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

Diagnosing and Managing Urinary Tract Infections in Kidney Transplant Recipients

In the article, the authors review antibiotic treatment options for both acute uncomplicated UTI and complicated UTI. In addition, they review alternative regimens which are needed in the setting of drug-resistant pathogens including vancomycin-resistant Enterococcus, -extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E), carbapenem-resistant Enterobacterales, and carbapenem-resistant Pseudomonas, which are encountered with more frequency.

Profile, Risk Factors, and Outcomes of Asymptomatic Bacteriuria in Kidney Transplant Recipients with Normal Pretransplant Genitourinary Tract: A Single-Center Experience

Introduction

There is a paucity of studies on asymptomatic bacteriuria (ASB) among kidney transplant recipients (KTR) in developing countries. This study assessed the clinical profile, risk factors, outcomes, and impact of treatment of ASB in KTRs with a normal genitourinary tract.

Methods

Consecutive KTRs from 2009 to 2018 with no clinical or radiological evidence of obstructive uropathy were included. Urinary tract infection (UTI) after ASB was defined as occurrence of cystitis, pyelonephritis, or urosepsis, with ASB being the first bacteriuric episode.

Results

Seven hundred ten out of 794 patients with median follow up of 47 months were included. The mean age was 35.5 ± 12 years. Eighty-one patients (11.4%) developed ASB at a median of 25 days (IQR 10, 134.5). Fifty-three percent and 4.9% of ASB episodes were extended-spectrum beta-lactamase (ESBL) positive and carbapenem-resistant organisms, respectively. Eighteen patients (32.1%) with early ASB (<3 months) and 5 (20%) with late ASB developed UTI on follow-up. Fifty-five percent of early and 16% of late ASB episodes were treated, with no significant difference observed in the risk of development of UTI when compared to untreated ASB episodes.

Conclusion

The incidence of ASB as first bacteriuric episode in our cohort was 11.4%, with there being significant antimicrobial resistance. Female gender, pretransplant UTI, and delayed graft function were independently associated with development of ASB. Treatment of ASB episodes either early or late did not decrease the risk of development of UTI.

Pneumocystis jirovecii pneumonia in a healthy immunocompetent patient: A case report and literature review

Pneumocystis jirovecii pneumonia, typically an opportunistic infection, is commonly associated with risk factors such as low CD4+ lymphocyte count, underlying malignancies, organ transplantation, or immunosuppressive medications. However, occurrences in healthy individuals without known risk factors are exceptionally rare and sparsely documented. In our retrospective analysis of a 42-year-old male without past medical history at Abderrahmane Mami Hospital, Tunisia, Pneumocystis jirovecii pneumonia was diagnosed. The patient presented with fever, productive cough, hemoptysis, and a decline in general health. Clinical examination revealed fever and hypoxemia, and imaging studies demonstrated bilateral necrotic alveolar opacities. Despite empirical antibiotics, nonresponse necessitated bronchoscopy, confirming Pneumocystis jirovecii. Treatment with oral Sulfamethoxazole-Trimethoprim yielded excellent outcomes. This case highlights the potential occurrence of Pneumocystis jirovecii pneumonia in immunocompetent individuals, underscoring the importance of direct microbiological methods in assessing suggestive clinical and radiological features.

Bacteremia During the First Year After Solid Organ Transplantation: An Epidemiological Update

Background

There are limited contemporary data on the epidemiology and outcomes of bacteremia in solid organ transplant recipients (SOTr).

Methods

Using the Swiss Transplant Cohort Study registry from 2008 to 2019, we performed a retrospective nested multicenter cohort study to describe the epidemiology of bacteremia in SOTr during the first year post-transplant.

Results

Of 4383 patients, 415 (9.5%) with 557 cases of bacteremia due to 627 pathogens were identified. One-year incidence was 9.5%, 12.8%, 11.4%, 9.8%, 8.3%, and 5.9% for all, heart, liver, lung, kidney, and kidney-pancreas SOTr, respectively (P = .003). Incidence decreased during the study period (hazard ratio, 0.66; P < .001). One-year incidence due to gram-negative bacilli (GNB), gram-positive cocci (GPC), and gram-positive bacilli (GPB) was 5.62%, 2.81%, and 0.23%, respectively. Seven (of 28, 25%) Staphylococcus aureus isolates were methicillin-resistant, 2/67 (3%) enterococci were vancomycin-resistant, and 32/250 (12.8%) GNB produced extended-spectrum beta-lactamases. Risk factors for bacteremia within 1 year post-transplant included age, diabetes, cardiopulmonary diseases, surgical/medical post-transplant complications, rejection, and fungal infections. Predictors for bacteremia during the first 30 days post-transplant included surgical post-transplant complications, rejection, deceased donor, and liver and lung transplantation. Transplantation in 2014-2019, CMV donor-negative/recipient-negative serology, and cotrimoxazole Pneumocystis prophylaxis were protective against bacteremia. Thirty-day mortality in SOTr with bacteremia was 3% and did not differ by SOT type.

Conclusions

Almost 1/10 SOTr may develop bacteremia during the first year post-transplant associated with low mortality. Lower bacteremia rates have been observed since 2014 and in patients receiving cotrimoxazole prophylaxis. Variabilities in incidence, timing, and pathogen of bacteremia across different SOT types may be used to tailor prophylactic and clinical approaches.

External ureteric stent versus internal double J stent in kidney transplantation: a retrospective analysis on the incidence of urological complications and urinary tract infections

Introduction

Urologic complications (UCs) and urinary tract infections (UTIs) are common after kidney transplantation. Intraoperative stent placement at the vesicoureteric anastomosis reduces UC risk, but increases UTI risk.

Methods

In 2014 our stenting protocol changed from external ureteric stent (ES) to internal double J stent (DJ). We retrospectively studied the occurrence of UCs and UTIs in relation to ES or DJ in 697 kidney recipients.

Methods

An ES was used in 403 patients (57.8%), in 294 (42.2%) a DJ. ES was removed 7-12 days and DJ 3-4 weeks post-operative. Induction immunosuppression was the same in both groups. Primary outcomes at 6 months follow-up were UC (urinary leakage/ureter stenosis) and UTI; they were related to stenting procedure and clinical and transplant characteristics. The incidence of UCs was similar for ES (8.4%) and DJ (6.8%), p=0.389. ES use was a significant risk factor for UTI (OR 1.69 (1.15-2.50), p=0.008). Post-transplant hospitalization was significantly shorter in the DJ group. Despite more acute rejection episodes with ES (ES/DJ: 16.4%/6.1%, p<0.001), no clinical relevant differences in graft outcomes existed.

Discussion

A DJ is, compared to ES, associated with a lower incidence of UTIs and comparable occurrence of UCs and is therefore the preferred technique for stenting the vesicoureteric anastomosis.

Asymptomatic Bacteriuria in Kidney Transplant Recipients-A Narrative Review

Urinary tract infections (UTIs) are the most prevalent complications in kidney transplant (KTx) recipients. The most frequent finding in this group of patients is asymptomatic bacteriuria (ASB). Here, we provide an overview of the available evidence regarding ASB in KTx recipients, including its etiopathology, clinical impact and management. There is a growing body of evidence from clinical trials that screening for and treating ASB is not beneficial in most KTx recipients. However, there are insufficient data to recommend or discourage the use of a "screen-and-treat strategy" for ASB during the first 1-2 months post-transplant or in the case of an indwelling urinary catheter. Despite its frequency, ASB after KTx is still an understudied phenomenon.

Recurrent Urinary Tract Infections in Renal Transplant Recipients: Risk Factors and Outcomes in Low-resource Settings

Recurrent urinary tract infections (UTIs) after kidney transplantation are a common problem adversely affecting graft outcomes. This retrospective study aimed to report the frequency and risk factors of recurrent UTI and their impact on graft and patient outcomes in kidney transplant recipients at the Sindh Institute of Urology and Transplantation, Karachi, Pakistan, in January-December 2015. Five-year graft and patient survival rates were compared among different groups using Kaplan-Meier analysis. Of the 251 recipients, 67 developed one episode of UTI. Of these 67, 29 had 76 episodes of recurrent UTI. Out of the 76 episodes of recurrent UTI, Escherichia coli was the most common pathogen in 32 cases. Organisms causing recurrent UTI showed resistance to carbapenem in 19 cases versus 2 in the non-recurrent UTI group (P = 0.006). The estimated glomerular filtration rate at 1 year was 57.8 ± 16.23 mL/min/1.73 m2 in the recurrent UTI group vs. 61.9 ± 15.7 mL/min/1.73 m2 in the non-recurrent UTI group (P = 0.001). Graft survival in the recurrent UTI group at 5 years was significantly lower (76%) than in the non-recurrent UTI (95%) and no UTI groups (93%) (log-rank P = 0.006), with no significant effect on patient survival in these groups (P = 0.429). The presence of double-J stent (P = 0.036) and cytomegalovirus infections (P = 0.013) independently predicted recurrent UTI. Recurrent UTIs are common in low-resource settings and adversely affect graft outcomes. Appropriate prophylaxis and treatment are important to reduce recurrent UTI to improve graft outcomes.

Comparison of early and late Pneumocystis jirovecii Pneumonia in kidney transplant patients: the Korean Organ Transplantation Registry (KOTRY) Study

Late Pneumocystis jirovecii pneumonia (PJP) is not rare in the era of universal prophylaxis after kidney transplantation. We aimed to determine the nationwide status of PJP prophylaxis in Korea and compare the incidence, risk factors, and outcomes of early and late PJP using data from the Korean Organ Transplantation Registry (KOTRY), a nationwide Korean transplant cohort. We conducted a retrospective analysis using data of 4,839 kidney transplant patients from KOTRY between 2014 and 2018, excluding patients who received multi-organ transplantation or were under 18 years old. Cox regression analysis was performed to determine risk factors for early and late PJP. A total of 50 patients developed PJP. The number of patients who developed PJP was same between onset before 6 months and onsets after 6 months. There were no differences in the rate, duration, or dose of PJP prophylaxis between early and late PJP. Desensitization, higher tacrolimus dose at discharge, and acute rejection were associated with early PJP. In late PJP, old age as well as acute rejection were significant risk factors. In conclusion late PJP is as common and risky as early PJP and requires individualized risk-based prophylaxis, such as prolonged prophylaxis for old patients with a history of rejection.

Urinary Tract Infections Caused by K. pneumoniae in Kidney Transplant Recipients – Epidemiology, Virulence and Antibiotic Resistance

Urinary tract infections are the most common complication in kidney transplant recipients, possibly resulting in the deterioration of a long-term kidney allograft function and an increased risk of recipient’s death. K. pneumoniae has emerged as one of the most prevalent etiologic agents in the context of recurrent urinary tract infections, especially with multidrug resistant strains. This paper discusses the epidemiology and risk factors associated with urinary tract infections in kidney transplant recipients, multi-drug resistance of K. pneumoniae (ESBL, KPC, NDM), treatment and pathogenesis of K. pneumoniae infections, and possible causes of recurrent UTIs. It also addresses the issue of colonization/becoming a carrier of K. pneumoniae in the gastrointestinal tract and asymptomatic bacteriuria in relation to a symptomatic UTI development and epidemiology.

Acute Allograft Pyelonephritis: Vague Symptoms, Indeterminate Laboratory Results, and the Necessity of Indication Biopsy

OBJECTIVES

In this study, we examined the clinical and biochemical features of biopsy-proven acute pyelonephritis among 769 kidney transplant recipients.

MATERIALS AND METHODS

This cohort study was performed between January 2003 and December 2019 at the University of Health Sciences (Izmir, Turkey). Acute pyelonephritis refers to urinary tract infection with acute graft dysfunction. All patients with suspected acute pyelonephritis underwent diagnostic biopsy and received antibiotic treatment for an average of 14 to 21 days. Patients with acute pyelonephritis (18/769, 2.3%) were categorized into groups of 9 patients each: group 1 developed acute pyelonephritis in the first 6 months, and group 2 developed acute pyelonephritis >6 months posttransplant.

RESULTS

All patients in group 1 had acute graft dysfunction; only 2 (22%) were symptomatic. All patients recovered baseline graft function after treatment. Patients in group 2 had at least 2 laboratory findings that included leukocytosis, neutrophilia, and high C-reactive protein values. Six patients had urine culture positivity. Recurrent pyelonephritis occurred in 3 patients. Four patients had graft loss. Over the mean follow-up of 48.0 ± 28.4 months, 14 patients (78%) were alive with a functioning graft.

CONCLUSIONS

Diagnostic biopsy is of great importance in patients with urinary tract infection accompanied by acute graft dysfunction in the first 6 months after transplant.

Urinary Tract Infections in Kidney Transplant Recipients-Is There a Need for Antibiotic Stewardship?

(1) Background: Urinary tract infections (UTI) are the most common infections after kidney transplantation. Given the risk of urosepsis and the potential threat to the graft, the threshold for treating UTI and asymptomatic bacteriuria with broad spectrum antibiotics is low. Historically fluoroquinolones were prescription favorites for patients that underwent kidney transplantation (KT). After the recent recommendation to avoid them in these patients, however, alternative treatment strategies need to be investigated (2) Methods: We retrospectively analyzed the charts of 207 consecutive adult kidney transplantations that were performed at the department of General, Visceral and Transplantation Surgery of the University Hospital of Tuebingen between January 2015 and August 2020. All charts were screened for the diagnosis and treatment of asymptomatic bacteriuria (ASB) and urinary tract infections (UTI) and the patients' clinical characteristics and outcomes were evaluated. (3) Results: Of the 207 patients, 68 patients suffered from urinary tract infections. Patients who developed UTI had worse graft function at discharge (p = 0.024) and at the 12 months follow-up (p < 0.001). The most commonly prescribed antibiotics were Ciprofloxacin and Piperacillin/Tazobactam. To both, bacterial resistance was more common in the study cohort than in the control group. (4) Conclusions: Urinary tract infections appear to be linked to worse graft functions. Thus, prevention and treatment should be accompanied by antibiotic stewardship teams.

Incidence and risk factors for urinary tract infections in the first year after renal transplantation

Background

The most common infections among renal transplant patients are urinary tract infections (UTI). Our main objective in this study is to determine the incidence of UTIs in patients who have undergone renal transplantation in our hospital, to identify the causative microbiological agents, risk factors and determine the effects of UTI on short-term graft survival.

Methods

Urinary tract infections, which developed within the first year of renal transplantation, were investigated. Patients were compared regarding demographic, clinical, laboratory characteristics and graft survival.

Results

102 patients were included in our study. Fifty-three patients (53%) were male and 49 (48%) were female. Sixty-seven urinary tract infection attacks in 21 patients (20.5%) were recorded. Age (p = 0.004; 95% Confidence Interval [CI]: 1.032–1.184), longer indwelling urinary catheter stay time (p = 0.039; 95% Confidence Interval [CI]: 1.013–1.661) and urologic complications (p = 0.006; 95% Confidence Interval [CI]: 0.001–0.320) were found as risk factors for UTI development in the first year of transplantation. Escherichia coli and Klebsiella pneumoniae were the most frequently isolated microorganisms. Of these bacteria, 63.2% were found to be extended spectrum beta lactamase (ESBL) positive. Multidrug resistant microorganisms (MDROs) were more frequent in male patients (32 episodes in males vs. 14 episodes in females, p = <0.001). UTI had no negative impact on short-term graft survival.

Conclusion

Our study results represent the high incidence of UTI with MDROs in KT recipients. Infection control methods should be applied even more vigorously especially in male transplant patients since a higher incidence of UTI caused by resistant microorganisms was reported in male patients.

Perioperative fosfomycin disodium prophylaxis against urinary tract infection in renal transplant recipients: a randomized clinical trial

Background

Symptomatic urinary tract infection (UTI) is the most common infectious complication in renal transplant recipients (RTRs). Fosfomycin (FOS) is an attractive alternative for prophylaxis because it does not interact with immunosuppressants; although 90% is excreted unchanged in the urine, it does not require adjustment for renal function for single dose prophylaxis.

Methods

RTRs were recruited into this randomized, double-blind, placebo-controlled trial. Participants were randomized (1:1) to receive one 4 g dose of FOS disodium intravenously 3 h (FOS group) or placebo (placebo group) before placement and removal of a urinary catheter and before removal of a double-J ureteral stent. All participants received prophylaxis with trimethoprim/sulfamethoxazole. The main outcome was a comparison of the mean number of symptomatic UTI and asymptomatic bacteriuria (AB) episodes per patient during a 7-week follow-up period. The study was registered at ClinicalTrials.gov, NTC03235947.

Results

Eighty-two participants were included (41 in the FOS group and 41 in placebo group). The mean number of AB or symptomatic UTI episodes per patient was lower in the FOS group [intention-to-treat (ITT) 0.29 versus 0.60, P = 0.04]. The incidence of symptomatic UTI was lower in the FOS group (ITT, 7.3% versus 36.6%, P = 0.001), and there was no difference in the incidence of AB between both groups. The incidence of adverse events was similar in both groups.

Conclusions

FOS addition is an effective and safe strategy to reduce the number of symptomatic UTIs during the first 7 weeks after renal transplant.

Clinical Practice Guideline for the Management of Asymptomatic Bacteriuria: 2019 Update by the Infectious Diseases Society of America

Asymptomatic bacteriuria (ASB) is a common finding in many populations, including healthy women and persons with underlying urologic abnormalities. The 2005 guideline from the Infectious Diseases Society of America recommended that ASB should be screened for and treated only in pregnant women or in an individual prior to undergoing invasive urologic procedures. Treatment was not recommended for healthy women; older women or men; or persons with diabetes, indwelling catheters, or spinal cord injury. The guideline did not address children and some adult populations, including patients with neutropenia, solid organ transplants, and nonurologic surgery. In the years since the publication of the guideline, further information relevant to ASB has become available. In addition, antimicrobial treatment of ASB has been recognized as an important contributor to inappropriate antimicrobial use, which promotes emergence of antimicrobial resistance. The current guideline updates the recommendations of the 2005 guideline, includes new recommendations for populations not previously addressed, and, where relevant, addresses the interpretation of nonlocalizing clinical symptoms in populations with a high prevalence of ASB.

Antimicrobial resistance and recurrent bacterial urinary tract infections in hospitalized patients following kidney transplantation: A single-center experience

PURPOSE

The burden of urinary tract infections (UTIs) and risk factors for developing infections with multidrug resistant organisms (MDROs) post-kidney transplantation (KT) are poorly understood.

METHODS

Single-center retrospective cohort study (January 2015-December 2017) evaluating first and recurrent episodes of bacteriuria and subsequent analysis of episodes caused by MDROs up to 6 months post-KT. Donor and recipient variables were reviewed.

RESULTS

A total of 743 adults underwent single KT during the study period, and 106 patients were hospitalized with bacteriuria. 45% were asymptomatic in their first episode. 73.6% had a single episode, and 26.4% had 2 or more episodes. A total of 28 patients had recurrent episodes; 64.3% had an MDRO on the first episode and 78.6% on the second episode. Escherichia coli was the most common organism isolated, 88.5% were resistant to trimethoprim-sulfamethoxazole (TMP-SMX), 9.3% were extended-spectrum beta-lactamase (ESBL) producers, and 38.1% were MDROs. Body mass index ≥30 was significantly associated with the presence of MDROs in both univariate and multivariate analyses (RR 1.37, 95% CI 1.01-1.88; OR 3.26, CI 1.29-8.25). A total of 12 donors had bacteremia or bacteriuria and 6 (50%) with E coli. A total of 10 KT recipients received antibiotic prophylaxis to prevent donor-derived infections.

CONCLUSIONS

Our results suggest that a significant proportion of patients develop recurrent bacteriuria post-transplantation; of those, more than half caused by MDROs. There is a possible association between obesity and MDROs in KT recipients that merits further investigation. With the global crisis in antimicrobial resistance, innovative strategies are needed to prevent and treat UTIs in KT patients.

Effect of co-trimoxazole prophylaxis on morbidity and mortality of HIV-exposed, HIV-uninfected infants in South Africa: a randomised controlled, non-inferiority trial

BACKGROUND

WHO guidelines recommend co-trimoxazole prophylaxis for HIV-exposed, HIV-uninfected infants. These guidelines date back to an era in which HIV testing of infants was impossible and mothers had poor access to antiretroviral treatment. To determine whether this guideline requires revision in the current era of effective prevention of mother-to-child transmission and early infant diagnosis programmes, we aimed to investigate whether receiving no co-trimoxazole prophylaxis is inferior to receiving co-trimoxazole prophylaxis in the resulting incidence of grade 3 or 4 common childhood illnesses or mortality in breastfed HIV-exposed, HIV-uninfected infants.

METHODS

We investigated our aim in a randomised controlled, non-inferiority trial. We enrolled the HIV-negative infants of mothers living with HIV who were actively involved in transmission prevention programmes in two clinics in Durban, South Africa. Infants were included in the study if they were breastfeeding at the screening and enrolment visits, and their mother was planning to breastfeed for at least 6 months; were a singleton birth and had a birthweight of 2 kg or more; had no clinically observed genetic disorders; and had no serious illnesses and had not received antibiotics or traditional medications (such as herbal remedies). Infants were randomly assigned (1:1) to receive co-trimoxazole or no co-trimoxazole. In the co-trimoxazole group, infants received the drug until all exposure to HIV had ceased (ie, 6 weeks after last exposure to breastmilk) and the infant was confirmed to be uninfected with HIV. The drug was administered by mothers in once-daily regimens of 20 mg trimethoprim and 100 mg sulfamethoxazole orally (age <6 months or bodyweight <5 kg), or 40 mg trimethoprim and 200 mg sulfamethoxazole orally (age >6 months or bodyweight >5 kg). Clinical and laboratory staff always remained masked to group assignment, but mothers and study counsellors were not. Infants and their mothers attended study visits at ages 6 weeks (for enrolment and randomisation), 10 weeks, 14 weeks, and then monthly from 4 to 12 months. Our primary outcome was the incidence of grade 3 or 4 common childhood illnesses (pneumonia or diarrhoea) or mortality in breastfed HIV-exposed, HIV-uninfected infants by age 12 months. A non-inferiority bound of 5% was used. The study is registered with the Pan African Clinical Trials Registry, number PACTR201311000621110, and the South African National Clinical Trials Registry, number DOH-27-0614-4728.

FINDINGS

We screened 1570 mother-child pairs for study enrolment, from whom (78%) eligible infants were enrolled into the study between Oct 16, 2013, and May 23, 2018. Of the infants enrolled, 611 (50%) were randomly assigned to the co-trimoxazole group and 609 (50%) were randomly assigned to the no co-trimoxazole group. One (<1%) infant in the no co-trimoxazole group was excluded from the analysis of the final outcomes for having received traditional medicine (which only became apparent after randomisation); therefore, 611 (50%) infants in the co-trimoxazole group and 608 (50%) infants in the no co-trimoxazole group were included in the final intention-to-treat analysis. 136 (22%) infants in the co-trimoxazole group and 139 (23%) infants in the no co-trimoxazole group did not complete the 12-month study visit, predominantly because of loss to follow-up (93 [15%] infants in the co-trimoxazole group; 90 [15%] infants in the no co-trimoxazole group). The cumulative probability of the composite primary outcome was 0·114 (95% CI 0·076 to 0·147; 49 events) in the co-trimoxazole group versus 0·0795 (0·044 to 0·115; 39 events) in the no co-trimoxazole group. The risk difference (no co-trimoxazole group minus co-trimoxazole group) was -0·0319 (-0·075 to 0·011), meaning that the risk was around 3 percentage points lower in the no co-trimoxazole group on the additive scale.

INTERPRETATION

We can conclude that no co-trimoxazole is not inferior to daily co-trimoxazole among breastfed HIV-exposed, HIV-uninfected infants whose mothers are accessing a prevention of mother-to-child transmission programme in an area unaffected by malaria. We therefore believe that WHO should revise the co-trimoxazole guidelines for HIV-exposed, HIV-uninfected infants in areas unaffected by malaria.

FUNDING

HIV Prevention Research Unit of the South African Medical Research Council and the Family Larsson-Rosenquist Foundation.

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.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

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.

Value of perioperative genitourinary screening culture and colonization status in predicting early urinary tract infection after renal transplantation

Background

We aimed to assess whether patients colonized with certain organisms in the genitourinary tract would have greater urinary tract infection (UTI) risk during the post-transplantation period, and whether information on the perioperatively colonized organisms may help identify the causal organisms during early UTI.

Methods

We retrospectively reviewed the culture results of preoperative urine, preoperative urethral swab, and postoperative urinary catheter tip specimens of 420 renal transplant recipients. The colonization status was compared to the culture results during the first UTI episode within 6 months after transplantation.

Results

Twenty six (6.2%) patients developed early UTI, and the presence of common uropathogens in the perioperative genitourinary specimen was positively associated with a higher early UTI risk odds ratio [OR], 3.23; 95% confidence interval [CI], 1.44 to 7.24; P = 0.003). However, the actual causal organism during UTI was observed perioperatively only in 15 patients (40.5%). Neither perioperative colonization nor early UTI was associated with subsequent acute cellular rejection or graft failure.

Conclusions

Renal transplantation patients who were colonized with common uropathogens were more likely to develop early UTI. However, the usefulness of the culture results of perioperative colonizers in predicting the causal organism during early UTI seems limited due to the low concordance rate.

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.

Increased resistance of gram-negative urinary pathogens after kidney transplantation

BACKGROUND

Urinary tract infection is the most common complication after kidney transplantation. It can cause severe sepsis and transplant loss. Emergence of drug resistance among gram-negative urinary pathogens is the current challenge for urinary tract infection treatment after kidney transplantation.

METHODS

This study analyzes the antimicrobial susceptibility of gram-negative urinary pathogens after kidney transplantation from 2009 to 2012 at the Transplant Outpatient Clinic of the University Hospital Essen, Germany. Kidney transplant patients at the University Hospital Essen receive regular follow up examinations after transplantation. Midstream urines were examined for bacteriuria at each follow up visit.

RESULTS

From 2009 to 2012 15.741 urine samples were obtained from 859 patients. In 2985 (19%) samples bacterial growth was detected. The most frequently detected gram-negative bacteria were E.coli 1109 (37%), Klebsiella spp. 242 (8%) and Pseudomonas aeruginosa 136 (4.5%). Klebsiella spp. showed a significant increase of resistance to trimethoprim-sulfamethoxazole by 19% (p = 0.02), ciprofloxacin by 15% (p = 0.01) and ceftazidime by 17% (p = 0.004). E.coli and P. aeruginosa isolates presented no significant differences of antimicrobial susceptibility to the analyzed antibiotics.

CONCLUSIONS

Antimicrobial resistance of Klebsiella spp. increased significant to trimethoprim-sulfamethoxazole, ciprofloxacin and ceftazidime from 2009 to 2012.