Ten-year experience with fungal peritonitis in peritoneal dialysis patients: antifungal susceptibility patterns in a North-American center

Candida parapsilosis complex in the clinical setting

Representatives of the Candida parapsilosis complex are important yeast species causing human infections, including candidaemia as one of the leading diseases. This complex comprises C. parapsilosis, Candida orthopsilosis and Candida metapsilosis, and causes a wide range of clinical presentations from colonization to superficial and disseminated infections with a high prevalence in preterm-born infants and the potential to cause outbreaks in hospital settings. Compared with other Candida species, the C. parapsilosis complex shows high minimal inhibitory concentrations for echinocandin drugs due to a naturally occurring FKS1 polymorphism. The emergence of clonal outbreaks of strains with resistance to commonly used antifungals, such as fluconazole, is causing concern. In this Review, we present the latest medical data covering epidemiology, diagnosis, resistance and current treatment approaches for the C. parapsilosis complex. We describe its main clinical manifestations in adults and children and highlight new treatment options. We compare the three sister species, examining key elements of microbiology and clinical characteristics, including the population at risk, disease manifestation and colonization status. Finally, we provide a comprehensive resource for clinicians and researchers focusing on Candida species infections and the C. parapsilosis complex, aiming to bridge the emerging translational knowledge and future therapeutic challenges associated with this human pathogen.

Autophagy in peritoneal fibrosis

Peritoneal dialysis (PD) is a widely accepted renal replacement therapy for patients with end-stage renal disease (ESRD). Morphological and functional changes occur in the peritoneal membranes (PMs) of patients undergoing long-term PD. Peritoneal fibrosis (PF) is a common PD-related complication that ultimately leads to PM injury and peritoneal ultrafiltration failure. Autophagy is a cellular process of "self-eating" wherein damaged organelles, protein aggregates, and pathogenic microbes are degraded to maintain intracellular environment homeostasis and cell survival. Growing evidence shows that autophagy is involved in fibrosis progression, including renal fibrosis and hepatic fibrosis, in various organs. Multiple risk factors, including high-glucose peritoneal dialysis solution (HGPDS), stimulate the activation of autophagy, which participates in PF progression, in human peritoneal mesothelial cells (HPMCs). Nevertheless, the underlying roles and mechanisms of autophagy in PF progression remain unclear. In this review, we discuss the key roles and potential mechanisms of autophagy in PF to offer novel perspectives on future therapy strategies for PF and their limitations.

Card9 protects fungal peritonitis through regulating Malt1-mediated activation of autophagy in macrophage

Fungal peritonitis is an inflammatory condition of the peritoneum which occurs secondary to peritoneal dialysis. Most cases of peritonitis are caused by microbial invasion into the peritoneal cavity, resulting in high morbidity and mortality. Unlike bacterial peritonitis, little is known on fungal peritonitis. Card9, an adapter protein, plays a critical role in anti-fungal immunity. In this study, by using zymosan-induced peritonitis and C. albicans-induced peritonitis mouse model, we demonstrated that fungal peritonitis was exacerbated in Card9^-/- mice, compared with WT mice. Next, we found the autophagy activation of peritonealmacrophages was impaired in Card9^-/- peritonitis mice. The autophagy agonist, MG132, ameliorated peritonitis in Card9^-/- mice. The result of microarray analysis indicates Malt1 was significantly decreased in Card9^-/- peritonitis mice. Furthermore, we demonstrated that Malt1 interacts with P62 and mediates the function of P62 to clear ubiquitinated proteins. After overexpression of Malt1, impaired autophagy activation caused by Card9 deficient was significantly rescued. Together, our results indicate that Card9 protects fungal peritonitis by regulating Malt1-mediated autophagy in macrophages. Our research provides a new idea for the pathogenesis of fungal peritonitis, which is of great significance for the clinical treatment of fungal peritonitis.

Characteristics Analysis, Clinical Outcome and Risk Factors for Fungal Peritonitis in Peritoneal Dialysis Patients: A 10-Year Case-Control Study

Background: Fungal peritonitis (FP) is a rare but severe complication that can appear in patients receiving peritoneal dialysis (PD). This study aimed to investigate the incidence rate and clinical characteristics of FP, evaluate clinical outcomes between FP and bacterial peritonitis (BP) patients on PD, and especially estimate the risk factors for FP outbreak.

Methods: All episodes of FP diagnosed in our hospital from January 1, 2011, to December 31, 2020, were reviewed in this single-center study. FP cases were analyzed and compared with patients diagnosed with BP in a 1:6 ratio matching for case-control study. Patient information, including clinical information, biochemical analysis, and outcomes, was recorded. Univariate and multivariate logistic regression model were used to analyze the risk factors for FP.

Results: A total of 15 FP episodes were observed in 15 PD patients, with an FP rate of 0.0071 episodes per patient-year. Seventeen strains of fungi were isolated and identified. Candida was the most common pathogen (15 strains, 88.2%), followed by Aspergillus fumigatus (2 strains, 11.8%). Between the groups, FP group showed a higher rate of HD transfer and catheter removal, and a lower rate of PD resumption in the short-term outcome (all P < 0.01), while no significant difference in the mortality was noted during the whole study period. The multivariate logistic regression analysis showed that longer PD duration (odds ratio [OR] 1.042, 95% confidence interval [CI] 1.012–1.073, P < 0.01), higher serum potassium (OR 3.373, 95% CI 1.068–10.649, P < 0.05), elevated estimated glomerular filtration rate (eGFR) (OR 1.845, 95% CI 1.151–2.955, P < 0.05), reduced serum albumin level (OR 0.820, 95% CI 0.695–0.968, P < 0.05) and peritoneal effluent polymorphonuclear (PMN) count (OR 0.940, 95%CI 0.900–0.981, P < 0.01) were significantly increased the risk for FP.

Conclusion: These results suggested that FP leads to higher rate of catheter removal and HD transfer, and a lower rate of PD resumption than BP, and that additional attention should be paid to hypoalbuminemia, increased serum potassium, long PD duration, and low peritoneal effluent PMN in PD patients.

Peritonitis in children on peritoneal dialysis: 12 years of tertiary center experience

Background and Objective

Peritoneal dialysis (PD) associated peritonitis is the most common cause of morbidity, mortality, and treatment failure in patients undergoing PD. We aimed to identify the incidence, pathogens, antibiotic susceptibility, and the outcome of peritoneal dialysis (PD)-associated peritonitis in children.

Methods

Data from medical records of children who underwent PD between 2007 and 2018 in King Fahad Medical City were retrospectively collected. All children aged <14 years undergoing chronic PD were included. The demographic characteristics of patients, peritonitis rates, and clinical outcomes‏ were collected.

Results

In total, 131 children [boys, 68 (51.9%)] underwent automated PD for 305 years. The most common age group was 6-12 years (61 patients, 46.6%). A total of 74.0% of patients were new to dialysis; 25.2% were transferred from hemodialysis. Peritonitis incidence was 0.6 episodes/patient-year. Gram-positive and -negative organisms were identified in 50.1% and 22% episodes, respectively, whereas cultures remained negative in 20.5% episodes. Coagulase-negative Staphylococcus was the most common isolated organism (22.1%), followed by methicillin-sensitive S. aureus (11.1%). Peritonitis was resolved in 153 (73.6%) episodes, whereas 52 (25.0%) episodes required removal through the catheter. The multivariate logistic regression analysis found the exit site infection to be a risk factor for catheter removal. Three (1.4%) episodes caused death due to peritonitis complicated by septic shock‏.

Conclusions

Our data showed that the most common organisms causing peritonitis were similar to those reported in the previous international registry. The rate of peritonitis was high, but markedly improved in the past two years.

Peritoneal Dialysis Guidelines 2019 Part 1 (Position paper of the Japanese Society for Dialysis Therapy)

Approximately 10 years have passed since the Peritoneal Dialysis Guidelines were formulated in 2009. Much evidence has been reported during the succeeding years, which were not taken into consideration in the previous guidelines, e.g., the next peritoneal dialysis PD trial of encapsulating peritoneal sclerosis (EPS) in Japan, the significance of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), the effects of icodextrin solution, new developments in peritoneal pathology, and a new international recommendation on a proposal for exit-site management. It is essential to incorporate these new developments into the new clinical practice guidelines. Meanwhile, the process of creating such guidelines has changed dramatically worldwide and differs from the process of creating what were “clinical practice guides.” For this revision, we not only conducted systematic reviews using global standard methods but also decided to adopt a two-part structure to create a reference tool, which could be used widely by the society’s members attending a variety of patients. Through a working group consensus, it was decided that Part 1 would present conventional descriptions and Part 2 would pose clinical questions (CQs) in a systematic review format. Thus, Part 1 vastly covers PD that would satisfy the requirements of the members of the Japanese Society for Dialysis Therapy (JSDT). This article is the duplicated publication from the Japanese version of the guidelines and has been reproduced with permission from the JSDT.

Clinical Features and Risk Factors of Fungal Peritonitis in Children on Peritoneal Dialysis

Objective: To analyse the clinical manifestations, aetiology, prognosis, and risk factors of fungal peritonitis (FP) in children on peritoneal dialysis (PD). Methods: Among 322 children undergoing PD at Children's Hospital of Fudan University, between January 2001 and December 2019, FP cases were retrospectively analysed and compared with those of bacterial peritonitis (BP) to analyse the risk factors of FP. Results: A total of 124 cases of peritonitis were treated, including 11 FP cases in 11 children (0.0019 episodes/patient^*month) and 113 BP cases in 64 children (0.02 episodes/patient^*month). Among the 11 FP cases, 7 cases (63.64%) were caused by Candida and Candida parapsilosis (5/7) was the most common pathogen of Candida. All FP patients were converted to haemodialysis (HD) and did not resume PD during follow-up. Two patients (18.2%) died after 6 months of HD due to heart failure, 2 patients underwent kidney transplant after 2 years of infection, and the other 7 patients were still on HD. The univariate analysis showed the usage rate of antibiotics in the month before the onset of peritonitis was higher (45.45 vs. 15.93%) and the mean serum albumin was lower (31.4 vs. 34.4 g/L) in the FP group when compared with BP group (P < 0.05), while multivariate analysis showed that serum albumin ≤ 30 g/L was an independent risk factor for FP (odds ratio 4.896, 95% confidence interval 1.335-17.961). Conclusion: FP is a rare complication of PD in children, but it is associated with high technique failure. Attention should be paid to hypoproteinaemia and antibiotic use in children on PD.

Continuous ambulatory peritoneal dialysis-associated Histoplasma capsulatum peritonitis: a case report and literature review

Background

Fungal peritonitis (FP) is a rare complication of peritoneal dialysis. We herein describe the second case in Asia of Histoplasma capsulatum peritonitis associated with continuous ambulatory peritoneal dialysis (CAPD).

Case presentation

An 85-year-old woman with end-stage renal disease (ESRD) who had been on CAPD for 3 years and who had a history of 3 prior episodes of peritonitis presented with intermittent abdominal pain for 2 weeks and high-grade fever for 3 days. Elevated white blood cell (WBC) count and rare small oval budding yeasts were found in her peritoneal dialysis (PD) fluid. From this fluid, a white mold colony was observed macroscopically after 7 days of incubation, and numerous large, round with rough-walled tuberculate macroconidia along with small smooth-walled microconidia were observed microscopically upon tease slide preparation, which is consistent with H. capsulatum. The peritoneal dialysis (PD) catheter was then removed, and it also grew H. capsulatum after 20 days of incubation. The patient was switched from CAPD to hemodialysis. The patient was successfully treated with intravenous amphotericin B deoxycholate (AmBD) for 2 weeks, followed by oral itraconazole for 6 months with satisfactory result. The patient remains on hemodialysis and continues to be clinically stable.

Conclusion

H. capsulatum peritonitis is an extremely rare condition that is associated with high morbidity and mortality. Demonstration of small yeasts upon staining of PD fluid, and isolation of slow growing mold in the culture of clinical specimen should provide important clues for diagnosis of H. capsulatum peritonitis. Prompt removal of the PD catheter and empirical treatment with amphotericin B or itraconazole is recommended until the culture results are known.

Fungal peritonitis in children on peritoneal dialysis at a tertiary care Centre

BACKGROUND

Fungal peritonitis (FP) is an infrequent but serious complication in children undergoing peritoneal dialysis (PD). This study aimed to explore the risk factors, clinical manifestations, causative organisms, fungal susceptibility findings, and outcomes of FP in children from Saudi Arabia.

METHODS

In this case-control study, the medical records and laboratory results of paediatric patients aged 0-14 years who underwent PD were reviewed for FP episodes. All FP episodes were matched with PD-related bacterial peritonitis episodes (1:4 ratio).

RESULTS

A total of 194 episodes of PD-related peritonitis occurred between 2007 and 2017, among which 11 were FP episodes (5.6%), representing a rate of 0.03 episodes per patient-year. Of these 11 episodes, 9 were caused by Candida species (82%). Compared with the bacterial peritonitis group, the FP group had a higher proportion of patients with congenital/infantile nephrotic syndrome (p = 0.005) and those younger than 5 years of age (p = 0.001). We observed a higher rate of catheter removal in the FP group than in the bacterial peritonitis group (p <  0.001); however, 1 patient died despite catheter removal. Moreover, 75% of Candida species isolates were susceptible to fluconazole.

CONCLUSIONS

This study revealed that FP is associated with a significant risk of peritoneal membrane failure among children undergoing PD. Therefore, early diagnosis and prompt management are essential. We also found that congenital/infantile nephrotic syndrome and young age (5 years old or younger) were risk factors for FP in children undergoing PD.

Chronic peritoneal dialysis in children: a single-centre experience in Jordan

The aim of the present study is to share the experience of chronic peritoneal dialysis (PD) at King Hussein Medical Center, Amman, Jordan, and to highlight the complications of this procedure. This is a retrospective chart review study for all the children from day 1 of life to 14 years, who underwent chronic PD for end-stage renal disease (ESRD) during the period of 10 years extending from 2009 to 2019. The following data were collected: mode of dialysis, type of peritoneal dialysis, age of starting peritoneal dialysis, gender, aetiology of ESRD, duration on PD, complications and outcome. A total number of 269 children were included: 229 patients received haemodialysis and 40 children (22 boys and 18 girls) received PD. Of those, two children were on automated PD and 38 children were on continuous ambulatory peritoneal dialysis. The mean age at the start of PD was 62 ± 38 months. The mean duration of PD was 43 months. The mean catheter duration was 34 months. Six patients were shifted to haemodialysis permanently and four patients received a kidney transplant. Eleven patients died. The most common complications were peritonitis (52.5%), exit-site infection (30%) and malfunctioning catheter (12.5%). The rate of peritonitis was one episode per 22 patient-months. Peritoneal dialysis is a promising mode of dialysis for children in Jordan. Peritonitis is the most common complication associated with PD. Kidney transplantation is the best modality of renal replacement therapy in terms of long-term survival and quality of life and should be encouraged on national level.

Salvage of the peritoneal dialysis catheter in Candida peritonitis using amphotericin B catheter lock

Candida species form biofilms, facilitating adherence to peritoneal dialysis (PD) catheters and making them less susceptible to antifungal therapy. Therefore, the International Society for Peritoneal Dialysis recommends immediate PD catheter removal in case of Candida peritonitis. However, in 2007, our institution showed that Candida peritonitis could be successfully treated without catheter removal with a treatment strategy including amphotericin B as catheter lock. To confirm the efficacy and safety of this lock-based protocol, we evaluated the outcome of Candida peritonitis episodes since then. A retrospective, single-centre study was conducted in which we analysed all Candida peritonitis episodes in PD patients, treated with the lock-based protocol between July 2006 and March 2018. Eleven non-relapse Candida peritonitis episodes in 10 patients were treated with the lock-based protocol. Seven of the 11 episodes (64%) were cured without PD catheter removal (5 episodes cured immediately, 1 episode cured after an early relapse and 1 episode cured after a late relapse), in 2 episodes (18%) the catheter had to be removed, and two patients died (18%). This study confirms our previous findings that an amphotericin B lock-based protocol has potential to cure Candida peritonitis without PD catheter removal. However, further research is needed given the limitations of this study. Until that time, the lock-based Candida protocol could be used in patients who are not severely ill and in whom PD catheter removal is not desirable.

Recent trends in molecular diagnostics of yeast infections: from PCR to NGS

The incidence of opportunistic yeast infections in humans has been increasing over recent years. These infections are difficult to treat and diagnose, in part due to the large number and broad diversity of species that can underlie the infection. In addition, resistance to one or several antifungal drugs in infecting strains is increasingly being reported, severely limiting therapeutic options and showcasing the need for rapid detection of the infecting agent and its drug susceptibility profile. Current methods for species and resistance identification lack satisfactory sensitivity and specificity, and often require prior culturing of the infecting agent, which delays diagnosis. Recently developed high-throughput technologies such as next generation sequencing or proteomics are opening completely new avenues for more sensitive, accurate and fast diagnosis of yeast pathogens. These approaches are the focus of intensive research, but translation into the clinics requires overcoming important challenges. In this review, we provide an overview of existing and recently emerged approaches that can be used in the identification of yeast pathogens and their drug resistance profiles. Throughout the text we highlight the advantages and disadvantages of each methodology and discuss the most promising developments in their path from bench to bedside.

Fungal peritonitis in peritoneal dialysis: 5-year review from a North China center

PURPOSE

Fungal peritonitis (FP) is a rare but devastating complication in peritoneal dialysis (PD), accounting for high rates of technique failure, morbidity and mortality. This study was conducted to investigate FPs with regard to peritonitis rate, microbiology testing, patient characteristics, clinical features, antifungal treatments, and clinical outcomes in patients on PD.

METHODS

This single-center study retrospectively reviewed all FP episodes diagnosed from June 1, 2012 to June, 2017. All FPs were matched in a 1:5 ratio with PD patients diagnosed with bacterial peritonitis. Clinical, biochemical characteristics and detailed data on peritonitis episodes were recorded.

RESULTS

Eleven fungal peritonitis episodes (rate of 0.0067 episodes per patient-year on dialysis) were identified. All FPs were caused by Candida species (identification and antifungal susceptibility testing were performed with VITEK 2^® compact system), including C. albicans (6/11), C. parapsilosis (4/11) and C. krusei (1/11). Except C. krusei, no Candida resistance to fluconazole was detected. Compared to bacterial peritonitis (matched cases, n = 55), FP group showed higher rate of previous antibiotic use (p = 0.002), higher total effluent cell count (p = 0.007), and lower serum albumin (p = 0.01), higher rate of infection-related surgery (p < 0.001), HD transfer (p = 0.001), and all-cause death (p = 0.006). High prevalence (≥ 50%) of female gender, anuria, CCI ≥ 4, hypoalbuminemia, anemia, and hypokalemia were also observed in FP patients. More than half of the FP patients presented gastrointestinal symptoms (7/11) and extraperitoneal infection (6/11). Eight (72.7%) patients had catheter surgically removed with a median 5.5 lag days, four (36.4%) patients died within 3 months and six (54.5%) cases led to technique failure.

CONCLUSIONS

FP results in high rates of catheter loss and all-cause mortality in 3 months of follow-up, candida species were the commonest pathogens in our center. Variations of clinical features and susceptibility patterns were observed. Gastrointestinal disorders maybe a potential risk factor for FP.

Fungal peritonitis in peritoneal dialysis: a 34-year single centre evaluation

Backgound

Fungal peritonitis (FP) is one of the most important causes of peritoneal dialysis (PD) failure, often burdened by increased morbility and mortality. This study evaluates the clinical course of FP cases that arose between 1983 and 2016 in a single PD unit.

Methods

We conducted a retrospective observational analysis of FP episodes recorded in the Baxter POET (Peritonitis Organism Exit sites Tunnel infections) registry and clinical records. FP incidence rate, PD and patients’ survival and clinical characteristics of the study population were analysed, taking into account the evolution of clinical practice during the study period as a result of technical innovation, scientific evidence and guideline history.

Results

Fourteen FP cases (2.8%) were detected. The overall incidence of PD peritonitis was one episode/27 patient-months. Candida parapsilosis was the most frequently (50%) detected yeast. Seventy-five per cent of cases were considered secondary FP. This group experienced 2.6±1.7 bacterial peritonitis before FP, most frequently due to Staphylococcus and Enterococcus species. Most patients were treated with fluconazole for ≥8 days. All subjects were hospitalized for a median time of 25 days. Tenckhoff catheter removal occurred in all cases of FP and all patients were transferred to haemodialysis. Two patients died. From December 2010 to December 2016, no FP episodes were recorded.

Conclusions

FP is confirmed as a significant cause of PD drop out and increases patients’ mortality risk. Prompt diagnosis of FP, targeted antifugal therapy and rapid PD catheter removal are essential strategies for improved patient and PD survival.

Peritoneal dialysis-related peritonitis: challenges and solutions

Peritoneal dialysis is an effective treatment modality for patients with end-stage renal disease. The relative use of peritoneal dialysis versus hemodialysis varies widely by country. Data from a 2004 survey reports the percentage of patients with end-stage renal disease treated with peritoneal dialysis to be 5%-10% in economically developed regions like the US and Western Europe to as much as 75% in Mexico. This disparity is probably related to the availability and access to hemodialysis, or in some cases patient preference for peritoneal over hemodialysis. Peritoneal dialysis-related peritonitis remains the major complication and primary challenge to the long-term success of peritoneal dialysis. Fifty years ago, with the advent of the Tenckhoff catheter, patients averaged six episodes of peritonitis per year on peritoneal dialysis. In 2016, the International Society for Peritoneal Dialysis proposed a benchmark of 0.5 episodes of peritonitis per year or one episode every 2 years. Despite the marked reduction in peritonitis over time, peritonitis for the individual patient is problematic. The mortality for an episode of peritonitis is 5% and is a cofactor for mortality in another 16% of affected patients. Prevention of peritonitis and prompt and appropriate management of peritonitis is essential for the long-term success of peritoneal dialysis in all patients. In this review, challenges and solutions are addressed regarding the pathogenesis, clinical features, diagnosis, treatment, and prevention of peritoneal dialysis-related peritonitis from the viewpoint of an infectious disease physician.

Global and Multi-National Prevalence of Fungal Diseases-Estimate Precision

Fungal diseases kill more than 1.5 million and affect over a billion people. However, they are still a neglected topic by public health authorities even though most deaths from fungal diseases are avoidable. Serious fungal infections occur as a consequence of other health problems including asthma, AIDS, cancer, organ transplantation and corticosteroid therapies. Early accurate diagnosis allows prompt antifungal therapy; however this is often delayed or unavailable leading to death, serious chronic illness or blindness. Recent global estimates have found 3,000,000 cases of chronic pulmonary aspergillosis, ~223,100 cases of cryptococcal meningitis complicating HIV/AIDS, ~700,000 cases of invasive candidiasis, ~500,000 cases of Pneumocystis jirovecii pneumonia, ~250,000 cases of invasive aspergillosis, ~100,000 cases of disseminated histoplasmosis, over 10,000,000 cases of fungal asthma and ~1,000,000 cases of fungal keratitis occur annually. Since 2013, the Leading International Fungal Education (LIFE) portal has facilitated the estimation of the burden of serious fungal infections country by country for over 5.7 billion people (>80% of the world's population). These studies have shown differences in the global burden between countries, within regions of the same country and between at risk populations. Here we interrogate the accuracy of these fungal infection burden estimates in the 43 published papers within the LIFE initiative.

Peritoneal dialysis-related infections recommendations: 2016 update. What is new?

In 2016, the International Society of Peritoneal Dialysis (ISPD) published guidelines that focus on the importance of both prevention and treatment of peritonitis. For once more, the need for annual reporting of peritonitis rates and recording of peritonitis and exit-site infections, isolated microorganism and antimicrobial susceptibilities as a central component of a quality improvement program is highlighted. Data on new antibiotic regimens, techniques for microorganism isolation and peritoneal dialysis solutions are included. Training of both peritoneal dialysis nurses and patients seems to be crucial, while the modifiable risk factors for peritonitis seem to be of great interest. In this article, we record the changes in the last ISPD (2016) guidelines compared to the previous ones published in 2010.

Fungal peritonitis in patients undergoing peritoneal dialysis (PD) in Brazil: molecular identification, biofilm production and antifungal susceptibility of the agents

This paper presents data on fungal peritonitis (FP) in patients undergoing peritoneal dialysis (PD) at the University Hospital of Botucatu Medical School, São Paulo, Brazil. In a total of 422 patients, 30 developed FP, from which the medical records and the fungal isolates of 23 patient cases were studied. All patients presented abdominal pain, cloudy peritoneal effluent, needed hospitalization, had the catheter removed and were treated with fluconazole or fluconazole plus 5-flucitosine; six of them died due to FP. Concerning the agents, it was observed that Candida parapsilosis was the leading species (9/23), followed by Candida albicans (5/23), Candida orthopsilosis (4/23), Candida tropicalis (3/23), Candida guilliermondii (1/23), and Kodamaea ohmeri (1/23). All the isolates were susceptible to amphotericin B, voriconazole and caspofungin whereas C. albicans isolates were susceptible to all antifungals tested. Resistance to fluconazole was observed in three isolates of C. orthopsilosis, and dose-dependent susceptibility to this antifungal was observed in two isolates of C. parapsilosis and in the K. ohmeri isolate. Biofilm production estimates were high or moderate in most isolates, especially in C. albicans species, and low in C. parapsilosis species, with a marked variation among the isolates. This Brazilian study reinforces that FP in PD is caused by a diverse group of yeasts, most prevalently C. parapsilosis sensu stricto species. In addition, they present significant variation in susceptibility to antifungals and biofilm production, thus contributing to the complexity and severity of the clinical features.

High-dose ascorbate with low-dose amphotericin B attenuates severity of disease in a model of the reappearance of candidemia during sepsis in the mouse

Amphotericin B (Ampho B) isa fungicidal drug that causes cell wall injury. Pharmacological ascorbate induces the extracellular prooxidants, which might enter the Ampho B-induced cell wall porosity and act synergistically.W e tested low-dose Ampho B with a short course of pharmacological ascorbate using a mouse model of sepsis preconditioned with an injection of Candida albicans 6 h prior to cecal ligation and puncture (CLP). In this model, candidemia reappeared as early as 6 h after CLP with a predictably high mortality rate. This characteristic mimics sepsis in the phase of immunosuppression inpatients. Using the model, at 12- and 18-h post-CLP, we administered isotonic (pH neutralized) pharmacological ascorbate intravenously with low-dose Ampho B or sodium deoxycholate, vehicle-controlled, administered IP. The survival rate of low-dose Ampho B plus ascorbate was 53%, compared with < 11% for low-dose Ampho B or high-dose Ampho B alone. In addition, a beneficial effect was demonstrated in terms of kidney damage,liver injury, spleen histopathology, and serum markers at 24 h after CLP. Kidney injury was less severe in low-dose Ampho B plus ascorbate combination therapy due to less severe sepsis. Moreover, ascorbate enhanced the effectiveness of phagocytosis against C. albicans in human phagocytic cells. Taken together, the data indicate that the new mouse model simulates sepsis-induced immunosuppression and that the combination of pharmacological ascorbate with an antifungal drug is a potentially effective treatment that may reduce nephrotoxicity, and perhaps also increase fungicidal activity in patients with systemic candidiasis caused by Candida albicans.

Intra-abdominal fungal infections

PURPOSE OF REVIEW

The clinical spectrum of intra-abdominal fungal infections has not been systematically analyzed in the literature.

RECENT FINDINGS

Even though intra-abdominal fungal infections have been recognized with increasing frequency in the recent years, most clinical experience is limited to case reports or uncontrolled case series. These infections are more common than clinically recognized disease. The clinical presentation varies broadly depending on the organism and host's immune status, but it is frequently severe, difficult to treat, and associated with significant morbimortality. Predisposing factors, clinical characteristics, and advances in the management are discussed.

SUMMARY

Intra-abdominal fungal infections are increasingly important in clinical practice. Early recognition and a combined treatment approach, usually consisting of surgical intervention and systemic antifungal therapy, are required for improved outcomes.

Characteristics and outcomes of fungal peritonitis in a modern North American cohort

INTRODUCTION

Peritonitis remains a common complication of peritoneal dialysis (PD). Although representing only 1 - 12% of overall peritonitis in dialysis patients, fungal peritonitis (FP) is associated with serious complications, including technique failure and death. Only scarce data have been published regarding FP outcomes in modern cohorts in North America. In this study we evaluated the rates, characteristics and outcomes of FP in a major North American PD center.

METHODS

We conducted a retrospective cohort study including all fungal peritonitis episodes among peritoneal dialysis patients followed in a large PD center between January 2000 and February 2013. Our pre-specified endpoints included rates of FP, characteristics, outcomes and determinants of death.

RESULTS

Thirty-six episodes of FP were identified during the follow-up period (one episode per 671 patient-months), representing 4.5% of the total peritonitis events. Patients' mean age and peritoneal dialysis vintage were 61.3 ± 15.5 and 2.9 (1.5 - 4.8) years, respectively. Of the 36 episodes of FP, seven (19%) resulted in death and 17 (47%) led to technique failure with permanent transfer to hemodialysis. Surprisingly, PD was eventually resumed in 33% of cases with a median delay of 15 weeks (interquartile range 8 - 23) between FP and catheter reinsertion. In a univariable analysis, a higher Charlson comorbidity index (Odds ratio [OR] 3.25 per unit increase, 95% confidence interval [CI] 1.23 - 8.58) and PD fluid white blood cell (WBC) count greater than 3,000/mm(3) at presentation (OR 6.56, 95% CI 1.05 - 40.95) predicted death.

CONCLUSION

While fungal peritonitis is still associated with a high frequency of death and technique failure, one third of our patients eventually returned to PD. Patients with a high burden of comorbidities appear at higher risk of death. We postulate that the high mortality associated with FP is partially related to the severity of comorbidity among patients with FP, rather than the infection per se. Importantly, PD can be resumed in a significant proportion of cases.