Urinary Tract Infection In Kidney Transplant Recipients Research Articles

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

Background Urinary tract infections (UTIs) are the most common infections following kidney transplantation. Risk factors for UTIs in kidney transplant recipients include female gender, age, pre-transplant urinary tract abnormalities, diabetes, and recurrent UTIs. Infections of the bladder or urethra are termed lower UTIs, while those involving the kidneys or ureters are called upper UTIs. Methods We retrospectively screened our hospital information system to identify all patients who underwent kidney transplantation in the surgery department at King Abdulaziz Medical Center in Riyadh. A total of 553 records were ultimately included in the final analysis. Results A total of 553 patients were ultimately included in the analysis. More than half of the patients were males (62.4%), and 31.1% were aged between 45 and 60 years. Of these, 230 patients had a UTI, representing 41.59% of the sample. The most commonly reported causes were hypertensive nephrosclerosis (43.4%) and diabetic nephropathy (28.8%). The most frequently isolated causative agents were Escherichiacoli (51.0%) and Klebsiella pneumoniae (21.8%). UTIs were significantly more prevalent among females, accounting for 73.6% of cases. Antibiotics were used in 86.5% of patients, with trimethoprim/sulfamethoxazole (65.8%) and ciprofloxacin (54.8%) being the most commonly prescribed. Conclusion About half of the patients in this study suffered from UTIs. E. coli and K. pneumoniae were the most commonly isolated organisms. Trimethoprim/sulfamethoxazole and ciprofloxacin were the most frequently prescribed antibiotics. A significant association was found between acquiring a UTI and being female (p < 0.001), as well as having pre-existing bladder dysfunction (p = 0.024).

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

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

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

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

1418. Single Center Treatment Patterns for Asymptomatic Bacteriuria and UTIs in Kidney Transplant Recipients: Are We Still Overtreating?

BackgroundIn February 2019, the American Society of Transplantation (AST) published guidelines on the management of asymptomatic bacteriuria (AB) and urinary tract infections (UTIs) in kidney transplant (KT) recipients. These recommendations include avoiding treatment of AB > 2 months post-transplant and outline the duration of treatment (DT) for uncomplicated and complicated UTIs. We reviewed management of these syndromes and guideline concordance at our institution.MethodsWe conducted a single-center, retrospective cohort study of KT recipients age > 18 years who underwent transplantation between June 2016 - June 2020. Patients were obtained through query of our electronic medical record for documented UTI syndromes and included if a diagnosis was confirmed between March 2019 - December 2020 upon chart review. Definitions of AB, complicated UTI, and uncomplicated UTI were based on AST definitions. Patients with AB < 2 months post-transplant were excluded. Outcomes included treatment of AB, DT, 30-day hospital admission and re-admission, and 30-day mortality. Bivariate analysis was conducted using chi square and t test. ResultsSeventy-four patients (mean age 55.4 years, 62.0% female) were included. Twenty-one patients had AB, 90% of whom received antibiotics. Distribution of diagnoses and median DT among those treated with antibiotics is outlined in Table 1. Overall DT was similar in patients whose care included infectious disease (ID) input and those who did not (10.0 vs. 10.0 days, p=0.12), although ID involvement was more common in complicated UTIs. There was no difference in 30-day admission rates for those receiving < 7 days vs. > 7 days of antibiotics (p=0.53) (Table 2) including those with complicated UTIs (5/15 in < 7 days (33%) vs. 4/18 in > 7 days (22%) p=0.49). There were no deaths within 30 days of diagnoses. ConclusionDespite guidelines, treatment of AB is common and uncomplicated UTIs often receive prolonged courses of antibiotics. There was no increased risk of admission or mortality with shorter DT, though these results should be interpreted cautiously given the small sample size. Greater stewardship efforts are needed in this high-risk population.Disclosures Kelsie Cowman, MPH, Merck (Research Grant or Support)

The retrospective analysis of urinary tract infection in renal transplant recipients

Infection is the most common reason for admission to the emergency department in the early period after transplantation. Urinary tract infections (UTIs) in adult kidney transplant patients are common. Their incidence is significantly higher than in the general population.1 The majority of sepsis cases in this period are composed of UTIs.2 While mild UTIs generally do not affect graft function, acute pyelonephritis observed in the post-transplant period causes a decrease in graft function and an increase in mortality.3 In the literature, a small amount of data has been published regarding the incidence, epidemiological features, and risk factors of UTIs in kidney transplant recipients. In this retrospective study, we evaluated the data of 550 patients who underwent kidney transplantation between January 2006 and May 2019 at our center and analyzed UTIs' characteristics.&#x0D; Among 550 recipients, 633 episodes were detected in 200 patients (36.4%). Recurrent infection was encountered in 74 (37%) of 200 patients. We determined 1 episode in 63 (31.5%), 2 episodes in 39 (19.5%), 3 episodes in 31 (15.5%), 4 episodes in 14 (7%), 5 episodes in 10 (5%), 6 episodes in 8 (4%), and 7 or more episodes in 35 (17.5%). While 48.3% (n=306) of 633 episodes were asymptomatic bacteriuria, 51.6% (n=327) was symptomatic. The risk factors for UTI were female gender, the advanced age of transplant and advanced donor age, long-term dialysis period before transplant, prolonged urinary catheterization and hospitalization time after transplant, cytomegalovirus infection, vesicoureteral reflux, and neurogenic bladder history. At the survival analysis, a transplant from living donor, female gender, use of tacrolimus, mycophenolate mofetil and corticosteroid combination as maintenance immunosuppressive therapy, preemptive transplant compared to patients receiving peritoneal dialysis was found to be associated with longer survival; advanced age of transplant, obesity, delayed graft function, acute rejection, diabetes mellitus and a history of cytomegalovirus infection was also associated with a shorter life span. Escherichia coli (64.9%) and Klebsiella pneumonia (51.6%) were the most common causative microorganisms, and ESBL (Expanded Spectrum Beta-Lactamase) was positive in 19.9% and 67.5% of them, respectively. &#x0D; Similarly, female gender, the advanced age of transplant, prolonged catheterization time, history of vesicoureteral reflux, neurogenic bladder, acute rejection, and deceased donor were dependent risk factors for developing of UTI in transplant recipients in other studies,4-6 but not body mass index, history of diabetes mellitus, dialysis type and duration, primary kidney disease, donor type, delayed graft function, and history of acute rejection in another study.7 UTI frequency in the female gender increases due to anatomical differences such as the shorter urethra compared to men and its relative proximity to the perianal region and vulva, as in the general population. Age-related changes in the urinary tract and existing additional diseases are important factors that predispose to bacterial colonization. Prolonged urinary catheterization and hospitalization durations facilitate pathogen entry into sterile body parts in the post-operative period. Immunosuppression, frequent hospitalizations, and surgical interventions increase the risk of nosocomial infections in dialysis patients. A history of vesicoureteral reflux facilitating bacterial invasion and a neurogenic bladder causing urinary stasis poses a UTI risk. &#x0D; Hospitalizations for septicemia are most commonly associated with UTI.8 In our cohort, antibiotics in the carbapenem group, started in more than half of the episodes. There is an increase in trimethoprim/sulfamethoxazole, ciprofloxacin and ceftazidime resistance in Klebsiella species.9 Although the microorganism spectrum in the studies is similar all world, ESBL positivity is noticeably higher than the average in UTI episodes is an observation in parallel with the increasing antibiotic resistance both in our country and in the world in recent years. This observation was considered as a cautionary finding for the review of antibiotic selection preferences in our clinic. Finally, UTIs being a threat to graft and patient survival in the post-transplant period should be treated effectively by carefully evaluating risk factors.

Asymptomatic bacteriuria and urinary tract infections in kidney transplant recipients.

Urinary tract infection (UTI) is the most common infection in kidney transplant recipients (KTRs). Several elements increase the risk of UTI and/or modify its clinical presentation among KTRs (e.g. immunosuppressive therapy, kidney allograft denervation, and use of urinary catheters). Also, KTRs may have UTIs because of difficult-to-identify and/or difficult-to-treat organisms. We provide an overview of the current knowledge regarding bacterial UTIs in KTRs, with a focus on recent findings. There is accumulating evidence from clinical trials that screening for and treating asymptomatic bacteriuria is not beneficial in most KTRs (i.e. those who are ≥1-2 months posttransplant and do not have a urinary catheter). These patients have a point-prevalence of asymptomatic bacteriuria of only 3% and treating asymptomatic bacteriuria probably does not improve their outcomes. There is no clinical trial evidence to guide the management of symptomatic UTI in KTRs. Several important clinical questions remain unanswered, especially regarding the management of posttransplant pyelonephritis and the prevention of UTI in KTRs. Despite its frequency and associated morbidity, UTI after kidney transplantation is an understudied infection. In an era of increasing antimicrobial resistance and limited resources, further research is needed to ensure optimal use of antimicrobials in KTRs with UTI.

Antibiotics versus no therapy in kidney transplant recipients with asymptomatic bacteriuria (BiRT): a pragmatic, multicentre, randomized, controlled trial

ObjectivesMany transplant physicians screen for and treat asymptomatic bacteriuria (ASB) during post-kidney-transplant surveillance. We investigated whether antibiotics are effective in reducing the occurrence of symptomatic urinary tract infection (UTI) in kidney transplant recipients with ASB. MethodsWe performed this multicentre, randomized, open-label trial in kidney transplant recipients who had ASB and were ≥2 months post-transplantation. We randomly assigned participants to receive antibiotics or no therapy. The primary outcome was the incidence of symptomatic UTI over the subsequent 12 months. ResultsOne hundred and ninety-nine kidney transplant recipients with ASB were randomly assigned to antibiotics (100 participants) or no therapy (99 participants). There was no significant difference in the occurrence of symptomatic UTI between the antibiotic and no-therapy groups (27%, 27/100 versus 31%, 31/99; univariate Cox model: hazard ratio 0.83, 95%CI: 0.50–1.40; log-rank test: p 0.49). Over the 1-year study period, antibiotic use was five times higher in the antibiotic group than in the no-therapy group (30 antibiotic days/participant, interquartile range 20–41, versus 6, interquartile range 0–15, p < 0.001). Overall, 155/199 participants (78%) had at least one further episode of bacteriuria during the follow-up. Compared with the participant's baseline episode of ASB, the second episode of bacteriuria was more frequently caused by bacteria resistant to clinically relevant antibiotics (ciprofloxacin, cotrimoxazole, third-generation cephalosporin) in the antibiotic group than in the no-therapy group (18%, 13/72 versus 4%, 3/83, p 0.003). ConclusionsApplying a screen-and-treat strategy for ASB does not reduce the occurrence of symptomatic UTI in kidney transplant recipients who are more than 2 months post-transplantation. Furthermore, this strategy increases antibiotic use and promotes the emergence of resistant organisms.

How to Treat Asymptomatic and Symptomatic Urinary Tract Infections in the Kidney Transplant Recipients?

Patients with end-stage renal functions are treated with renal transplantation. After the transplantation, kidney transplant recipients (KTR) are at the risk of urinary tract infection (UTI). UTI in KTR may be symptomatic and asymptomatic. Asymptomatic UTI is the presence of the organisms without any signs and symptoms. There are various ways suggested in the published research papers to deal with UTI in the KTR. The goal of this literature review is to explore how to treat symptomatic and asymptomatic UTI in KTR. A PubMed search was conducted to identify the studies explaining the methods used to deal with UTI in KTR. A total number of 2158 articles were found while searching for regular keywords; however, we found 996 articles with the medical subject heading (Mesh) keywords. After applying the inclusion/ exclusion criteria, 56 articles with the regular keywords search and 29 articles with the Mesh keywords search were selected. These articles included 24 randomized clinical trials, 16 clinical trials, 7 review articles, 5 case reports, 2 controlled clinical trials, 2 observational studies, and 1 cross-sectional study. Our analysis has shown that the early removal of the stent after the transplantation and the use of antibiotics are beneficial in reducing the incidence of symptomatic UTI in the KTR; whereas, treating asymptomatic UTI in KTR has not been proven helpful in reducing the incidence of developing symptomatic UTI later on.

Multiple Drug Resistant Urinary Tract Infection in Kidney Transplant Recipients: A Retrospective Cohort Study.

Urinary tract infection (UTI) is the most common infectious disease in post-kidney transplantation patients. The objective of the study was to investigate the prevalence, impact and risk factors of multiple drug resistant (MDR) UTI in kidney transplant recipients. This retrospective cohort study recruited 72 kidney transplant recipients between March 2017 and February 2018. Urine cultures performed during the 1st year of posttransplantation with reference to clinical data were evaluated. Predesigned questionnaire was used to collect data regarding demographic, transplant related, and microbiological information. Multivariate analysis was performed to ascertain risk factors of MDR UTI. Out of 72 patients, 28 (38.9%) had culture guided clinical UTI. Overall, 59 UTI episodes were noted throughout the duration of this study. Eschericia coli were found to be the most frequent uropathogen of UTI among kidney transplant recipients (n = 32, 54.2%). MDR bacteria were responsible for 27.1% (n = 16) of the post-transplantation UTI episodes among patients, with E. coli (n = 9, 56.3%) being the predominant bacterial pathogen. Most of the MDR strains of E. coli (n = 7, 77.8%) were extended spectrum beta-lactamase positive. Female gender (P <0.001), prolonged Foley's catheterization (P = 0.002), coexisting diabetes mellitus (DM) (P <0.001) and induction of anti-thymocyte globulin (ATG) therapy (P <0.001) were independently associated with high risk of MDR UTI. The allograft rejection was found to be significantly higher in patients of posttransplantation UTI with MDR uropathogen (P = 0.009). In conclusion, E. coli were the most prominent uropathogen of UTI with and without MDR pathogen in the present study. Female gender, prolonged Foley's catheterization, coexisting DM, and induction of ATG therapy were the risk factors independently associated with MDR UTI in kidney transplant recipients. MDR organisms were significantly associated with allograft rejection.

Fosfomycin-trometamol for Urinary Tract Infections in Kidney Transplant Recipients.

The treatment of urinary tract infections (UTIs) in kidney transplant recipients (KTRs) with oral antibiotics is complicated by increasing resistance to trimethoprim-sulfamethoxazole, amoxicillin/clavulanic acid, and ciprofloxacin. Fosfomycin-trometamol (FT) could be an alternative, but evidence on clinical effectiveness is scarce. We evaluated the use, effectiveness and safety of FT for UTI in KTRs. Data were retrospectively collected in 2 Dutch transplant hospitals from adult KTRs that were treated with FT as initial treatment for lower UTI or asymptomatic bacteriuria (ASB) or as stepdown treatment for upper UTI after initial intravenous antibiotics. Exclusion criteria were in vitro resistance to FT or concomitant antibiotic treatment. Endpoints were clinical cure within 14 days and severe clinical failure, microbiological cure, relapse, recurrence, and acquired resistance within 90 days postend of treatment. Fifty-three episodes in 40 KTRs were included (ASB, n = 15; lower UTI, n = 33; upper UTI, n = 5). Fosfomycin-trometamol was used for a median short duration in a heterogeneous gift interval. Fosfomycin-trometamol resulted in microbiological cure in 25%, 28%, and 100% of ASB, lower UTI and upper UTI with initial positive culture and follow-up culture performed, respectively. Clinical cure rates were 67% for lower UTI and 80% for upper UTI. Relapses or recurrences occurred in 31% and 24% of symptomatic UTI episodes, without severe clinical failure. Acquired resistance to fosfomycin was observed in 6 episodes. Fosfomycin-trometamol has a reasonable effectiveness as last-resort oral treatment for lower UTI and stepdown treatment for upper UTI in KTRs. Randomized controlled trials with optimal dosage regimens are warranted. Use of FT is not recommended for ASB.

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 2months after post-transplant. Further research is needed on management of AB in the early (<2months) 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.

Asymptomatic bacteriuria in pediatric kidney transplant recipients: to treat or not to treat? A retrospective study.

Urinary tract infections (UTI) are common infectious complications in kidney transplant recipients (KTR); asymptomatic bacteriuria (AB) is also frequent. It is unclear whether treatment of AB reduces subsequent UTI in KTR; no guideline is available in pediatric KTR. In this retrospective study, we analyzed the incidence of AB in pediatric KTR and the impact of screening and treating AB on the onset of subsequent UTI. Thirty-seven pediatric patients were included. Inclusion criteria were the occurrence of one or more episodes of AB between 2 and 24months post-renal transplantation. Primary outcome was the cumulative incidence of acute pyelonephritis (APN) or lower urinary tract infections (LUTI) occurring between 2 and 24months post-renal transplantation. Thirty-seven patients presented 171 AB episodes. One hundred sixty-four AB episodes were untreated (95.9%); among them, 150 episodes (91.5%) were not followed by a clinical infection. Ten episodes (6.1%) led to APN, and 4 (2.4%) to LUTI. There were 53 episodes of APN: 10 (18.9%) after untreated AB and 43 (81.1%) de novo. There were 11 episodes of LUTI: 4 (36.4%) after untreated AB and 7 (63.6%) de novo. Multi-drug resistant bacteria were present in 27% of the patients and in 20% of patients with pre-existing uropathy. Our results are not in favor of systematic treatment of AB in pediatric KTR. Notably, limitation of antibiotic treatment is an urgent and important health issue in this population, in order to reduce multi-drug resistant bacteria emergence.

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.

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

Urinary tract infection (UTI) recurrence and antimicrobial resistance remain a common problem in kidney transplant recipients. Whilst the use of annual institutional antibiograms may help guide appropriate empirical antibiotic selection, these non-disease specific antibiograms do not always account for patient-specific risk factors or disease-specific resistance patterns. This study determined the frequency of UTI recurrence during the first year after kidney transplantation as well as differences in antimicrobial susceptibility between an institutional antibiogram and the disease-specific antibiogram for patients following kidney transplantation. In this study, adult patients with at least one UTI during an inpatient admission within 1 year post kidney transplantation were evaluated. A disease-specific antibiogram for UTIs in kidney transplant recipients was prepared based on culture results and was compared with the annual institutional antibiograms. Of 299 kidney transplants performed during the study period, 66 subjects meet the study inclusion criteria, of whom 47% had two or more UTIs within the first year after kidney transplant. In comparison with the institutional antibiogram, Escherichia coli isolated from urine samples from kidney transplant recipients were significantly more resistant to trimethoprim/sulfamethoxazole, ceftriaxone, cefepime, ciprofloxacin and gentamicin (P<0.0001). Multiple UTIs are common in kidney transplant recipients during the first year post-transplantation. E. coli urinary isolates were significantly more resistant to multiple antibiotic drug classes in this patient population compared with the general hospital population. Antimicrobial stewardship programmes at transplant centres should consider producing disease-specific antibiograms specifically for transplant recipients to improve empirical antibiotic selection guidance.

Posttransplant urinary tract infections and surgical site infections among renal transplant recipients in a transplant unit in Sri Lanka

Aim: Kidney transplant (KT) recipients are at higher risks of infections due to the chronic disease conditions, the surgical procedure and immunosuppressive therapy following transplantation. We aimed to assess the incidence and the microbiology of urinary tract infections (UTIs) and surgical site infections (SSIs) in KT recipients at the transplant unit in Kandy Teaching Hospital, Sri Lanka. Methods: A prospective, descriptive study was carried out in patients undergoing KT for 6 months postoperatively. A urine full report and culture were carried out before transplantation and on days 1, 3, 7 and monthly for 6 months posttransplantation. Urine specimens yielding growth of ≥105 CFU/ml were considered significant. In addition, patients were screened preoperatively for Staphylococcus aureus colonization by multi-site swabbing. The surgical sites were inspected daily for SSI. Results: Thirty-nine patients were recruited in the study. Two patients (5.1%) had preoperative UTI and 4 (10.3%) developed UTI within 6 months. Majority of post-KT UTI (75.0%) occurred in the 1st month. UTI was commonly due to coliforms (50.0%) while S. aureus and Pseudomonas spp. accounted 25% each. All screened patients were colonized with S. aureus and majority (62.9%) were methicillin-resistant S. aureus. Only 3 (8.6%) KT recipients had SSIs. Conclusion: The incidence of UTI in KT recipients within the first 6 months was 10.3%, and majority occurred in the 1st month. Patients, who were treated for UTI preoperatively, did not develop post-KT UTI. Coliforms were the most common organism. Although there was high S. aureus colonization index, the incidence of SSI in post-KT recipients was low.

ESBL-producing enterobacteriaceae-related urinary tract infections in kidney transplant recipients: incidence and risk factors for recurrence

Background: Urinary tract infections (UTIs) represent the first cause of bacterial infections in renal transplant recipients. In a period of increasing resistance to antimicrobial agents, the factors leading to the development of UTI in previously urinary colonized renal transplant recipients as well as the factors associated with recurrence of UTIs have to be determined. The aims of this retrospective study were (1) to assess the incidence of extended-spectrum beta-lactamase-producing enterobacteriaceae (ESBL-PE)-related UTI in kidney transplant recipients, (2) to identify factors associated with ESBL-PE infection and (3) to determine the risk factors for recurrence. Methods: We included all kidney transplant recipients admitted in our hospital between January 2009 and January 2012 who had a monobacterial ESBL-PE UTI or bacteriuria. Results: During the study period, 659 patients underwent kidney transplantation; 72 patients had ESBL-PE bacteriuria, representing a 10.9% prevalence, and among the latter 34 (47.2%) presented an ESBL-PE-related UTI. Fourteen patients (41.2%) experienced a UTI relapse associated with two factors: advanced age (p = 0.032) and persistent bacteriuria 48 h after appropriate antibiotic therapy (p = 0.04). No other risk factor for recurrence was found, including the presence and management of a ureteral stent during the first UTI, causative microorganisms, or diabetes mellitus. Conclusions: In this specific population, regarding the risk of relapse there is an urgent need for prospective studies to test the best treatment strategy.

Should we treat asymptomatic bacteriuria after renal transplantation?

Infections remain a major cause of morbidity and mortality in the modern kidney transplantation era [1]. Symptomatic urinary tract infections (UTIs), which are defined as the association of a positive urine culture with the presence of symptoms or signs referable to UTI, are usually divided into lower tract (cystitis) and upper tract (pyelonephritis) infections. It is the most common infection in this population, both short-term as well as long-term post-transplantation [2]. As a consequence, UTI is the leading cause of antibiotic administration in kidney transplant recipients [3]. The highest incidence of symptomatic UTIs occurs during the first months after transplantation [4, 5]. In a registry study conducted by the Spanish Network for Research on Infection in Transplantation (RESITRA) in 2052 kidney transplant recipients with at least 1 year of follow-up, symptomatic UTIs occurred in 150 patients (7.3%) with an incidence rate of 0.45 episodes per 1000 transplantation days [4]. Escherichia coli and Enterococcus are known to account for more than half of bacterial UTIs post-kidney transplantation [2–5]. In a time of increasing resistance to antimicrobial agents and rising health-related costs, factors that trigger UTIs need to be understood, and if possible prevented. As in the general population, female gender is the strongest risk factor for UTI in kidney transplant recipients [4, 6, 7]. In comparison with men, the shorter urethra contributes to this phenomenon. Other risk factors such as advanced age, diabetes mellitus, primary end-stage renal disease, urinary tract abnormalities, cadaveric donor kidney, graft dysfunction and rejection, CMV infection and prolonged time on dialysis prior to transplantation have been pinpointed in some series [2, 6–10]. Identification of treatable risk factors is of interest as it may lead to a reduction in the frequency of symptomatic UTIs. Whether asymptomatic bacteriuria is a modifiable risk factor for symptomatic episodes and could impact the global prognosis of the transplanted patient (and should therefore be screened for and treated) remains controversial [11]. The Infectious Diseases Society of America (IDSA) defines asymptomatic bacteriuria as isolation of a specified quantitative count of bacteria (≥10 CFU/mL) in an appropriately collected urine sample obtained from a person without symptoms or signs referable to a UTI [12]. While a single urine specimen is sufficient to define asymptomatic bacteriuria in men, it is usually defined in women as two consecutively voided urine specimens with isolation of the same bacterial strain in quantitative counts ≥10 CFU/mL. This definition stems from a study showing that, in non-transplanted women, when the first specimen contains at least 10 bacteria per millilitre of urine, there is an 80% probability that the patient has true bacteriuria [13]. That 20% of women have a negative second culture is thought to reflect transient bacteriuria rather than contamination [14]. Asymptomatic bacteriuria is a common event after renal transplantation. For instance, Fiorante et al. showed that 51% of the recipients develop asymptomatic bacteriuria—as defined by the IDSA guidelines—during the 3 years following transplantation [15]. Therefore, the question of its management remains a daily unsolved problem for transplant physicians. Antibiotic overuse could lead to the emergence of bacterial resistance and antimicrobial agents’ side effects. In addition, important costs are associated with the strategy of systematic screening and treatment of post-kidney transplantation asymptomatic bacteriuria, such as the costs of urinalyses, antibiotics and even hospitalization of asymptomatic patients. This is a matter of concern in a time of limited health-care resources. To date, no study has demonstrated a clear benefit in treating asymptomatic bacteriuria with antimicrobial agents in kidney transplant recipients [15–17]. Of the studies published addressing this question, only one was prospective. This small trial, conducted in 88 Iranian patients, did not show a statistically significant decreased rate of symptomatic UTIs when kidney transplant recipients with asymptomatic bacteriuria were treated with a 10-day course of antibiotics [17]. Nine of the 43 treated patients (21%) developed symptomatic UTI during the 9–12 months of follow-up, in comparison with 14 F U L L R E V IE W

Urinary tract infections in kidney transplant recipients: Role of gender, urologic abnormalities, and antimicrobial prophylaxis

Urinary tract infections (UTI), the most common infectious complications after kidney transplantation, are associated with poor allograft survival. Identifying its predisposing factors is therefore remarkably important in order to optimize prevention strategies. A retrospective study was performed in a cohort of patients who received kidney transplantation between June 2007 and June 2009. Factors associated with development of UTI were assessed. The population consisted of 301 patients, with majority receiving allograft from living donors (85%). A total of 101 patients (34%) developed at least one episode of UTI, and 25% of the episodes occurred during the first year after transplantation. Risk factors associated with increased risk of UTI were female gender, recurrent UTI prior to transplant, and presence of urological abnormalities. Trimethoprim-sulfamethoxazole (TMP-SMZ) use was associated with a lower risk of UTI, including a lower risk of recurrent UTI. In this cohort of predominantly living donor kidney transplant recipients, we report a high incidence of UTI, despite our practice of early ureteral and Foley catheter removal. Female gender and prior recurrent UTI or urological abnormalities were predisposing factors, while TMP-SMZ use had a protective role. These clinical relevant findings should guide clinicians in optimizing prevention strategies against UTI in kidney transplant recipients.

Risk Factors for Recurrent Urinary Tract Infection in Kidney Transplant Recipients

Introduction: Urinary tract infections (UTI) are the most common infectious complication in kidney transplant recipients (KTRs). This study aims to investigate the risk factors and causative organisms of UTI and evaluate the effect of UTI on allograft function in KTRs. Methods: We analyzed the patients who underwent kidney transplantation between January 2000 and December 2010. Among a total of 344 KTRs, 50 (14.5%) patients had 106 UTI episodes during mean follow-up period of 35.9±26.0 months. Twenty-three recurrent UTI patients (recurrent group) were compared with twenty-seven non-recurrent UTI patients (non-recurrent group). Results: Renal calculi were significantly higher in recurrent group compared to non-recurrent group (43.5 vs. 7.4%, p=0.003). Diabetes mellitus, benign prostate hypertrophy and vesicoureteral reflux showed higher tendency in recurrent group. The most common causative organism was Escherichia coli (64.1%), followed by Enterococcus species (20.5%). The distributions of organisms were not different between the two groups. In terms of antibiotic resistance in Escherichia coli, the extended-spectrum beta-lactamase (ESBL) production was significantly higher in recurrent group than in non-recurrent group (53.1 vs. 0%, p=0.013). The estimated glomerular filtration rate (eGFR) fell from 76.7±42.3 mL/min/1.73m2 to 56.4±27.3 mL/min/1.73m2 in recurrent group (p=0.006), while eGFR fell from 68.7±26.9 mL/min/1.73m2 to 65.6±28.5 mL/min/1.73m2 in non-recurrent group (p=0.313). Conclusion: This study suggests that renal calculi are the major risk factor for recurrent UTI in KTRs. The recurrent group showed higher rates of antibiotic resistance, especially the ESBL production. The decline of eGFR was statistically significant only in recurrent group during the study period. It is reasonable to treat initial UTI adequately to prevent recurrent infection and prolong graft longevity, especially in KTRs with risk factors for recurrent UTI.