Candiduria in renal transplant recipients: incidence, clinical repercussion, and treatment indication

Uncommon Haemorrhagic Cystitis of Infectious Origin: A Narrative Review for Urologists

Purpose

Haemorrhagic cystitis may be due to different etiologies with infectious diseases representing an insidious cause to diagnose. The aim of this narrative review is to provide a comprehensive overview of less common but difficult-to-diagnose causes of infectious haemorrhagic cystitis of bacterial, mycobacterial, and parasitic origin, Moreover, we highlight possible diagnostic tools and currently available treatment options in order to give an updated tool for urologists to use in daily practice.

Patients and Methods

The search engine PubMed was used to select peer-reviewed articles published from 1/Jan/2010 to 31/Aug/2022.

Results

Bacteria, fungal, TB and schistosomiasis are uncommon causes of haemorrhagic cystitis burdened by high morbidity, especially if not promptly diagnosed.

Conclusion

Because haemorrhagic cystitis ranges in severity from mild dysuria associated with pelvic discomfort to severe life-threatening haemorrhage, punctual diagnosis, and immediate treatment are essential to avoid further complications.

Candida urinary tract infections in adults

Candiduria is commonly seen in hospitalized patients and most of the patients are asymptomatic, but it may be due to cystitis, pyelonephritis, prostatitis, epididymo-orchitis or disseminated candidiasis. Major risk factors are diabetes mellitus, indwelling urinary catheters, use of broad-spectrum antibiotics, urinary obstruction, and admission to intensive care units. Candida urinary tract infections can be caused by hematogenous spread following candidemia, or retrograde route via the urethra. The presence of Candida species in urine in asymptomatic patients does not warrant antifungal therapy except neutropenic patients, very low-birth-weight infants and patients undergoing urologic procedures. Fluconazole is the treatment of choice for symptomatic infections, it achieves high urinary levels. The other azole antifungals and echinocandins do not reach sufficient urine levels. Amphotericin B deoxycholate is the alternative antifungal agent if fluconazole can not be used because of resistance, allergy or failure.

Successful eradication of chronic symptomatic Candida krusei urinary tract infection with increased dose micafungin in a liver and kidney transplant recipient: Case report and review of the literature

Treatment of symptomatic candiduria is notoriously challenging because of the limited repository of antifungals that achieve adequate urinary concentrations. Fluconazole, amphotericin B-based products, and flucytosine are established treatment options for most Candida species. Candida krusei exhibits intrinsic resistance to fluconazole and decreased susceptibility to amphotericin B and flucytosine. In transplant patients, both amphotericin B-based products and flucytosine are less desirable because of their toxicities. Other triazole antifungals are unappealing because they do not achieve adequate urinary concentrations, have multiple toxicities, and interact with transplant-related immunosuppressive medications. Echinocandins are well-tolerated but have been traditionally deferred in the treatment of symptomatic funguria because of their poor urinary concentrations but there is a small but emerging body of literature supporting their use. Here, we present a case of successful eradication of chronic symptomatic C krusei urinary tract infection with micafungin 150 milligrams daily in a liver and kidney transplant recipient, and we review the literature on treatment of symptomatic candiduria.

Candiduria in kidney transplant recipients: Is antifungal therapy useful?

A French single-centre retrospective study between 2010 and 2014 was undertaken to assess candiduria's incidence in kidney transplant recipients (KTR), and the use and impact of antifungal treatment on outcome. Candiduria was defined as a urine culture with ≥10³  cfu/mL of Candida species. Candiduria clearance, severe complications and death rates were estimated by Kaplan-Meier methods and the effect of treatment by Cox models. 52/1223 (4.3%) KTR had ≥1 episode of candiduria, 42 (81%) were females, 18 (35%) had diabetes, with an incidence of 2.3/100 person-year of follow-up. Candiduria was asymptomatic in 51 (98%) patients. Candida glabrata was the most frequent pathogen identified. Overall fungal clearance rate was 89%. Antifungal therapy was initiated in only 14 episodes (12%), according to guidelines. Three patients (6%) developed severe complications in the first 2 weeks after transplantation, and 8 (15%) died. Antifungal treatment had no impact on candiduria clearance (HR, 0.6; 95% CI, 0.3-1.1; P = .10), on recurrence rate (HR, 0.5; 95% CI, 0.1-2.3; P = .41) and on the risk of severe complications or death (HR, 1.1; 95% CI, 0.3-4.8; P = .89). Candiduria is rare and usually asymptomatic among KTR. Candiduria management in the immediate post-transplant period deserves careful attention.

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.

Nosocomial Candiduria in the Elderly: Microbiological Diagnosis

Candiduria is associated with high morbidity, mortality, and long hospitalization, involving high costs for the healthcare system. The use of increasingly aggressive treatments has prolonged the lives of patients susceptible to candiduria, namely the immunosuppressed, the premature, and the elderly. Our objective was to evaluate the incidence of nosocomial candiduria and the implicated species in hospitalized patients aged over 80 years old from three Spanish centers during 2012 and 2013. Urine samples received from these patients were cultured and analyzed by flow cytometry in search of leukocyturia, hematuria, proteinuria, and microbial nitrate reductase activity. The isolated yeast species were identified microscopically, by germ tube formation in serum, colony morphology after subculture onto CHROMagar Candida (Becton-Dickinson, UK), assimilation of carbon compounds ID32C (bioMérieux, France), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDITOF) (Bruker Daltonics, Germany) and, in case of inconsistency, by sequencing of the ITS regions of ribosomal DNA (ITS1-5, 8S-ITS2). Susceptibility tests were also performed. The incidence of candiduria in the elderly population was 10.3%. A total of 155 strains of yeasts were isolated. The predominant species was Candida albicans, followed by Candida glabrata and then Candida tropicalis. Several infrequent species were found; among them, the first isolate of candiduria-producing Candida pulcherrima described in the literature. Our finding should raise concerns about the elderly population, which is probably the most important risk group for candiduria in the present moment, and the emergence of unusual yeast species producing candiduria, which are resistant against the commonly used antifungal agents.

[Candiduria! What now? : Therapy of urinary tract infections with Candida]

BACKGROUND

Yeasts are found in urine specimens relatively often, especially in the elderly and patients under treatment with broad spectrum antibiotics, i. e. especially in intensive care unit (ICU) patients. In some cases, the number of pathogens is very high, i. e. >10⁵/ml. The clinical relevance of detecting Candida in urine is difficult to assess. In the German S3 guidelines it is apodictically stated that an ascending infection of the urinary tract by yeasts does not occur but this may undoubtedly happen in certain instances in patients at risk, for example in the elderly, in diabetic persons and in the case of foreign bodies in the urinary tract. A hematogenous spread of yeasts can lead to pyelonephritis, which accompanies candiduria. In rare cases this can be induced by prostatitis and epididymitis. Therapy is indicated in all cases when a urological manipulation is planned, particularly those with injury to the mucosal barrier, in order to prevent an intraoperative spread of pathogens.

AIM

The antimicrobial agents suitable for therapy of candiduria are limited, namely flucytosine, amphotericin B, which is also used for irrigation and fluconazole.

MATERIAL AND METHODS

The in vitro effect of nitroxoline on 100 isolates of yeasts from urine was tested by an agar diffusion test.

RESULTS

Nitroxoline exerted a good activity against all yeast isolates.

DISCUSSION

The antibiotic nitroxoline has a good antifungal activity. It achieves high concentrations in urine and in addition, it is effective at low pH as well as against pathogens in biofilms, which most antimycotics cannot achieve. Hence, nitroxoline is suitable for termination of candiduria. Foreign bodies in the urinary tract, on which biofilms are formed, should be removed whenever possible.

Association Between Candiduria and Candidemia: A Clinical and Molecular Analysis of Cases

The risk of developing candidemia after candiduria is reportedly very low, but it has not been adequately investigated. The aim of this study was to examine the molecular relatedness between Candida strains isolated from adult patients with candidemia and concomitant candiduria in association with the clinical characteristics of the cases. All episodes of candidemia occurring in a tertiary care academic hospital during a 5-year period were recorded prospectively. Patients with episodes of candiduria occurring two weeks preceding to or one week following a positive for Candida blood culture were included in the study. The genotypic relatedness of Candida strains isolated from blood and urine was investigated by pulsed-field gel electrophoresis after digestion with the BssHII restriction endonuclease. We recorded 141 candidemia episodes, occurring in 134 patients. Twelve episodes of candidemia with concomitant candiduria occurred in 11 patients (8% of all candidemias). In six of these episodes, the strains in the blood-urine pairs belonged to different species. In two episodes, the isolates belonged to the same species but were not genetically related, and only in four (2.8% of all candidemias), the strains were related. All four patients were severely ill and had multiple risk factors for candidemia. These findings indicate that in hospitalized patients with candidemia, concomitant candiduria is rare and usually an independent event, confirming previous reports. In the critically ill, however, the existence of genetically related strains in blood and urine appears to be more frequent, with more probable the hematogenous dissemination.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

[Fungal infections and ureteral material: How to manage?]

INTRODUCTION

Urinary tract infections due to Candida species are mostly encountered in hospital environment. The management of candiduria on ureteral catheter is not consensual. The objective of our work was to make a review of medical literature related to definition, physiopathology, management and prevention of candiduria on ureteral catheter.

MATERIAL AND METHODS

The research was made on Medline using the following keywords: Candida; fungal; urinary tract infection; ureteral stent; ureteric stent; double-J pigtail.

RESULTS

The threshold defining candiduria is 10(5) CFU/mL. Candiduria corresponds to many different clinical presentations from colonization to candidemia. Species found are mostly Candida albicans (19-72%) and Candida glabrata (15.6-49.4%). The colonization of ureteral stent due to Candida is of 10% and comes with candiduria in 40% of the cases, due to the presence of biofilm. Prevention of infections on ureteral stents requires a regular change of material every 3-6 months depending on the patients risk groups. In case of symptomatic candiduria on ureteral stent, an anti-fungal therapy should be initiated 48 hours to 3 weeks before the change of the stent, in order to get a sterilization of urines and prevent the recolonization of the stent. Fluconazole is the drug of choice to use.

CONCLUSION

Colonization of ureteral stents due to Candida is common and can be responsible of symptomatic infection. Anti-fungal therapy should be introduced before the change of the stent but a consensual duration of treatment before surgery is not found in the literature.

Case report of a ureteral obstruction by Candida albicans fungus balls detected by magnetic resonance imaging in kidney transplant recipient

In kidney transplant recipients, acute renal failure resulting from a ureteral obstruction by fungus balls is uncommon. We report a 60-year-old man diagnosed with ureteral obstruction caused by Candida albicans fungus balls early after transplant. Diagnosis was made by a T2-weighted magnetic resonance image, which demonstrated fungus balls as a low-intensity mass in the pelvis and microscopic examination findings in the urine. The patient was treated successfully with an antifungal agent and direct irrigation. It should be noted that fungus balls may cause ureteral obstruction of transplanted kidneys, possibly resulting in graft failure. Imaging of the kidneys and collecting system and aggressive debridement that adds to systemic therapy are necessary for early diagnosis and are central to a successful outcome.

Antifungal susceptibility and distribution of Candida spp. isolates from the University Hospital in the municipality of Dourados, State of Mato Grosso do Sul, Brazil

INTRODUCTION

Hospital infections caused by Candida spp. are a leading cause of morbidity and mortality in hospitalized patients, particularly those that are critically ill or immunocompromised. In this study, the distribution of Candida species in isolates from the University Hospital of the Federal University at Grande Dourados and their in vitro susceptibility to antifungal drugs were analyzed.

METHODS

Yeasts were phenotypically identified using classical methodologies. Antifungal susceptibility tests to amphotericin B and fluconazole were performed using the broth microdilution technique.

RESULTS

A total of 50 Candida isolates were obtained from hospitalized patients during the study period. We analyzed yeast isolates from urine (n=31; 62%), blood (n=12; 24%), and tracheal secretions (n=7; 14%). The following Candida species were identified: C. tropicalis (n=21; 42%), C. albicans (n=18; 36%), C. glabrata (n=10; 20%), and C. krusei (n=1; 2%). Antifungal susceptibility tests demonstrated that C. albicans was susceptible to both antifungal agents. However, 31.2% of the non-C. albicans Candida isolates displayed dose-dependent susceptibility to fluconazole, and 3.1% were resistant to amphotericin B.

CONCLUSIONS

In contrast to previous reports, our results indicated that C. tropicalis was the most commonly isolated yeast species among the hospital patients. The predominance of non-C. albicans Candida infections confirms the importance of species-level identification for implementing appropriate antifungal therapies.

Candida nivariensis isolated from a renal transplant patient with persistent candiduria-Molecular identification using ITS PCR and MALDI-TOF

We report on the isolation of Candida nivariensis from a renal transplant patient with persistent candiduria. Biochemical profiling misidentified isolates as Candida glabrata (3/5) and Candida inconspicua (2/5). All isolates produced white colonies on CHROMagar^™ Candida medium. Internal transcribed spacer (ITS) ribosomal gene sequence analysis and MALDI-TOF-MS analysis (Bruker Biotyper^™ 2.0) identified all isolates as C. nivariensis, demonstrating the utility of MALDI-TOF as a rapid, accurate approach for the identification of cryptic Candida species.

Candiduria in haematologic malignancy patients without a urinary catheter: nothing more than a frailty marker?

There is scarcity of data regarding significance of candiduria in patients with haematologic malignancies and its association with invasive candidiasis. To that end, we retrospectively evaluated all hospitalised, non-intensive care unit patients with haematologic malignancies and candiduria during a 10-year period (2001-2011). To decrease the possibility of bladder colonisation and sample contamination, we excluded all patients with candiduria who had urinary catheters and those with concomitant bacteriuria. Twenty-four such patients (21 females) were identified, with median age at diagnosis 62 years (range, 20-82 years). Acute leukaemia was the most common underlying disease (54%); 62% of these cases were not in remission. Twenty-nine percent of the patients had diabetes mellitus and 25% were neutropenic. The most common isolated Candida species was Candida glabrata (37%), followed by C. albicans (29%). Only 8% of them had urinary tract infection symptoms. However, 88% received systemic antifungals. Candidemia and crude mortality rates at 4 weeks were low (4% and 12% respectively). Isolated candiduria in patients with haematologic malignancies has risk factors similar to those in other hospitalised patients, and it does not seem to be a strong predictor of subsequent invasive candidiasis.

Candidal psoas abscess following persistent pyuria in a renal transplant recipient

Candidal infections occur commonly in renal transplant recipients especially in genitourinary system. Although the epidemiology of candiduria has not been well characterized in renal transplant population, it is the most common cause of fungal infections. However, candidal psoas abscess is very rare in the literature. We report a 42-year-old male renal transplant recipient with prolonged pyuria and candiduria followed by candidal psoas abscess formation. The treatment consisted of prolonged antifungal therapy along with percutaneous drainage. However, eventually, a surgical drainage had to be performed for the successful eradication.

Invasive fungal infections in solid organ transplant recipients

Invasive fungal infections are a major problem in solid organ transplant (SOT) recipients. Overall, the most common fungal infection in SOT is candidiasis, followed by aspergillosis and cryptococcosis, except in lung transplant recipients, where aspergillosis is most common. Development of invasive disease hinges on the interplay between host factors (e.g., integrity of anatomical barriers, innate and acquired immunity) and fungal factors (e.g., exposure, virulence and resistance to prophylaxis). In this article, we describe the epidemiology and clinical features of the most common fungal infections in organ transplantation. Within this context, we review recent advances in diagnostic modalities and antifungal chemotherapy, and their impact on evolving prophylaxis and treatment paradigms.

Urinary tract infection in renal transplantation

INTRODUCTION

Urinary tract infection (UTI), especially recurrent UTI, is a common problem, occurring in >75% of kidney transplant (KTX) recipients. UTI degrades the health-related quality of life and can impair graft function, potentially reducing graft and patient survival. As urologists are often involved in treating UTI after KTX, previous reports were searched to elucidate underlying causes, risk factors and treatment options, as well as recommendations for prophylaxis of UTI after KTX.

METHODS

Pubmed/Medline was searched and international guidelines and recommendations for prevention and treatment of UTI after KTX were also assessed.

RESULTS

Most studies on UTI after KTX have a small sample, and are descriptive and retrospective. Many transplant- and recipient-related risk factors have been identified. While asymptomatic bacteriuria is often treated, even though some studies advise against it, symptomatic UTI should be treated empirically after collecting urine for microbiological analysis, to avoid the development of transplant pyelonephritis with a high chance of urosepsis. The duration of treatment has not been determined in studies and recommendations refer to the treatment of complicated UTI in the non-transplant population. Prophylaxis has not been the focus of studies either.

CONCLUSION

UTI after KTX is still largely an under-represented field of study, despite many recipients developing UTI after KTX. Prospective studies on this topic are urgently needed.