Impact of prophylactic echinocandin on the development of neurological complications in patients receiving busulfan-containing conditioning regimens for stem cell transplantation: A single-center retrospective study

BACKGROUND

Although neurotoxicity is a major adverse event associated with busulfan, little information is available regarding the association between drug interactions and neurological symptoms during busulfan-based regimens. This study evaluated the association between prophylactic echinocandins and neurological complications in patients receiving busulfan-containing conditioning regimens for stem cell transplantation.

METHODS

We retrospectively included consecutive patients who administered intravenous busulfan as a conditioning regimen at our facility between 2007 and 2022. Prophylactic echinocandin use was defined as the use of an echinocandin antifungal drug to prevent invasive fungal disease in SCT recipients. The primary outcome was the incidence of neurological complications within 7 days of busulfan initiation and was compared between the echinocandin group (patients received prophylactic echinocandin) and nonechinocandin group (patients received prophylactic antifungal drugs other than echinocandin and those without antifungal prophylaxis).

RESULTS

Among the 59 patients included in this study, the incidence of neurological complications in the echinocandin (n = 26) and nonechinocandin groups (n = 33) was 30.8% and 63.6%, respectively. We observed a negative association between prophylactic echinocandin use and the development of neurological complications after adjusting for the propensity score for receiving prophylactic echinocandins (adjusted odds ratio 0.294, 95% confidence interval 0.090 to 0.959). We observed a lower incidence of neurological complications in the echinocandin group than in the nonechinocandin group.

CONCLUSION

Our results suggested that the choice of antifungal prophylaxis is associated with busulfan neurotoxicity.

Candidemia in Adult Patients in the ICU: A Reappraisal of Susceptibility Testing and Antifungal Therapy

OBJECTIVE

To provide updates on the epidemiology and recommendations for management of candidemia in patients with critical illness.

DATA SOURCES

A literature search using the PubMed database (inception to March 2023) was conducted using the search terms "invasive candidiasis," "candidemia," "critically ill," "azoles," "echinocandin," "antifungal agents," "rapid diagnostics," "antifungal susceptibility testing," "therapeutic drug monitoring," "antifungal dosing," "persistent candidemia," and "Candida biofilm."

STUDY SELECTION/DATA EXTRACTION

Clinical data were limited to those published in the English language. Ongoing trials were identified through ClinicalTrials.gov.

DATA SYNTHESIS

A total of 109 articles were reviewed including 25 pharmacokinetic/pharmacodynamic studies and 30 studies including patient data, 13 of which were randomized controlled clinical trials. The remaining 54 articles included fungal surveillance data, in vitro studies, review articles, and survey data. The current 2016 Infectious Diseases Society of America (IDSA) Clinical Practice Guideline for the Management of Candidiasis provides recommendations for selecting empiric and definitive antifungal therapies for candidemia, but data are limited regarding optimized dosing strategies in critically ill patients with dynamic pharmacokinetic changes or persistent candidemia complicated.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Outcomes due to candidemia remain poor despite improved diagnostic platforms, antifungal susceptibility testing, and antifungal therapy selection for candidemia in critically ill patients. Earlier detection and identification of the species causing candidemia combined with recognition of patient-specific factors leading to dosing discrepancies are crucial to improving outcomes in critically ill patients with candidemia.

CONCLUSIONS

Treatment of candidemia in critically ill patients must account for the incidence of non-albicans Candida species and trends in antifungal resistance as well as overcome the complex pathophysiologic changes to avoid suboptimal antifungal exposure.

An evaluation of Rezafungin: the latest treatment option for adults with candidemia and invasive candidiasis

INTRODUCTION

Invasive fungal infections, especially candidemia and invasive candidiasis, continue to cause substantial morbidity and mortality. In addition, the emergence of drug-resistant Candida species, notably C. glabrata and C. auris, along with limitations in available treatments, highlights the urgent need for novel, effective antifungal agents.

AREAS COVERED

This review discusses the results of in vitro studies evaluating the spectrum and highlights the pharmacokinetic/pharmacodynamic properties. It also includes discussions on two key clinical studies that assess safety, tolerability, and efficacy.

EXPERT OPINION

Rezafungin has demonstrated comparable efficacy to other echinocandins in two clinical studies and exhibits in vitro activity against a broad range of Candida species and Aspergillus spp. It has a favorable safety profile with minimal side effects, and no drug interactions or effects on QT intervals. In contrast to other echinocandins, it demonstrates dose-dependent killing, a prolonged half-life, and low clearance make it suitable for once-weekly dosing, which is supported by clinical trials confirming its efficacy. Rezafungin offers a promising option for the outpatient management of difficult to treat fungal infections. It has become a valuable addition to the antifungal arsenal, with the potential to reduce hospital length of stay and hospitalization costs and combat drug-resistant Candida species.

Genomic description of acquired fluconazole- and echinocandin-resistance in patients with serial Candida glabrata isolates

Candida glabrata is one of the most common causes of systemic candidiasis, often resistant to antifungal medications. To describe the genomic context of emerging resistance, we conducted a retrospective analysis of 82 serially collected isolates from 33 patients from population-based candidemia surveillance in the United States. We used whole-genome sequencing to determine the genetic relationships between isolates obtained from the same patient. Phylogenetic analysis demonstrated that isolates from 29 patients were clustered by patient. The median SNPs between isolates from the same patient was 30 (range: 7-96 SNPs), while unrelated strains infected four patients. Twenty-one isolates were resistant to echinocandins, and 24 were resistant to fluconazole. All echinocandin-resistant isolates carried a mutation either in the FKS1 or FKS2 HS1 region. Of the 24 fluconazole-resistant isolates, 17 (71%) had non-synonymous polymorphisms in the PDR1 gene, which were absent in susceptible isolates. In 11 patients, a genetically related resistant isolate was collected after recovering susceptible isolates, indicating in vivo acquisition of resistance. These findings allowed us to estimate the intra-host diversity of C. glabrata and propose an upper boundary of 96 SNPs for defining genetically related isolates, which can be used to assess donor-to-host transmission, nosocomial transmission, or acquired resistance. IMPORTANCE In our study, mutations associated to azole resistance and echinocandin resistance were detected in Candida glabrata isolates using a whole-genome sequence. C. glabrata is the second most common cause of candidemia in the United States, which rapidly acquires resistance to antifungals, in vitro and in vivo.

The added value of (1,3)-β-D-glucan for the diagnosis of Invasive Candidiasis in ICU patients: a prospective cohort study

PURPOSE

Beta-D-Glucan (BDG) testing has been suggested to support the diagnosis of candidemia and invasive candidiasis. The actual benefit in critically ill high-risk patients in intensive care units (ICU) has not been verified so far.

METHODS

In ICU patients receiving empirical echinocandin treatment for suspected invasive candidiasis (IC), serial BDG testing using the Fujifilm Wako Beta-Glucan Test was performed, starting on the first day of echinocandin administration and every 24-48 h afterwards. Diagnostic accuracy was determined for single testing and serial testing strategies using a range of cut-off values. In addition, we compared the added value of these testing strategies when their results were introduced as additional predictors into a multivariable logistic regression model controlling for established risk factors of IC.

RESULTS

A total of 174 ICU patients, forty-six of which (25.7%) classified as cases of IC, were included in our study. Initial BDG testing showed moderate sensitivity (74%, 95%CI 59-86%) and poor specificity (45%, 95% CI 36-54%) for IC which could hardly be improved by follow-up testing. While raw BDG values or test results obtained with very high thresholds improved the predictive performance of our multivariable logistic regression model for IC, neither single nor serial testing with the manufacturer-proposed low-level cut-off showed substantial benefit.

CONCLUSIONS

In our study of critically ill intensive care patients at high risk for candidemia or invasive candidiasis, diagnostic accuracy of BDG testing was insufficient to inform treatment decisions. Improved classification was only achieved for cases with very high BDG values.

Antifungal Therapies for Aspergillus spp.: Present and Future

Currently available and recommended options for the treatment of pulmonary aspergillosis include the triazoles, echinocandins, and amphotericin B products. These therapies have significant limitations. Only the azoles are available orally, but their use is often limited by toxicities, drug-drug interactions, pharmacokinetic variability, and emerging resistance. While the echinocandins are safe agents and may have a role in combination therapy, they are unproven as monotherapy. Amphotericin B preparations are toxic and require intensive monitoring. Finally, aspergillosis continues to be a disease conferring substantial morbidity and mortality, and clinical trials have not identified a therapeutic approach clearly associated with improved outcomes. As a result, there is a great need for new options in the treatment of invasive aspergillosis. Ideally, such options would be safe, have high oral bioavailability, have favorable pharmacokinetics to sequestered sites and retain activity against azole-resistant isolates. Reassuringly, there is a robust pipeline of novel therapies in development. Rezafungin (a once-weekly dosed echinocandin) and ibrexafungerp (oral agent with same mechanism of action as echinocandins) will likely be reserved for combination therapy or refractory/intolerance scenarios with no other options. Inhaled opelconazole is an attractive option for combination therapy and prophylaxis of pulmonary aspergillosis. Development of an oral form of amphotericin B that avoids nephrotoxicity and electrolyte disturbances is an exciting development. Finally, olorofim and fosmanogepix, two agents with novel mechanisms of action and oral formulations, hold significant potential to challenge the triazole antifungals place as preferred therapies. However, many questions remain regarding these novel agents, and at the time of this writing, none of these agents have been robustly studied in Phase III studies of aspergillosis, and so their promise remains investigational.

New and emerging options for management of invasive fungal diseases in paediatric patients

Invasive fungal diseases (IFDs) play an important role in the supportive care of paediatric patients with acute leukaemia and those undergoing allogeneic haematopoietic cell transplantation, and they are associated with significantly decreased overall survival rates in affected individuals. Relative to adults, children and adolescents are distinct in terms of host biology, predisposing conditions, presentation and epidemiology of fungal diseases, and in the pharmacology of antifungal agents. The paediatric development of antifungal agents has moved forward in a coordinated manner, and major advances have been made regarding concepts and recommendations for the prevention and treatment of IFDs. However, antifungal therapy is increasingly complex, and a solid knowledge of the available options is needed more than ever for successful management. This narrative review provides a summary of the paediatric development of agents that have been recently approved (anidulafungin, posaconazole) or are in advanced stages of development (isavuconazole). It also reviews the emerging evidence for the efficacy of echinocandins for prophylaxis of invasive aspergillosis, presents new data on alternative dosing regimens of echinocandins and voriconazole, and provides a brief overview of new antifungal agents in clinical development that are expected to be developed for paediatric patients.

Natural history and prognostic factors of candidemia in kidney transplant recipients: A retrospective, multinational study

BACKGROUND

The natural history of candidemia in kidney transplant recipients (KTR) remains poorly understood. This study aimed to evaluate mortality, prognostic factors and overall graft loss after candidemia in KTRs.

METHODS

This is a retrospective multicentre study enrolling all KTRs ≥15 years old with candidemia diagnosed at hospitals in Brazil, Spain and Italy from 2010 to 2020. Primary endpoints were mortality rates at 14 and 30 days. Secondary endpoints were prognostic factors of 14-day mortality and overall graft loss.

RESULTS

We enrolled 93 KTRs of which 75 were from Brazil. The mean time interval from transplantation to the onset of candidemia was 45.2 ± 61.5 months. 42% of all patients were on haemodialysis, 31.3% had an episode of sepsis and 39% underwent surgery within 30 days before fungemia. European patients were more likely to receive echinocandin (32 vs. 72%, p < .001). 22.7% of Brazilian patients did not receive any antifungal before death. All-cause mortality at 14 days was higher in Brazil (41.3 vs. 11.1%, p = .016). Candida colonisation (OR 6.91 [95% CI: 1.08-44.3], p = .042) and hypotension (OR 4.87 [95% CI: 1.62-14.66], p = .005) were associated with 14-day mortality. Echinocandin treatment had a protective effect (OR 0.19 [95% CI: 0.05-0.73], p = .015). Graft loss at 90 days occurred in 48% of patients (70.7 in Brazil vs. 22.2% in Europe, p < .01).

CONCLUSIONS

Candidemia in KTR is usually documented late after engraftment in patients requiring HD, surgical procedures and dysbiosis secondary to antibiotic use. Mortality was higher in Brazil. Echinocandin therapy was associated with improved survival.

Susceptibility to caspofungin is regulated by temperature and is dependent on calcineurin in Candida albicans

IMPORTANCE

Echinocandins are the newest antifungal drugs and are first-line treatment option for life-threatening systemic infections. Due to lack of consensus regarding what temperature should be used when evaluating susceptibility of yeasts to echinocandins, typically either 30°C, 35°C, or 37°C is used. However, the impact of temperature on antifungal efficacy of echinocandins is unexplored. In the current study, we demonstrated that Candida albicans laboratory strain SC5314 was more susceptible to caspofungin at 37°C than at 30°C. We also found that calcineurin was required for temperature-modulated caspofungin susceptibility. Surprisingly, the altered caspofungin susceptibility was not due to differential expression of some canonical genes such as FKS, CHS, or CHT genes. The molecular mechanism of temperature-modulated caspofungin susceptibility is undetermined and deserves further investigations.

Predictors for Prolonged Hospital Stay Solely to Complete Intravenous Antifungal Treatment in Patients with Candidemia: Results from the ECMM Candida III Multinational European Observational Cohort Study

BACKGROUND

To date, azoles represent the only viable option for oral treatment of invasive Candida infections, while rates of azole resistance among non-albicans Candida spp. continue to increase. The objective of this sub-analysis of the European multicenter observational cohort study Candida III was to describe demographical and clinical characteristics of the cohort requiring prolonged hospitalization solely to complete intravenous (iv) antifungal treatment (AF Tx).

METHODS

Each participating hospital (number of eligible hospitals per country determined by population size) included the first ~ 10 blood culture proven adult candidemia cases occurring consecutively after July 1st, 2018, and treating physicians answered the question on whether hospital stay was prolonged only for completion of intravenous antifungal therapy. Descriptive analyses as well as binary logistic regression was used to assess for predictors of prolonged hospitalization solely to complete iv AF Tx.

FINDINGS

Hospital stay was prolonged solely for the completion of iv AF Tx in 16% (100/621) of candidemia cases by a median of 16 days (IQR 8 - 28). In the multivariable model, initial echinocandin treatment was a positive predictor for prolonged hospitalization to complete iv AF Tx (aOR 2.87, 95% CI 1.55 - 5.32, p < 0.001), while (i) neutropenia, (ii) intensive care unit admission, (iii) catheter related candidemia, (iv) total parenteral nutrition, and (v) C. parapsilosis as causative pathogen were found to be negative predictors (aOR 0.22 - 0.45; p < 0.03).

INTERPRETATION

Hospital stays were prolonged due to need of iv AF Tx in 16% of patients with candidemia. Those patients were more likely to receive echinocandins as initial treatment and were less severely ill and less likely infected with C. parapsilosis.

Caspofungin sequestration in a polyacrylonitrile-derived filter: Increasing the dose does not mitigate sequestration

OBJECTIVES

Critically ill patients frequently require continuous renal replacement therapy. Echinocandins are recommended as first-line treatment of candidemia. Preliminary results suggested echinocandin sequestration in a polyacrylonitrile filter. The present study aimed to determine whether increasing the dose might balance sequestration.

METHODS

An STX filter (Baxter-Gambro) was used. A liquid chromatography-mass spectrometry method was used for dosage of caspofungin. In vitro drug disposition was evaluated by NeckEpur (Neckepur, Versailles, France) technology using a crystalloid medium instead of diluted/reconstituted blood, focusing on the disposition of the unbound fraction of drugs. Two concentrations were assessed.

RESULTS

At the low dose, the mean measured initial concentration in the central compartment (CC) was 5.1 ± 0.6 mg/L. One hundred percent of the initial amount was eliminated from the CC within the 6-h session. The mean total clearance from the CC was 9.6 ± 2.5 L/h. The mean percentages of elimination resulting from sequestration and diafiltration were 96.0 ± 5.0 and 4.0 ± 5.2%, respectively. At high dose, the mean measured initial concentration in the CC was 13.1 mg/L. One hundred percent of the initial amount was eliminated from the CC within the 6-h session. The mean total clearance from the CC was 9.5 L/h. The mean percentages of elimination resulting from sequestration and filtration were 88.5% and 11.5%, respectively.

CONCLUSION

Increasing the dose does not mitigate caspofungin sequestration in the STX filter. The results raise caution about the simultaneous use of caspofungin and polyacrylonitrile-derived filters. Intermittent modes of renal replacement therapy might be considered. For sensitive species, fluconazole might be an alternative.

Assessment of micafungin dosage regimens against Candida spp. in pediatric patients undergoing hematopoietic stem cell transplantation: a pharmacokinetic/pharmacodynamic analysis using Monte Carlo simulation

The objective of this study was to evaluate the efficacy of various micafungin dosing regimens against Candida spp. in pediatric patients undergoing hematopoietic stem cell transplantation (HSCT). Monte Carlo simulations were conducted using pharmacokinetic (PK) parameters and pharmacodynamic (PD) data to determine the probabilities of target attainment and cumulative fractions of response in terms of area under the concentration curve/minimum inhibition concentration targets of micafungin. Current standard clinical micafungin dosing regimens of 1 and 2 mg/kg/day were appropriate for the prevention and treatment of Candida glabrata infection in pediatric patients undergoing HSCT, respectively. Moreover, the high-dose prophylactic dosage (2 mg/kg/day) and therapeutic dosage (4 mg/kg/day) should be the preferred option to optimize efficacy against Candida albicans. However, none of the simulated regimens was effective against Candida parapsilosis in pediatric HSCT patients. These PK/PD-based simulations rationalize and optimize the micafungin dosing regimens against Candida spp. in pediatric patients undergoing HSCT.

The Role of Novel Antifungals in the Management of Candidiasis: A Clinical Perspective

Mucosal and invasive candidiasis can be challenging to treat in the setting of drug intolerance, antifungal resistance, drug-drug interactions, or host immune status. Antifungals with novel mechanisms of action and distinct pharmacokinetic/pharmacodynamic properties have been developed in recent years. Rezafungin is an echinocandin with high-tissue penetration and an extended half-life that allows for once-weekly administration, making it a convenient treatment option for invasive candidiasis while obviating the need for central catheter placement. Ibrexafungerp is an oral glucan synthase inhibitor that is active against most echinocandin-resistant Candida species. At present, it is approved for the treatment of acute vulvovaginal candidiasis and is under investigation as an oral step-down therapy following initial treatment with an echinocandin for cases of invasive candidiasis. Oteseconazole is a long-acting tetrazole that exhibits a higher affinity for the fungal enzyme CYP51, resulting in a potentially lower risk of drug-drug interactions and side effects compared to other azoles. It is currently approved for the treatment of recurrent vulvovaginal candidiasis. Fosmanogepix has a novel mechanism of action and potent activity against several Candida strains resistant to other antifungals. Due to its considerable bioavailability and tissue penetration, it holds promise as a potential treatment option in patients with invasive candidiasis, including those with chorioretinitis or meningitis. Results from clinical trials and observational studies will further delineate the role of these agents in the management of candidiasis. As the usage of these novel antifungals becomes widespread, we expect to acquire a greater understanding of their efficacy and potential benefits.

Whole genome sequencing analysis demonstrates therapy-induced echinocandin resistance in Candida auris isolates

Candida auris is an emerging, multidrug-resistant yeast, causing outbreaks in healthcare facilities. Echinocandins are the antifungal drugs of choice to treat candidiasis, as they cause few side effects and resistance is rarely found. Previously, immunocompromised patients from Kuwait with C. auris colonisation or infection were treated with echinocandins, and within days to months, resistance was reported in urine isolates. To determine whether the development of echinocandin resistance was due to independent introductions of resistant strains or resulted from intra-patient resistance development, whole genome sequencing (WGS) single-nucleotide polymorphism (SNP) analysis was performed on susceptible (n = 26) and echinocandin-resistant (n = 6) isolates from seven patients. WGS SNP analysis identified three distinct clusters differing 17-127 SNPs from two patients, and the remaining isolates from five patients, respectively. Sequential isolates within patients had a maximum of 11 SNP differences over a time period of 1-10 months. The majority of isolates with reduced susceptibility displayed unique FKS1 substitutions including a novel FKS1M690V substitution, and nearly all were genetically related, ranging from only three to six SNP differences compared to susceptible isolates from the same patient. Resistant isolates from three patients shared the common FKS1S639F substitution; however, WGS analysis did not suggest a common source. These findings strongly indicate that echinocandin resistance is induced during antifungal treatment. Future studies should determine whether such echinocandin-resistant strains are capable of long-term colonisation, cause subsequent breakthrough candidiasis, have a propensity to cross-infect other patients, or remain viable for longer time periods in the hospital environment.

Whole genome analysis of echinocandin non-susceptible Candida Glabrata clinical isolates: a multi-center study in China

BACKGROUND

Candida glabrata is an important cause of invasive candidiasis. Echinocandins are the first-line treatment of invasive candidiasis caused by C. glabrata. The epidemiological echinocandin sensitivity requires long-term surveillance and the understanding about whole genome characteristics of echinocandin non-susceptible isolates was limited.

RESULTS

The present study investigated the echinocandin susceptibility of 1650 C. glabrata clinical isolates in China from August 2014 to July 2019. The in vitro activity of micafungin was significantly better than those of caspofungin and anidulafungin (P < 0.001), assessed by MIC50/90 values. Whole genome sequencing was conducted on non-susceptible isolates and geography-matched susceptible isolates. Thirteen isolates (0.79%) were resistant to at least one echinocandin. Six isolates (0.36%) were solely intermediate to caspofungin. Common evolutionary analysis of echinocandin-resistant and echinocandin-intermediate isolates revealed genes related with reduced caspofungin sensitivity, including previously identified sphinganine hydroxylase encoding gene SUR2. Genome-wide association study identified SNPs at subtelometric regions that were associated with echinocandin non-susceptibility. In-host evolution of echinocandin resistance of serial isolates revealed an enrichment for non-synonymous mutations in adhesins genes and loss of subtelometric regions containing adhesin genes.

CONCLUSIONS

The echinocandins are highly active against C. glabrata in China with a resistant rate of 0.79%. Echinocandin non-susceptible isolates carried common evolved genes which are related with reduced caspofungin sensitivity. In-host evolution of C. glabrata accompanied intensive changing of adhesins profile.

Treatment pathways, switches, and inappropriate treatment during invasive pulmonary aspergillosis: real-world experiences from a global research network study

Despite advancements in diagnosing and treating invasive pulmonary aspergillosis (IPA), there is limited knowledge of real-world treatment pathways and medication switches. We queried the TrinetX global research network database and identified 5,410 patients diagnosed with IPA. The most common initial treatments were voriconazole (49%), fluconazole (11%), and posaconazole (7%). Most patients remained on voriconazole (80%) or isavuconazole (78%) throughout the treatment duration. Switches were more frequent for those initially treated with fluconazole, echinocandins, or posaconazole.

Critical appraisal beyond clinical guidelines for intraabdominal candidiasis

BACKGROUND

Regardless of the available antifungals, intraabdominal candidiasis (IAC) mortality continues to be high and represents a challenge for clinicians.

MAIN BODY

This opinion paper discusses alternative antifungal options for treating IAC. This clinical entity should be addressed separately from candidemia due to the peculiarity of the required penetration of antifungals into the peritoneal cavity. Intraabdominal concentrations may be further restricted in critically ill patients where pathophysiological facts alter normal drug distribution. Echinocandins are recommended as first-line treatment in guidelines for invasive candidiasis. However, considering published data, our pharmacodynamic analysis suggests the required increase of doses, postulated by some authors, to attain adequate pharmacokinetic (PK) levels in peritoneal fluid. Given the limited evidence in the literature on PK/PD-based treatments of IAC, an algorithm is proposed to guide antifungal treatment. Liposomal amphotericin B is advocated as first-line therapy in patients with sepsis/septic shock presenting candidemia or endophthalmitis, or with prior exposure to echinocandins and/or fluconazole, or with infections by Candida glabrata. Other situations and alternatives, such as new compounds or combination therapy, are also analysed.

CONCLUSION

There is a critical need for more robust clinical trials, studies examining patient heterogeneity and surveillance of antifungal resistance to enhance patient care and optimise treatment outcomes. Such evidence will help refine the existing guidelines and contribute to a more personalised and effective approach to treating this serious medical condition. Meanwhile, it is suggested to broaden the consideration of other options, such as liposomal amphotericin B, as first-line treatment until the results of the fungogram are available and antifungal stewardship could be implemented to prevent the development of resistance.

Fluconazole and echinocandin resistance of Candida species in invasive candidiasis at a university hospital during pre-COVID-19 and the COVID-19 outbreak

Antifungal susceptibility of Candida species is decreasing. Successful treatment for antifungal-resistant candida infection is challenging and associated with significant mortality. We performed a prospective observational study to identify the species and antifungal susceptibilities of invasive isolates of Candida species over a 5-year period at a university hospital in southern Thailand. Between 2017 and 2021, the species distribution was 39.1% Candida tropicalis, 24.8% Candida albicans, 20.3% Candida parapsilosis complex, 10.5% Candida glabrata, and 5.2% miscellaneous Candida spp. Notable observations include elevated minimal inhibitory concentration (MIC) and decrease susceptibility of C. tropicalis and C. glabrata to echinocandin and all tested triazoles. A shift of MIC90 value in the COVID-19 era was seen in C. albicans and C. tropicalis with azoles and echinocandins. Azole resistance increased among C. tropicalis isolates, and echinocandin resistance also increased among C. parapsilosis and C. glabrata isolates. Novel alterations in FKS1 HS1 and HS2 were detected in both isolates of anidulafungin-resistant C. parapsilosis. As Candida species have become more resistant to azoles and less susceptible to echinocandin development, the need arose to observe the emergence of resistance to both antifungal classes in candida clinical isolates, for a more effective infection control in the hospital.

Rapid Evolution of Multidrug Resistance in a Candida lusitaniae Infection during Micafungin Monotherapy

Candida (Clavispora) lusitaniae is a rare, emerging non-albicans Candida species that can cause life-threatening invasive infections, spread within hospital settings, and rapidly acquire antifungal drug resistance, including multidrug resistance. The frequency and spectrum of mutations causing antifungal drug resistance in C. lusitaniae are poorly understood. Analyses of serial clinical isolates of any Candida species are uncommon and often analyze a limited number of samples collected over months of antifungal therapy with multiple drug classes, limiting the ability to understand relationships between drug classes and specific mutations. Here, we performed comparative genomic and phenotypic analysis of 20 serial C. lusitaniae bloodstream isolates collected daily from an individual patient treated with micafungin monotherapy during a single 11-day hospital admission. We identified isolates with decreased micafungin susceptibility 4 days after initiation of antifungal therapy and a single isolate with increased cross-resistance to micafungin and fluconazole, despite no history of azole therapy in this patient. Only 14 unique single nucleotide polymorphisms (SNPs) were identified between all 20 samples, including three different FKS1 alleles among isolates with decreased micafungin susceptibility and an ERG3 missense mutation found only in the isolate with increased cross-resistance to both micafungin and fluconazole. This is the first clinical evidence of an ERG3 mutation in C. lusitaniae that occurred during echinocandin monotherapy and is associated with cross-resistance to multiple drug classes. Overall, the evolution of multidrug resistance in C. lusitaniae is rapid and can emerge during treatment with only first-line antifungal therapy.

COVID-19-associated candidiasis and the emerging concern of Candida auris infections

The incidence of COVID-19-associated candidiasis (CAC) is increasing, resulting in a grave outcome among hospitalized patients with COVID-19. The most alarming condition is the increasing incidence of multi-drug resistant Candida auris infections among patients with COVID-19 worldwide. The therapeutic strategy towards CAC caused by common Candida species, such as Candida albicans, Candida tropicalis, and Candida glabrata, is similar to the pre-pandemic era. For non-critically ill patients or those with a low risk of azole resistance, fluconazole remains the drug of choice for candidemia. For critically ill patients, those with a history of recent azole exposure or with a high risk of fluconazole resistance, echinocandins are recommended as the first-line therapy. Several novel therapeutic agents alone or in combination with traditional antifungal agents for candidiasis are potential options in the future. However, for multidrug-resistant C. auris infection, only echinocandins are effective. Infection prevention and control policies, including strict isolation of the patients carrying C. auris and regular screening of non-affected patients, are suggested to prevent the spread of C. auris among patients with COVID-19. Whole-genome sequencing may be used to understand the epidemiology of healthcare-associated candidiasis and to better control and prevent these infections.

Molecular characterization of Candida auris outbreak isolates in Qatar from patients with COVID-19 reveals the emergence of isolates resistant to three classes of antifungal drugs

OBJECTIVES

During the COVID-19 pandemic in Qatar, many patients who were severely ill were colonized and infected by Candida auris, an invasive multidrug-resistant yeast pathogen that spreads through nosocomial transmission within healthcare facilities. Here, we investigated the molecular epidemiology of these C. auris isolates and the mechanisms associated with antifungal drug resistance.

METHODS

Whole genomes of 76 clinical C. auris isolates, including 65 from patients with COVID-19 collected from March 2020 to June 2021, from nine major hospitals were sequenced on Illumina NextSeq. Single nucleotide polymorphisms were used to determine their epidemiological patterns and mechanisms for antifungal resistance. The data were compared with those published prior to the COVID-19 pandemic from 2018 to 2020 in Qatar.

RESULTS

Genomic analysis revealed low genetic variability among the isolates from patients with and without COVID-19, confirming a clonal outbreak and ongoing dissemination of C. auris among various healthcare facilities. Based on antifungal susceptibility profiles, more than 70% (22/28) of isolates were resistant to both fluconazole and amphotericin B. Variant analysis revealed the presence of multi-antifungal resistant isolates with prominent amino acid substitutions: Y132F in ERG11 and V704L in CDR1 linked to reduced azole susceptibility and the emergence of echinocandin resistance samples bearing mutations in FKS1 in comparison with pre-COVID-19 pandemic samples. One sample (CAS109) was resistant to three classes of antifungal drugs with a unique premature stop codon in ERG3 and novel mutations in CDR2, which may be associated with elevated amphotericin B and azole resistance.

DISCUSSION

Candida auris isolates from patients with COVID-19 and from most patient samples without COVID-19 in Qatar were highly clonal. The data demonstrated the emergence of multidrug-resistant strains that carry novel mutations linked to enhanced resistance to azoles, echinocandins, and amphotericin B. Understanding the epidemiology and drug resistance will inform the infection control strategy and drug therapy.

Recalcitrant cutaneous fungal infections-A growing problem

The incidence and prevalence of recalcitrant cutaneous fungal infections is on the rise. Terbinafine-resistant Trichophyton has not only been widespread in India, but has also been reported in countries spread throughout the globe. Strains of yeasts such as Malassezia and Candida, which exist both as commensals and as pathogens to the human skin, have also been found to develop resistance to antifungals. Non-dermatophyte moulds which can colonize and infect damaged nails are especially difficult to treat, not only due to resistance, but also because of poor drug penetration of hard keratin. Psychosocial factors such as the indiscriminate broad-spectrum antifungal use in agriculture and in medicine, and poor adherence to hygienic measures to break the chain of infection contribute to the development of antifungal resistance. Such environments encourage fungi to develop various resistance mechanisms to withstand antifungal treatment. These include: (a) alteration of the drug target, (b) increasing efflux of drug/metabolites, (c) inactivation of drug, (d) bypass mechanisms or substitution of the pathway affected by the drug, (e) stress adaptation mechanisms and (f) biofilm formation. Understanding of such mechanisms and how they arise are crucial for development of new ways to prevent or overcome resistance. Novel antifungal treatments have recently been approved in the United States of America for treatment of vulvovaginal candidiasis. Ibrexafungerp (enfumafungin derivative) and oteseconazole (tetrazole) differ from their respective related drug classes of echinocandins and triazoles by having different structures, which lend these medicines advantage compared to traditional treatment by having a different binding site and more selectivity for fungi respectively. Other drugs designed to circumvent the known mechanisms of antifungal resistance are also at various phases of development. Concurrent measures at an institutional and individual level to address and limit inappropriate antifungal use to reduce development of antifungal resistance should be undertaken in a concerted effort to address this epidemic.

Invasive Candida infection: epidemiology, clinical and therapeutic aspects of an evolving disease and the role of rezafungin

INTRODUCTION

Invasive Candida Infections (ICIs) have undergone a series of significant epidemiological, pathophysiological, and clinical changes during the last decades, with a shift toward non-albicans species, an increase in the rate of exogenous infections and clinical manifestations ranging from candidemia to an array of highly invasive and life-threatening clinical syndromes. The long-acting echinocandin rezafungin exhibits potent in-vitro activity against most wild-type and azole-resistant Candida spp. including C.auris.

AREAS COVERED

The following topics regarding candidemia only and ICIs were reviewed and addressed: i) pathogenesis; ii) epidemiology and temporal evolution of Candida species; iii) clinical approach; iv) potential role of the novel long-acting rezafungin in the treatment of ICIs.

EXPERT OPINION

Authors' expert opinion focused on considering the potential role of rezafungin in the evolving context of ICIs. Rezafungin, which combines a potent in-vitro activity against Candida species, including azole-resistant strains and C.auris, with a low likelihood of drug-drug interactions and a good safety profile, may revolutionize the treatment of candidemia/ICI. Indeed, it may shorten the length of hospital stays when clinical conditions allow and extend outpatient access to treatment of invasive candidiasis, especially when prolonged treatment duration is expected.

Detection and Characterization of Two Phenotypes of Candida parapsilosis in South Korea: Clinical Features and Microbiological Findings

We newly detected two (sinking and floating) phenotypes of Candida parapsilosis among bloodstream infection (BSI) isolates from Korean hospitals and assessed their microbiological and clinical characteristics. During the performance of a Clinical and Laboratory Standards Institute (CLSI) broth microdilution antifungal susceptibility testing, the sinking phenotype had a characteristic smaller button-like appearance because all yeast cells sank to the bottoms of the CLSI U-shaped round-bottom wells, whereas the floating phenotype comprised dispersed cells. Phenotypic analysis, antifungal susceptibility testing, ERG11 sequencing, microsatellite genotyping, and clinical analysis were performed on C. parapsilosis isolates from 197 patients with BSI at a university hospital during 2006 to 2018. The sinking phenotype was detected in 86.7% (65/75) of the fluconazole-nonsusceptible (FNS) isolates, 92.9% (65/70) of the isolates harboring the Y132F ERG11 gene substitution, and 49.7% (98/197) of all isolates. Clonality was more frequently observed for the Y132F-sinking isolates (84.6% [55/65]) than for all other isolates (26.5% [35/132]; P < 0.0001). Annual incidence of Y132F-sinking isolates increased 4.5-fold after 2014, and two dominant genotypes, persistently recovered for 6 and 10 years, accounted for 69.2% of all Y132F-sinking isolates. Azole breakthrough fungemia (odds ratio [OR], 6.540), admission to the intensive care unit (OR, 5.044), and urinary catheter placement (OR, 6.918) were independent risk factors for BSIs with Y132F-sinking isolates. The Y132F-sinking isolates exhibited fewer pseudohyphae, a higher chitin content, and lower virulence in the Galleria mellonella model than the floating isolates. These long-term results illustrate the increasing BSIs caused by clonal transmission of the Y132F-sinking isolates of C. parapsilosis. IMPORTANCE We believe that this is the first study describe the microbiological and molecular characteristics of bloodstream isolates of C. parapsilosis in Korea exhibiting two phenotypes (sinking and floating). An important aspect of our findings is that the sinking phenotype was observed predominantly in isolates harboring a Y132F substitution in the ERG11 gene (92.9%), fluconazole-nonsusceptible (FNS) isolates (86.7%), and clonal BSI isolates (74.4%) of C. parapsilosis. Although the increase in the prevalence of FNS C. parapsilosis isolates has been a major threat in developing countries, in which the vast majority of candidemia cases are treated with fluconazole, our long-term results show increasing numbers of BSIs caused by clonal transmission of Y132F-sinking isolates of C. parapsilosis in the period with an increased echinocandin use for candidemia treatment in Korea, which suggests that C. parapsilosis isolates with the sinking phenotype continue to be a nosocomial threat in the era of echinocandin therapy.

Update on the treatment of chronic pulmonary aspergillosis

PURPOSE OF REVIEW

Chronic pulmonary aspergillosis is a major global infection in individuals with preexisting structural lung diseases and those with immunodeficiencies, in particular cytokine defects. Current treatment options are confined to just three drug classes, the triazoles, the echinocandins and amphotericin B. However, antifungal resistance is rapidly emerging for the triazoles, the only available oral therapy for this chronic condition.

RECENT FINDINGS

Fortunately, there are now a number of novel antifungals in the development pipeline, mostly now in Phase 3 studies, with a potential for the treatment of chronic pulmonary aspergillosis. However, almost all current randomized triazoles of novel antifungals are primarily undertaken in patients with invasive candidiasis or invasive mould infections. Given the poor outcomes from treatment with antifungals in chronic pulmonary aspergillosis, in part associated with triazole resistance, we urgently need clinical trials of novel agents either as monotherapy or in combination for this disease. In addition, there is an emerging understanding of the role of immunotherapies for the treatment of chronic pulmonary aspergillosis, especially in the context of cytokine defects. Therefore, better understanding of the role of adjunctive immunotherapies such as interferon-gamma is also required.

SUMMARY

In this review, we give an overview of current management of chronic pulmonary aspergillosis, and novel antifungals and immunotherapies for the future.

Anidulafungin Treatment Blocks the Sexual Cycle of Pneumocystis murina and Prevents Growth and Survival without Rescue by an Alternative Mode of Replication

The proposed life cycle of fungi in the genus Pneumocystis has typically included both an asexual cycle via binary fission and a sexual cycle. Until recently, the strategy used for sexual replication was largely unknown, but genomic and functional assays now support a mode known as primary homothallism (self-fertilization). The question of whether an asexual cycle contributes to the growth of these fungi remains. Treatment of Pneumocystis pneumonia in immunosuppressed rodent models with the class of drugs known as echinocandins is challenging the historical concept of asexual replication. The echinocandins target 1,3-β-D-glucan (BG) synthesis resulting in death for most fungi. Because Pneumocystis species have both non-BG expressing life cycle stages (trophic forms) and BG-expressing asci, treatment with anidulafungin and caspofungin resulted in elimination of asci, with large numbers of non-BG expressing organisms remaining in the lungs. Transcriptional analyses of anidulafungin treated Pneumocystis murina-infected lungs indicated that these agents were blocking the sexual cycle. In the present study, we explored whether there was an asexual or alternative method of replication that could rescue P. murina survival and growth in the context of anidulafungin treatment. The effects of anidulafungin treatment on early events in the sexual cycle were investigated by RT-qPCR targeting specific mating genes, including mam2, map3, matMi, matPi, and matMc. Results from the in vivo and gene expression studies clearly indicated there was no rescue by an asexual cycle, supporting these fungi's reliance on the sexual cycle for survival and growth. Dysregulation of mating-associated genes showed that anidulafungin induced effects early in the mating process. IMPORTANCE The concept of a sexually obligate fungus is unique among human fungal pathogens. This reliance can be exploited for drug development and here we show a proof of principle for this unusual target. Most human fungal pathogens eschew the mammalian environment with its battery of immune responses. Pneumocystis appear to have evolved to survive in such an environment, perhaps by using sexual replication to help in DNA repair and to introduce genetic variation in its major surface antigen family because the lung is the primary environment of these pathogens. The concept of primary homothallism fits well into its chosen ecosystem, with ready mating partners expressing both mating type receptors, and a sexual cycle that can introduce beneficial genetic variation without the need for outbreeding.

An Alanine Aminotransferase Is Required for Biofilm-Specific Resistance of Aspergillus fumigatus to Echinocandin Treatment

Alanine metabolism has been suggested as an adaptation strategy to oxygen limitation in organisms ranging from plants to mammals. Within the pulmonary infection microenvironment, Aspergillus fumigatus forms biofilms with steep oxygen gradients defined by regions of oxygen limitation. An alanine aminotransferase, AlaA, was observed to function in alanine catabolism and is required for several aspects of A. fumigatus biofilm physiology. Loss of alaA, or its catalytic activity, results in decreased adherence of biofilms through a defect in the maturation of the extracellular matrix polysaccharide galactosaminogalactan (GAG). Additionally, exposure of cell wall polysaccharides is also impacted by loss of alaA, and loss of AlaA catalytic activity confers increased biofilm susceptibility to echinocandin treatment, which is correlated with enhanced fungicidal activity. The increase in echinocandin susceptibility is specific to biofilms, and chemical inhibition of alaA by the alanine aminotransferase inhibitor β-chloro-l-alanine is sufficient to sensitize A. fumigatus biofilms to echinocandin treatment. Finally, loss of alaA increases susceptibility of A. fumigatus to in vivo echinocandin treatment in a murine model of invasive pulmonary aspergillosis. Our results provide insight into the interplay of metabolism, biofilm formation, and antifungal drug resistance in A. fumigatus and describe a mechanism of increasing susceptibility of A. fumigatus biofilms to the echinocandin class of antifungal drugs. IMPORTANCE Aspergillus fumigatus is a ubiquitous filamentous fungus that causes an array of diseases depending on the immune status of an individual, collectively termed aspergillosis. Antifungal therapy for invasive pulmonary aspergillosis (IPA) or chronic pulmonary aspergillosis (CPA) is limited and too often ineffective. This is in part due to A. fumigatus biofilm formation within the infection environment and the resulting emergent properties, particularly increased antifungal resistance. Thus, insights into biofilm formation and mechanisms driving increased antifungal drug resistance are critical for improving existing therapeutic strategies and development of novel antifungals. In this work, we describe an unexpected observation where alanine metabolism, via the alanine aminotransferase AlaA, is required for several aspects of A. fumigatus biofilm physiology, including resistance of A. fumigatus biofilms to the echinocandin class of antifungal drugs. Importantly, we observed that chemical inhibition of alanine aminotransferases is sufficient to increase echinocandin susceptibility and that loss of alaA increases susceptibility to echinocandin treatment in a murine model of IPA. AlaA is the first gene discovered in A. fumigatus that confers resistance to an antifungal drug specifically in a biofilm context.

Genotypic, proteomic, and phenotypic approaches to decipher the response to caspofungin and calcineurin inhibitors in clinical isolates of echinocandin-resistant Candida glabrata

Background

Echinocandin resistance represents a great concern, as these drugs are recommended as first-line therapy for invasive candidiasis. Echinocandin resistance is conferred by mutations in FKS genes. Nevertheless, pathways are crucial for enabling tolerance, evolution, and maintenance of resistance. Therefore, understanding the biological processes and proteins involved in the response to caspofungin may provide clues indicating new therapeutic targets.

Objectives

We determined the resistance mechanism and assessed the proteome response to caspofungin exposure. We then evaluated the phenotypic impact of calcineurin inhibition by FK506 and cephalosporine A (CsA) on caspofungin-resistant Candida glabrata isolates.

Methods

Twenty-five genes associated with caspofungin resistance were analysed by NGS, followed by studies of the quantitative proteomic response to caspofungin exposure. Then, susceptibility testing of caspofungin in presence of FK506 and CsA was performed. The effects of calcineurin inhibitor/caspofungin combinations on heat stress (40°C), oxidative stress (0.2 and 0.4 mM menadione) and on biofilm formation (polyurethane catheter) were analysed. Finally, a Galleria mellonella model using blastospores (1 × 10⁹ cfu/mL) was developed to evaluate the impact of the combinations on larval survival.

Results

F659-del was found in the FKS2 gene of resistant strains. Proteomics data showed some up-regulated proteins are involved in cell-wall biosynthesis, response to stress and pathogenesis, some of them being members of calmodulin–calcineurin pathway. Therefore, the impact of calmodulin inhibition was explored. Calmodulin inhibition restored caspofungin susceptibility, decreased capacity to respond to stress conditions, and reduced biofilm formation and in vivo pathogenicity.

Conclusions

Our findings confirm that calmodulin-calcineurin-Crz1 could provide a relevant target in life-threatening invasive candidiasis.

Post-Prescription Audit Plus Beta-D-Glucan Assessment Decrease Echinocandin Use in People with Suspected Invasive Candidiasis

Background and Objectives: Overtreatment with antifungal drugs is often observed. Antifungal stewardship (AFS) focuses on optimizing the treatment for invasive fungal diseases. The objective of the present study was to evaluate the utility of a post-prescription audit plus beta-D-glucan (BDG) assessment on reducing echinocandin use in persons with suspected invasive candidiasis. Materials and Methods: This is a prospective, pre-post quasi-experimental study of people starting echinocandins for suspected invasive candidiasis. The intervention of the study included review of each echinocandin prescription and discontinuation of treatment if a very low probability of fungal disease or a negative BDG value were found. Pre-intervention data were compared with the intervention phase. The primary outcome of the study was the duration of echinocandin therapy. Secondary outcomes were length of hospital stay and mortality. Results: Ninety-two echinocandin prescriptions were reviewed, 49 (53.3%) in the pre-intervention phase and 43 (46.7%) in the intervention phase. Discontinuation of antifungal therapy was possible in 21 of the 43 patients in the intervention phase (48.8%). The duration of echinocandin therapy was 7.4 (SD 4.7) in the pre-intervention phase, 4.1 days (SD 2.9) in persons undergoing the intervention, and 8.6 (SD 7.3) in persons in whom the intervention was not feasible (p at ANOVA = 0.016). Length of stay and mortality did not differ between pre-intervention and intervention phases. Conclusions: An intervention based on pre-prescription restriction and post-prescription audit when combined with BDG measurement is effective in optimizing antifungal therapy by significantly reducing excessive treatment duration.

Emerging echinocandin-resistant Candida albicans and glabrata in Switzerland

Echinocandins represent the first-line therapy of candidemia. Echinocandin resistance among Candida spp. is mainly due to acquired FKS mutations. In this study, we report the emergence of FKS-mutant Candida albicans/glabrata in Switzerland and provide the microbiological and clinical characteristics of 9 candidemic episodes. All patients were previously exposed to echinocandins (median 26 days; range 15–77). Five patients received initial echinocandin therapy with persistent candidemia in 4 of them. Overall mortality was 33%.

Cell Wall-Modifying Antifungal Drugs

Antifungal therapy is a critical component of patient management for invasive fungal diseases. Yet, therapeutic choices are limited as only a few drug classes are available to treat systemic disease, and some infecting strains are resistant to one or more drug classes. The ideal antifungal inhibits a fungal-specific essential target not present in human cells to avoid off-target toxicities. The fungal cell wall is an ideal drug target because its integrity is critical to cell survival and a majority of biosynthetic enzymes and wall components is unique to fungi. Among currently approved antifungal agents and those in clinical development, drugs targeting biosynthetic enzymes of the cell wall show safe and efficacious antifungal properties, which validates the cell wall as a target. The echinocandins, which inhibit β-1,3-glucan synthase, are recommended as first-line therapy for Candida infections. Newer cell wall-active drugs in clinical development encompass next-generation glucan synthase inhibitors including a novel echinocandin and an enfumafungin, an inhibitor of Gwt1, a key component of GPI anchor protein biosynthesis, and a classic inhibitor of chitin biosynthesis. As the cell wall is rich in potential drug discovery targets, it is primed to help deliver the next generation of antifungal drugs.

Choosing the Right Antifungal Agent in ICU Patients

Fungi are responsible for around 20% of microbiologically documented infections in intensive care units (ICU). In the last decade, the incidence of invasive fungal infections (IFI), including candidemia, has increased steadily because of increased numbers of both immunocompromised and ICU patients. To improve the outcomes of patients with IFI, intensivists need to be aware of the inherent challenges. This narrative review summarizes the features of routinely used treatments directed against IFI in non-neutropenic ICU patients, which include three classes of antifungals: polyenes, azoles, and echinocandins. ICU patients’ pathophysiological changes are responsible for deep changes in the pharmacokinetics of antifungals. Moreover, drug interactions affect the response to antifungal treatments. Consequently, appropriate antifungal dosage is a challenge under these special conditions. Dosages should be based on renal and liver function, and serum concentrations should be monitored. This review summarizes recent guidelines, focusing on bedside management.

First report on echinocandin resistant Polish Candida isolates

PURPOSE

Candida spp. are ranked as one of the four major causative agents of fungal infections. The number of infections caused by Candida species resistant to fluconazole, which is applied as the first line drug in candidiasis treatment, increases every year. In such cases the application of echinocandin is necessary. Echinocandin susceptibility testing has become a routine laboratory practice in many countries due to the increasing frequency of clinical failures during treatment with these drugs.

METHODS

We performed anidulafungin, micafungin and caspofungin susceptibility testing according to the microdilution broth method on 240 Candida isolates collected in Polish hospitals.

RESULTS

We identified 12 isolates resistant to all echinocandins within 240 examined isolates. Moreover, 6 of the examined samples were identified as rare Candida species and among them we observed very high echinocandin MIC values.

CONCLUSION

Our research proves that in Poland there is a problem of echinocandin resistance. Moreover, we identified two species of Candida which are rare causative agents of human infections, and there was no reported incidence of such infections in Poland until now.

Educational ICU Antimicrobial Stewardship model: the daily activities of the AMS team over a 10-month period

The emergence of antibiotic resistance as a consequence of inappropriate use results in higher mortality rates and has become a major public health challenge worldwide. Antimicrobial stewardship programs (ASPs) aim to ensure proper use of antimicrobials and reduce health care costs. We assessed the impact of using a behavioral approach during a persuasive ASP on antibiotic appropriateness, consumption and costs. We conducted a prospective interventional cohort before-and-after study in the intensive care unit (ICU) of a 554-bed, university teaching hospital in Terni, Italy, 14 of which are located in the ICU. We describe a 10-month persuasive ASP intervention model used in a referral ICU with daily rounds. The aim of the study was to improve medication appropriateness through educational action and reduce the consumption of carbapenems and echinocandins by conducting post-prescription reviews, prescribing reviews and holding daily discussions with the ICU team. We analyzed the prescribing appropriateness of the ICU team in accordance with the decisions made by the Antimicrobial Stewardship (AMS) team to improve the quality of antibiotic prescribing during the first five months and the last five months of the surveillance period. The results were expressed as the defined daily dose (DDD) per 100 occupied bed-days and costs. The data were compared with those previously obtained during the pre-educational period (the year before ASP implementation). Comparisons were made between the decisions taken to improve antimicrobial treatments administered during the first half of the surveillance period (March-July) and those administered during the second half (August-December). In all, 116 decisions were made from March to July while only 65 were made from August to December (p-value 0.00001). A significant reduction was observed in the consumption of carbapenems and echinocandins (11.15% and 25.62%, respectively). Total antibiotic cost savings amounted to 57,541.16 euros. The persuasive ASP strategy positively influenced the prescribing behavior of physicians, thus improving the appropriateness of antibiotic therapy and reducing antimicrobial consumption.

Candida auris and multidrug resistance: Defining the new normal

Candida auris is an emerging species of yeast characterized by colonization of skin, persistence in the healthcare environment, and antifungal resistance. C. auris was first described in 2009 from a single isolate but has since been reported in more than 25 countries worldwide. Resistance to fluconazole and amphotericin B is common, and resistance to the echinocandins is emerging in some countries. Antifungal resistance has been shown to be acquired rather than intrinsic and the primary mechanisms of resistance to the echinocandins and azoles have been determined. There are a number of new antifungal agents in phase 2 and phase 3 clinical trials and many have activity against C. auris. This review will discuss what is currently known about antifungal resistance in C. auris, limitations to antifungal susceptibility testing, the mechanisms of resistance, and the new antifungals that are on the horizon.

Drugs in Clinical Development for Fungal Infections

Despite increasing rates of invasive fungal infections being reported globally, only a single antifungal drug has been approved during the last decade. Resistance, toxicity, drug interactions and restricted routes of administration remain unresolved issues. This review focuses on new antifungal compounds which are currently in various clinical phases of development. We discuss two azoles with a tetrazole moiety that allows selective activity against the fungal CYP: VT-1161 for Candida infections and VT-1129 for cryptococcal meningoencephalitis. We also discuss two glucan synthesis inhibitors: CD101, an echinocandin with an increased half-life, and SCY-078 with oral bioavailability and increased activity against echinocandin-resistant isolates. Among the polyenes, we discuss MAT023, an encochleated amphotericin B formulation that allows oral administration. Two novel classes of antifungal drugs are also described: glycosylphosphatidylinositol inhibitors, and the leading drug APX001, which disrupt the integrity of the fungal wall; and the orotomides, inhibitors of pyrimidine synthesis with the leading drug F901318. Finally, a chitin synthesis inhibitor and progress on human monoclonal antifungal antibodies are discussed.

Antifungal susceptibility of Saccharomyces cerevisiae and therapy in a murine model of disseminated infection

BACKGROUND

The incidence of systemic infections by Saccharomyces cerevisiae has increased in recent years, especially among immunocompromised patients. Amphotericin B, voriconazole or echinocandins have been used with favorable outcome against systemic infections by this fungus. However, clinical experience is limited and no in vivo studies have been conducted.

AIMS

We evaluated the in vitro activity of nine antifungal compounds against S.cerevisiae and the in vivo efficacy of those three antifungals showing the highest in vitro activity by using a murine model of systemic infection.

METHODS

Minimal inhibitory concentrations (MICs) were determined by the microdilution method against three strains of S. cerevisiae. After intravenous infection with 5×10⁷ CFUs, animals received liposomal amphotericin B (5mg/kg), voriconazole (25mg/kg) or anidulafungin (5mg/kg). Treatment efficacy was assessed by determining of CFUs/g in liver, kidney, brain, lung and spleen.

RESULTS

5-Fluorocytosine was the most in vitro active compound followed by amphotericin B, voriconazole and anidulafungin. The in vivo study showed that liposomal amphotericin B was the most effective drug driving highest fungal clearance.

CONCLUSIONS

All treatments reduced the fungal load in comparison to the control group, being liposomal amphotericin B the most effective drug followed by anidulafungin and finally voriconazole.

Aspergillus pseudodeflectus: a new human pathogen in liver transplant patients

BACKGROUND

Liver transplant recipients are at high risk of developing invasive aspergillosis and in particular by Aspergillus fumigatus which is the most commonly encountered species in this population. Other non-fumigatus Aspergillus species with reduced susceptibility to antifungal drugs can also be involved. Accurate identification associated to antifungal susceptibility testing is essential for therapy adjustment. We report a case of invasive pulmonary aspergillosis due to Aspergillus pseudodeflectus in a liver transplant recipient. To our knowledge, this is the first reported case of invasive aspergillosis due to this species with a reduced susceptibility to azoles.

CASE PRESENTATION

A 64 year-old woman with drug-induced fulminant hepatitis underwent liver transplantation. Prophylactic treatment with caspofungin was introduced due to aspergillosis risk factors consisting in hemodialysis and fulminant hepatitis. Six weeks after transplantation, CT scan showed a right pulmonary opacity associated with an increase of galactomannan (index 5.4). Culture of BAL grew with several colonies of Aspergillus sp. The diagnosis of invasive aspergillosis was probable according to the EORTC criteria. The antifungal susceptibility tests (Etest®) revealed low MICs to echinocandins and amphotericin B) but high MICs to azoles. After these results, voriconazole was switched to liposomal amphotericin B. The patient died one month after diagnosis from a refractory septic shock with multiple organ failure. A molecular identification of isolate, based on partial β-tubulin and calmodulin genes, was performed and identified A. pseudodeflectus.

CONCLUSIONS

Our case raises the question of pathogenicity of this species, which belongs to Aspergillus section Usti and is genetically and morphologically very close to Aspergillus calidoustus that was previously reported in human transplant recipients.

Invasive pulmonary aspergillosis is associated with adverse clinical outcomes in critically ill patients receiving veno-venous extracorporeal membrane oxygenation

To identify the incidence, risk factors and impact on long-term survival of invasive pulmonary aspergillosis (IPA) and Aspergillus colonisation in patients receiving vv-extracorporeal membrane oxygenation (ECMO). A retrospective evaluation was performed of patients receiving vv-ECMO at a tertiary hospital in Manchester (UK) between January 2012 and December 2016. Data collected included epidemiological data, microbiological cultures, radiographic findings and outcomes. Cases were classified as proven IPA, putative IPA or Aspergillus colonisation according to a validated clinical algorithm. One hundred thirty-four patients were supported with vv-ECMO, median age of 45.5 years (range 16.4-73.4). Ten (7%) patients had putative IPA and nine (7%) had Aspergillus colonisation. Half of the patients with putative IPA lacked classical host risk factors for IPA. The median number of days on ECMO prior to Aspergillus isolation was 5 days. Immunosuppression and influenza A infection were significantly associated with developing IPA in a logistic regression model. Cox regression model demonstrates a three times greater hazard of death associated with IPA. Overall 6-month mortality rate was 38%. Patients with putative IPA and colonised patients had a 6-month mortality rate of 80 and 11%, respectively. Immunosuppression and influenza A infection are independent risk factors for IPA. IPA, but not Aspergillus colonisation, is associated with high long-term mortality in patients supported with vv-ECMO.

Overcoming the Resistance Hurdle: Pharmacokinetic-Pharmacodynamic Target Attainment Analyses for Rezafungin (CD101) against Candida albicans and Candida glabrata

Rezafungin (CD101) is a novel echinocandin antifungal agent with activity against Aspergillus and Candida species, including azole- and echinocandin-resistant isolates. The objective of these analyses was to conduct pharmacokinetic (PK)-pharmacodynamic (PD) target attainment analyses to evaluate single and once-weekly rezafungin dosing to provide dose selection support for future clinical studies. Using a previously developed rezafungin population PK model, Monte Carlo simulations were conducted utilizing the following three intravenous rezafungin regimens: (i) a single 400 mg dose, (ii) 400 mg for week 1 followed by 200 mg weekly for 5 weeks, and (iii) 400 mg weekly for 6 weeks. Percent probabilities of achieving the nonclinical PK-PD targets associated with net fungal stasis and 1-log10 CFU reductions from baseline for Candida albicans and Candida glabrata were calculated for each rezafungin regimen. At the MIC90 for C. albicans and C. glabrata, a single 400 mg dose of rezafungin achieved probabilities of PK-PD target attainment of ≥90% through week 3 of therapy for all PK-PD targets evaluated. When evaluating the multiple-dose (i.e., weekly) regimens under these conditions, percent probabilities of PK-PD target attainment of 100% were achieved through week 6. Moreover, high (>90%) probabilities of PK-PD target attainment were achieved through week 6 following administration of the weekly regimens at or above the MIC100 values for C. albicans and C. glabrata based on contemporary in vitro surveillance data. These analyses support the use of single and once-weekly rezafungin regimens for the treatment of patients with candidemia and/or candidiasis due to C. albicans or C. glabrata.

Three cases of Candida fermentati fungemia following hematopoietic stem cell transplantation

Bloodstream infection with non-Candida albicans Candida species is one of the serious complications among patients with hematological malignancies who receive long-term prophylactic antifungal agents. Here we describe three cases of Candida fermentati (C. fermentati) candidemia after allogeneic stem cell transplantation for hematological malignancies. Case 1 is fluconazole-breakthrough C. fermentati fungemia, which was well controlled with liposomal amphotericin B. Case 2 and 3 were caspofungin-breakthrough C. fermentati fungemia. In case 2, blood culture turned negative for Candida responding to liposomal amphotericin B. Although in vitro susceptibility data for the isolated pathogen suggested the efficacy of both caspofungin and liposomal amphotericin B in all three cases, clinically liposomal amphotericin B seemed to have been more effective for eradication of the pathogen from blood stream. C. fermentati needs to be considered as a possible cause for breakthrough candidemia among post-transplant patients with prolonged antifungal prophylaxis. Discrepancy between in vitro and in vivo susceptibility to antifungals, especially to echinocandins, might provide a clue for the optimal choice of antifungals for C. fermentati infections.

What has changed in the treatment of invasive candidiasis? A look at the past 10 years and ahead

The treatment of invasive candidiasis has changed greatly in the past decade and must continue to evolve if we are to improve outcomes in this serious infection. A review of recent history may provide insights for the future. The morbidity and mortality of invasive candidiasis remain difficult to measure despite an obvious clinical burden. Current treatment guidelines now recommend echinocandins as first-line empirical treatment, with fluconazole as an acceptable alternative for selected patients, reflecting the efficacy demonstrated by echinocandins and increasing resistance observed with fluconazole. The selection of antifungal therapy now must consider not only resistance but also the shift in predominance from Candida albicans to non-albicans species, notably Candida glabrata. The recent emergence of Candida auris has been met with great interest, although the longer-term implications of this phenomenon remain unclear. The broad goal of treatment continues to be administration of safe, efficacious antifungal therapy as soon as possible. Diagnostic methods beyond traditional blood culture present an opportunity to shorten the time to an accurate diagnosis, and earlier treatment initiation based on prophylactic and empirical or pre-emptive strategies seeks to ensure timely therapeutic intervention. In addition, there are novel agents in the antifungal pipeline. These developments, as well as ongoing studies of dosing, toxicity and resistance development, are important items on the current research agenda and may play a role in future changes to the treatment of invasive candidiasis.

Efficacy and safety of micafungin for the treatment of patients with proven or probable invasive aspergillosis: A non-comparative, multicenter, phase IV, open-label study

INTRODUCTION

Few studies have assessed the efficacy and safety of micafungin in patients with proven or probable invasive aspergillosis (IA). This was the aim of the current study, which was conducted in 22 hospitals in China, where micafungin was approved for treatment of IA in 2006.

METHODS

This was a non-comparative, phase IV open-label study (NCT02646774). Eligible patient were adults with proven or probable IA. Efficacy endpoints included rates of overall treatment success (primary endpoint) and clinical improvement, fungal clearance, mortality, and the site of Aspergillus infection (all secondary endpoints). Safety endpoints included incidences of treatment-emergent adverse events (TEAEs), serious AEs (SAEs), and adverse drug reactions (ADRs). These endpoints were reported descriptively with associated 95% confidence intervals (CI); no hypotheses were tested.

RESULTS

The study was discontinued early due to low patient recruitment, which did not allow for the planned sample size to be reached. In total, 68 patients were enrolled: 42 into the full analysis set (for efficacy) and 61 into the safety analysis set. All patients were Han Chinese; the majority were male (n = 26; 61.9%) and ≤60 years of age (n = 35; 83.3%). Rates of overall treatment success, clinical improvement, fungal clearance, and mortality were 45.2% (n = 19/42; 95% CI: 29.85-61.33); 59.5% (n = 25/42; 95% CI: 43.28-74.37), 80.0% (n = 4/5; 95% CI: 28.36-99.49), and 7.1% (n = 3/42; 95% CI: 1.50-19.48), respectively. All patients were diagnosed with pulmonary Aspergillus infection. Overall, 155 TEAEs and 8 SAEs were reported by 37 (60.7%) and 7 (11.5%) patients. The most common TEAEs were decreased platelet count and fatigue (both n = 5; 8.2%) and the most common SAEs were intracranial hemorrhage and lung infection (n = 3; 4.9% and n = 2; 3.3%). Eight ADRs (n = 6; 9.8%) were reported but all were completely remitted or remitting during follow-up.

CONCLUSIONS

Results suggest that micafungin is efficacious and well-tolerated in patients with proven or probable IA in China. However, these findings should be interpreted with care, due to the small number of patients included in this study. Further comparative trials should be used to confirm the efficacy and safety of micafungin in patients with proven or probable IA.

Antifungal treatment with echinocandins: a 10-year clinical experience

OBJECTIVE

The number of studies evaluating the use of echinocandins, whether or not its indication meets international guidelines, in clinical practice is limited. The objective of the present study was to determine the use of echinocandins in a tertiary Spanish hospital in 10 years of clinical practice, and to evaluate its impact on prognosis.

METHODS

This retrospective study involved adult nonneutropenic ill patients with suspicion of fungal invasion who started treatment with echinocandins between 2006 and 2015.

RESULTS

The number of patients treated with echinocandins was 153, and candidemia was detected thereafter in 25.5%. Factors associated with in-hospital mortality in patients receiving echinocandins were: sex male, septic shock, Charlson comorbidity index, and total stay at the hospital. In-hospital mortality after 7, 30 and 90 days was 13.7%, 24.8%, and 56.8%, respectively. From patients receiving echinocandins, 98 did no show multifocal colonization, 50 had Candida score <2.5, and 49 did not meet Ostrosky-Zeichner prediction rule. A total of 19 patients did not show any of these 3 potential risk factors for candidemia.

CONCLUSIONS

The use of echinocandins in 10 years of clinical practice in our tertiary hospital has been performed according to international guidelines; however, candidemia was only diagnosed thereafter in only 25.5% of cases. Furthermore, according to our results, the adequate use of echinocandins seems not to be associated with reduced mortality rates. Further studies, involving a large cohort of patients and more hospitals, are required to corroborate these results.

Evaluation of the efficacy of a posaconazole and anidulafungin combination in a murine model of pulmonary aspergillosis due to infection with Aspergillus fumigatus

Posaconazole (PSC) in combination with anidulafungin (AFG) was evaluated in a murine model of pulmonary aspergillosis. Immunosuppressed animals were infected via the nasal cavity with 2 different A. fumigatus strains. The animals received PSC (oral, 20mg/kg per day) and/or AFG (i.p., 10mg/kg per day) for 7days. On Day 8, the mice were euthanized and fungal burdens were determined from the lungs. Survival curves were constructed for mortality analysis. Compared to untreated groups, groups singly treated with PSC or AFG showed a reduced fungal burden in the lungs (P=0.0001-0.006) and prevention of mortality (66.66-83.33% of survival). Combination treatment with PSC and AFG significantly reduced the fungal burden (or sterilized the lungs) compared to the findings in the untreated and monotherapy groups and improved the survival rate to 100%. The PSC and AFG combination therapy was highly effective and should be evaluated in larger-scale experiments.

Uncommon cause of fungemia in a patient with renal cell cancer: A case report of Candida lusitaniae Fungemia

INTRODUCTION

We present an interesting case of Candida lusitaniae infection in a patient diagnosed with renal clear cell carcinoma.An 82-year-old male presented with worsening back pain for 1 week. Physical examination including neurologic examination was normal. A computed tomography scan of the abdomen revealed a mass in the right upper pole of the kidney suggestive of a renal neoplasm. Pathology from a percutaneous biopsy of the kidney revealed clear cell carcinoma. During his hospitalization the patient developed fungemia due to C lusitaniae. He was started on fluconazole, which was later switched to caspofungin due to worsening transaminitis. The patient's clinical status improved and repeat blood cultures were negative for fungal growth.

CONCLUSION

To our knowledge, this is the first case of C lusitaniae reported in a patient diagnosed with clear cell carcinoma of the kidney.

[Candidemia and invasive candidiasis approach in critically ill patients: role of the echinocandins]

OBJECTIVE

Invasive infections caused by Candida spp. in critically ill patients may significantly worsen their prognosis, so it is of great importance to establish an early detection and a suitable therapeutic strategy. The objective of this study was to define the differential role of echinocandins in treating certain critical patient profiles.

METHODS

A scientific committee of 9 experts in infectious diseases, critical care, microbiology, and hospital pharmacy reviewed the existing evidence on the treatment of candidemia and invasive candidiasis in critically ill patients. After that, a questionnaire with 35 items was elaborated to be agreed by 26 specialists in the aforementioned disciplines using a modified Delphi method.

RESULTS

After two rounds of evaluation, a consensus was reached in terms of agreement in 66% of the items. Some of the consensuses achieved included: it is not necessary to adjust the dose of echinocandins during renal replacement therapy; the echinocandins are the empirical and/or directed treatment of choice for candidemia and invasive candidiasis associated with biofilms; these drugs may be used in the antifungal prophylaxis of high-risk liver transplantation. In the absence of additional clinical data, it should be noted that micafungin is the echinocandin with the most available scientific evidence.

CONCLUSIONS

The experts consulted showed a high degree of agreement on some of the most controversial aspects regarding the management of candidemia and invasive candidiasis in critical patients, which could inform of practical recommendations for their treatment.