COVID-19-associated fungal infections

Identification and characterization of a novel antifungal compound tubeimoside I targeting cell wall

Due to fungal diseases that threaten immunocompromised patients, along with the limited availability of antifungal agents, there is an urgent need for new antifungal compounds to treat fungal infections. Here, we aimed to identify potential antifungal drugs from natural products using the fission yeast Schizosaccharomyces pombe as a model organism since it shares many features with some pathogenic fungi. Here, we identified tubeimoside I (TBMS1), an extract from Chinese herbal medicine, that showed strong antifungal activity against S. pombe. To gain insight into the underlying mechanism, we performed transcriptomics analyses of S. pombe cells exposed to TBMS1. A significant proportion of the differential expressed genes were involved in cell wall organization or biogenesis. Additionally, TBMS1 treatment of S. pombe cells resulted in pleiotropic phenotypes, including increased sensitivity to β-glucanase, enhanced calcineurin activity, translocation of GFP-Prz1 to the nucleus, as well as enhanced dephosphorylation of Prz1, suggesting that TBMS1 disrupted cell wall integrity of S. pombe cells. Notably, calcofluor staining showed that abnormal deposits of cell wall materials were observed in the septum and cell wall of the TBMS1-treated cells, which were further corroborated by electron microscopy analysis. We also found that oxidative stress might be involved in the antifungal action of TBMS1. Moreover, we confirmed the antifungal activities of TBMS1 against several clinical isolates of pathogenic fungi. Collectively, our findings suggest that TBMS1, a novel antifungal compound, exerts its antifungal activity by targeting cell walls, which may pave the way for the development of a new class of antifungals.

IMPORTANCE

Fungal infections pose a serious threat to public health and have become an emerging crisis worldwide. The development of new antifungal agents is urgently needed. Here, we identified compound tubeimoside I (TBMS1) for the first time showing strong antifungal activity, and explored the underlying mechanisms of its antifungal action by using the model yeast Schizosaccharomyces pombe. Notably, we presented multiple evidence that TBMS1 exerts its antifungal activity through targeting fungal cell walls. Moreover, we verified the antifungal activities of TBMS1 against several pathogenic fungi. Our work indicated that TBMS1 may serve as a novel antifungal candidate, which provides an important foundation for designing and developing new cell wall-targeting agents for combating life-threatening fungal infections.

The discovery of an anti-Candida xanthone with selective inhibition of Candida albicans GAPDH

OBJECTIVES

This study aimed to discover novel antifungals targeting Candida albicans glyceraldehyde-3-phosphate dehydrogenase (CaGAPDH), have an insight into inhibitory mode, and provide evidence supporting CaGAPDH as a target for new antifungals.

METHODS

Virtual screening was utilized to discover inhibitors of CaGAPDH. The inhibitory effect on cellular GAPDH was evaluated by determining the levels of ATP, NAD, NADH, etc., as well as examining GAPDH mRNA and protein expression. The role of GAPDH inhibition in C. albicans was supported by drug affinity responsive target stability and overexpression experiments. The mechanism of CaGAPDH inhibition was elucidated by Michaelis-Menten enzyme kinetics and site-specific mutagenesis based on docking. Chemical synthesis was used to produce an improved candidate. Different sources of GAPDH were used to evaluate inhibitory selectivity across species. In vitro and in vivo antifungal tests, along with anti-biofilm activity, were carried out to evaluate antifungal potential of GAPDH inhibitors.

RESULTS

A natural xanthone was identified as the first competitive inhibitor of CaGAPDH. It demonstrated in vitro anti-C. albicans potential but also caused hemolysis. XP-W, a synthetic side-chain-optimized xanthone, demonstrated a better safety profile, exhibiting a 50-fold selectivity for CaGAPDH over human GAPDH. XP-W also exhibited potent anti-biofilm activity and displayed broad-spectrum anti-Candida activities in vitro and in vivo, including multi-azole-resistant C. albicans.

CONCLUSIONS

These results demonstrate for the first time that CaGAPDH is a valuable target for antifungal drug discovery, and XP-W provides a promising lead.

Study protocol: A randomized, double-blind, placebo-controlled trial of isavuconazole prophylaxis for the prevention of covid-19-associated pulmonary aspergillosis

Background

During the early stages of the coronavirus disease 2019 (COVID-19) pandemic, those with severe COVID-19 infection were at risk for a number of opportunistic infections including COVID-19-associated pulmonary aspergillosis (CAPA). We initiated a randomized clinical trial to evaluate whether isavuconazole, a triazole antifungal, could prevent CAPA and improve survival in patients admitted to the ICU with severe COVID-19 infection.

Methods

We designed a phase III/IV randomized, double-blind, two-arm, placebo-controlled trial evaluating standard of care (SOC) plus isavuconazole versus SOC plus placebo and were to enroll participants admitted to the ICU with severe COVID-19 infection at three medical centers in California, United States. The projected sample size was 162 participants.

Results

Due to poor enrollment and the declining number of COVID-19 cases over time, the study was terminated after 7 participants were enrolled, all enrolled at one study site (UC San Diego Health). CAPA was suspected in two participants and they were started on open-label isavuconazole. One was withdrawn due to possible isavuconazole-related adverse side effects.

Conclusion

Enrollment was slower-than-expected due to multiple factors, including competing COVID-19-related studies and hesitancy from potential study participants or their families to join the study. Our experience highlights some of the difficulties in planning and running a clinical trial focused on fungal superinfections involving severely ill patients during the height of the COVID-19 pandemic. Lessons learned from this study will help in the design of proposed studies examining antifungal prophylaxis against aspergillosis following other severe respiratory viral infections.

Changes in respiratory infection trends during the COVID-19 pandemic in patients with haematologic malignancy

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has changed respiratory infection patterns globally. However, its impact on community-acquired pneumonia (CAP) in high-risk patients with haematological malignancies (HM) is uncertain. We aimed to examine how community-acquired pneumonia aetiology in patients with haematological malignancies changed during the COVID-19 pandemic.

METHODS

This was a retrospective study that included 524 patients with haematological malignancies hospitalised with community-acquired pneumonia between March 2018 and February 2022. Patients who underwent bronchoscopy within 24 h of admission to identify community-acquired pneumonia aetiology were included. Data on patient characteristics, laboratory findings, and results of bronchioalveolar lavage fluid cultures and polymerase chain reaction tests were analysed and compared to identify changes and in-hospital mortality risk factors.

RESULTS

Patients were divided into the 'pre-COVID-19 era' (44.5%) and 'COVID-19 era' (55.5%) groups. The incidence of viral community-acquired pneumonia significantly decreased in the COVID-19 era, particularly for influenza A, parainfluenza, adenovirus, and rhinovirus (pre-COVID-19 era vs. COVID-19 era: 3.0% vs. 0.3%, P = 0.036; 6.5% vs. 0.7%, P = 0.001; 5.6% vs. 1.4%, P = 0.015; and 9.5% vs. 1.7%, P < 0.001, respectively), whereas that of bacterial, fungal, and unknown community-acquired pneumonia aetiologies remain unchanged. Higher Sequential Organ Failure Assessment scores and lower platelet counts correlated with in-hospital mortality after adjusting for potential confounding factors.

CONCLUSIONS

In the COVID-19 era, the incidence of community-acquired pneumonia with viral aetiologies markedly decreased among patients with haematological malignancies, with no changes in the incidence of bacterial and fungal pneumonia. Further studies are required to evaluate the impact of COVID-19 on the prognosis of patients with haematological malignancies and community-acquired pneumonia.

Mapping the Burden of Fungal Diseases in the United Arab Emirates

The United Arab Emirates has very little data on the incidence or prevalence of fungal diseases. Using total and underlying disease risk populations and likely affected proportions, we have modelled the burden of fungal disease for the first time. The most prevalent serious fungal conditions are recurrent vulvovaginitis (~190,000 affected) and fungal asthma (~34,000 affected). Given the UAE's low prevalence of HIV, we estimate an at-risk population of 204 with respect to serious fungal infections with cryptococcal meningitis estimated at 2 cases annually, 15 cases of Pneumocystis pneumonia (PCP) annually, and 20 cases of esophageal candidiasis in the HIV population. PCP incidence in non-HIV patients is estimated at 150 cases annually. Likewise, with the same low prevalence of tuberculosis in the country, we estimate a total chronic pulmonary aspergillosis prevalence of 1002 cases. The estimated annual incidence of invasive aspergillosis is 505 patients, based on local data on rates of malignancy, solid organ transplantation, and chronic obstructive pulmonary disease (5.9 per 100,000). Based on the 2022 annual report of the UAE's national surveillance database, candidaemia annual incidence is 1090 (11.8/100,000), of which 49.2% occurs in intensive care. Fungal diseases affect ~228,695 (2.46%) of the population in the UAE.

Comprehensive Review on the Virulence Factors and Therapeutic Strategies with the Aid of Artificial Intelligence against Mucormycosis

Mucormycosis, a rare but deadly fungal infection, was an epidemic during the COVID-19 pandemic. The rise in cases (COVID-19-associated mucormycosis, CAM) is attributed to excessive steroid and antibiotic use, poor hospital hygiene, and crowded settings. Major contributing factors include diabetes and weakened immune systems. The main manifesting forms of CAM─cutaneous, pulmonary, and the deadliest, rhinocerebral─and disseminated infections elevated mortality rates to 85%. Recent focus lies on small-molecule inhibitors due to their advantages over standard treatments like surgery and liposomal amphotericin B (which carry several long-term adverse effects), offering potential central nervous system penetration, diverse targets, and simpler dosing owing to their small size, rendering the ability to traverse the blood-brain barrier via passive diffusion facilitated by the phospholipid membrane. Adaptation and versatility in mucormycosis are facilitated by a multitude of virulence factors, enabling the pathogen to dynamically respond to various environmental stressors. A comprehensive understanding of these virulence mechanisms is imperative for devising effective therapeutic interventions against this highly opportunistic pathogen that thrives in immunocompromised individuals through its angio-invasive nature. Hence, this Review delineates the principal virulence factors of mucormycosis, the mechanisms it employs to persist in challenging host environments, and the current progress in developing small-molecule inhibitors against them.

Synthesis, In Silico Study, and In Vitro Antifungal Activity of New 5-(1,3-Diphenyl-1H-Pyrazol-4-yl)-4-Tosyl-4,5-Dihydrooxazoles

The increase in multi-drug resistant Candida strains has caused a sharp rise in life-threatening fungal infections in immunosuppressed patients, including those with SARS-CoV-2. Novel antifungal drugs are needed to combat multi-drug-resistant yeasts. This study aimed to synthesize a new series of 2-oxazolines and evaluate the ligands in vitro for the inhibition of six Candida species and in silico for affinity to the CYP51 enzymes (obtained with molecular modeling and protein homology) of the same species. The 5-(1,3-diphenyl-1H-pyrazol-4-yl)-4-tosyl-4,5-dihydrooxazoles 6a-j were synthesized using the Van Leusen reaction between 1,3-diphenyl-4-formylpyrazoles 4a-j and TosMIC 5 in the presence of K2CO3 or KOH without heating, resulting in short reaction times, high compound purity, and high yields. The docking studies revealed good affinity for the active site of the CYP51 enzymes of the Candida species in the following order: 6a-j > 4a-j > fluconazole (the reference drug). The in vitro testing of the compounds against the Candida species showed lower MIC values for 6a-j than 4a-j, and for 4a-j than fluconazole, thus correlating well with the in silico findings. According to growth rescue assays, 6a-j and 4a-j (like fluconazole) inhibit ergosterol synthesis. The in silico toxicity assessment evidenced the safety of compounds 6a-j, which merit further research as possible antifungal drugs.

Exploring European Consensus About the Remaining Treatment Challenges and Subsequent Opportunities to Improve the Management of Invasive Fungal Infection (IFI) in the Intensive Care Unit

BACKGROUND

The global prevalence of invasive fungal infections (IFI) is increasing, particularly within Intensive Care Units (ICU), where Candida spp. and Aspergillus spp. represent the most important pathogens. Diagnosis and management of IFIs becomes progressively challenging, with increasing antifungal resistance and the emergence of rare fungal species. Through a consensus survey focused on assessing current views on how IFI should be managed, the aim of this project was to identify challenges around diagnosing and managing IFIs in the ICU. The current status in different countries and perceived challenges to date amongst a multidisciplinary cohort of healthcare professionals involved in the care of IFI in the ICU was assessed.

METHODS

Using a modified Delphi approach, an expert panel developed 44 Likert-scale statements across 6 key domains concerning patient screening and minimal standards for diagnosis of IFIs in ICU; initiation and termination of antifungal treatments and how to minimise their side effects and insights for future research on this topic. These were used to develop an online survey which was distributed on a convenience sampling basis utilising the subscriber list held by an independent provider (M3 Global). This survey was distributed to intensivists, infectious disease specialists, microbiologists and antimicrobial/ICU pharmacists within the UK, Germany, Spain, France and Italy. The threshold for consensus was set at 75%.

RESULTS

A total of 335 responses were received during the five-month collection period. From these, 29/44 (66%) statements attained very high agreement (≥ 90%), 11/44 (25%) high agreement (< 90% and ≥ 75%), and 4/44 (9%) did not meet threshold for consensus (< 75%).

CONCLUSION

The results outline the need for physicians to be aware of the local incidence of IFI and the associated rate of azole resistance in their ICUs. Where high clinical suspicion exists, treatment should start immediately and prior to receiving the results from any diagnostic test. Beta-D-glucan testing should be available to all ICU centres, with results available within 48 h to inform the cessation of empirical antifungal therapy. These consensus statements and proposed measures may guide future areas for further research to optimise the management of IFIs in the ICU.

Universal digital high-resolution melting for the detection of pulmonary mold infections

Invasive mold infections (IMIs) are associated with high morbidity, particularly in immunocompromised patients, with mortality rates between 40% and 80%. Early initiation of appropriate antifungal therapy can substantially improve outcomes, yet early diagnosis remains difficult to establish and often requires multidisciplinary teams evaluating clinical and radiological findings plus supportive mycological findings. Universal digital high-resolution melting (U-dHRM) analysis may enable rapid and robust diagnoses of IMI. A universal fungal assay was developed for U-dHRM and used to generate a database of melt curve signatures for 19 clinically relevant fungal pathogens. A machine learning algorithm (ML) was trained to automatically classify these pathogen curves and detect novel melt curves. Performance was assessed on 73 clinical bronchoalveolar lavage samples from patients suspected of IMI. Novel curves were identified by micropipetting U-dHRM reactions and Sanger sequencing amplicons. U-dHRM achieved 97% overall fungal organism identification accuracy and a turnaround time of ~4 hrs. U-dHRM detected pathogenic molds (Aspergillus, Mucorales, Lomentospora, and Fusarium) in 73% of 30 samples classified as IMI, including mixed infections. Specificity was optimized by requiring the number of pathogenic mold curves detected in a sample to be >8 and a sample volume to be 1 mL, which resulted in 100% specificity in 21 at-risk patients without IMI. U-dHRM showed promise as a separate or combination diagnostic approach to standard mycological tests. U-dHRM's speed, ability to simultaneously identify and quantify clinically relevant mold pathogens in polymicrobial samples, and detect emerging opportunistic pathogens may aid treatment decisions, improving patient outcomes.

IMPORTANCE

Improvements in diagnostics for invasive mold infections are urgently needed. This work presents a new molecular detection approach that addresses technical and workflow challenges to provide fast pathogen detection, identification, and quantification that could inform treatment to improve patient outcomes.

[Mucormycosis in the time of COVID-19: risks and challenges]

The first patients positive for SARS-CoV-2 were registered in December 2019. In March 2020, the World Health Organization (WHO) declared the COVID-19 outbreak a global pandemic, the beginning of a worldwide health crisis that revealed numerous medical challenges for healthcare systems and pandemic emergency strategies.Among these challenges, mucormycosis, a typically rare fungal infection, gained global attention. With an average global incidence of about 2 per 1 million people, mucormycosis is considered a very rare disease, an opportunistic infection mostly affecting the lungs or skin and soft tissues in immunocompromised patients. Poorly controlled diabetes mellitus is one of the leading risk factors for rhino-orbital mucormycosis. Countries with a high prevalence of diabetes and limited healthcare resources have higher mucormycosis rates, with India and Pakistan being among the nations with particularly high incidences.During the second wave of the COVID-19 pandemic in India, mucormycosis rates surged dramatically within a few weeks, with over 47,500 cases of COVID-19-associated mucormycosis (CAM) reported between May and August 2021. Mucormycosis is characterized by a high mortality rate of up to 90%, especially when the diagnosis is delayed, and treatment commences late. There were concerns about a potentially global threat.In this article, we explore the risk factors and mechanisms leading to this viral-fungal coinfection. We present global distribution patterns, clinical presentation, and challenges in the diagnosis and treatment of COVID-19-associated mucormycosis.

Navigating the Challenges of Candida auris Colonization in Rehabilitation Settings

ABSTRACT

Candida auris is a highly transmissible yeast that is capable of causing invasive and fatal infections, particularly among persons with underlying medical conditions. Its incidence is rising, especially among patients cared for in post-acute care facilities. Individuals colonized with the yeast may be cared for in inpatient rehabilitation settings, without heightened risk for invasive infection and/or transmission to others, as long as appropriate infection control measures are followed. This article reviews key information for rehabilitation nurses caring for persons with C. auris , including risk factors for infection, the need for contact precautions, appropriate disinfection practices for therapy and diagnostic equipment, and critical components of safe transitions in the care of these patients.

Elevated serum level of progranulin is associated with increased mortality in critically ill patients with candidemia

Candidemia is a severe disease with high mortality in both intensive care unit (ICU) and non-ICU settings. Considering that progranulin (PGRN) is a potential therapeutic target for the candidemia caused by Candida albicans, we determined the serum level of PGRN after candidemia and evaluated its association with mortality. A retrospective discovery cohort (62 patients) and a validation cohort (70 patients) were enrolled. Blood was collected on day of first blood culture positivity for C. albicans, and serum PGRN levels were then measured. In the discovery cohort, all serum PGRN studied were expressed at higher levels in candidemia patients than in bacteremia patients and healthy volunteers, non-survivors presented with significantly higher serum PGRN concentrations when compared with survivors. Serum PGRN concentration was associated with 30-day mortality and patients at a higher risk of death showed higher serum PGRN levels. These results were confirmed in the independent validation cohort. Interestingly, in vitro study demonstrated that macrophages, neutrophils and lymphocytes may be the major source of PGRN production after C. albicans infection instead of epithelial cells. Our findings highlight that serum PGRN appears as a biomarker in candidemia patients and as a promising tool for mortality risk stratification in managing candidemia.

[Innovative therapies for treatment of invasive fungal diseases]

Invasive fungal diseases (IFD) are difficult to treat and pose a significant threat to immunocompromised individuals. Current antifungal agents face limitations, including antifungal resistance and adverse effects. This review aims to give a comprehensive overview of emerging treatment strategies.Novel drugs in development are Ibrexafungerp, an orally available triterpenoid inhibiting glucan synthesis, and Rezafungin representing the echinocandins with extended half-life and improved tissue penetration, both recently licensed for certain indications. Fosmanogepix targets glycosylphosphatidylinositol biosynthesis, while Olorofim, an orotomide, inhibits fungal nucleic acid synthesis, both currently assessed in advanced clinical trials.Immunotherapeutic approaches include immune checkpoint inhibitors to enhance immune response in immunosuppressed individuals and fungal-specific allogeneic CAR-T cell therapy. For prophylactic purpose in high-risk populations to develop IFD, monoclonal antibodies against different virulence factors of Candida spp. have been discovered but are not yet seen in clinical trials. Vaccines against distinct fungal antigens as well as pan fungal vaccines to prevent IFD are under development in preclinical stages, notably for Candida spp., Cryptococcus spp., and Aspergillus spp., however, their clinical value is still discussed.In summary, major advances to treat IFD have been observed, but challenges for their establishment in the clinical routine persist.

Purification and characterization of Cdr1, the drug-efflux pump conferring azole resistance in Candida species

Candida albicans and C. glabrata express exporters of the ATP-binding cassette (ABC) superfamily and address them to their plasma membrane to expel azole antifungals, which cancels out their action and allows the yeast to become multidrug resistant (MDR). In a way to understand this mechanism of defense, we describe the purification and characterization of Cdr1, the membrane ABC exporter mainly responsible for such phenotype in both species. Cdr1 proteins were functionally expressed in the baker yeast, tagged at their C-terminal end with either a His-tag for the glabrata version, cgCdr1-His, or a green fluorescent protein (GFP) preceded by a proteolytic cleavage site for the albicans version, caCdr1-P-GFP. A membrane Cdr1-enriched fraction was then prepared to assay several detergents and stabilizers, probing their level of extraction and the ATPase activity of the proteins as a functional marker. Immobilized metal-affinity and size-exclusion chromatographies (IMAC, SEC) were then carried out to isolate homogenous samples. Overall, our data show that although topologically and phylogenetically close, both proteins display quite distinct behaviors during the extraction and purification steps, and qualify cgCdr1 as a good candidate to characterize this type of proteins for developing future inhibitors of their azole antifungal efflux activity.

Efficacy of an oral lipid nanocrystal formulation of amphotericin B (MAT2203) in the neutropenic mouse model of pulmonary mucormycosis

Invasive mucormycosis (IM) is associated with high mortality and morbidity. MAT2203 is an orally administered lipid nanocrystal formulation of amphotericin B, which has been shown to be safe and effective against other fungal infections. We sought to compare the efficacy of MAT2203 to liposomal amphotericin B (LAMB) treatment in a neutropenic mouse model of IM due to Rhizopus arrhizus var. delemar or Mucor circinelloides f. jenssenii DI15-131. In R. arrhizus var. delemar-infected mice, 15 mg/kg of MAT2203 qd was as effective as 10 mg/kg of LAMB in prolonging median survival time vs placebo (13.5 and 16.5 days for MAT2203 and LAMB, respectively, vs 9 days for placebo) and enhancing overall survival vs placebo-treated mice (40% and 45% for MAT2203 and LAMB, respectively, vs 0% for placebo). A higher dose of 45 mg/kg of MAT2203 was not well tolerated by mice and showed no benefit over placebo. Similar results were obtained with mice infected with M. circinelloides. Furthermore, while both MAT2203 and LAMB treatment resulted in a significant reduction of ~1.0-2.0log and ~2.0-2.5log in Rhizopus delemar or M. circinelloides lung and brain burden vs placebo mice, respectively, LAMB significantly reduced tissue fungal burden in mice infected with R. delemar vs tissues of mice treated with MAT2203. These results support continued investigation and development of MAT2203 as a novel and oral formulation of amphotericin for the treatment of mucormycosis.

Integrating genetic and immune factors to uncover pathogenetic mechanisms of viral-associated pulmonary aspergillosis

Invasive pulmonary aspergillosis is a severe fungal infection primarily affecting immunocompromised patients. Individuals with severe viral infections have recently been identified as vulnerable to developing invasive fungal infections. Both influenza-associated pulmonary aspergillosis (IAPA) and COVID-19-associated pulmonary aspergillosis (CAPA) are linked to high mortality rates, emphasizing the urgent need for an improved understanding of disease pathogenesis to unveil new molecular targets with diagnostic and therapeutic potential. The recent establishment of animal models replicating the co-infection context has offered crucial insights into the mechanisms that underlie susceptibility to disease. However, the development and progression of human viral-fungal co-infections exhibit a significant degree of interindividual variability, even among patients with similar clinical conditions. This observation implies a significant role for host genetics, but information regarding the genetic basis for viral-fungal co-infections is currently limited. In this review, we discuss how genetic factors known to affect either antiviral or antifungal immunity could potentially reveal pathogenetic mechanisms that predispose to IAPA or CAPA and influence the overall disease course. These insights are anticipated to foster further research in both pre-clinical models and human patients, aiming to elucidate the complex pathophysiology of viral-associated pulmonary aspergillosis and contributing to the identification of new diagnostic and therapeutic targets to improve the management of these co-infections.

Novel antifungals and treatment approaches to tackle resistance and improve outcomes of invasive fungal disease

SUMMARYFungal infections are on the rise, driven by a growing population at risk and climate change. Currently available antifungals include only five classes, and their utility and efficacy in antifungal treatment are limited by one or more of innate or acquired resistance in some fungi, poor penetration into "sequestered" sites, and agent-specific side effect which require frequent patient reassessment and monitoring. Agents with novel mechanisms, favorable pharmacokinetic (PK) profiles including good oral bioavailability, and fungicidal mechanism(s) are urgently needed. Here, we provide a comprehensive review of novel antifungal agents, with both improved known mechanisms of actions and new antifungal classes, currently in clinical development for treating invasive yeast, mold (filamentous fungi), Pneumocystis jirovecii infections, and dimorphic fungi (endemic mycoses). We further focus on inhaled antifungals and the role of immunotherapy in tackling fungal infections, and the specific PK/pharmacodynamic profiles, tissue distributions as well as drug-drug interactions of novel antifungals. Finally, we review antifungal resistance mechanisms, the role of use of antifungal pesticides in agriculture as drivers of drug resistance, and detail detection methods for antifungal resistance.

Incidence and Mortality of COVID-19-Associated Invasive Fungal Infections Among Critically Ill Intubated Patients: A Multicenter Retrospective Cohort Analysis

Background

An association between coronavirus disease 2019 (COVID-19)-associated invasive fungal infections (CAIFIs) and high mortality among intubated patients has been suggested in previous research. However, some of the current evidence was derived from small case series and multicenter studies conducted during different waves of the COVID-19 pandemic. We examined the incidence of CAIFIs and their associated mortality using a large, multicenter COVID-19 database built throughout the pandemic.

Methods

We conducted a retrospective analysis of the National COVID Cohort Collaborative (N3C) database collected from 76 medical centers in the United States between January 2020 and August 2022. Patients were 18 years or older and intubated after severe acute respiratory syndrome coronavirus 2 infection. The primary outcomes were incidence and all-cause mortality at 90 days. To assess all-cause mortality, we fitted Cox proportional hazard models after adjusting for confounders via inverse probability weighting.

Results

Out of the 4 916 229 patients with COVID-19 diagnosed during the study period, 68 383 (1.4%) met our cohort definition. The overall incidence of CAIFI was 2.80% (n = 1934/68 383). Aspergillus (48.2%; n = 933/1934) and Candida (41.0%; n = 793/1934) were the most common causative organisms. The incidence of CAIFIs associated with Aspergillus among patients who underwent BAL was 6.2% (n = 83/1328). Following inverse probability weighting, CAIFIs caused by Aspergillus (hazard ratio [HR], 2.0; 95% CI, 1.8-2.2) and Candida (HR, 1.7; 95% CI, 1.5-1.9) were associated with increased all-cause mortality. Systemic antifungals reduced mortality in 17% of patients with CAIFI with Aspergillus and 24% of patients with CAIFI with Candida.

Conclusions

The incidence of CAIFI was modest but associated with higher 90-day all-cause mortality among intubated patients. Systemic antifungals modified mortality.

Biocompatible carbon quantum dots as versatile imaging nanotrackers of fungal pathogen - Candida albicans

Aim: The development of carbon quantum dots (C-QDs) as nanotrackers to understand drug-pathogen interactions, virulence and multidrug resistance. Methods: Microwave synthesis of C-QDs was performed using citric acid and polyethylene glycol. Further, in vitro toxicity was evaluated and imaging applications were demonstrated in Candida albicans isolates. Results: Well-dispersed, ultra small C-QDs exhibited no cyto/microbial/reactive oxygen species-mediated toxicity and internalized effectively in Candida yeast and hyphal cells. C-QDs were employed for confocal imaging of drug-sensitive and -resistant cells, and a study of the yeast-to-hyphal transition using atomic force microscopy in Candida was conducted for the first time. Conclusion: These biocompatible C-QDs have promising potential as next-generation nanotrackers for in vitro and in vivo targeted cellular and live imaging, after functionalization with biomolecules and drugs.

Wake-up Call: Rapid Increase in Human Fungal Diseases under Climate Change

Rising temperatures and extreme weather are setting the stage for increases in fungal diseases. As new pathogenic fungi emerge and known threats spread and evolve, scientists and decision makers are responding.

Molecular mechanisms that govern infection and antifungal resistance in Mucorales

SUMMARYThe World Health Organization has established a fungal priority pathogens list that includes species critical or highly important to human health. Among them is the order Mucorales, a fungal group comprising at least 39 species responsible for the life-threatening infection known as mucormycosis. Despite the continuous rise in cases and the poor prognosis due to innate resistance to most antifungal drugs used in the clinic, Mucorales has received limited attention, partly because of the difficulties in performing genetic manipulations. The COVID-19 pandemic has further escalated cases, with some patients experiencing the COVID-19-associated mucormycosis, highlighting the urgent need to increase knowledge about these fungi. This review addresses significant challenges in treating the disease, including delayed and poor diagnosis, the lack of accurate global incidence estimation, and the limited treatment options. Furthermore, it focuses on the most recent discoveries regarding the mechanisms and genes involved in the development of the disease, antifungal resistance, and the host defense response. Substantial advancements have been made in identifying key fungal genes responsible for invasion and tissue damage, host receptors exploited by the fungus to invade tissues, and mechanisms of antifungal resistance. This knowledge is expected to pave the way for the development of new antifungals to combat mucormycosis. In addition, we anticipate significant progress in characterizing Mucorales biology, particularly the mechanisms involved in pathogenesis and antifungal resistance, with the possibilities offered by CRISPR-Cas9 technology for genetic manipulation of the previously intractable Mucorales species.

Candida auris outbreak at a tertiary care hospital during the COVID-19 pandemic

BACKGROUND

Candida auris (C auris) is a fungal pathogen that has the potential for environmental persistence leading to outbreaks in health care settings. There has been a worldwide surge in C auris outbreaks during the COVID-19 pandemic. In this report, we describe an outbreak of C auris, its control, patient outcomes, and lessons learned.

METHODS

The outbreak occurred in a 600-bed adult academic tertiary care hospital. Contact tracing was initiated immediately after identification of the index case and surveillance testing for C auris was obtained from patients who were exposed to the index case. Infection prevention measures were closely followed.

RESULTS

A total of 560 cultures were performed on 453 unique patients between August 2021 and December 2021. Of those, 31 cultures (5.5%) were positive for C auris; 27 (87.1%) were colonized with C auris, while 4 patients developed a clinical infection (12.9%). The secondary attack rate was 6.8% (31/453). The 30-day all-cause mortality rate for all patients who tested positive for C auris was 9.7%.

DISCUSSION

C auris can cause protracted outbreaks that result in colonization and invasive infections. Multidisciplinary work to improve adherence to infection prevention measures as well as targeted admission screening are essential to limit outbreaks.

Invasive candidiasis

Invasive candidiasis is an important fungal disease caused by Candida albicans and, increasingly, non-albicans Candida pathogens. Invasive Candida infections originate most frequently from endogenous human reservoirs and are triggered by impaired host defences. Signs and symptoms of invasive candidiasis are non-specific; candidaemia is the most diagnosed manifestation, with disseminated candidiasis affecting single or multiple organs. Diagnosis poses many challenges, and conventional culture techniques are frequently supplemented by non-culture-based assays. The attributable mortality from candidaemia and disseminated infections is ~30%. Fluconazole resistance is a concern for Nakaseomyces glabratus, Candida parapsilosis, and Candida auris and less so in Candida tropicalis infection; acquired echinocandin resistance remains uncommon. The epidemiology of invasive candidiasis varies in different geographical areas and within various patient populations. Risk factors include intensive care unit stay, central venous catheter use, broad-spectrum antibiotics use, abdominal surgery and immune suppression. Early antifungal treatment and central venous catheter removal form the cornerstones to decrease mortality. The landscape of novel therapeutics is growing; however, the application of new drugs requires careful selection of eligible patients as the spectrum of activity is limited to a few fungal species. Unanswered questions and knowledge gaps define future research priorities and a personalized approach to diagnosis and treatment of invasive candidiasis is of paramount importance.

Discovery of New Tricyclic Oxime Sampangine Derivatives as Potent Antifungal Agents for the Treatment of Cryptococcosis and Candidiasis

Cryptococcus neoformans (C. neoformans) and Candida albicans (C. albicans) are classified as the critical priority groups among the pathogenic fungi, highlighting the urgent need for developing more effective antifungal therapies. On the basis of antifungal natural product sampangine, herein, a series of tricyclic oxime and oxime ether derivatives were designed. Among them, compound WZ-2 showed excellent inhibitory activity against C. neoformans (MIC80 = 0.016 μg/mL) and synergized with fluconazole to treat resistant C. albicans (FICI = 0.078). Interestingly, compound WZ-2 effectively inhibited virulence factors (e.g., capsule, biofilm, and yeast-to-hypha morphological transition), suggesting the potential to overcome drug resistance. In a mouse model of cryptococcal meningitis, compound WZ-2 (5 mg/kg) effectively reduced the brain C. neoformans H99 burden. Furthermore, compound WZ-2 alone and its combination with fluconazole also significantly reduced the kidney burden of the drug-resistant strain (0304103) and sensitive strain (SC5314) of C. albicans.

From Synergy to Monotherapy: Discovery of Novel 2,4,6-Trisubstituted Triazine Hydrazone Derivatives with Potent Antifungal Potency In Vitro and In Vivo

Invasive fungal infections pose a serious threat to public health and are associated with high mortality and incidence rates. The development of novel antifungal agents is urgently needed. Based on hit-to-lead optimization, a series of 2,4,6-trisubstituted triazine hydrazone compounds were designed, synthesized, and biological evaluation was performed, leading to the identification of compound 28 with excellent in vitro synergy (FICI range: 0.094-0.38) and improved monotherapy potency against fluconazole-resistant Candida albicans and Candida auris (MIC range: 1.0-16.0 μg/mL). Moreover, 28 exhibited broad-spectrum antifungal activity against multiple pathogenic strains. Furthermore, 28 could inhibit hyphal and biofilm formation, which may be related to its ability to disrupt the fungal cell wall. Additionally, 28 significantly reduced the CFU in a mouse model of disseminated infection with candidiasis at a dose of 10 mg/kg. Overall, the triazine-based hydrazone compound 28 with low cytotoxicity, hemolysis, and favorable ADME/T characteristics represents a promising lead to further investigation.

New treatment options for critically important WHO fungal priority pathogens

BACKGROUND

Yet often overlooked in public health discourse, fungal infections pose a crucial global disease burden associated with annual mortality rates approximately equal to tuberculosis and HIV. In response, the WHO published its first global priority list of fungal pathogens in 2022 assigning Aspergillus fumigatus, Candida albicans, Candida auris, and Cryptococcus neoformans to the critical group.

OBJECTIVES

This review provides succinct insights into novel antifungals in development, aiming to contribute valuable information and perspectives with a focus on recent clinical findings and new treatment approaches for critical members of the WHO fungal pathogen priority list.

SOURCES

PubMed literature search using 'Aspergillus fumigatus', 'Cryptococcus neoformans', 'Candida auris', and 'Candida albicans', along with the names of novel antifungal substances, including 'fosmanogepix', 'ibrexafungerp', 'opelconazole', 'oteseconazole', 'MAT2203', 'olorofim', and 'rezafungin' was conducted.

CONTENT

For each critical pathogen, current issues and global clinical data from recent trials are covered. The remarkable development of three new antifungal therapeutics recently receiving Food and Drug Administration approval (ibrexafungerp-June 2021, oteseconazole -April 2022, and rezafungin-March 2023) is outlined, with two more exciting new antifungal substances, namely, olorofim and fosmanogepix expecting approval within the next years. Ibrexafungerp, fosmanogepix, and rezafungin have additionally been granted orphan drug status by the European Medicines Agency in Europe (ibrexafungerp-November 2021, fosmanogepix-July 2022, and rezafungin-January 2024).

IMPLICATIONS

Although the limited number of targets and the emergence of resistance have posed challenges to antifungal treatment, new drugs such as ibrexafungerp, rezafungin, fosmanogepix, or olorofim have shown promising clinical efficacy. These drugs not only provide alternative options for invasive fungal infections but also alleviate treatment in outpatient settings. More clinical data, implementation of stewardship programmes, and surveillance, including utilization of drugs in agriculture, are necessary to prevent resistance development and to ensure the safety and efficacy of these new agents.

Epidemiology of fungal infection in COVID 19 in Spain during 2020 and 2021: a nationwide study

We realize a nationwide population-based retrospective study to analyze the characteristics and risk factors of fungal co-infections in COVID-19 hospitalized patients as well as describe their causative agents in the Spanish population in 2020 and 2021. Data were obtained from records in the Minimum Basic Data Set of the National Surveillance System for Hospital Data in Spain, provided by the Ministry of Health, and annually published with two years lag. The assessment of the risk associated with the development of healthcare-associated fungal co-infections was assessed using an adjusted logistic regression model. The incidence of fungal co-infection in COVID-19 hospitalized patients was 1.41%. The main risk factors associated were surgery, sepsis, age, male gender, obesity, and COPD. Co-infection was associated with worse outcomes including higher in-hospital and in ICU mortality, and higher length of stay. Candida spp. and Aspergillus spp. were the microorganisms more frequent. This is the first study analyzing fungal coinfection at a national level in hospitalized patients with COVID-19 in Spanish population and one of the few studies available that demonstrate that surgery was an independent risk factor of Aspergillosis coinfection in COVID-19 patients.

Funding for research on cryptococcal disease: an analysis based on the G-finder report

Members of the genus Cryptococcus are the causative agents of cryptococcal meningitis, a disease mainly associated with HIV-induced immunosuppression. Patients with cryptococcal meningitis are at a serious risk of death. Most patients suffering from cryptococcosis belong to neglected populations. With reduced support for research, new therapies are unlikely to emerge. In this essay, we used the Policy Cures/G-finder platform as a reference database for funding research on cryptococcal disease. Funding for cryptococcal research started being tracked by G-finder in 2013 and has continued to appear in the annual reports ever since. In total, 15 institutions were reported as major funders for research on cryptococcal disease over the years. The US National Institutes of Health (NIH) was the main funder, followed by the UK's Wellcome Trust. The annual analysis suggested slow yearly growth in funding from 2013 to 2021. The development of new tools to prevent and fight cryptococcal disease is urgent but requires improved funding.

Lower respiratory tract single-cell RNA sequencing and neutrophil extracellular trap profiling of COVID-19-associated pulmonary aspergillosis: a single centre, retrospective, observational study

BACKGROUND

COVID-19-associated pulmonary aspergillosis (CAPA) is a severe superinfection with the fungus Aspergillus affecting patients who are critically ill with COVID-19. The pathophysiology and the role of neutrophil extracellular traps (NETs) in this infection are largely unknown. We aimed to characterise the immune profile, with a focus on neutrophils and NET concentrations, of critically ill patients with COVID-19, with or without CAPA.

METHODS

We conducted a single-centre, retrospective, observational study in two patient cohorts, both recruited at University Hospitals Leuven, Belgium. We included adults aged 18 years or older who were admitted to the intensive care unit because of COVID-19 between March 31, 2020, and May 18, 2021, and who were included in the previous Contagious trial (NCT04327570). We investigated the immune cellular landscape of CAPA versus COVID-19 only by performing single-cell RNA sequencing (scRNA-seq) on bronchoalveolar lavage fluid. Bronchoalveolar lavage immune cell fractions were compared between patients with CAPA and patients with COVID-19 only. Additionally, we determined lower respiratory tract NET concentrations using biochemical assays in patients aged 18 years and older who were admitted to the intensive care unit because of severe COVID-19 between March 15, 2020, and Dec 31, 2021, for whom bronchoalveolar lavage was available in the hospital biobank. Bronchoalveolar lavage NET concentrations were compared between patients with CAPA and patients with COVID-19 only and integrated with existing data on immune mediators in bronchoalveolar lavage and 90-day mortality.

FINDINGS

We performed scRNA-seq of bronchoalveolar lavage on 43 samples from 39 patients, of whom 36 patients (30 male and six female; 14 with CAPA) were included in downstream analyses. We performed bronchoalveolar lavage NET analyses in 59 patients (46 male and 13 female), of whom 26 had CAPA. By scRNA-seq, patients with CAPA had significantly lower neutrophil fractions than patients with COVID-19 only (16% vs 33%; p=0·0020). The remaining neutrophils in patients with CAPA preferentially followed a hybrid maturation trajectory characterised by expression of genes linked to antigen presentation, with enhanced transcription of antifungal effector pathways. Patients with CAPA also showed depletion of mucosal-associated invariant T cells, reduced T helper 1 and T helper 17 differentiation, and transcriptional defects in specific aspects of antifungal immunity in macrophages and monocytes. We observed increased formation of NETs in patients with CAPA compared with patients with COVID-19 only (DNA complexed with citrullinated histone H3 median 15 898 ng/mL [IQR 4588-86 419] vs 7062 ng/mL [775-14 088]; p=0·042), thereby explaining decreased neutrophil fractions by scRNA-seq. Low bronchoalveolar lavage NET concentrations were associated with increased 90-day mortality in patients with CAPA.

INTERPRETATION

Qualitative and quantitative disturbances in monocyte, macrophage, B-cell, and T-cell populations could predispose patients with severe COVID-19 to develop CAPA. Hybrid neutrophils form a specialised response to CAPA, and an adequate neutrophil response to CAPA is a major determinant for survival in these patients. Therefore, measuring bronchoalveolar lavage NETs could have diagnostic and prognostic value in patients with CAPA. Clinicians should be wary of aspergillosis when using immunomodulatory therapy that might inhibit NETosis to treat patients with severe COVID-19.

FUNDING

Research Foundation Flanders, KU Leuven, UZ Leuven, VIB, the Fundação para a Ciência e a Tecnologia, the European Regional Development Fund, la Caixa Foundation, the Flemish Government, and Horizon 2020.

Risk factors for COVID-19-associated pulmonary aspergillosis: a systematic review and meta-analysis

BACKGROUND

COVID-19-associated pulmonary aspergillosis (CAPA) has been reported to be an emerging and potentially fatal complication of severe COVID-19. However, risk factors for CAPA have not been systematically addressed to date.

METHODS

In this systematic review and meta-analysis to identify factors associated with CAPA, we comprehensively searched five medical databases: Ovid MEDLINE; Ovid Embase; the Cochrane Database of Systematic Reviews; the Cochrane Central Register of Controlled Trials; and the WHO COVID-19 Database. All case-control and cohort studies in adults (aged >18 years) that described at least six cases of CAPA and evaluated any risk factors for CAPA, published from Dec 1, 2019, to July 27, 2023, were screened and assessed for inclusion. Only studies with a control population of COVID-19-positive individuals without aspergillosis were included. Two reviewers independently screened search results and extracted outcome data as summary estimates from eligible studies. The primary outcome was to identify the factors associated with CAPA. Meta-analysis was done with random-effects models, with use of the Mantel-Haenszel method to assess dichotomous outcomes as potential risk factors, or the inverse variance method to assess continuous variables for potential association with CAPA. Publication bias was assessed with funnel plots for factors associated with CAPA. The study is registered with PROSPERO, CRD42022334405.

FINDINGS

Of 3561 records identified, 27 articles were included in the meta-analysis. 6848 patients with COVID-19 were included, of whom 1324 (19·3%) were diagnosed with CAPA. Diagnosis rates of CAPA ranged from 2·5% (14 of 566 patients) to 47·2% (58 of 123). We identified eight risk factors for CAPA. These factors included pre-existing comorbidities of chronic liver disease (odds ratio [OR] 2·70 [95% CI 1·21-6·04], p=0·02; I2=53%), haematological malignancies (OR 2·47 [1·27-4·83], p=0·008; I2=50%), chronic obstructive pulmonary disease (OR 2·00 [1·42-2·83], p<0·0001; I2=26%), and cerebrovascular disease (OR 1·31 [1·01-1·71], p=0·05; I2=46%). Use of invasive mechanical ventilation (OR 2·83; 95% CI 1·88-4·24; p<0·0001; I2=69%), use of renal replacement therapy (OR 2·26 [1·76-2·90], p<0·0001; I2=14%), treatment of COVID-19 with interleukin-6 inhibitors (OR 2·88 [1·52-5·43], p=0·001; I2=89%), and treatment of COVID-19 with corticosteroids (OR 1·88 [1·28-2·77], p=0·001; I2=66%) were also associated with CAPA. Patients with CAPA were typically older than those without CAPA (mean age 66·6 years [SD 3·6] vs 63·5 years [5·3]; mean difference 2·90 [1·48-4·33], p<0·0001; I2=86%). The duration of mechanical ventilation in patients with CAPA was longer than in those without CAPA (n=7 studies; mean duration 19·3 days [8·9] vs 13·5 days [6·8]; mean difference 5·53 days [1·30-9·77], p=0·01; I2=88%). In post-hoc analysis, patients with CAPA had higher all-cause mortality than those without CAPA (n=20 studies; OR 2·65 [2·04-3·45], p<0·0001; I2=51%).

INTERPRETATION

The identified risk factors for CAPA could eventually be addressed with targeted antifungal prophylaxis in patients with severe COVID-19.

FUNDING

None.

Utility of galactomannan diagnostic assay in rhino-orbito-cerebral mycosis in COVID-19 patients

An increasing number of fungal infections were reported post COVID-19 and many of them were caused by fungi of mixed aetiologies. This study was carried out to assess the utility of serum galactomannan (GM) assay in establishing the etiology of acute rhino-orbito-cerebral mycosis caused by Aspergillus spp. Two serum samples were obtained from 41 suspected post COVID-19 rhino-orbito-cerebral mycosis patients to perform GM assay. Serum GM assay was positive in 68.7% of the cases of proven aspergillosis at cut off OD = 1.0. Serum GM assay can be used as a supplementary test in the diagnosis of rhino-orbito-cerebral mycosis caused by Aspergillus spp.

Point-of-care testing for viral-associated pulmonary aspergillosis

INTRODUCTION

Over the last years, severe respiratory viral infections, particularly those caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the influenza virus, have emerged as risk factor for viral-associated pulmonary aspergillosis (VAPA) among critically ill patients. Delays in diagnosis of VAPA are associated with increased mortality. Point-of-care-tests may play an important role in earlier diagnosis of VAPA and thus improve patient outcomes.

AREAS COVERED

The following review will give an update on point-of-care tests for VAPA, analyzing performances in respiratory and blood specimens.

EXPERT OPINION

Point-of-care tests have emerged, and particularly the IMMY Aspergillus galactomannan lateral flow assay (LFA) shows performances comparable to the galactomannan ELISA for diagnosis of VAPA. Notably, nearly all evaluations of POC tests for VAPA have been performed in COVID-19 patients, with very limited data in influenza patients. For early diagnosis of COVID associated pulmonary aspergillosis (CAPA), the LFA has shown promising performances in respiratory samples, particularly in bronchoalveolar lavage fluid, and may thereby help in improving patient outcomes. In contrast, serum LFA testing may not be useful for early diagnosis of disease, except in cases with invasive tracheobronchial aspergillosis.

Activation of leukotriene B4 receptor 1 is a prerequisite for complement receptor 3-mediated antifungal responses of neutrophils

Invasive fungal infections are life-threatening, and neutrophils are vital cells of the innate immune system that defend against them. The role of LTA4H-LTB4-BLT1 axis in regulation of neutrophil responses to fungal infection remains poorly understood. Here, we demonstrated that the LTA4H-LTB4-BLT1 axis protects the host against Candida albicans and Aspergillus fumigatus, but not Cryptococcus neoformans infection, by regulating the antifungal activity of neutrophils. Our results show that deleting Lta4h or Blt1 substantially impairs the fungal-specific phagocytic capacity of neutrophils. Moreover, defective activation of the spleen tyrosine kinase (Syk) and extracellular signal-related kinase (ERK1/2) pathways in neutrophils accompanies this impairment. Mechanistically, BLT1 regulates CR3-mediated, β-1,3-glucan-induced neutrophil phagocytosis, while a physical interaction with CR3 with slight influence on its dynamics is observed. Our findings thus demonstrate that the LTA4H-LTB4-BLT1 axis is essential for the phagocytic function of neutrophils in host antifungal immune response against Candida albicans and Aspergillus fumigatus.

Circulatory Inflammatory Proteins as Early Diagnostic Biomarkers for Invasive Aspergillosis in Patients with Hematologic Malignancies-an Exploratory Study

OBJECTIVES

Invasive aspergillosis (IA) is a major cause of mortality in immunocompromised patients and it is difficult to diagnose because of the lack of reliable highly sensitive diagnostics. We aimed to identify circulating immunological markers that could be useful for an early diagnosis of IA.

METHODS

We collected longitudinally serum samples from 33 cases with probable/proven IA and two matched control cohorts without IA (one with microbiological and clinical evidence of bacterial or viral non-fungal pneumonia and one without evidence of infection, all matched for neutropenia, primary underlying disease, and receipt of corticosteroids/other immunosuppressants) at a tertiary university hospital. In addition, samples from an independent cohort (n = 20 cases of proven/probable IA and 20 matched controls without infection) were obtained. A panel of 92 circulating proteins involved in inflammation was measured by proximity extension assay. A random forest model was used to predict the development of IA using biomarkers measured before diagnosis.

RESULTS

While no significant differences were observed between IA cases and infected controls, concentrations of 30 inflammatory biomarkers were different between cases and non-infected controls, of which nine were independently replicated: PD-L1, MMP-10, Interleukin(IL)-10, IL-15RA, IL-18, IL-18R1, CDCP1, CCL19 and IL-17C. From the differential abundance analysis of serum samples collected more than 10 days before diagnosis and at diagnosis, increased IL-17C concentrations in IA patients were replicated in the independent cohort.

CONCLUSIONS

An increased circulating concentration of IL-17C was detected both in the discovery and independent cohort, both at the time of diagnosis and in samples 10 days before the diagnosis of IA, suggesting it should be evaluated further as potential (early) biomarker of infection.

COVID-19 in pulmonary critically ill patients: metagenomic identification of fungi and characterization of pathogenic microorganisms

Background

Fungal co-infection is prevalent in critically ill patients with COVID-19. The conventional approach applied to fungal identification has relatively low sensitivity and is time-consuming. The metagenomic next-generation sequencing (mNGS) technology can simultaneously detect a variety of microorganisms, and is increasingly being used for the rapid detection and diagnosis of pathogens.

Methods

In this single-center retrospective study, we described the clinical presentation and outcomes of COVID-19 and mNGS positive for fungi in pulmonary critically ill patients during the outbreak of Omicron infection from December 2022 to January 2023.

Results

Among 43 COVID-19 patients with acute respiratory distress syndrome (ARDS) on a single intensive care unit (ICU), 10 were reported to be fungal positive using the mNGS test. The number of pathogenic microorganisms detected by mNGS was significantly higher than that via traditional methods, especially in the detection of fungi and viruses. Aspergillus infection was dominant, and most of these patients also had concurrent bacterial or viral infections. Probable or possible COVID-19-associated pulmonary aspergillosis (CAPA) was diagnosed in all 10 patients, and the prognosis was poor.

Conclusion

Patients with COVID-19 may be at increased risk of developing fungal infections as well as concurrent bacterial or viral infections, and mNGS can be a powerful tool in identifying these infections. Clinicians should be aware of the increased risk of fungal infections in COVID-19 patients, particularly those who have underlying immunocompromising conditions, and should monitor for early signs of infection.

High Burden of COVID-19-Associated Pulmonary Aspergillosis in Severely Immunocompromised Patients Requiring Mechanical Ventilation

BACKGROUND

Coronavirus disease 2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) is a frequent superinfection in critically ill patients with COVID-19 and is associated with increased mortality rates. The increasing proportion of severely immunocompromised patients with COVID-19 who require mechanical ventilation warrants research into the incidence and impact of CAPA during the vaccination era.

METHODS

We performed a retrospective, monocentric, observational study. We collected data from adult patients with severe COVID-19 requiring mechanical ventilation who were admitted to the intensive care unit (ICU) of University Hospitals Leuven, a tertiary referral center, between 1 March 2020 and 14 November 2022. Probable or proven CAPA was diagnosed according to the 2020 European Confederation for Medical Mycology/International Society for Human and Animal Mycology (ECMM/ISHAM) criteria.

RESULTS

We included 335 patients. Bronchoalveolar lavage sampling was performed in 300 (90%), and CAPA was diagnosed in 112 (33%). The incidence of CAPA was 62% (50 of 81 patients) in European Organisation for Research and Treatment of Cancer (EORTC)/Mycosis Study Group Education and Research Consortium (MSGERC) host factor-positive patients, compared with 24% (62 of 254) in host factor-negative patients. The incidence of CAPA was significantly higher in the vaccination era, increasing from 24% (57 of 241) in patients admitted to the ICU before October 2021 to 59% (55 of 94) in those admitted since then. Both EORTC/MSGERC host factors and ICU admission in the vaccination era were independently associated with CAPA development. CAPA remained an independent risk factor associated with mortality risk during the vaccination era.

CONCLUSIONS

The presence of EORTC/MSGERC host factors for invasive mold disease is associated with increased CAPA incidence and worse outcome parameters, and it is the main driver for the significantly higher incidence of CAPA in the vaccination era. Our findings warrant investigation of antifungal prophylaxis in critically ill patients with COVID-19.

Mimicking Charged Host-Defense Peptides to Tune the Antifungal Activity and Biocompatibility of Amphiphilic Polymers

Invasive fungal infections impose a substantial global health burden. They cause more than 1.5 million deaths annually and are insufficiently met by the currently approved antifungal drugs. Antifungal peptides are a promising alternative to existing antifungal drugs; however, they can be challenging to synthesize, and are often susceptible to proteases in vivo. Synthetic polymers which mimic the properties of natural antifungal peptides can circumvent these limitations. In this study, we developed a library of 29 amphiphilic polyacrylamides with different charged units, namely, amines, guanidinium, imidazole, and carboxylic acid groups, representative of the natural amino acids lysine, arginine, histidine, and glutamic acid. Ternary polymers incorporating primary ammonium (lysine-like) or imidazole (histidine-like) groups demonstrated superior activity against Candida albicans and biocompatibility with mammalian cells compared to the polymers containing the other charged groups. Furthermore, a combination of primary ammonium, imidazole, and guanidinium (arginine-like) within the same polymer outperformed the antifungal drug amphotericin B in terms of therapeutic index and exhibited fast C. albicans-killing activity. The most promising polymer compositions showed synergistic effects in combination with caspofungin and fluconazole against C. albicans and additionally demonstrated activity against other clinically relevant fungi. Collectively, these results indicate the strong potential of these easily producible polymers to be used as antifungals.

Antifungal Resistance in Pulmonary Aspergillosis

Aspergilli may cause various pulmonary diseases in humans, including allergic bronchopulmonary aspergillosis (ABPA), chronic pulmonary aspergillosis (CPA), and acute invasive pulmonary aspergillosis (IPA). In addition, chronic colonization may occur in cystic fibrosis (CF). Aspergillus fumigatus represents the main pathogen, which may employ different morphotypes, for example, conidia, hyphal growth, and asexual sporulation, in the various Aspergillus diseases. These morphotypes determine the ease by which A. fumigatus can adapt to stress by antifungal drug exposure, usually resulting in one or more resistance mutations. Key factors that enable the emergence of resistance include genetic variation and selection. The ability to create genetic variation depends on the reproduction mode, including, sexual, parasexual, and asexual, and the population size. These reproduction cycles may take place in the host and/or in the environment, usually when specific conditions are present. Environmental resistance is commonly characterized by tandem repeat (TR)-mediated mutations, while in-host resistance selection results in single-resistance mutations. Reported cases from the literature indicate that environmental resistance mutations are almost exclusively present in patients with IA indicating that the risk for in-host resistance selection is very low. In aspergilloma, single-point mutations are the dominant resistance genotype, while in other chronic Aspergillus diseases, for example, ABPA, CPA, and CF, both TR-mediated and single-resistance mutations are reported. Insights into the pathogenesis of resistance selection in various Aspergillus diseases may help to improve diagnostic and therapeutic strategies.

From Spores to Solutions: A Comprehensive Narrative Review on Mucormycosis

Mucormycosis is an infrequent but fatal illness that mainly affects patients with uncontrolled diabetes mellitus, diabetic ketoacidosis, solid and hematologic neoplasms, organ transplantation, chronic steroid intake, prolonged neutropenia, iron overload states, neonatal prematurity, severe malnutrition, and HIV. Many cases were reported across the world recently following the COVID-19 pandemic. Recent research has led to a better understanding of the pathogenesis of the disease, and global guidelines are now available for managing this serious infection. Herein, we comprehensively review the etiological agents, pathogenesis, clinical presentations, diagnosis, and management of mucormycosis.

Multicentric Study on the Clinical Mycology Capacity and Access to Antifungal Treatment in Portugal

The success of the clinical management of invasive fungal diseases (IFD) is highly dependent on suitable tools for timely and accurate diagnosis for effective treatment. An in-depth analysis of the ability of European institutions to promptly and accurately diagnose IFD was previously conducted to identify limitations and aspects to improve. Here, we evaluated and discussed the specific case of Portugal, for which, to our knowledge, there are no reports describing the national mycological diagnostic capacity and access to antifungal treatment. Data from 16 Portuguese medical institutions were collected via an online electronic case report form covering different parameters, including institution profile, self-perceived IFD incidence, target patients, diagnostic methods and reagents, and available antifungals. The majority of participating institutions (69%) reported a low-very low incidence of IFD, with Candida spp. indicated as the most relevant fungal pathogen, followed by Aspergillus spp. and Cryptococcus spp. All institutions had access to culture and microscopy, whereas 94 and 88% were able to run antigen-detection assays and molecular tests, respectively. All of the institutions capable of providing antifungal therapy declared to have access to at least one antifungal. However, echinocandins were only available at 85% of the sites. Therapeutic drug monitoring (TDM) was reported to remain a very restricted practice in Portugal, being available in 19% of the institutions, with the TDM of itraconazole and posaconazole performed in only 6% of them. Importantly, several of these resources are outsourced to external entities. Except for TDM, Portugal appears to be well-prepared concerning the overall capacity to diagnose and treat IFD. Future efforts should focus on promoting the widespread availability of TDM and improved access to multiple classes of antifungals, to further improve patient outcomes.

Clinical courses and outcomes of COVID-19 associated pulmonary aspergillosis in 168 patients with the SARS-CoV-2 omicron variant

PURPOSE

We aimed to analyze the clinical features of COVID-19-associated pulmonary aspergillosis (CAPA) during the SARS-CoV-2 Omicron variant pandemic and to reveal the risk factors for CAPA and death.

METHODS

A retrospective cohort study was conducted on 168 CAPA patients from December 8, 2022 to January 31, 2023. 168 COVID-19 patients without secondary fungal infection during this period were matched 1:1 using propensity score matching as controls.

RESULTS

The incidence of CAPA was 3.8% (168/4421). Compared with patients without fungal infection, CAPA patients had a higher mortality (43.5% vs. 10.1%, P < 0.001). Patients in the death group (n = 73) were more likely to be admitted to ICU (91.8% vs. 26.3%, p < 0.001), had a shorter ICU length of hospitalization (10 (IQR, 6 ~ 16.5) days vs. 14 (IQR, 8 ~ 37) days, p = 0.012). Immunocompromised status (p = 0.023), NLR ≥ 5.7 (p = 0.004), CRP ≥ 50 mg/L (p = 0.043), and the number of antibiotics ≥ 3 (p < 0.001) were all risk factors for CAPA; NLR ≥ 5.7 (p = 0.009) and the number of antibiotics ≥ 3 (p = 0.018) were all independent risk factors for death.

CONCLUSIONS

During the Omicron variant pandemic, CAPA increased death and ICU length of hospitalization. The risk factors of CAPA and death obtained from the study can help us further understand the disease characteristics of CAPA and better guide our clinical decision-making.

COVID-19 associated Pulmonary Aspergillosis in Patients Admitted to the Intensive Care Unit: Impact of Antifungal Prophylaxis

Early after the beginning of the coronavirus disease 2019 (COVID-19)-pandemic, it was observed that critically ill patients in the intensive care unit (ICU) were susceptible to developing secondary fungal infections, particularly COVID-19 associated pulmonary aspergillosis (CAPA). Here we report our local experience on the impact of mold active antifungal prophylaxis on CAPA occurrence in critically ill COVID-19 patients. This is a monocentric, prospective cohort study including all consecutive patients with COVID-19 associated acute respiratory failure who were admitted to our local medical ICU. Based on the treating physician's discretion, patients may have received antifungal prophylaxis or not. All patients were retrospectively characterized as having CAPA according to the 2020 ECMM/ISHAM consensus definitions. Seventy-seven patients were admitted to our medical ICU during April 2020 and May 2021 and included in the study. The majority of patients received invasive-mechanical ventilation (61%). Fifty-three patients (68.8%) received posaconazole prophylaxis. Six cases of probable CAPA were diagnosed within clinical routine management. All six cases were diagnosed in the non-prophylaxis group. The incidence of CAPA in the overall study cohort was 0.57 events per 100 ICU days and 2.20 events per 100 ICU days in the non-prophylaxis group. No difference of cumulative 84-days survival could be observed between the two groups (p = 0.115). In this monocentric cohort, application of posaconazole prophylaxis in patients with COVID-19 associated respiratory failure did significantly reduce the rate of CAPA.

COVID-19 associated mucormycosis surge: A review on multi-pathway mechanisms

Mucormycosis is a fungal infection caused by moulds from the Mucorales order. Concerns have been mounting due to the alarming increase in severe morbidity and mortality associated with mucormycosis during the COVID-19 pandemic. This condition, known as COVID-19-associated mucormycosis (CAM), has been linked to various environmental, host-related, and medical factors on a global scale. We have categorized the most significant potential risk factors for developing mucormycosis in individuals with a previous history of coronavirus infection into 10 major categories. These categories include acute hyperglycemia, the impact of cytokine release, immune response deficiencies in COVID-19 patients, microvasculopathy and dysfunction of endothelial cells, imbalances in iron metabolism, metabolic acidosis, organ damage resulting from COVID-19, underlying health conditions (such as diabetes), environmental factors, and medical treatments that can be iatrogenic in nature (such as inappropriate glucocorticoid use). Many of these factors can lead to potentially life-threatening infections that can complicate the treatment of COVID-19. Physicians should be vigilant about these factors because early detection of mucormycosis is crucial for effective management of this condition.

Intrahospital transmission and infection control of Candida auris originating from a severely infected COVID-19 patient transferred abroad

BACKGROUND

Intrahospital spread of Candida auris, which survives tenaciously in many environments, can cause sustained colonization and infection. A large outbreak of C. auris was experienced in the intensive care units (ICUs) at the study hospital during the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

The index patient with severe COVID-19, who was transferred from Vietnam in January 2022, developed C. auris candidaemia 10 days after hospitalization. From mid-June 2022 to January 2023, strengthened infection prevention and control (IPC) measures were implemented in three ICUs: (1) contact precautions and isolation (CPI) for C. auris-positive cases; (2) surveillance cultures including point-prevalence (N=718) for patients or close contacts or ICU-resident healthcare workers (HCWs); (3) intensive environmental disinfection with 10-fold diluted bleach; and (4) 2% chlorhexidine bathing for all ICU patients. Environmental cultures (ECx) on surfaces and shared objects (N=276) were conducted until early September 2022, when all ECx were negative.

RESULTS

Among 53 C. auris-positive patients between February 2022 and January 2023, invasive infections resulted in seven cases of candidaemia and one case of pneumonia. C. auris was isolated from reusable tympanic thermometers (TTMs) contaminated with earwax. The isolation rate of C. auris in ECx decreased from 6.8% in June 2022 to 2.0% in August 2022, and was no longer detected in TTMs. Colonization in HCWs was remarkably rare (0.5%). The number of C. auris-positive patients peaked in July (N=10) then decreased gradually. By January 2023, no C. auris were isolated in the ICU.

CONCLUSION

Aggressive IPC measures with CPI, ECx and surveillance, decontamination of TTMs, and bathing were effective in successfully controlling this C. auris outbreak.

Heterogeneity of treatment effect of higher dose dexamethasone by geographic region (Europe vs. India) in patients with COVID-19 and severe hypoxemia - a post hoc evaluation of the COVID STEROID 2 trial

Background

In the COVID-STEROID 2 trial there was suggestion of heterogeneity of treatment effects (HTE) between patients enrolled from Europe vs. India on the primary outcome. Whether there was HTE for the remaining patient-centred outcomes is unclear.

Methods

In this post hoc analysis of the COVID-STEROID 2 trial, which compared 12 mg vs. 6 mg dexamethasone in adults with COVID-19 and severe hypoxemia, we evaluated HTE by geographical region (Europe vs. India) for secondary outcomes with analyses adjusted for stratification variables. Results are presented as risk differences (RDs) or mean differences (MDs) with 99% confidence intervals (CIs) and P-values from interaction tests.

Findings

There were differences in mortality at day 28 (RD for Europe -8.3% (99% CI: -17.7 to 1.0) vs. India 0.1% (99% CI: -10.0 to 10.0)), mortality at day 90 (RD for Europe -7.4% (99% CI: -17.1 to 2.0) vs. India -1.4% (99% CI: -12.8 to 9.8)), mortality at day 180 (RD for Europe -6.7% (99% CI: -16.4 to 2.9) vs. India -1.0% (99% CI: -12.3 to 10.3)), and number of days alive without life support at day 90 (MD for Europe 6.1 days (99% CI: -1.3 to 13.4) vs. India 1.7 days (99% CI: -8.4 to 11.8)). For serious adverse reactions, the direction was reversed (RD for Europe -1.0% (99% CI: -7.1 to 5.2) vs. India -5.3% (99% CI: -16.2 to 5.0).

Interpretation

Our analysis suggests higher dose dexamethasone may have less beneficial effects for patients in India as compared with those in Europe; however, the evidence is weak, and this could represent a chance finding.

Funding

None for this analysis. The COVID STEROID 2 trial was funded by The Novo Nordisk Foundation and supported by Rigshospitalet's Research Council.

Nanotechnology-based fungal detection and treatment: current status and future perspective

Fungal infections impose a significant impact on global health and encompass major expenditures in medical treatments. Human mycoses, a fungal co-infection associated with SARS-CoV-2, is caused by opportunistic fungal pathogens and is often overlooked or misdiagnosed. Recently, there is increasing threat about spread of antimicrobial resistance in fungus, mostly in hospitals and other healthcare facilities. The diagnosis and treatment of fungal infections are associated with several issues, including tedious and non-selective detection methods, the growth of drug-resistant bacteria, severe side effects, and ineffective drug delivery. Thus, a rapid and sensitive diagnostic method and a high-efficacy and low-toxicity therapeutic approach are needed. Nanomedicine has emerged as a viable option for overcoming these limitations. Due to the unique physicochemical and optical properties of nanomaterials and newer biosensing techniques, nanodiagnostics play an important role in the accurate and prompt differentiation and detection of fungal diseases. Additionally, nano-based drug delivery techniques can increase drug permeability, reduce adverse effects, and extend systemic circulation time and drug half-life. This review paper is aimed at highlighting recent, promising, and unique trends in nanotechnology to design and develop diagnostics and treatment methods for fungal diseases.