 95% CI, 1.79-7.92), ICU stay in days (MD, 21.30; 95% CI, 19.81-22.79), and mechanical ventilation (OR, 12.95; 95% CI, 6.28-26.73).

CONCLUSIONS

Identifying RFs that contribute to develop HAIs may support the implementation of strategies for their prevention, therefore maximizing patient safety.

Urinary tract infections caused by ESBL-producing Enterobacteriaceae in renal transplant recipients: A systematic review and meta-analysis

BACKGROUND

Urinary tract infections (UTIs) are the most common infectious complications among renal transplant recipients (RTR). UTIs caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-PE) have been associated with inferior clinical outcomes and increased financial burden.

METHODS

We performed a systematic review and meta-analysis by searching through the PubMed and EMBASE databases (to May 20, 2016) and identifying studies that reported data on the number of RTR who developed an ESBL-PE UTI.

RESULTS

Our analysis included seven studies, out of 357 non-duplicate articles, that provided data on 2824 patients. Among them, 10% (95% confidence interval [CI] 4%-17%) developed an ESBL-PE UTI over their follow-up periods. The proportion of RTR affected by an ESBL-PE UTI was 2% in North America (95% CI 1%-3%), 5% in Europe (95% CI 4%-6%), 17% in South America (95% CI 10%-27%), and 33% in Asia (95% CI 27%-41%). In addition, patients affected with an ESBL-PE UTI were 2.75-times (95% CI 1.97-3.83) more likely to suffer a recurrent UTI.

CONCLUSIONS

Based on a limited number of studies, one in 10 RTR will develop a UTI caused by an ESBL-PE, and these patients face an almost 3 times greater risk of recurrence. A more rigorous monitoring of RTR, both during and after resolution of their infection, should be evaluated in order to reduce the incidence and the clinical impact of these resistant infections.

Infections in De Novo Kidney Transplant Recipients Treated With the RANKL Inhibitor Denosumab

BACKGROUND

Infections are a major cause of morbidity and mortality in kidney allograft recipients. In this post hoc analysis of a randomized clinical trial which tested the effect of denosumab on bone mineral density, we assessed the impact of this drug on the incidence and severity of infections in the first year after kidney transplantation.

METHODS

In this clinical trial, we randomized 90 de novo kidney transplant recipients shortly after transplantation to either denosumab on top of standard treatment (calcium and vitamin D) (n = 46), or to standard treatment alone (n = 44). Among all adverse events, we analyzed all infections that occurred within the first year after transplantation, and compared their incidence and severity in both groups.

RESULTS

Overall, we identified more infections (n = 146) in the denosumab group than in the control group (n = 99). The most common infections were urinary tract infection (cystitis) (34.9% vs 25.2%), cytomegalovirus viremia (17.8% vs 24.2%), flu-like syndrome (11.6% vs 14.1%), polyoma (BK) viremia (8.2% vs 11.1%), and herpes simplex infections (5.5% vs 4.0%). Episodes of urinary tract infection (cystitis) occurred more often in the denosumab than in the control group (51 vs 25 episodes in 24 vs 11 patients, P = 0.008), whereas episodes of transplant pyelonephritis or urosepsis were not more frequent (3 vs 5 episodes).

CONCLUSIONS

This post hoc analysis reveals that treatment with denosumab to prevent bone loss in first-year kidney transplant recipients was associated with more frequent episodes of urinary tract infections, whereas other infections occurred with similar frequency in both treatment groups.

Management of multidrug resistant Gram-negative bacilli infections in solid organ transplant recipients: SET/GESITRA-SEIMC/REIPI recommendations

Solid organ transplant (SOT) recipients are especially at risk of developing infections by multidrug resistant (MDR) Gram-negative bacilli (GNB), as they are frequently exposed to antibiotics and the healthcare setting, and are regulary subject to invasive procedures. Nevertheless, no recommendations concerning prevention and treatment are available. A panel of experts revised the available evidence; this document summarizes their recommendations: (1) it is important to characterize the isolate's phenotypic and genotypic resistance profile; (2) overall, donor colonization should not constitute a contraindication to transplantation, although active infected kidney and lung grafts should be avoided; (3) recipient colonization is associated with an increased risk of infection, but is not a contraindication to transplantation; (4) different surgical prophylaxis regimens are not recommended for patients colonized with carbapenem-resistant GNB; (5) timely detection of carriers, contact isolation precautions, hand hygiene compliance and antibiotic control policies are important preventive measures; (6) there is not sufficient data to recommend intestinal decolonization; (7) colonized lung transplant recipients could benefit from prophylactic inhaled antibiotics, specially for Pseudomonas aeruginosa; (8) colonized SOT recipients should receive an empirical treatment which includes active antibiotics, and directed therapy should be adjusted according to susceptibility study results and the severity of the infection.

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.

Epidemiology and outcome of antimicrobial resistance to gram-negative pathogens in bacteriuric kidney transplant recipients

BACKGROUND

In kidney transplant recipients, episodes of bacteriuria are often treated regardless of the presence of symptoms because of the lack of clear treatment guidelines suggesting otherwise. This practice may lead to the development of antimicrobial resistance. Our aim was to determine the incidence, determinants, and impact of antimicrobial resistance in kidney transplant recipients with gram-negative bacteriuria.

METHOD

We conducted a single-center, retrospective cohort study in patients who underwent kidney transplantation between January 2008 and June 2013. To identify risk factors for the development of resistance, we used a logistic regression model with generalized estimating equations to account for within-subject correlation.

RESULTS

Among the 318 patients who underwent kidney transplantation during the study period, 147 patients developed 555 gram-negative episodes of bacteriuria. Resistance to trimethoprim-sulfamethoxazole and quinolones, and production of extended-spectrum β-lactamase (ESBL) occurred in 52%, 21%, and 5% of isolated microorganisms, respectively. An increased risk of resistance to quinolones and production of ESBL were associated with concomitant diabetes (odds ratio [OR]: 2.29, 95% confidence interval [CI]: 1.11-4.74), the first year post transplantation (OR: 2.88, 95% CI: 1.36-6.09), and antibiotic treatment in the previous 6 months (OR: 3.36, 95% CI: 1.66-6.81). This resistance profile was also associated with the presence of symptoms, a longer duration of antibiotic treatment, and a higher rate of hospitalization.

CONCLUSION

Antimicrobial resistance to quinolones and production of ESBL were commonly seen, and were shown to demonstrate an adverse impact on outcomes in kidney transplant recipients with gram-negative bacteriuria. The decision on treatment for asymptomatic bacteriuria should be made with caution, given the potential for the selection of resistant strains.

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

BACKGROUND

Infection of the urinary tract (UTI) is the most common form of bacterial infection in renal transplant patients, but its management is still controversial. We compared symptomatic and asymptomatic bacteriuria, treated or untreated, during two different months (summer or winter).

METHODS

This longitudinal, prospective study involved routine urine cultures collected during September 2014 or March 2015. Demographic, clinical, and microbiological characteristics from the patients with positive urine cultures were described. The main outcomes were the need of hospitalization, the bacterial clearance, and the selection of the resistant pathogen.

RESULTS

From the 538 urine cultures collected, only 61 were positive urine cultures. Twenty were untreated asymptomatic bacteriuria (AB), 28 were treated AB, and 13 were treated symptomatic bacteriuria. The more prevalent micro-organisms were E coli (27%), K pneumoniae (11%), and E faecalis (7%). There were no differences in the demographic, clinical, and microbiological characteristics depending on the month when the urine cultures were collected. Only 10 patients required hospitalization during follow-up, and all of them belonged to the treated group. Bacterial clearance after the treatment occurred in 20 patients of the 41 treated (48.9%) and spontaneously in 14 of the 20 patients untreated (70%). Of the treated patients, 47.6% developed a new resistance to another antibiotic.

CONCLUSIONS

Only 7.6% of the routine urine cultures on renal transplant were positive. Untreated AB did not require hospitalization, and 70% had spontaneous bacterial clearance.

Bacterial Infections After Kidney Transplantation: A Single-Center Experience

BACKGROUND

Bacterial infections significantly affect graft loss and mortality after kidney transplantation (KT). We reviewed the frequencies, risk factors, and sources of bacterial infections after KT and their impact on graft and patient survivals.

METHODS

The data of 154 kidney recipients who underwent transplantation from 2010 to 2015 were explored. Donor, recipient, and surgical parameters were collected, and source, type, and frequency of infectious complications, number of infective episodes, multidrug-resistant (MDR) bacteria, and the bacterial spectrum were established.

RESULTS

The most common infection was urinary tract infection, which is in line with the literature. Out of the 154 recipients, 72.1% (n = 111) had at least 1 occasion of a bacterial infection episode with clinical symptoms. It occurred 0-43 months (mean, 19.5 mo) after transplantation. Ninety-three KT recipients (67.9%) developed 274 episodes of infection in the postoperative 1st year (1.8 episodes/patient/y), and 42 patients had admission to the hospital ward (5.2 d/patient/y). MDR was detected in 19.8% of the infections.

CONCLUSIONS

A bacterial infection had no significant impact on survival by itself. However, in case of sepsis graft and patient survivals were lower compared with normal control subjects.

Urinary Tract Infections in Kidney Transplant Recipients Hospitalized at a Transplantation and Nephrology Ward: 1-Year Follow-up

INTRODUCTION

The aim of this study was to investigate risk factors for urinary tract infections (UTI), the causative organisms of UTI and also their management and treatment. In addition, we evaluated the effects of UTI on renal graft function.

METHODS

This analysis included 107 kidney transplant recipients (64% women) with a diagnosis of UTIs confirmed by positive results on urine culture. Type of pathogens, sensitivity to drugs, risk factors for infection, incidence of urosepsis, hospitalization period, treatment methods, and recurrence rates were analyzed. Statistical analysis was performed by using Pearson's χ(2) test, Yates' χ(2) test, the Student t test, Welch's t test, the Mann-Whitney U test, Fisher's exact test, and the Shapiro-Wilk normality test.

RESULTS

The most common species isolated from urine samples included Escherichia coli (42%), Klebsiella pneumoniae (15%), and Enterococcus faecalis (10%). The percentage of multidrug-resistant strains was 31%, and urosepsis was diagnosed in 16% of patients. Recurrences developed in 76% of infected patients. Bricker ureterointestinal anastomosis was performed in 11% of patients. Risk factors for severe infections included: pre-transplantation urinary tract surgery (P = .02), double-J stent insertion (more common in men) during KTx (N = 34; 32%), (P = .021), reoperations following transplantation (P = .36), elevated tacrolimus levels at the time of infection (P = .024). Severe infections were diagnosed in patients with lower eGFRs, were associated with a need for longer hospitalization (P = .04) and escalation of antibacterial treatment. Carbapenems were used in 22 patients (20.5%).

CONCLUSIONS

UTIs were more common in women, in patients with impaired function of the kidney transplant, and in those with a history of urinary tract interventions. Severe infections were associated with a risk of urosepsis, longer hospitalization, and a need for escalation of antibiotic treatment.

Screening for asymptomatic bacteruria at one month after adult kidney transplantation: Clinical factors and implications

OBJECTIVE

Urinary tract infections (UTIs) account for significant morbidity after kidney transplantation (KT). Screening for asymptomatic bacteruria (AB) has proven to be beneficial in certain population including pregnant women; however, it is not well-studied in KT population. We reviewed the incidence, clinical features, and implications of asymptomatic bacteruria one month after KT.

METHODS

A total of 171 adult KT patients (86 [50.3%] living transplants, 87 [50.9%] males, mean age 47.3 ± 13.7 years), between 2005 and 2012, were analyzed. Immunosuppression induction and maintenance were as per protocol. Protocol urine cultures were taken at 1 month post-transplantation. Patients were stratified for presence of AB and analyzed for demographics and clinical parameters. Outcomes of hospitalization for symptomatic UTIs, graft, and patient survival were ascertained.

RESULTS

Forty-one (24%) KT recipients had AB at 30 days post-transplant. Multiresistant organisms accounted for 43.9% of these infections. Logistic regression confirms female sex and deceased donor recipients as independent predictors of 30-day bacteruria, which predicts subsequent hospitalization for symptomatic UTI. One-year patient and graft survival were similar in recipient with or without AB.

CONCLUSION

Asymptomatic bacteruria 30 days post-transplant can be predicted in female recipients and kidneys from deceased donors probably due to anatomical and functional differences respectively. There is increased morbidity of subsequent hospitalization for symptomatic UTI and more research in prevention of UTI is needed, particularly non-antibiotic prophylaxis.

Urinary Tract Infections Among Hospitalized Adults in the Early Post-Liver Transplant Period: Prevalence, Risk Factors, Causative Agents, and Microbial Susceptibility

OBJECTIVES

Urinary tract infections are among the most common infections after liver transplant, especially soon after surgery. This study analyzed urinary tract infections or bacteriuria, their causative agents, and related risk factors in the early period after liver transplant in hospitalized adult transplant recipients in the main liver transplant referral center in Iran.

MATERIALS AND METHODS

In this prospective study, 389 consecutive adult patients who underwent liver transplant at the Nemazee Teaching Hospital were enrolled between October 2014 and October 2015. Risk factors were compared for patients who developed urinary tract infections or bacteriuria ("infection group "; n = 63 [16.2% ]) and patients without evidence of infection ("control group "; n = 211 [54.2% ]). Patients with sites of infection other than the urinary tract were excluded. Antimicrobial sus ceptibility testing was performed using the Kirby-Bauer disk-diffusion method. Univariate and multivariate analyses compared variables between the 2 groups.

RESULTS

Seventy-nine episodes of urinary tract infections or bacteriuria occurred in the infection group. Multiple logistic regression analysis showed that female sex, hospitalization 2 to 7 days before transplant, and frequency of abdominal exploration were 11.0, 5.9, and 3.0 times more common in the infection group than in the control group. The chance of infection rises 1.1 times with each one unit increase of body mass index. The most common infection causes were gram-negative bacteria (n = 50; 63.3%), predominantly Escherichia coli (n = 24; 30.4%); followed by gram-positive bacteria (n = 20; 25.3%), predominantly Enterococcus species (n = 14; 17.8%) that had a high incidence of vancomycin resistance (n = 10; 71.4%); and non-Candida albicans species isolates (n = 9; 11.4%).

CONCLUSIONS

Urinary tract infections are a common infection in hospitalized adult patients soon after liver transplant. Female sex, hospitalization shortly before transplant, more frequent abdominal exploration, and higher body mass index substantially increased the risk of developing such infections in this period.

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.

Should Asymptomatic Bacteriuria Be Systematically Treated in Kidney Transplant Recipients? Results From a Randomized Controlled Trial

The indication for antimicrobial treatment of asymptomatic bacteriuria (AB) after kidney transplantation (KT) remains controversial. Between January 2011 and December 2013, 112 KT recipients that developed one episode or more of AB beyond the second month after transplantation were included in this open-label trial. Participants were randomized (1:1 ratio) to the treatment group (systematic antimicrobial therapy for all episodes of AB occurring ≤24 mo after transplantation [53 patients]) or control group (no antimicrobial therapy [59 patients]). Systematic screening for AB was performed similarly in both groups. The primary outcome was the occurrence of acute pyelonephritis at 24-mo follow-up. Secondary outcomes included lower urinary tract infection, acute rejection, Clostridium difficile infection, colonization or infection by multidrug-resistant bacteria, graft function and all-cause mortality. There were no differences in the primary outcome in the intention-to-treat population (7.5% [4 of 53] in the treatment group vs. 8.4% [5 of 59] in the control group; odds ratio [OR] 0.88, 95% confidence interval [CI] 0.22-3.47) or the per-protocol population (3.8% [1 of 26] in the treatment group vs. 8.0% [4 of 50] in the control group; OR 0.46, 95% CI 0.05-4.34). Moreover, we found no differences in any of the secondary outcomes. In conclusion, systematic screening and treatment of AB beyond the second month after transplantation provided no apparent benefit among KT recipients (NCT02373085).

Incidence, risk factors, and the impact of allograft pyelonephritis on renal allograft function

BACKGROUND

The impact of allograft pyelonephritis (AGPN) on renal allograft function is controversial. In this study, we evaluated the incidence, risk factors, and the impact of AGPN on renal allograft function.

METHODS

Retrospective cohort study in adult renal allograft recipients with 1-year follow-up after transplantation (Tx). Renal allograft function was evaluated by estimated glomerular filtration rate (eGFR) (by Modification of Diet in Renal Disease formula) and 24-h urine protein excretion.

RESULTS

A total of 431 renal allograft recipients were analyzed; 57 (13.2%) developed AGPN within 1 year after Tx. Median time between Tx and AGPN was 50 days. Risk factors for AGPN were the presence of a urological catheter (odds ratio [OR] = 18.93, 95% confidence interval [CI] = 8.00-44.81, P < 0.001) and preceding asymptomatic bacteriuria (ASB) (OR = 2.16, 95% CI = 1.20-3.90, P = 0.009). In 72.7%, the causative microorganism of ASB was identical to that of the succeeding AGPN episode. Multivariable linear regression analysis showed that experiencing AGPN did not decrease the eGFR (P = 0.61) nor did increased proteinuria (P = 0.29) 1 year after Tx. For the eGFR, an interaction was found between AGPN/bacteriuria (BU) and acute rejection (AR): the group experiencing BU preceding AR had significantly (P < 0.001) lower eGFR compared with the group that experienced only AR (21 mL/min/1.73 m² vs. 48 mL/min/1.73 m² ), as a result of increased prevalence of combined rejections within the BU group.

CONCLUSION

Indwelling urological catheters and preceding ASB are associated with developing AGPN. An incident of AGPN itself does not impair renal allograft function 1 year after Tx. However, a relevant interaction occurs between BU and AR, in which the sequence of occurrence of these 2 events synergistically impairs the eGFR.

Pyelonephritis with bacteremia caused by Listeria monocytogenes: A case report

Listeria monocytogenes is a well-known cause of meningitis, colitis, and bacteremia; however, obstructive pyelonephritis caused by L. monocytogenes has never been reported. We herein report on a 90-year-old Japanese woman with obstructive pyelonephritis and bacteremia due to uterus carcinoma invading the ureter. She was admitted to our hospital complaining of fever and chills, and her physical examination revealed left costovertebral angle tenderness. Computed tomography showed hydronephrosis and complete ureteral obstruction due to tumor invasion. Blood and urine cultures upon nephrostomy revealed the growth of L. monocytogenes. We treated the patient with two weeks of intravenous ampicillin and an additional one-week treatment of oral sulfamethoxazole/trimethoprim. This case shows the importance to recognize L. monocytogenes as a potential causative agent of urinary tract infection.

Progressive increase of resistance in Enterobacteriaceae urinary isolates from kidney transplant recipients over the past decade: narrowing of the therapeutic options

BACKGROUND

Antibiotic resistance is an emerging phenomenon in kidney transplantation (KT).

METHODS

We compared species distribution and antimicrobial susceptibility patterns in 1052 isolates from urine cultures obtained in 2 different cohorts of kidney transplant recipients in a single center (Cohort A: 189 patients undergoing KT between January 2002 and December 2004 [336 isolates]; Cohort B: 115 patients undergoing KT between January 2011 and December 2013 [716 isolates]).

RESULTS

Asymptomatic bacteriuria accounted for most of the isolates (86.9% in Cohort A and 92.3% in Cohort B). Klebsiella pneumoniae (9.5% vs. 15.6%), Pseudomonas aeruginosa (1.8% vs. 7.9%), and Enterobacter cloacae (0.6% vs. 3.1%) were significantly more common in Cohort B. The isolation of K. pneumoniae in Cohort B was associated with the occurrence of acute pyelonephritis (9.8% of all K. pneumoniae isolates vs. 2.8% of the remaining uropathogens; P = 0.001). Non-susceptibility rates among Enterobacteriaceae in Cohort B were higher for every class of antibiotics (P ≤ 0.003) with the exception of fosfomycin. Compared to Cohort A, significant increases were seen in isolates from Cohort B for multidrug-resistant (MDR) (43.9% vs. 67.8%, respectively; P = 0.001), extended-spectrum beta-lactamase (ESBL)-producing (6.6% vs. 26.1%; P = 0.001), and carbapenemase-producing Enterobacteriaceae strains (0.0% vs. 5.0%; P = 0.001). Such differences were mostly attributable to K. pneumoniae (as 54.5% and 13.4% of isolates in Cohort B were ESBL-producing and carbapenemase-producing, respectively). MDR isolates were responsible for 69.1% of episodes of symptomatic urinary tract infection in Cohort B.

CONCLUSION

The increase in resistance rates among Enterobacteriaceae uropathogens is significant and may have an effect on KT programs.

The Distribution and Resistance of Pathogens Among Solid Organ Transplant Recipients with Pseudomonas aeruginosa Infections

BACKGROUND

Pseudomonas aeruginosa infection remains a life-threatening complication after solid organ transplantation (SOT). We aimed to investigate the distribution and drug susceptibility of pathogens, and clinical characteristics of SOT recipients with Pseudomonas aeruginosa infections.

MATERIAL/METHODS

A total of 55 SOT recipients who developed 61 episodes of Pseudomonas aeruginosa infections between January 1, 2003 and July 31, 2015 were retrospectively analyzed. The distribution and the drug susceptibility of Pseudomonas aeruginosa were reviewed.

RESULTS

The most common site from which 61 Pseudomonas aeruginosa rods were isolated were the lungs (57.4%, n=37), followed by the blood (27.9%, n=17). There were 35, 18, and 9 recipients accompanied with a serum creatinine level of >1.5 mg/dL, lymphocyte count of <300/mm(3), and a serum albumin level of <30 g/L, respectively. Seven patients each presented with white blood cell count of >15,000/mm(3) and platelet count of <50,000/mm(3). There were 6 (10.9%) cases of septic shocks and 18 (32.7%) deaths. Antibiotic resistance rate of all Pseudomonas aeruginosa to 4 of 10 antibiotics investigated was more than 50%. Of these 61 Pseudomonas aeruginosa isolates, 47.5% were carbapenem-resistant. The rods were relatively sensitive to piperacillin-tazobactam, levofloxacin, amikacin, and cefoperazone-sulbactam (resistance rate <40%).

CONCLUSIONS

The clinical presentation of Pseudomonas aeruginosa infections included high body temperature, decreased platelet count, elevated white blood cell count, a high nosocomial origin and mortality, and onset in the late period after transplantation. According to our findings, piperacillin-tazobactam, levofloxacin, amikacin, and cefoperazone-sulbactam, alone or combination, are recommended to treat SOT recipients with Pseudomonas aeruginosa infections.

The impact of trimethoprim-sulfamethoxazole as Pneumocystis jiroveci pneumonia prophylaxis on the occurrence of asymptomatic bacteriuria and urinary tract infections among renal allograft recipients: a retrospective before-after study

BACKGROUND

The international guidelines recommend the administration of trimethoprim-sulfamethoxazole (TMP-SMX) as Pneumocystis jiroveci pneumonia (PJP) prophylaxis for six months after transplantation. The aim of this study is to evaluate the influence of TMP-SMX prophylaxis on the occurrence of asymptomatic bacteriuria (ASB) and urinary tract infections (UTIs) as cystitis and allograft pyelonephritis (AGPN) and its impact on the antimicrobial resistance pattern of causative microorganisms.

METHODS

We have conducted a retrospective before-after study in adult renal allograft recipients with one year follow-up after transplantation. We compared the ("after") group that received TMP-SMX as PJP prophylaxis to the ("before") group that did not receive it.

RESULTS

In total, 343 renal allograft recipients were analysed, of whom 212 (61.8 %) received TMP-SMX as PJP prophylaxis. In this study, 63 (18.4 %) did only develop ASB without UTI, 26 (7.6 %) developed cystitis and 43 (12.5 %) developed AGPN. The remaining 211 (61.5 %) renal allograft recipients did not develop any bacteriuria at all. Multivariable Cox proportional regression analysis indicated that TMP-SMX as PJP prophylaxis was not associated with reduced prevalence of ASB (Hazard ratio (HR) = 1.52, 95 % CI = 0.79-2.94, p = 0.213), nor with reduced incidence of cystitis (HR = 2.21, 95 % CI = 0.76-6.39, p = 0.144), nor AGPN (HR = 1.12, 95 % CI = 0.57-2.21, p = 0.751). Among the group receiving TMP-SMX as PJP prophylaxis there was a trend was observed in increase of both amoxicillin (86 % versus 70 %) and TMP-SMX (89 % versus 48 %) resistance which already appeared within the first 30 days after TMP-SMX exposure.

CONCLUSIONS

Among renal allograft recipients, administration of TMP-SMX as PJP prophylaxis does not prevent ASB nor UTI, however it is associated with tendency towards increased amoxicillin and TMP-SMX resistance.

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.

Bloodstream infections after solid-organ transplantation

Solid-organ transplantation (SOT) has become the preferred strategy to treat a number of end-stage organ disease, because a continuous improvement in survival and quality of life. While preventive strategies has decreased the risk for classical opportunistic infections (such as viral, fungal and parasite infections), bacterial infections, and particularly bloodstream infections (BSIs) remain the most common and life-threatening complications in SOT recipients. The source of BSI after transplant depends on the type of transplantation, being urinary tract infection, pneumonia, and intraabdominal infections the most common infections occurring after kidney, lung and liver transplantation, respectively. The risk for candidemia is higher in abdominal-organ than in thoracic-organ transplantation. Currently, the increasing prevalence of multi-drug resistant (MDR) Gram-negative pathogens, such as extended-spectrum betalactamase-producing Enterobacteriaciae and carbapenem-resistant Klebsiella pneumoniae, is causing particular concerns in SOT recipients, a population which presents several risk factors for developing infections due to MDR organisms. The application of strict preventive policies to reduce the incidence of post transplant BSIs and to control the spread of MDR organisms, including the implementation of specific stewardship programs to avoid the overuse of antibiotics and antifungal drugs, are essential steps to reduce the impact of post transplant infections on allograft and patient outcomes.

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.

The Impact of Infection on Chronic Allograft Dysfunction and Allograft Survival After Solid Organ Transplantation

Infectious diseases after solid organ transplantation (SOT) are a significant cause of morbidity and reduced allograft and patient survival; however, the influence of infection on the development of chronic allograft dysfunction has not been completely delineated. Some viral infections appear to affect allograft function by both inducing direct tissue damage and immunologically related injury, including acute rejection. In particular, this has been observed for cytomegalovirus (CMV) infection in all SOT recipients and for BK virus infection in kidney transplant recipients, for community-acquired respiratory viruses in lung transplant recipients, and for hepatitis C virus in liver transplant recipients. The impact of bacterial and fungal infections is less clear, but bacterial urinary tract infections and respiratory tract colonization by Pseudomonas aeruginosa and Aspergillus spp appear to be correlated with higher rates of chronic allograft dysfunction in kidney and lung transplant recipients, respectively. Evidence supports the beneficial effects of the use of antiviral prophylaxis for CMV in improving allograft function and survival in SOT recipients. Nevertheless, there is still a need for prospective interventional trials assessing the potential effects of preventive and therapeutic strategies against bacterial and fungal infection for reducing or delaying the development of chronic allograft dysfunction.