Epidemiology and antifungal susceptibility patterns of candidemia from a tertiary centre in Western Australia

Candida parapsilosis: A systematic review to inform the World Health Organization fungal priority pathogens list

Candida parapsilosis is globally distributed and recognised for causing an increasing proportion of invasive Candida infections. It is associated with high crude mortality in all age groups. It has been particularly associated with nosocomial outbreaks, particularly in association with the use of invasive medical devices such as central venous catheters. Candida parapsilosis is one of the pathogens considered in the WHO priority pathogens list, and this review was conducted to inform the ranking of the pathogen in the list. In this systematic review, we searched PubMed and Web of Science to find studies between 2011 and 2021 reporting on the following criteria for C. parapsilosis infections: mortality, morbidity (hospitalisation and disability), drug resistance, preventability, yearly incidence, and distribution/emergence. We identified 336 potentially relevant papers, of which 51 were included in the analyses. The included studies confirmed high mortality rates, ranging from 17.5% to 46.8%. Data on disability and sequelae were sparse. Many reports highlighted concerns with azole resistance, with resistance rates of >10% described in some regions. Annual incidence rates were relatively poorly described, although there was clear evidence that the proportion of candidaemia cases caused by C. parapsilosis increased over time. While this review summarises current data on C.parapsilosis, there remains an urgent need for ongoing research and surveillance to fully understand and manage this increasingly important pathogen.

Update on therapeutic approaches for invasive fungal infections in adults

Invasive fungal infections are increasingly encountered with the expansion of iatrogenic immunosuppression, including not only solid organ and hematopoietic stem cell transplant recipients but also patients with malignancies or autoimmune diseases receiving immunomodulatory therapies, such as Bruton Tyrosine Kinase (BTK) inhibitor. Their attributable mortality remains elevated, part of which is a contribution from globally emerging resistance in both molds and yeasts. Because antifungal susceptibility test results are often unavailable or delayed, empiric and tailored antifungal approaches including choice of agent(s) and use of combination therapy are heterogeneous and often based on clinician experience with knowledge of host's net state of immunosuppression, prior antifungal exposure, antifungal side effects and interaction profile, clinical severity of disease including site(s) of infection and local resistance data. In this review, we aim to summarize previous recommendations and most recent literature on treatment of invasive mold and yeast infections in adults to guide optimal evidence-based therapeutic approaches. We review the recent data that support use of available antifungal agents, including the different triazoles that have now been studied in comparison to previously preferred agents. We discuss management of complex infections with specific emerging fungi such as Scedosporium spp., Fusarium spp., Trichosporon asahii, and Candida auris. We briefly explore newer antifungal agents or formulations that are now being investigated to overcome therapeutic pitfalls, including but not limited to olorofim, rezafungin, fosmanogepix, and encochleated Amphotericin B. We discuss the role of surgical resection or debridement, duration of treatment, follow-up modalities, and need for secondary prophylaxis, all of which remain challenging, especially in patients chronically immunocompromised or awaiting more immunosuppressive therapies.

Clinical, Epidemiological and Laboratory Features of Invasive Candida parapsilosis Complex Infections in a Brazilian Pediatric Reference Hospital during the COVID-19 Pandemic

The present study aimed to describe the clinical, epidemiological and laboratory characteristics of invasive candidiasis by C. parapsilosis complex (CPC) in a Brazilian tertiary pediatric hospital during the COVID-19 pandemic. Clinical samples were processed in the BACT/ALERT® 3D system or on agar plates. Definitive identification was achieved by MALDI-TOF MS. Antifungal susceptibility was initially analyzed by the VITEK 2 system (AST-YS08 card) and confirmed by the CLSI protocol. Patient data were collected from the medical records using a structured questionnaire. CPC was recovered from 124 patients over an 18-month period, as follows: C. parapsilosis (83.87%), C. orthopsilosis (13.71%) and C. metapsilosis (2.42%). Antifungal resistance was not detected. The age of the patients with invasive CPC infections ranged from <1 to 18 years, and most of them came from oncology-related sectors, as these patients were more affected by C. parapsilosis. C. orthopsilosis infections were significantly more prevalent in patients from critical care units. Invasive infections caused by different pathogens occurred in 75 patients up to 30 days after the recovery of CPC isolates. Overall, 23 (18.55%) patients died within 30 days of CPC diagnosis. Catheter removal and antifungal therapy were important measures to prevent mortality. COVID-19 coinfection was only detected in one patient.

Novel Therapeutic Approaches to Invasive Candidiasis: Considerations for the Clinician

Invasive candidiasis (IC), due to the yeast pathogen Candida, is still a major cause of in-hospital morbidity and mortality. The limited number of antifungal drug classes and the emergence of multi-resistant Candida species, such as Candida auris and some Candida glabrata isolates, is concerning. However, recent advances in antifungal drug development provide promising perspectives for the therapeutic approach of IC. Notably, three novel antifungal agents, currently in Phase II/III clinical trials, are expected to have an important place for the treatment of IC in the future. Rezafungin is a novel echinocandin with prolonged half-life. Ibrexafungerp and fosmanogepix are two first-in-class antifungal drugs with broad spectrum activity against Candida spp., including C. auris and echinocandin-resistant species. These novel antifungal agents also represent interesting alternative options because of their acceptable oral bioavailability (ibrexafungerp and fosmanogepix) or their large interdose interval (once weekly intravenous administration for rezafungin) for prolonged and/or outpatient treatment of complicated IC. This review discusses the potential place of these novel antifungal drugs for the treatment of IC considering their pharmacologic properties and their preclinical and clinical data.

Enzymatic and antifungal susceptibility profiles of Candida glabrata isolates from pediatric patients and their genetic diversity based on microsatellite length polymorphism

This study aimed to detect different genotypes of Candida glabrata isolates in pediatric patients with and without neutropenia utilizing microsatellite length polymorphism (MLP) and its correlation with drug resistance and enzymatic activity were assessed. Samples from neutropenic and non-neutropenic patients were collected from November 2020 to November 2021. Thirty-six C. glabrata strains were isolated and identified using classical and molecular methods. Then, C. glabrata isolates were genotyped by the MLP technique, and their antifungal susceptibility was performed based on the CLSI M27 guideline. Eighteen different multi-loci genotypes (G1 - G18) were detected based on MLP analysis. Analysis of molecular variance revealed high genetic variation within populations (94%) and low genetic differentiation among populations (6%). Also, 40% (n=4) of isolates from neutropenic patients were non-wild-type for posaconazole, and 30% (n=3) were resistant to caspofungin. Very strong hemolytic and proteinase activity were seen in 97.2 and 86.1% of isolates. Candida glabrata strains from neutropenic patients were genetically divergent from other populations. The minimum spanning tree shows that observed genotypes were mainly related to previously reported genotypes from Iran, Spain, and China.

Antifungal Resistance in Clinical Isolates of Candida glabrata in Ibero-America

In different regions worldwide, there exists an intra-and inter-regional variability in the rates of resistance to antifungal agents in Candida glabrata, highlighting the importance of understanding the epidemiology and antifungal susceptibility profiles of C. glabrata in each region. However, in some regions, such as Ibero-America, limited data are available in this context. Therefore, in the present study, a systematic review was conducted to determine the antifungal resistance in C. glabrata in Ibero-America over the last five years. A literature search for articles published between January 2015 and December 2020 was conducted without language restrictions, using the PubMed, Embase, Cochrane Library, and LILACS databases. The search terms that were used were "Candida glabrata" AND "antifungal resistance" AND "Country", and 22 publications were retrieved from different countries. The use of azoles (fluconazole, itraconazole, voriconazole, posaconazole, isavuconazole, ketoconazole, and miconazole) varied between 4.0% and 100%, and that of echinocandins (micafungin, caspofungin, and anidulafungin) between 1.1% and 10.0%. The limited information on this subject in the region of Ibero-America emphasizes the need to identify the pathogens at the species level and perform antifungal susceptibility tests that may lead to the appropriate use of these drugs and the optimal doses in order to avoid the development of antifungal resistance or multi-resistance.

Consensus guidelines for antifungal prophylaxis in haematological malignancy and haemopoietic stem cell transplantation, 2021

Antifungal prophylaxis can reduce morbidity and mortality from invasive fungal disease (IFD). However, its use needs to be optimised and appropriately targeted to patients at highest risk to derive the most benefit. In addition to established risks for IFD, considerable recent progress in the treatment of malignancies has resulted in the development of new 'at-risk' groups. The changing epidemiology of IFD and emergence of drug resistance continue to impact choice of prophylaxis, highlighting the importance of active surveillance and knowledge of local epidemiology. These guidelines aim to highlight emerging risk groups and review the evidence and limitations around new formulations of established agents and new antifungal drugs. It provides recommendations around use and choice of antifungal prophylaxis, discusses the potential impact of the changing epidemiology of IFD and emergence of drug resistance, and future directions for risk stratification to assist optimal management of highly vulnerable patients.

Candida glabrata Antifungal Resistance and Virulence Factors, a Perfect Pathogenic Combination

In recent years, a progressive increase in the incidence of invasive fungal infections (IFIs) caused by Candida glabrata has been observed. The objective of this literature review was to study the epidemiology, drug resistance, and virulence factors associated with the C. glabrata complex. For this purpose, a systematic review (January 2001-February 2021) was conducted on the PubMed, Scielo, and Cochrane search engines with the following terms: "C. glabrata complex (C. glabrata sensu stricto, C. nivariensis, C. bracarensis)" associated with "pathogenicity" or "epidemiology" or "antibiotics resistance" or "virulence factors" with language restrictions of English and Spanish. One hundred and ninety-nine articles were found during the search. Various mechanisms of drug resistance to azoles, polyenes, and echinocandins were found for the C. glabrata complex, depending on the geographical region. Among the mechanisms found are the overexpression of drug transporters, gene mutations that alter thermotolerance, the generation of hypervirulence due to increased adhesion factors, and modifications in vital enzymes that produce cell wall proteins that prevent the activity of drugs designed for its inhibition. In addition, it was observed that the C. glabrata complex has virulence factors such as the production of proteases, phospholipases, and hemolysins, and the formation of biofilms that allows the complex to evade the host immune response and generate fungal resistance. Because of this, the C. glabrata complex possesses a perfect pathogenetic combination for the invasion of the immunocompromised host.

Isolation of Candida auris in large hospitals in the Autonomous Community of Valencia; population-based study (2013-2017)

BACKGROUND

Candida auris is an emerging multidrug-resistant and highly virulent yeast that spreads easily among patients.

AIMS

To describe the characteristics of candidemia caused by C. auris in the southeast of Spain (Autonomous Community of Valencia - ACV) through a 5-year population-based study.

METHODS

An analysis of all the episodes of candidemia diagnosed in the ACV, with approximately 4,500,000 inhabitants, during 2013-2017, was done. Data were obtained from the Epidemiological Surveillance Valencian Network, a network that collects all the microbiological data from the hospitals in the study region.

RESULTS

Based on the records, 1.9% of the isolates recovered from the positive blood cultures (corresponding to 1789 patients) were yeasts. This implies an annual rate of 7.09 cases/100,000 inhabitants. Of the 23 yeast species isolated, Candida albicans was the most frequent (37.3%), showing a higher frequency than Candida parapsilosis (28.4%) and Candida glabrata (15.6%) (p<0.0001). It is remarkable the emergence of C. auris during 2016 and 2017, as this species became the fourth more prevalent in 2016 (9.2%), and the third in 2017 (15.7%). Fungemia was more common in hospitals with >500 beds (63.3% versus 36.7% in small hospitals) (p<0.0001), and C. auris was mostly isolated in large hospitals (8.5% versus 0.3%); its incidence was higher in autumn and among the age group of 65-84 years.

CONCLUSIONS

The information about the local epidemiology of candidemia is essential in order to decide the best empirical treatment approach. This study reports the novel presence of C. auris in large hospitals. This pathogen has usually resistance to several antifungals and causes severe fungemia, so the results of this work reveal the need to monitor the presence of this species systematically.

Direct Blood Culturing of Candida spp. on Solid Medium by a Rapid Enrichment Method with Magnetic Beads Coated with Recombinant Human Mannan-Binding Lectin

A rapid and accurate method to identify the species and antibiotic resistance of Candida spp. in blood is vital to increase the survival rates of patients with bloodstream infections. However, the extremely low levels of Candida spp. in blood make rapid diagnosis by standard blood culture difficult. In this study, we constructed a direct blood culturing method (i.e., the M1 method) by a rapid enrichment method with magnetic beads coated with a recombined human mannan-binding lectin (rhMBL; i.

A rapid and accurate method to identify the species and antibiotic resistance of Candida spp. in blood is vital to increase the survival rates of patients with bloodstream infections. However, the extremely low levels of Candida spp. in blood make rapid diagnosis by standard blood culture difficult. In this study, we constructed a direct blood culturing method (i.e., the M1 method) by a rapid enrichment method with magnetic beads coated with a recombined human mannan-binding lectin (rhMBL; i.e., M1 protein), which demonstrated much higher Candida sp.-binding capacity than that of full-length MBL expressed in vitro (i.e., M2). With the M1 method, individual colonies were obtained before the standard blood culture method for each species of Candida spp. tested at <1 CFU/ml (an average of 29 h earlier). Additionally, the clinical sensitivity of the M1 method was 90.5% compared with that of the standard blood culture method when detecting frozen plasma from patients. More significantly, the turnaround time of the M1 method for blood culture could be reduced by approximately 37 to 43 h compared with that of the standard blood culture method in clinical sample identification.