Transcriptional analysis of developing biofilms reveals metabolic shifts required for biofilm maintenance.

Unlabelled: is a filamentous fungus found in compost and soil that can cause invasive and/or chronic disease in a broad spectrum of individuals. Diagnosis and treatment of aspergillosis often occur during stages of infection when has formed dense networks of hyphae within the lung. These dense hyphal networks are multicellular, encased in a layer of extracellular matrix, and have reduced susceptibility to contemporary antifungal drugs, characteristics which are defining features of a microbial biofilm.

Propranolol is efficacious against and corneal isolates and in a murine model of keratitis.

Fungal keratitis is a severe corneal infection most commonly caused by filamentous fungi. Even with prompt treatment with current antifungals, it often results in corneal perforation and blindness. In this report, we observe that the beta-adrenergic antagonist, propranolol, displays antifungal activity against and corneal isolates o and strikingly blocks disease establishment in a murine model of keratitis.

Giant transposons promote strain heterogeneity in a major fungal pathogen.

Fungal infections are difficult to prevent and treat in large part due to strain heterogeneity, which confounds diagnostic predictability. Yet, the genetic mechanisms driving strain-to-strain variation remain poorly understood. Here, we determined the extent to which -giant transposons capable of mobilizing numerous fungal genes-generate genetic and phenotypic variability in the opportunistic human pathogen .

Targeting fungal lipid synthesis for antifungal drug development and potentiation of contemporary antifungals.

Two of the three most commonly used classes of antifungal drugs target the fungal membrane through perturbation of sterol biosynthesis or function. In addition to these triazole and polyene antifungals, recent research is identifying new antifungal molecules that perturb lipid biosynthesis and function. Here, we review fungal lipid biosynthesis pathways and their potential as targets for antifungal drug development.

Recent developments in research: diversity, drugs, and disease.

SUMMARYAdvances in modern medical therapies for many previously intractable human diseases have improved patient outcomes. However, successful disease treatment outcomes are often prevented due to invasive fungal infections caused by the environmental mold . As contemporary antifungal therapies have not experienced the same robust advances as other medical therapies, defining mechanisms of disease initiation and progression remains a critical research priority.

New developments in Aspergillus fumigatus and host reactive oxygen species responses.

Aspergillus fumigatus is a filamentous fungus abundant in the environment and the most common causative agent of a spectrum of human diseases collectively termed aspergillosis. Invasive pulmonary aspergillosis is caused by deficiencies in innate immune function that result in the inability of the host to clear inhaled Aspergillus conidia that then germinate and form invasive hyphae. Myeloid cells, and their ability to generate reactive oxygen species (ROS), are essential for conidia clearance from the host.

Giant transposons promote strain heterogeneity in a major fungal pathogen.

Unlabelled: Fungal infections are difficult to prevent and treat in large part due to strain heterogeneity which confounds diagnostic predictability. Yet the genetic mechanisms driving strain-to-strain variation remain poorly understood. Here, we determined the extent to which -giant transposons capable of mobilizing numerous fungal genes-generate genetic and phenotypic variability in the opportunistic human pathogen .

Unsaturated fatty acid perturbation combats emerging triazole antifungal resistance in the human fungal pathogen .

Contemporary antifungal therapies utilized to treat filamentous fungal infections are inhibited by intrinsic and emerging drug resistance. Consequently, there is an urgent need to develop novel antifungal compounds that are effective against drug-resistant filamentous fungi. Here, we utilized an cell-based high-throughput screen to identify small molecules with antifungal activity that also potentiated triazole activity.

BTK drives neutrophil activation for sterilizing antifungal immunity.

We describe a previously unappreciated role for Bruton's tyrosine kinase (BTK) in fungal immune surveillance against aspergillosis, an unforeseen complication of BTK inhibitors (BTKi) used for treating B cell lymphoid malignancies. We studied BTK-dependent fungal responses in neutrophils from diverse populations, including healthy donors, patients who were treated with BTKi, and X-linked agammaglobulinemia patients. Upon fungal exposure, BTK was activated in human neutrophils in a TLR2-, Dectin-1-, and FcγR-dependent manner, triggering the oxidative burst.

Intestinal modulates inflammation, systemic cytokines, and microbial ecology via propionate in a mouse model of cystic fibrosis.

Persons with cystic fibrosis (CF), starting in early life, show intestinal microbiome dysbiosis characterized in part by a decreased relative abundance of the genus is a major producer of the intestinal short chain fatty acid propionate. We demonstrate here that cystic fibrosis transmembrane conductance regulator-defective (CFTR-/-) Caco-2 intestinal epithelial cells are responsive to the anti-inflammatory effects of propionate. Furthermore, isolates inhibit the IL-1β-induced inflammatory response of CFTR-/- Caco-2 intestinal epithelial cells and do so in a propionate-dependent manner.

cytochrome c impacts conidial survival during sterilizing immunity.

can cause a life-threatening infection known as invasive pulmonary aspergillosis (IPA), which is marked by fungus-attributable mortality rates of 20%-30%. Individuals at risk for IPA harbor genetic mutations or incur pharmacologic defects that impair myeloid cell numbers and/or function, exemplified by bone marrow transplant recipients, patients that receive corticosteroid therapy, or patients with chronic granulomatous disease (CGD). However, treatments for infections remain limited, and resistance to the few existing drug classes is emerging.

Recent Advances in Understanding the Human Fungal Pathogen Hypoxia Response in Disease Progression.

Fungal-mediated disease progression and antifungal drug efficacy are significantly impacted by the dynamic infection microenvironment. At the site of infection, oxygen often becomes limiting and induces a hypoxia response in both the fungal pathogen and host cells. The fungal hypoxia response impacts several important aspects of fungal biology that contribute to pathogenesis, virulence, antifungal drug susceptibility, and ultimately infection outcomes.

cytochrome c impacts conidial survival during sterilizing immunity.

Unlabelled: Invasive pulmonary aspergillosis (IPA) is a life-threatening infection caused by species in the ubiquitous fungal genus . While leukocyte-generated reactive oxygen species (ROS) are critical for the clearance of fungal conidia from the lung and resistance to IPA, the processes that govern ROS-dependent fungal cell death remain poorly defined. Using a flow cytometric approach that monitors two independent cell death markers, an endogenous histone H2A:mRFP nuclear integrity reporter and Sytox Blue cell impermeable (live/dead) stain, we observed that loss of cytochrome c ( ) results in reduced susceptibility to cell death from hydrogen peroxide (H O ) treatment.

Luciferase-Based High-Throughput Screen with Aspergillus fumigatus to Identify Antifungal Small Molecules.

Only three classes of contemporary antifungal drugs are routinely utilized in the clinic against filamentous fungal pathogens such as Aspergillus fumigatus. High-throughput phenotypic screens to identify small molecules with activity against filamentous fungi remain challenging due to the hyphal, biofilm-like growth morphology of these important organisms. In this chapter, we describe a protocol for utilizing a bioluminescent A.

The pan-genome of Aspergillus fumigatus provides a high-resolution view of its population structure revealing high levels of lineage-specific diversity driven by recombination.

Aspergillus fumigatus is a deadly agent of human fungal disease where virulence heterogeneity is thought to be at least partially structured by genetic variation between strains. While population genomic analyses based on reference genome alignments offer valuable insights into how gene variants are distributed across populations, these approaches fail to capture intraspecific variation in genes absent from the reference genome. Pan-genomic analyses based on de novo assemblies offer a promising alternative to reference-based genomics with the potential to address the full genetic repertoire of a species.

Postinfluenza Environment Reduces Aspergillus fumigatus Conidium Clearance and Facilitates Invasive Aspergillosis .

Aspergillus fumigatus is a human fungal pathogen that is most often avirulent in immunecompetent individuals because the innate immune system is efficient at eliminating fungal conidia. However, recent clinical observations have shown that severe influenza A virus (IAV) infection can lead to secondary A. fumigatus infections with high mortality.

A Fungal Sterylglucosidase at the Intersection of Virulence, Host Immunity, and Therapeutic Development.

Human fungal infections (mycoses) cause significant morbidity and mortality in high-risk populations. Contemporary antifungal therapies rely heavily on three classes of antifungal drugs, and to date, no fungal vaccine is in clinical use for invasive mycosis. A major gap in knowledge related to fungal vaccine development is identifying lasting mechanisms of protective immunity in immunocompromised individuals.

The future of fungi: threats and opportunities.

The fungal kingdom represents an extraordinary diversity of organisms with profound impacts across animal, plant, and ecosystem health. Fungi simultaneously support life, by forming beneficial symbioses with plants and producing life-saving medicines, and bring death, by causing devastating diseases in humans, plants, and animals. With climate change, increased antimicrobial resistance, global trade, environmental degradation, and novel viruses altering the impact of fungi on health and disease, developing new approaches is now more crucial than ever to combat the threats posed by fungi and to harness their extraordinary potential for applications in human health, food supply, and environmental remediation.

CF-Seq, an accessible web application for rapid re-analysis of cystic fibrosis pathogen RNA sequencing studies.

Researchers studying cystic fibrosis (CF) pathogens have produced numerous RNA-seq datasets which are available in the gene expression omnibus (GEO). Although these studies are publicly available, substantial computational expertise and manual effort are required to compare similar studies, visualize gene expression patterns within studies, and use published data to generate new experimental hypotheses. Furthermore, it is difficult to filter available studies by domain-relevant attributes such as strain, treatment, or media, or for a researcher to assess how a specific gene responds to various experimental conditions across studies.

Avian-associated Aspergillus fumigatus displays broad phylogenetic distribution, no evidence for host specificity, and multiple genotypes within epizootic events.

Birds are highly susceptible to aspergillosis, which can manifest as a primary infection in both domestic and wild birds. Aspergillosis in wild birds causes mortalities ranging in scale from single animals to large-scale epizootic events. However, pathogenicity factors associated with aspergillosis in wild birds have not been examined.

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

Alanine metabolism has been suggested as an adaptation strategy to oxygen limitation in organisms ranging from plants to mammals. Within the pulmonary infection microenvironment, Aspergillus fumigatus forms biofilms with steep oxygen gradients defined by regions of oxygen limitation. An alanine aminotransferase, AlaA, was observed to function in alanine catabolism and is required for several aspects of A.

Host Lung Environment Limits Aspergillus fumigatus Germination through an SskA-Dependent Signaling Response.

Aspergillus fumigatus isolates display significant heterogeneity in growth, virulence, pathology, and inflammatory potential in multiple murine models of invasive aspergillosis. Previous studies have linked the initial germination of a fungal isolate in the airways to the inflammatory and pathological potential, but the mechanism(s) regulating A. fumigatus germination in the airways is unresolved.

Model Systems to Study the Chronic, Polymicrobial Infections in Cystic Fibrosis: Current Approaches and Exploring Future Directions.

A recent workshop titled "Developing Models to Study Polymicrobial Infections," sponsored by the Dartmouth Cystic Fibrosis Center (DartCF), explored the development of new models to study the polymicrobial infections associated with the airways of persons with cystic fibrosis (CF). The workshop gathered 35+ investigators over two virtual sessions. Here, we present the findings of this workshop, summarize some of the challenges involved with developing such models, and suggest three frameworks to tackle this complex problem.