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.

Impact of Initial Antifungal Therapy on the Outcome of Patients With Candidemia and Septic Shock Admitted to Medical Wards: A Propensity Score-Adjusted Analysis

Background

Echinocandins are recommended as firstline therapy in patients with candidemia. However, there is debate on their efficacy in survival outcomes. The aim of this study is to evaluate whether the choice of initial antifungal therapy improves mortality in patients with candidemia in relation to the presence of septic shock.

Methods

Patients with candidemia hospitalized in internal medicine wards of 5 tertiary care centers were included in the study (December 2012–December 2014). Patient characteristics, therapeutic interventions, and outcome were reviewed. Propensity score (PS) was used as a covariate of the multivariate analysis to perform a stratified analysis according to PS quartiles and to match patients receiving “echinocandins” or “azoles.”

Results

Overall, 439 patients with candidemia were included in the study. A total of 172 (39.2%) patients had septic shock. Thirty-day mortality was significantly higher in patients with septic shock (45.3%) compared with those without septic shock (31.5%; P = .003). Among patients with septic shock, the use of echinocandins in the first 48 hours, compared with azoles, did not affect 30-day mortality in the PS-adjusted Cox regression analysis (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.37–1.59; P = .48), the PS-stratified analysis, or the logistic regression model in matched cohorts (adjusted HR, 0.92; 95% CI, 0.51–1.63; P = .77).

Conclusions

Echinocandin therapy seems not to improve the outcome of non–intensive care unit patients with septic shock due to candidemia. These findings support the urgent need of further studies in this patient population.

Cysteine-Rich Antifungal Proteins from Filamentous Fungi are Promising Bioactive Natural Compounds in Anti-Candida Therapy

The emerging number of life-threatening invasive fungal infections caused by drug-resistant Candida strains urges the need for the development and application of fundamentally new and safe antifungal strategies in the clinical treatment. Recent studies demonstrated that the extracellular cysteine-rich and cationic antifungal proteins (crAFPs) originating from filamentous fungi, and de novo designed synthetic peptide derivatives of these crAFPs provide a feasible basis for this approach. This mini-review focuses on the global challenges of the anti-Canidia therapy and on the crAFPs as potential drug candidates to overcome existing problems. The advantages and limitations in the use of crAFPs and peptide derivatives compared to those of conventional antifungal drugs will also be critically discussed.

Pharmacokinetics of antifungal drugs: practical implications for optimized treatment of patients

Introduction

Because of the high mortality of invasive fungal infections (IFIs), appropriate exposure to antifungals appears to be crucial for therapeutic efficacy and safety.

Materials and methods

This review summarises published pharmacokinetic data on systemically administered antifungals focusing on co-morbidities, target-site penetration, and combination antifungal therapy.

Conclusions and discussion

Amphotericin B is eliminated unchanged via urine and faeces. Flucytosine and fluconazole display low protein binding and are eliminated by the kidney. Itraconazole, voriconazole, posaconazole and isavuconazole are metabolised in the liver. Azoles are substrates and inhibitors of cytochrome P450 (CYP) isoenzymes and are therefore involved in numerous drug–drug interactions. Anidulafungin is spontaneously degraded in the plasma. Caspofungin and micafungin undergo enzymatic metabolism in the liver, which is independent of CYP. Although several drug–drug interactions occur during caspofungin and micafungin treatment, echinocandins display a lower potential for drug–drug interactions. Flucytosine and azoles penetrate into most of relevant tissues. Amphotericin B accumulates in the liver and in the spleen. Its concentrations in lung and kidney are intermediate and relatively low myocardium and brain. Tissue distribution of echinocandins is similar to that of amphotericin. Combination antifungal therapy is established for cryptococcosis but controversial in other IFIs such as invasive aspergillosis and mucormycosis.

The Surgical Infection Society Revised Guidelines on the Management of Intra-Abdominal Infection

BACKGROUND

Previous evidence-based guidelines on the management of intra-abdominal infection (IAI) were published by the Surgical Infection Society (SIS) in 1992, 2002, and 2010. At the time the most recent guideline was released, the plan was to update the guideline every five years to ensure the timeliness and appropriateness of the recommendations.

METHODS

Based on the previous guidelines, the task force outlined a number of topics related to the treatment of patients with IAI and then developed key questions on these various topics. All questions were approached using general and specific literature searches, focusing on articles and other information published since 2008. These publications and additional materials published before 2008 were reviewed by the task force as a whole or by individual subgroups as to relevance to individual questions. Recommendations were developed by a process of iterative consensus, with all task force members voting to accept or reject each recommendation. Grading was based on the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) system; the quality of the evidence was graded as high, moderate, or weak, and the strength of the recommendation was graded as strong or weak. Review of the document was performed by members of the SIS who were not on the task force. After responses were made to all critiques, the document was approved as an official guideline of the SIS by the Executive Council.

RESULTS

This guideline summarizes the current recommendations developed by the task force on the treatment of patients who have IAI. Evidence-based recommendations have been made regarding risk assessment in individual patients; source control; the timing, selection, and duration of antimicrobial therapy; and suggested approaches to patients who fail initial therapy. Additional recommendations related to the treatment of pediatric patients with IAI have been included.

SUMMARY

The current recommendations of the SIS regarding the treatment of patients with IAI are provided in this guideline.

A complex game of hide and seek: the search for new antifungals

Fungal infections directly affect millions of people each year. In addition to the invasive fungal infections of humans, the plants and animals that comprise our primary food source are also susceptible to diseases caused by these eukaryotic microbes. The need for antifungals, not only for our medical needs, but also for use in agriculture and livestock causes a high demand for novel antimycotics. Herein, we provide an overview of the most commonly used antifungals in medicine and agriculture. We also present a summary of the recent progress (from 2010-2016) in the discovery/development of new agents against fungal strains of medical/agricultural relevance, as well as information related to their biological activity, their mode(s) of action, and their mechanism(s) of resistance.

How much European prescribing physicians know about invasive fungal infections management?

BACKGROUND

The use of systemic antifungal agents has increased in most tertiary care centers. However, antifungal stewardship has deserved very little attention. Our objective was to assess the knowledge of European prescribing physicians as a first step of an international program of antifungal stewardship.

METHODS

Staff physicians and residents of 4 European countries were invited to complete a 20-point questionnaire that was based on current guidelines of invasive candidiasis and invasive aspergillosis.

RESULTS

121 physicians (44.6% staff, 55.4% residents) from Spain 53.7%, Italy 17.4%, Denmark 16.5% and Germany 12.4% completed the survey. Hospital departments involved were: medical 51.2%, ICUs 43%, surgical 3.3% and pharmaceutical 2.5%. The mean score of adequate responses (± SD) was 5.8 ± 1.7 points, with statistically significant differences between study site and type of physicians. Regarding candidiasis, 69% of the physicians clearly distinguished colonization from infection and the local rate of fluconazole resistance was known by 24%. The accepted indications of antifungal prophylaxis were known by 38%. Regarding aspergillosis, 52% of responders could differentiate colonization from infection and 42% knew the diagnostic value of galactomannan. Radiological features of invasive aspergillosis were well recognized by 58% of physicians and 57% of them were aware of the antifungal considered as first line treatment. However, only 37% knew the recommended length of therapy.

CONCLUSIONS

This simple, easily completed questionnaire enabled us to identify some weakness in the knowledge of invasive fungal infection management among European physicians. This survey could serve as a guide to design a future tailored European training program.