Fungi: the neglected allergenic sources

Pathogenic potential of an environmental Aspergillus fumigatus strain recovered from soil of Pygoscelis papua (Gentoo penguins) colony in Antarctica

Aspergillus fumigatus is a common opportunistic pathogen in different animals, including birds such as penguins. For the first time, a fungal strain identified as A. fumigatus was isolated from soil in the nests of gentoo penguins, Pygoscelis papua, on Livingston Island, South Shetland Islands (maritime Antarctica). This isolate (A. fumigatus UFMGCB 11829) displayed a series of potentially pathogenic characteristics in vitro. We evaluated its detailed molecular taxonomy and submitted the A. fumigatus UFMGCB 11829 Antarctic strain to in vivo pathogenic modelling. The isolate was confirmed to represent A. fumigatus morphological and phylogenetic analysis showed that it was closely related to A. fumigatus sequences reported from animals, immunosuppressed humans, storage grains, plants and soils. The strain displayed the best mycelial growth and conidia production at 37 ºC; however, it was also able to grow and produce conidia at 15º, demonstrating its capability to survive and colonize penguin nest at least in the summer season in maritime Antarctica. In pathogenicity tests, healthy mice did not showed symptoms of infection; however, 50% lethality was observed in immunosuppressed mice that were inoculated with 106 and 107 spores. Lethality increased to 100% when inoculated with 108 spores. Our data highlight the potential pathogenicity of opportunistic A. fumigatus that may be present in the Antarctic, and the risks of both their further transfer within Antarctica and outwards to other continents, risks which may be exacerbated due global climatic changes.

Bayesian analysis suggests independent development of sensitization to different fungal allergens

Background

Fungi are known for their ability to cause allergies, but data on individual sensitization to them are insufficient. The purpose of the study was to carry out a comprehensive analysis of the fungal allergens' sensitization profile in the Ukrainian population and to determine both population and individual sensitivity to these allergens.

Methods

We utilized a set of ALEX allergy test data from 20,033 inhabitants of 17 regions of Ukraine from 1 to 89 years conducted in 2020-2022. A complex of programs in the Python language was developed and Bayesian network analysis was applied to determine the sensitivity combinations in individual patients to various fungal components.

Results

Sensitivity to Alt a 1 dominated and was observed in 79.39% of patients, and 62.17% of them were sensitive solely to Alt a 1. Exclusive sensitivity to Mala s 6 was second in individual patient profiles with a frequency of 4.06%. Combined sensitivity to Alt a 1 - Asp f 3 was third with a share of 3.28%. Pen ch and Cla h extracts stimulated the production of the lowest median sIgE levels. The highest median sIgE levels were for Alt a 1, Mala s 11 and Asp f 6, respectively. Median sIgE levels increased in adults compared to children for all components of Aspergillus fumigatus, as well as for Mala s 5 and Mala s 11. In the rest of the cases, they decreased in adults compared to children. The sensitization rates to fungi in general and specifically to Alternaria were lower in the western parts of Ukraine, especially in the Carpathian region, situated within the Broad-leaved Forest zone. The results of Bayesian modeling revealed that in the case of Alt a 1, the simultaneous absence of sensitivity to Cla h 8, Mala s 11, Mala s 5 and Mala s 6 molecules could condition the presence of sensitization to the major Alternaria allergen with a probability of 92.42%. In all other cases, there was a high probability of absence of sensitivity to particular allergen against the background of absence of sensitivity to other ones, which may indicate the independent development of sensitization to different fungal allergens.

Conclusions

Sensitivity to Alt a 1 dominated in the studied population with a lower rate in the western regions. The highest median sIgE levels were induced by Alt a 1, Mala s 11 and Asp f 6. Bayesian Analysis suggest a high probability of the independent development of sensitization to different fungal allergens. The idea that sensitization to one allergen may be protective against sensitization to another one(s) requires further clinical study.

[Allergen immunotherapy for rare allergens]

Among allergies to aeroallergens, approximately 20% are allotted to the so-called rare allergens. These include ash pollen, weed pollen, storage mites, molds, and animal allergens. The prevalences of allergies to these allergens are lower, but affected patients also suffer considerably from their "rare" allergy. Hence, these allergies should neither be overseen nor completely forgotten in daily practice. Especially mold, mite, and animal allergens often induce asthma, so that the significance of allergen-specific immunotherapy (AIT) should not be neglected in causal therapy. This work summarizes the current state of knowledge on the groups of rare aeroallergens in terms of characteristics, prevalences, and data on AIT. It is based on a systematic literature search performed in the MEDLINE (PubMed®) and Google Scholar databases. AIT preparations for rare allergens are classified as individual formulations and are not subject to the German Therapy Allergen Ordinance. Due to the low case numbers, the levels of evidence for these formulations are not as high as those for dust mites, grass, or birch pollen, but exhibit good efficacy in practical experience.

Assessing the contributions of phylogenetic and environmental determinants of allergic cosensitization to fungi in humans

BACKGROUND

Understanding how allergies to 1 environmental fungus can lead to cosensitization to related fungi is important for the clinical management of allergies. Cosensitization can be caused by monosensitization combined with antibody cross-reactivity, or by coexposures driving independent sensitizations. A pioneering study showed that patterns of IgE cosensitization among 17 fungal species mirror fungal phylogeny. This could reflect either epitope or habitat similarity. Thanks to an improved understanding of fungal phylogeny, larger serologic testing datasets, and environmental data on household fungi, we can now characterize the relationship between cosensitization, species similarity, and likely coexposure with greater precision.

OBJECTIVE

To assess the degree to which IgE cosensitization in a group of 17 fungi can be attributed to species similarity or environmental coexposure.

METHODS

Cosensitization patterns among 17 fungal species were estimated from a dataset of approximately 8 million serologic tests on 1.6 million patients. Linear regression of cosensitization on phylogenetic distance and imputed coexposure was performed. In addition, branch lengths for the phylogenetic tree were re-estimated on the basis of cosensitization and compared with corresponding phylogenetic branch lengths.

RESULTS

Phylogenetic distance explains much of the observed cosensitization (adjusted r2 = .68, p < .001). Imputed environmental coexposures and test co-ordering patterns do not significantly predict cosensitization. Branch length comparisons between the cosensitization and phylogenetic trees identified several species as less cosensitizing than phylogenetic distance predicts.

CONCLUSION

Combined evidence from clinical IgE testing data on fungi, along with phylogenetic and environmental exposure data, supports the hypothesis that cosensitization is caused primarily by monosensitization plus cross-reactivity, rather than multisensitization. A serologic test result should be interpreted as pointing to a group of related species that include the sensitizing agent rather than as uniquely identifying the agent. The identified patterns of cross-reactivity may help optimize test panel design.

The Impact of Climate Change on the Sporulation of Atmospheric Fungi

The U.S. Global Change Research Program, Fourth National Climate Assessment reports that it is extremely likely that human activities, especially emissions of greenhouse gases, are the dominant cause of the observed warming since the mid-20th century. There are no convincing alternative explanations supported by observational evidence.

New generation sequencing: molecular approaches for the detection and monitoring of bioaerosols in an indoor environment: a systematic review

INTRODUCTION

The exposure of occupants to indoor air pollutants has increased in recent decades. The aim of this review is to discuss an overview of new approaches that are used to study fungal aerosols. Thus, this motivation was to compensate the gaps caused by the use of only traditional approaches in the study of fungal exposure.

CONTENT

The search involved various databases such as; Science Direct, PubMed, SAGE, Springer Link, EBCOHOST, MEDLINE, CINAHL, Cochrane library, Web of Science and Wiley Online Library. It was limited to full text research articles that reported the use of non-viable method in assessing bioaerosol, written in English Language, full text publications and published from year 2015-2022.

SUMMARY AND OUTLOOK

A total of 15 articles met the inclusion criteria and was included in this review. The use of next-generation sequencing, which is more commonly referred to as high-throughput sequencing (HTS) or molecular methods in microbial studies is based on the detection of genetic material of organisms present in a given sample. Applying these methods to different environments permitted the identification of the microorganisms present, and a better comprehension of the environmental impacts and ecological roles of microbial communities. Based on the reviewed articles, there is evidence that dust samples harbour a high diversity of human-associated bacteria and fungi. Molecular methods such as next generation sequencing are reliable tools for identifying and tracking the bacterial and fungal diversity in dust samples using 18S metagenomics approach.

ABPA and AFRS: addressing prevalence, early diagnosis, allergens, and occupational concerns

OBJECTIVE

This study aimed to comprehensively investigate the prevalence of ABPA and AFRS, scrutinize existing diagnostic criteria and immunoassays, pinpoint their limitations, highlight ABPA as an occupational health implication, and identify suggestive measures to improve ABPA diagnosis in the context of Occupational Health Nursing and primary healthcare.

DATA SOURCES

The data sources such as PubMed, Health and Safety Science Abstracts, OSH Update, Medline, and Google Scholar were searched.

STUDY SELECTIONS

All published studies in the English language from 1990 till Oct, 2023 using Mesh terms keywords "Allergic bronchopulmonary aspergillosis," "Allergic fungal rhinosinusitis," "Signs and Symptoms," "Rapid Diagnostic Tests," "Diagnosis," "Occupational Health," "Occupational Health Nursing," "Prevalence," "Allergens" following "Boolean operators" search strategy were selected.

RESULTS

This review succinctly covered signs, symptoms, and prevalence data concerning ABPA and AFRS. It briefly discussed existing diagnostic criteria and immunoassays, highlighted factors influencing the assay's variability, and underscored the role and scope of specific allergens toward improved, simple, and early ABPA diagnosis. ABPA as a neglected occupational health concern was emphasized, and the importance of RDTs in the context of healthcare professionals and OHNs was stated. Finally, this study suggested analyzing the impact of compromised post-pandemic immune status and the use of immunosuppressive drugs on ABPA prevalence among vulnerable communities and occupations.

CONCLUSION

To conclude, global and Indian ABPA and AFRS prevalence data, factors influencing existing assay variability, and the scope of improvement in RDTs for ABPA diagnosis in the background of primary healthcare professionals and OHNs were addressed.

Association between ambient temperature and common allergenic pollen and fungal spores: A 52-year analysis in central England, United Kingdom

Exposure to pollen and fungal spores can trigger asthma/allergic symptoms and affect health. Rising temperatures from climate change have been associated with earlier seasons and increasing intensity for some pollen, with weaker evidence for fungal spores. It is unclear whether climate change has resulted in changes in the exposure-response function between temperature and pollen/fungal spore concentrations over time. This study examined associations between temperature and pollen/fungal spores in different time periods and assessed potential adaptation using the longest pollen/fungal spore dataset in existence (52 years). Daily concentrations of pollen (birch and grass) and fungal spores (Cladosporium, Alternaria, Sporobolomyces and Tilletiopsis) collected between April and October from Derby (1970-2005) and Leicester (2006-2021), UK, were analysed. Cumulative seasonal concentrations (seasonal integral) and start-of-season were calculated and linked to seasonal mean temperatures (Tmeans) using generalized additive models. Daily concentrations were evaluated against daily Tmean with distributed lagged nonlinear models. Models were adjusted for precipitation, relative humidity, long-term trend and location. Seasonal and daily analyses were respectively stratified into two periods (1970-1995, 1997-2021) and five decades. Warmer seasonal Tmeans were associated with higher seasonal integral for birch, Cladosporium and Alternaria, as well as earlier start-of-season for birch, grass and Cladosporium. There were indications of changing associations with temperature in the recent decades. A warmer January was associated with higher seasonal integral for grass in 1997-2021, but not in 1970-1995. In 2000-2021, daily concentrations of birch pollen tended to remain at higher levels, vs. decrease during 1990s, when Tmean was between 13 and 15 °C. Our study suggests higher temperatures experienced in recent decades are associated with higher overall abundance of some pollen/fungal spores, which may increase future disease burdens of allergies. The changing responses of some pollen to higher temperatures over time may indicate adaptation to increasing temperatures and should be considered in climate change mitigation and adaptation planning.

Allergy to fungi: Advances in the understanding of fungal allergens

Allergic diseases are a major health problem due to their increasing incidence and high prevalence worldwide. Asthma has several aetiologies, and allergy plays an important role in its development in approximately 60% of adults and 80% of children and adolescents. Although the link between aeroallergen sensitization and asthma exacerbations has been long recognized, the investigations of the triggering allergens may be superficial in many asthma cases. The main allergenic sources related to asthma, and other allergic diseases, are pollens, mites, fungi, and animal epithelia. Fungi are considered the third most frequent cause of respiratory pathologies. Asthma caused by several fungi species may have a bad prognosis in some cases due to its severity and difficulty in avoidance methods. Despite the recognised relevance of fungi in respiratory allergies, the knowledge about fungal allergens seems to be scarce, with few descriptions of new allergens, compared to other allergenic sources. The study of major, minor, and cross-reactive fungal allergens, and their relevance in the allergic disease, might be crucial, not only to accurately diagnose these allergies, but also to predict exacerbations and responses to therapies, as well as for the development of personalized treatment plans in a fast-changing climate scenario.

Comprehensive insights into advances in ambient bioaerosols sampling, analysis and factors influencing bioaerosols composition

While the study of bioaerosols has a long history, it has garnered heightened interest in the past few years, focusing on both culture-dependent and independent sampling and analysis approaches. Observations have been made regarding the seasonal fluctuations in microbial communities and their connection to particular ambient atmospheric factors. The study of airborne microbial communities is important in public health and atmospheric processes. Nevertheless, the establishment of standardized protocols for evaluating airborne microbial communities and utilizing microbial taxonomy as a means to identify distinct bioaerosols sources and seasonal patterns remains relatively unexplored. This article discusses the challenges and limitations of ambient bioaerosols sampling and analysis, including the lack of standardized methods and the heterogeneity of sources. Future prospects in the field of bioaerosols, including the use of high-throughput sequencing technologies, omics studies, spectroscopy and fluorescence-based monitoring to provide comprehensive incite on metabolic capacity, and activity are also presented. Furthermore, the review highlights the factors that affect bioaerosols composition, including seasonality, atmospheric conditions, and pollution levels. Overall, this review provides a valuable resource for researchers, policymakers, and stakeholders interested in understanding and managing bioaerosols in various environments.

Potential Proallergenic Activity of Phytopathogenic Erysiphe palczewskii and Erysiphe convolvuli in in vitro Studies

Purpose

Allergic diseases have reached epidemic proportions globally, affecting nearly 30% of the world's population. One of the most prominent sources of allergens is fungi, causing up to 6% of respiratory diseases in the general population. However, the cause of respiratory allergies is not always identifiable. Therefore, we studied the ability of two representatives of common powdery mildew (Erysiphales), Erysiphe palczewskii and Erysiphe convolvuli, to induce a proinflammatory response in in vitro models of the upper and lower respiratory tract.

Materials and Methods

Two cell lines, BEAS-2B and A549, were used to mimic upper and lower respiratory epithelial cells. The toxicity of fungal extracts was assessed with MTT and flow cytometry assay. The production of reactive oxygen species in the cells was measured with flow cytometry. ELISA tests were used to determine the production of proinflammatory cytokines. The presence of the cell integrity marker was assessed with the immunofluorescence method.

Results

In both cell lines, the extract of E. palczewskii and E. convolvuli microfungi induced marked production of proinflammatory IL-1β, TNF-α, and GM-CSF cytokines involved in developing allergic reactions. The higher levels of these cytokines with higher reactive oxygen species synthesis positively correlated with the disruption of epithelial cell junctions.

Conclusion

We conclude that E. palczewskii and E. convolvuli microfungi have strong proinflammatory and proallergenic potential, but this finding needs in vivo confirmation.

Allergy immunotherapy for allergic fungal respiratory diseases

Background: Allergy immunotherapy (AIT) with fungal extracts is not as straight forward as that with other inhalants. The complexities relate to the number of airborne fungal spores, the limited data on the exposure to the spores of individual species of fungi and their clinical importance, the poor quality of the fungal allergen extracts that are available for the diagnosis and treatment, and the lack of controlled studies establishing dosing and efficacy of AIT with fungal extracts except for Alternaria. Objective: The objective was to review what is known with regard to the role of fungi in causing allergic respiratory diseases as well as the evidence that exists for the role of AIT as a treatment for these conditions. Methods: A search was conducted of PubMed, textbooks, known articles on immunotherapy with fungal extracts, and references derived from these primary sources. Results: Nine immunotherapy studies that used Alternaria or its major allergen Alt a 1 and two studies that used Cladosporium herbarum were identified. When a good quality extract was administered in adequate doses, immunotherapy with Alternaria was as effective as that with other inhalant allergens. There was a suggestion of efficacy with a specially prepared Cladosporium extract, but systemic reactions were common and limited the tolerated dose. The use of immunotherapy as an adjunct treatment for allergic fungal sinusitis is briefly reviewed, but controlled trials are lacking. Conclusion: Fungal immunotherapy should largely be limited to Alternaria alternata and perhaps C. herbarum. Under conditions of demonstrated exposure to a particular species of fungus and with symptoms that correlate with that exposure as well as availability of an apparently potent extract of that fungus to which the patient is sensitive that fungus may be considered for immunotherapy. Fungal (mold) mixes should not be used for diagnosis or therapy.

Natural polysaccharides exert anti-tumor effects as dendritic cell immune enhancers

With the development of immunotherapy, the process of tumor treatment is also moving forward. Polysaccharides are biological response modifiers widely found in plants, animals, fungi, and algae and are mainly composed of monosaccharides covalently linked by glycosidic bonds. For a long time, polysaccharides have been widely used clinically to enhance the body's immunity. However, their mechanisms of action in tumor immunotherapy have not been thoroughly explored. Dendritic cells (DCs) are a heterogeneous population of antigen presenting cells (APCs) that play a crucial role in the regulation and maintenance of the immune response. There is growing evidence that polysaccharides can enhance the essential functions of DCs to intervene the immune response. This paper describes the research progress on the anti-tumor immune effects of natural polysaccharides on DCs. These studies show that polysaccharides can act on pattern recognition receptors (PRRs) on the surface of DCs and activate phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT), mitogen-activated protein kinase (MAPK), nuclear factor-κB (NF-κB), Dectin-1/Syk, and other signalling pathways, thereby promoting the main functions of DCs such as maturation, metabolism, antigen uptake and presentation, and activation of T cells, and then play an anti-tumor role. In addition, the application of polysaccharides as adjuvants for DC vaccines, in combination with adoptive immunotherapy and immune checkpoint inhibitors (ICIs), as well as their co-assembly with nanoparticles (NPs) into nano drug delivery systems is also introduced. These results reveal the biological effects of polysaccharides, provide a new perspective for the anti-tumor immunopharmacological research of natural polysaccharides, and provide helpful information for guiding polysaccharides as complementary medicines in cancer immunotherapy.

Relationship between Aspergillus and asthma

Fungal sensitization is highly prevalent in severe asthma. The relationship between fungus and asthma, especially Aspergillus fumigatus, has been the subject of extensive research. The ubiquitous presence of A. fumigatus, its thermotolerant nature, the respirable size of its conidia, and its ability to produce potent allergens are pivotal in worsening asthma control. Due to the diverse clinical manifestations of fungal asthma and the lack of specific biomarkers, its diagnosis remains intricate. Diagnosing fungal asthma requires carefully assessing the patient's clinical history, immunological tests, and imaging. Depending on the severity, patients with fungal asthma require personalized treatment plans, including inhaled corticosteroids and bronchodilators, and antifungal therapy. This review provides a comprehensive overview of the association between Aspergillus and asthma by reviewing the relevant literature and highlighting key findings. We discuss the diagnosis of various entities included in fungal asthma. We also debate whether newer definitions, including allergic fungal airway disease, offer any additional advantages over the existing ones. Finally, we provide the current treatment options for the individual entities, including A. fumigatus-associated asthma, severe asthma with fungal sensitization, and allergic bronchopulmonary mycoses.

Laboratory mice with a wild microbiota generate strong allergic immune responses

Allergic disorders are caused by a combination of hereditary and environmental factors. The hygiene hypothesis postulates that early-life microbial exposures impede the development of subsequent allergic disease. Recently developed "wildling" mice are genetically identical to standard laboratory specific pathogen-free (SPF) mice but are housed under seminatural conditions and have rich microbial exposures from birth. Thus, by comparing conventional SPF mice with wildlings, we can uncouple the impact of lifelong microbial exposures from genetic factors on the allergic immune response. We found that wildlings developed larger populations of antigen-experienced T cells than conventional SPF mice, which included interleukin-10-producing CD4 T cells specific for commensal Lactobacilli strains and allergy-promoting T helper 2 (TH2) cells. In models of airway exposure to house dust mite (HDM), recombinant interleukin-33, or Alternaria alternata, wildlings developed strong allergic inflammation, characterized by eosinophil recruitment, goblet cell metaplasia, and antigen-specific immunoglobulin G1 (IgG1) and IgE responses. Wildlings developed robust de novo TH2 cell responses to incoming allergens, whereas preexisting TH2 cells could also be recruited into the allergic immune response in a cytokine-driven and TCR-independent fashion. Thus, wildling mice, which experience diverse and lifelong microbial exposures, were not protected from developing pathological allergic immune responses. Instead, wildlings mounted robust allergic responses to incoming allergens, shedding new light on the hygiene hypothesis.

Problems Encountered Using Fungal Extracts as Test Solutions for Fungal Allergy Diagnosis

Fungal allergy is a worldwide public health burden, and problems associated with a reliable allergy diagnosis are far from being solved. Especially, the lack of high-quality standardized fungal extracts contributes to the underdiagnosis of fungal allergy. Compared to the manufacturing processes of extracts from other allergen sources, the processes used to manufacture extracts from fungi show the highest variability. The reasons for the high variability are manifold as the starting material, the growth conditions, the protein extraction methods, and the storage conditions all have an influence on the presence and quantity of individual allergens. Despite the vast variety of studies that have analyzed the impact of the different production steps on the allergenicity of fungal allergen extracts, much remains unknown. This review points to the need for further research in the field of fungal allergology, for standardization and for generally accepted guidelines on the preparation of fungal allergen extracts. In particular, the standardization of fungal extracts has been and will continue to be difficult, but it will be crucial for improving allergy diagnosis and therapy.

A scoping review: What are the cellular mechanisms that drive the allergic inflammatory response to fungal allergens in the lung epithelium?

Allergic airway disease (AAD) is a collective term for respiratory disorders that can be exacerbated upon exposure to airborne allergens. The contribution of fungal allergens to AAD has become well established over recent years. We conducted a comprehensive review of the literature using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to better understand the mechanisms involved in the allergic response to fungi in airway epithelia, identify knowledge gaps and make recommendations for future research. The search resulted in 61 studies for final analysis. Despite heterogeneity in the models and methods used, we identified major pathways involved in fungal allergy. These included the activation of protease-activated receptor 2, the EGFR pathway, adenosine triphosphate and purinergic receptor-dependent release of IL33, and oxidative stress, which drove mucin expression and goblet cell metaplasia, Th2 cytokine production, reduced barrier integrity, eosinophil recruitment, and airway hyperresponsiveness. However, there were several knowledge gaps and therefore we recommend future research should focus on the use of more physiologically relevant methods to directly compare key allergenic fungal species, clarify specific mechanisms of fungal allergy, and assess the fungal allergy in disease models. This will inform disease management and future interventions, ultimately reducing the burden of disease.

Going over Fungal Allergy: Alternaria alternata and Its Allergens

Fungal allergy is the third most frequent cause of respiratory pathologies and the most related to a poor prognosis of asthma. The genera Alternaria and Cladosporium are the most frequently associated with allergic respiratory diseases, with Alternaria being the one with the highest prevalence of sensitization. Alternaria alternata is an outdoor fungus whose spores disseminate in warm and dry air, reaching peak levels in temperate summers. Alternaria can also be found in damp and insufficiently ventilated houses, causing what is known as sick building syndrome. Thus, exposure to fungal allergens can occur outdoors and indoors. However, not only spores but also fungal fragments contain detectable amounts of allergens and may function as aeroallergenic sources. Allergenic extracts of Alternaria hyphae and spores are still in use for the diagnosis and treatment of allergic diseases but are variable and insufficiently standardised, as they are often a random mixture of allergenic ingredients and casual impurities. Thus, diagnosis of fungal allergy has been difficult, and knowledge about new fungal allergens is stuck. The number of allergens described in Fungi remains almost constant while new allergens are being found in the Plantae and Animalia kingdoms. Given Alt a 1 is not the unique Alternaria allergen eliciting allergy symptoms, component-resolved diagnosis strategies should be applied to diagnose fungal allergy. To date, twelve A. alternata allergens are accepted in the WHO/IUIS Allergen Nomenclature Subcommittee, many of them are enzymes: Alt a 4 (disulfide isomerase), Alt a 6 (enolase), Alt a 8 (mannitol de-hydrogenase), Alt a 10 (aldehyde dehydrogenase), Alt a 13 (glutathione-S-transferase) and Alt a MnSOD (Mn superoxide dismutase), and others have structural and regulatory functions such as Alt a 5 and Alt a 12, Alt a 3, Alt a 7. The function of Alt a 1 and Alt a 9 remains unknown. Other four allergens are included in other medical databases (e.g., Allergome): Alt a NTF2, Alt a TCTP, and Alt a 70 kDa. Despite Alt a 1 being the A. alternata major allergen, other allergens, such as enolase, Alt a 6 or MnSOD, Alt a 14 have been suggested to be included in the diagnosis panel of fungal allergy.

Fungal Aeroallergens-The Impact of Climate Change

The incidence of allergic diseases worldwide is rapidly increasing, making allergies a modern pandemic. This article intends to review published reports addressing the role of fungi as causative agents in the development of various overreactivity-related diseases, mainly affecting the respiratory tract. After presenting the basic information on the mechanisms of allergic reactions, we describe the impact of fungal allergens on the development of the allergic diseases. Human activity and climate change have an impact on the spread of fungi and their plant hosts. Particular attention should be paid to microfungi, i.e., plant parasites that may be an underestimated source of new allergens.

Alternaria spore exposure in Bavaria, Germany, measured using artificial intelligence algorithms in a network of BAA500 automatic pollen monitors

Although Alternaria spores are well-known allergenic fungal spores, automatic bioaerosol recognition systems have not been trained to recognize these particles until now. Here we report the development of a new algorithm able to classify Alternaria spores with BAA500 automatic bioaerosol monitors. The best validation score was obtained when the model was trained on both data from the original dataset and artificially generated images, with a validation unweighted mean Intersection over Union (IoU), also called Jaccard Index, of 0.95. Data augmentation techniques were applied to the training set. While some particles were not recognized (false negatives), false positives were few. The results correlated well with manual counts (mean of four Hirst-type traps), with R² = 0.78. Counts from BAA500 were 1.92 times lower than with Hirst-type traps. The algorithm was then used to re-analyze the historical automatic pollen monitoring network (ePIN) dataset (2018-2022), which lacked Alternaria spore counts. Re-analysis of past data showed that Alternaria spore exposure in Bavaria was very variable, with the highest counts in the North (Marktheidenfeld, 154 m a.s.l.), and the lowest values close to the mountains in the South (Garmisch-Partenkirchen, 735 m a.s.l.). This approach shows that in our network future algorithms can be run on past datasets. Over time, the use of different algorithms could lead to misinterpretations as stemming from climate change or other phenological causes. Our approach enables consistent, homogeneous treatment of long-term series, thus preventing variability in particle counts owing to changes in the algorithms.

Fungal Aeroallergen Sensitization Patterns among Airway-Allergic Patients in Zagazig, Egypt

BACKGROUND

Airway allergies such as asthma and allergic rhinitis, as well as their comorbidities, are increasing worldwide, causing significant socioeconomic health burdens to societies. It is estimated that between 3% and 10% of the population is allergic to fungi. The type of fungal sensitization varies from one geographical region to another. The present study aimed to identify the common fungal aeroallergen sensitization patterns among airway-allergic patients residing in the Zagazig locality, Egypt, in order to obtain a better understanding of fungal allergy, in addition to improving the awareness and management strategies for those patients.

METHODS

The present cross-sectional study included 200 allergic rhinitis and asthma patients. Sensitization to fungal aeroallergens was evaluated by skin prick testing and in vitro measurement of total and specific immunoglobulin E.

RESULTS

As determined by a skin prick test, 58% of the patients studied were allergic to mixed molds. Alternaria alternata was the predominant fungal aeroallergen among the studied patients (72.2%), which was followed by Aspergillus fumigatus (53.45%), Penicillium notatum (52.6%), Candida albicans (34.5%), and Aspergillus niger (25%).

CONCLUSION

Mixed mold sensitization ranked fourth among the most frequent aeroallergens in airway-allergic patients, and Alternaria alternata was the most frequently encountered fungal aeroallergen in the Zagazig locality.

Fungal exposome, human health, and unmet needs: A 2022 update with special focus on allergy

Humans inhale, ingest, and touch thousands of fungi each day. The ubiquity and diversity of the fungal kingdom, reflected by its complex taxonomy, are in sharp contrast with our scarce knowledge about its distribution, pathogenic effects, and effective interventions at the environmental and individual levels. Here, we present an overview of salient features of fungi as permanent players of the human exposome and key determinants of human health, through the lens of fungal allergy and other fungal hypersensitivity reactions. Improved understanding of the fungal exposome sheds new light on the epidemiology of fungal-related hypersensitivity diseases, their immunological substratum, the currently available methods, and biomarkers for environmental and medical fungi. Unmet needs are described and potential approaches are highlighted as perspectives.

Recent Advances in the Allergic Cross-Reactivity between Fungi and Foods

Airborne fungi are one of the most ubiquitous kinds of inhalant allergens which can result in allergic diseases. Fungi tend to grow in warm and humid environments with regional and seasonal variations. Their nomenclature and taxonomy are related to the sensitization of immunoglobulin E (IgE). Allergic cross-reactivity among different fungal species appears to be widely existing. Fungus-related foods, such as edible mushrooms, mycoprotein, and fermented foods by fungi, can often induce to fungus food allergy syndrome (FFAS) by allergic cross-reactivity with airborne fungi. FFAS may involve one or more target organs, including the oral mucosa, the skin, the gastrointestinal and respiratory tracts, and the cardiovascular system, with various allergic symptoms ranging from oral allergy syndrome (OAS) to severe anaphylaxis. This article reviews the current knowledge on the field of allergic cross-reactivity between fungal allergens and related foods, as well as the diagnosis and treatment on FFAS.

Characteristics of annual mold variations and association with childhood allergic symptoms/diseases via combining surveys and home visit measurements

The presence of dampness and visible molds leads to concerns of poor indoor air quality which has been consistently linked with increased exacerbation and development of allergy and respiratory diseases. Due to the limitations of epidemiological surveys, the actual fungal exposure characteristics in residences has not been sufficiently understood. This study aimed to characterize household fungal diversity and its annual temporal and spatial variations. We developed combined cross-sectional survey, repeated air sampling around a year, and DNA sequencing methods. The questionnaire survey was conducted in 2019, and 4943 valid cases were received from parents; a follow-up case-control study (11 cases and 12 controls) was designed, and onsite measurements of indoor environments were repeated in typical summer, transient season, and winter; dust from floor and beddings in children's room were collected and ITS based DNA sequencing of totally 68 samples was conducted. Results from 3361 children without changes to their residences since birth verified the significant associations of indoor dampness/mold indicators and prevalence of children-reported diseases, with increased adjusted odd ratios (aORs) >1 for studied asthma, wheeze, allergic rhinitis, and eczema. The airborne fungal concentrations from air sampling were higher than 1000 CFU/m³ in summer, regardless of indoors and outdoors, indicating an intermediate pollution level. The DNA sequencing for dust showed the Aspergillus was the predominant at genus level and the Aspergillus_penicillioides was the most common at species level; while the fungal community and composition varied significantly in different homes and seasons, according to α and β diversity analyses. The comprehensive research methods contribute to a holistic understanding of indoor fungal exposure, including the concentrations, seasonal variations, community, and diversity, and verifies the relations with children's adverse health outcomes. The study further elucidates the role of microbiome in human health, which helps setting health-protective thresholds and managing mold treatments in buildings, to promote indoor air quality and human well-beings.

Assessing global fungal threats to humans

Fungi are an integral part of the earth's biosphere. They are broadly distributed in all continents and ecosystems and play a diversity of roles. Here, I review our current understanding of fungal threats to humans and describe the major factors that contribute to various threats. Among the 140,000 or so known species out of the estimated six million fungal species on Earth, about 10% directly or indirectly threaten human health and welfare. Major threats include mushroom poisoning, fungal allergies, infections of crop plants, food contamination by mycotoxins, and mycoses in humans. A growing number of factors have been identified to impact various fungal threats, including human demographics, crop distributions, anthropogenic activities, pathogen dispersals, global climate change, and/or the applications of antifungal drugs and agricultural fungicides. However, while models have been developed for analyzing various processes of individual threats and threat managements, current data are primarily descriptive and incomplete, and there are significant obstacles to integration of the diverse factors into accurate quantitative assessments of fungal threats. With increasing technological advances and concerted efforts to track the spatial and temporal data on climate and environmental variables; mycotoxins in the feed and food supply chains; fungal population dynamics in crop fields, human and animal populations, and the environment; human population demographics; and the prevalence and severities of fungal allergies and diseases, our ability to accurately assess fungal threats will improve. Such improvements should help us develop holistic strategies to manage fungal threats in the future.

Fungal-mediated lung allergic airway disease: The critical role of macrophages and dendritic cells

Fungi are abundant in the environment, causing our lungs to be constantly exposed to a diverse range of species. While the majority of these are cleared effectively in healthy individuals, constant exposure to spores (especially Aspergillus spp.) can lead to the development of allergic inflammation that underpins and worsen diseases such as asthma. Despite this, the precise mechanisms that underpin the development of fungal allergic disease are poorly understood. Innate immune cells, such as macrophages (MΦs) and dendritic cells (DCs), have been shown to be critical for mediating allergic inflammation to a range of different allergens. This review will focus on the crucial role of MΦ and DCs in mediating antifungal immunity, evaluating how these immune cells mediate allergic inflammation within the context of the lung environment. Ultimately, we aim to highlight important future research questions that will lead to novel therapeutic strategies for fungal allergic diseases.

Caspase-1 inhibition by YVAD generates tregs pivoting IL-17 to IL-22 response in β-glucan induced airway inflammation

BACKGROUND

During Aspergillus fumigatus mediated lung inflammation, NLRP3 inflammasome is rapidly activated that aggravates IL-1β production contributing to lung inflammation. Previously, we have shown the protective role of SYK-1 inhibition in inhibiting inflammasome activation during lung inflammation. In the current manuscript, we explored the protective role of direct caspase-1 inhibition during β-glucan-induced lung inflammation.

METHODS

We have mimicked the lung inflammation by administering intranasal β-glucan in mice model. YVAD was used for caspase-1 inhibition.

RESULTS

We have shown that caspase-1 inhibition by YVAD did not alter inflammasome independent inflammatory cytokines, while it significantly reduced inflammasome activation and IL-1β secretion. Caspase-1 inhibited bone marrow derived dendritic cells (BMDCs), co-cultured with T cells showed decreased T-cell proliferation and direct them to secrete high TGF-β and IL-10 compared to the T cells co-cultured with β-glucan primed dendritic cells. Caspase-1 inhibition in BMDCs also induced IL-22 secretion from CD4+T cells. Caspase-1 inhibition in intranasal β-glucan administered mice showed decreased tissue damage, immune cell infiltration and IgA secretion compared to control mice. Further, splenocytes challenged with β-glucan show high IL-10 secretion and increased FOXp3 and Ahr indicating an increase in regulatory T cells on caspase-1 inhibition.

CONCLUSION

Caspase-1 inhibition can thus be an attractive target to prevent inflammation mediated tissue damage during Aspergillus fumigatus mouse model and can be explored as an attractive therapeutic strategy.HIGHLIGHTSCaspase-1 inhibition protects lung damage from inflammation during β-glucan exposureCaspase-1 inhibition in dendritic cells decreases IL-1β production resulting in decreased pathogenic Th17Caspase-1 inhibition promotes regulatory T cells thereby inhibiting lung inflammation.

Spatiotemporal assessment of aeromycoflora under differing urban green space, sampling height, and meteorological regimes: the atmospheric fungiscape of Thessaloniki, Greece

We studied the diversity and abundance of the airborne fungal spores in the city of Thessaloniki, Greece, for two consecutive years. Air samples were collected at one rooftop station (at 30 m) and six near-ground stations (at 1.5 m) that differed in the size and composition of adjacent green spaces. The effects of meteorological factors on airborne fungal spore concentrations were also explored. Cladosporium spores were dominant everywhere in the air of the city. The total concentration of the airborne fungal spores at 30 m was 10 times lower than near the ground. Differences in concentration and composition were far less pronounced among near-ground stations. The attributes of the fungal spore season did not change in a consistent way among stations and years. Concentrations at the near-ground stations matched the grouping of the latter into stations of high, intermediate, and low urban green space. Minimum air temperature was the primary meteorological factor affecting spore abundance, followed by relative humidity. Airborne fungal spores are more homogeneously distributed in the air of the city, but their concentrations decrease more rapidly with height than pollen.

A systematic review of outdoor airborne fungal spore seasonality across Europe and the implications for health

Fungal spores make up a significant proportion of organic matter within the air. Allergic sensitisation to fungi is associated with conditions including allergic fungal airway disease. This systematic review analyses outdoor fungal spore seasonality across Europe and considers the implications for health. Seventy-four studies met the inclusion criteria, the majority of which (n = 64) were observational sampling studies published between 1978 and 2020. The most commonly reported genera were the known allergens Alternaria and Cladosporium, measured in 52 and 49 studies, respectively. Both displayed statistically significant increased season length in south-westerly (Mediterranean) versus north-easterly (Atlantic and Continental) regions. Although there was a trend for reduced peak or annual Alternaria and Cladosporium spore concentrations in more northernly locations, this was not statistically significant. Peak spore concentrations of Alternaria and Cladosporium exceeded clinical thresholds in nearly all locations, with median peak concentrations of 665 and 18,827 per m³, respectively. Meteorological variables, predominantly temperature, precipitation and relative humidity, were the main factors associated with fungal seasonality. Land-use was identified as another important factor, particularly proximity to agricultural and coastal areas. While correlations of increased season length or decreased annual spore concentrations with increasing average temperatures were reported in multi-decade sampling studies, the number of such studies was too small to make any definitive conclusions. Further, up-to-date studies covering underrepresented geographical regions and fungal taxa (including the use of modern molecular techniques), and the impact of land-use and climate change will help address remaining knowledge gaps. Such knowledge will help to better understand fungal allergy, develop improved fungal spore calendars and forecasts with greater geographical coverage, and promote increased awareness and management strategies for those with allergic fungal disease.

Fungal Allergen and Mold Allergy Diagnosis: Role and Relevance of Alternaria alternata Alt a 1 Protein Family

Alternaria is a genus of worldwide fungi found in different habitats such as soil, the atmosphere, plants or indoor environments. Alternaria species are saprobic—largely involved in the decomposition of organic material—but they can also act as animal pathogens, causing disease in humans and animals, developing infections, toxicosis and allergic diseases. A. alternata is considered one of the most important sources of fungal allergens worldwide and it is associated with severe asthma and respiratory status. Among the A. alternata allergens, Alt a 1 is the main sensitizing allergen and its usefulness in diagnosis and immunotherapy has been demonstrated. Alt a 1 seems to define a protein family that can be used to identify related pathogenic fungi in plants and fruits, and to establish taxonomic relationships between the different fungal divisions.

Airborne Alt a 1 Dynamic and Its Relationship with the Airborne Dynamics of Alternaria Conidia and Pleosporales Spores

Fungal spores are universal atmospheric components associated to allergic reactions. Alternaria (Ascomycota) is considered the most allergenic spore taxa. Alt a 1 is the major allergen of Alternaria and is present also in other Pleosporales. In this study, standard Hirst-based sampling and analyzing methods for measuring spore daily concentrations of Alternaria, Curvularia, Drechslera-Helminthosporium, Epicoccum, Leptosphaeria, Pithomyces, Pleospora and Stemphylium (all included in the taxon Pleosporales) have been used as well as two high-volume samplers, Burkard Cyclone (2017) and MCV CAV-A/mb (2019–2020), and ELISA kits for measuring the allergen. The detection and quantification of Alt a 1 was only possible in the samples from the MCV sampler. Although Alt a 1 was better correlated with Alternaria spores than with Pleosporales spores, the three of them showed high correlations. It is shown that there is a high and significant correlation of Alt a 1 with temperature, a negative correlation with relative humidity and no correlation with precipitation. The aerobiological monitoring of these three elements ensures the best information for understanding the affectation to allergy sufferers, but, if this is not possible, as a minimum public health service aimed at the detection, treatment and prevention of allergies, the study of the airborne Alternaria spores should be ensured.

Innate and mild Th17 cutaneous immune responses elicited by subcutaneous infection of immunocompetent mice with Cladosporium cladosporioides

Cladosporium cladosporioides is a dematiaceous hyphomycete that is pathogenic in the superficial and deep tissues of both immunodeficient and immunocompetent humans and animals. Our aim was to evaluate the antifungal immune responses elicited by C. cladosporioides in immunocompetent mice. Hence, we subcutaneously injected suspensions of C. cladosporioides spores into immunocompetent mice to investigate the anti-fungal immune responses in the skin. We collected skin tissue samples for histopathological examination, immunofluorescence staining, and quantitative real-time polymerase chain reaction analysis. We observed subcutaneous abscesses in mice after subcutaneous injection of C. cladosporioides. A large number of inflammatory cells, including dendritic cells, macrophages, and neutrophils, infiltrated the focal abscess, with comparatively few infiltrating inflammatory cells in the epidermal and dermal layers of the skin. We detected the expression of CD54 in the abscesses and the skin. Gene expression of the pattern recognition receptors Dectin-1 and TLR-2 was higher in infected mice than in controls. Gene expression of the cytokines IL-6, IL-1β, and IL-17A also increased after infection, suggesting that the Th17 signaling pathway may be involved in the anti-fungal response. Although the pathogenicity of C. cladosporioides in healthy mice was weak after subcutaneous infection, resulting in few serious pathological phenomena, it appears that innate and Th17 immune responses play important roles in the cutaneous host response to C. cladosporioides. These findings lay a foundation for further study of the pathogenic mechanism and treatment of C. cladosporioides infection.

The Clinical Relevance of Pollen Versus Fungal Spores in Allergic Diseases

Pollen and fungal spores are associated with seasonal and perennial allergies. However, most scientific literature thus far suggests that pollen allergy is more clinically relevant than fungal allergy. Several environmental and biological factors and the difficulty in producing reliable fungal extracts account for this. Biodiversity, taxonomy, and meteorology are responsible for the types and levels of pollen and fungal spores, their fragments, and the presence of free airborne allergens. Therefore, it is difficult to accurately measure both pollen and fungal allergen exposure. In addition, understanding the enzymatic nature of fungal and some pollen allergens, the presence of allergenic and nonallergenic substances that may modulate the allergic immune response, and allergen cross-reactivity are all necessary to appropriately evaluate both sensitivity and exposure. The raw materials and manufacturing processes used to prepare pollen versus fungal extracts differ, further increasing the complexity to properly determine allergic sensitivity and degrees of exposure. The pollen extracts used for diagnosis and treatment are relatively consistent, and some have been standardized. However, obtaining clinically relevant fungal extracts is more difficult. Doing so will allow for the proper selection of such extracts to more appropriately diagnose and treat both pollen- and fungal-induced allergic diseases.

The causes of a peripheral blood eosinophilia in a secondary care setting

BACKGROUND

A peripheral blood eosinophilia of greater than 1.0 × 10⁹ /L is relatively unusual and offers a clue to the underlying diagnosis. In 2003, we established a specialist service to diagnose unexplained eosinophilia.

OBJECTIVE

To describe the causes of an eosinophilia in our service and the diagnostic algorithm we developed.

METHODS

Subjects were referred by physician colleagues across a range of specialties and undertook standard investigations following a semi-structured protocol. Data were extracted from a bespoke database.

RESULTS

Three hundred and eighty two subjects were referred over a 17-year period. Average age was 54 years and 183 (48%) of subjects were female, with 21 of 25 (84%) females in the idiopathic eosinophilic pneumonia group (p < 0001), 22 of 30 (73%) females in the gastrointestinal disease group (p < .008), but 11 of 37 (30%) females in the eosinophilic granulomatosis with polyangiitis group (p < .04). A diagnosis was assigned after systematic evaluation using a pre-defined algorithm in 361 (94.5%) of cases. Fungal allergy (82 subjects: 21%), parasitic infection (61 subjects: 16%) and severe eosinophilic asthma (50 subjects: 13%) were the three commonest individual diagnoses. Hypereosinophilic syndrome (HES) disease including eosinophilic granulomatosis with polyangiitis (EGPA) accounted for 85 subjects (20%) of which seven subjects (2%) had myeloproliferative disease (M-HES). A high IgE was common, and 79 (91%) of subjects with complete data who had an IgE of ≥1000 IU/L had fungal allergy or parasite infection. The serum tryptase was raised in 44 of 302 (14.5%) of individuals across all diagnostic groups, though none had mastocytosis.

CONCLUSION

A diagnosis of an unexplained eosinophilia can usually be determined using as semi-structured algorithm. Parasitic infection and fungal allergy often with severe eosinophilic asthma were common causes, whereas HES, particularly myeloproliferative, disease was relatively rare.

Allergic fungal airways disease (AFAD): an under-recognised asthma endotype

The term allergic fungal airways disease has a liberal definition based on IgE sensitisation to thermotolerant fungi and evidence of fungal-related lung damage. It arose from a body of work looking into the role of fungi in asthma. Historically fungi were considered a rare complication of asthma, exemplified by allergic bronchopulmonary aspergillosis; however, there is a significant proportion of individuals with Aspergillus fumigatus sensitisation who do not meet these criteria, who are at high risk for the development of lung damage. The fungi that play a role in asthma can be divided into two groups; those that can grow at body temperature referred to as thermotolerant, which are capable of both infection and allergy, and those that cannot but can still act as allergens in IgE sensitised individuals. Sensitisation to thermotolerant filamentous fungi (Aspergillus and Penicillium), and not non-thermotolerant fungi (Alternaria and Cladosporium) is associated with lower lung function and radiological abnormalities (bronchiectasis, tree-in-bud, fleeting shadows, collapse/consolidation and fibrosis). For antifungals to play a role in treatment, the focus should be on fungi capable of growing in the airways thereby causing a persistent chronic allergenic stimulus and releasing tissue damaging proteases and other enzymes which may disrupt the airway epithelial barrier and cause mucosal damage and airway remodelling. All patients with IgE sensitisation to thermotolerant fungi in the context of asthma and other airway disease are at risk of progressive lung damage, and as such should be monitored closely.

New Perspectives in the Diagnosis and Management of Allergic Fungal Airway Disease

Allergy to airway-colonising, thermotolerant, filamentous fungi represents a distinct eosinophilic endotype of often severe lung disease. This endotype, which particularly affects adult asthma, but also complicates other airway diseases and sometimes occurs de novo, has a heterogeneous presentation ranging from severe eosinophilic asthma to lobar collapse. Its hallmark is lung damage, characterised by fixed airflow obstruction (FAO), bronchiectasis and lung fibrosis. It has a number of monikers including severe asthma with fungal sensitisation (SAFS) and allergic bronchopulmonary aspergillosis/mycosis (ABPA/M), but these exclusive terms constitute only sub-sets of the condition. In order to capture the full extent of the syndrome we prefer the inclusive term allergic fungal airway disease (AFAD), the criteria for which are IgE sensitisation to relevant fungi in association with airway disease. The primary fungus involved is Aspergillus fumigatus, but a number of other thermotolerant species from several genera have been implicated. The unifying mechanism involves germination of inhaled fungal spores in the lung in the context of IgE sensitisation, leading to a persistent and vigorous eosinophilic inflammatory response in association with release of fungal proteases. Most allergenic fungi, including Alternaria and Cladosporium species, are not thermotolerant and cannot germinate in the airways so only act as aeroallergens and do not cause AFAD. Studies of the airway mycobiome have shown that A. fumigatus colonises the normal as much as the asthmatic airway, suggesting it is the tendency to become IgE-sensitised that is the critical triggering factor for AFAD rather than colonisation per se. Treatment is aimed at preventing exacerbations with glucocorticoids and increasingly by the use of anti-T2 biological therapies. Anti-fungal therapy has a limited place in management, but is an effective treatment for fungal bronchitis which complicates AFAD in about 10% of cases.

The Architecture of Metabolism Maximizes Biosynthetic Diversity in the Largest Class of Fungi

Ecological diversity in fungi is largely defined by metabolic traits, including the ability to produce secondary or “specialized” metabolites (SMs) that mediate interactions with other organisms. Fungal SM pathways are frequently encoded in biosynthetic gene clusters (BGCs), which facilitate the identification and characterization of metabolic pathways. Variation in BGC composition reflects the diversity of their SM products. Recent studies have documented surprising diversity of BGC repertoires among isolates of the same fungal species, yet little is known about how this population-level variation is inherited across macroevolutionary timescales. Here, we applied a novel linkage-based algorithm to reveal previously unexplored dimensions of diversity in BGC composition, distribution, and repertoire across 101 species of Dothideomycetes, which are considered the most phylogenetically diverse class of fungi and known to produce many SMs. We predicted both complementary and overlapping sets of clustered genes compared with existing methods and identified novel gene pairs that associate with known secondary metabolite genes. We found that variation among sets of BGCs in individual genomes is due to nonoverlapping BGC combinations and that several BGCs have biased ecological distributions, consistent with niche-specific selection. We observed that total BGC diversity scales linearly with increasing repertoire size, suggesting that secondary metabolites have little structural redundancy in individual fungi. We project that there is substantial unsampled BGC diversity across specific families of Dothideomycetes, which will provide a roadmap for future sampling efforts. Our approach and findings lend new insight into how BGC diversity is generated and maintained across an entire fungal taxonomic class.

The evolution of IgE-mediated type I hypersensitivity and its immunological value

The allergic phenotype manifests itself in a spectrum of troublesome to life-threatening diseases, from seasonal hay fever, through the food allergies, atopic eczema, asthma, to anaphylaxis. Allergy, that is an overreaction to allergen in hypersensitive individuals, results from the production of IgE, mast cell and basophil sensitisation and degranulation, requiring a range of medications to manage the conditions. Yet it is highly likely that allergy evolved for a purpose and that allergic diseases are accidental consequences of an insufficiently regulated immune response. This article presents a viewpoint from which to restore the immunological reputation of the allergic phenotype. We consider the evolutionary origins of potential allergens, toxins and parasites, and how they might have influenced early-mammal species in existence when IgE first developed. We conclude that the allergic phenotype has likely saved the lives of many more mammals than have ever died from allergy, so justifying the positive role of IgE in our evolution.

Assessment of the pulmonary adaptive immune response to Cladosporium cladosporioides infection using an experimental mouse model

Cladosporium cladosporioides causes asthma and superficial and deep infections, mostly in immunodeficient individuals and animals. This study aimed to investigate whether C. cladosporioides spores can enter the lungs through pulmonary circulation and influence pulmonary immune response. We intravenously injected mice with C. cladosporioides spore suspension and conducted several assays on the lungs. Pulmonary hemorrhage symptoms and congestion were most severe on days 1, 2, and 3 post-inoculation (PI). Extensive inflammatory cell infiltration occurred throughout the period of infection. More spores and hyphae colonizing the lungs were detected on days 1, 2, and 3 PI, and fewer spores and hyphae were observed within 21 d of infection. Numerous macrophages, dendritic cells, and neutrophils were observed on day 5 PI, along with upregulation of CD54, an intercellular adhesion molecule. Th1 and Th2 cells increased after infection; specifically, Th2 cells increased considerably on day 5 PI. These results suggest that days 2 and 5 PI represent the inflammatory peak in the lungs and that the Th2 and Th1 signaling pathways are potentially involved in pulmonary immune responses. In conclusion, the further adaptive immune responses played important roles in establishing effective pulmonary immunity against C. cladosporioides systemic infections based on innate immune responses.

Aspergillus fumigatus and Its Allergenic Ribotoxin Asp f I: Old Enemies but New Opportunities for Urine-Based Detection of Invasive Pulmonary Aspergillosis Using Lateral-Flow Technology

Invasive pulmonary aspergillosis (IPA) caused by Aspergillus fumigatus is a life-threatening lung disease of immunocompromised patients. Diagnosis currently relies on non-specific chest CT, culture of the fungus from invasive lung biopsy, and detection of the cell wall carbohydrate galactomannan (GM) in serum or in BAL fluids recovered during invasive bronchoscopy. Urine provides an ideal bodily fluid for the non-invasive detection of pathogen biomarkers, with current urine-based immunodiagnostics for IPA focused on GM. Surrogate protein biomarkers might serve to improve disease detection. Here, we report the development of a monoclonal antibody (mAb), PD7, which is specific to A. fumigatus and related species in the section Fumigati, and which binds to its 18 kDa ribotoxin Asp f I. Using PD7, we show that the protein is secreted during hyphal development, and so represents an ideal candidate for detecting invasive growth. We have developed a lateral-flow device (Afu-LFD^®) incorporating the mAb which has a limit of detection of ~15 ng Asp f I/mL urine. Preliminary evidence of the test’s diagnostic potential is demonstrated with urine from a patient with acute lymphoid leukaemia with probable IPA. The Afu-LFD^® therefore provides a potential novel opportunity for non-invasive urine-based detection of IPA caused by A. fumigatus.

Biochemical Characteristics and Allergenic Activity of Common Fungus Allergens

Fungi form a large kingdom with more than 1.5 million species. Fungal spores are universal atmospheric components and are generally recognized as important causes of allergic disorders, including allergic rhinitis, allergic rhinosinusitis, asthma, and allergic bronchopulmonary aspergillosis. The 4 genera which have the closest connection with allergic disorder are Cladosporium, Alternaria, Aspergillus and Penicillium. The cDNA sequences of many fungi allergens and the amino acids involved in their immunoglobulin E binding and T-cell activation have already been elucidated. Until now, 111 allergens from 29 fungal genera have been approved by the International Allergen Nomenclature Sub-committee. This review mainly focuses on the biochemical characteristics and allergenic activity of important allergens from common environmental fungi.

PC945, a Novel Inhaled Antifungal Agent, for the Treatment of Respiratory Fungal Infections

Disease due to pulmonary Aspergillus infection remains a significant unmet need, particularly in immunocompromised patients, patients in critical care and those with underlying chronic lung diseases. To date, treatment using inhaled antifungal agents has been limited to repurposing available systemic medicines. PC945 is a novel triazole antifungal agent, a potent inhibitor of CYP51, purpose-designed to be administered via inhalation for high local lung concentrations and limited systemic exposure. In preclinical testing, PC945 is potent versus Aspergillus spp. and Candida spp. and showed two remarkable properties in preclinical studies, in vitro and in vivo. The antifungal effects against Aspergillus fumigatus accumulate on repeat dosing and improved efficacy has been demonstrated when PC945 is dosed in combination with systemic anti-fungal agents of multiple classes. Resistance to PC945 has been induced in Aspergillus fumigatus in vitro, resulting in a strain which remained susceptible to other antifungal triazoles. In healthy volunteers and asthmatics, nebulised PC945 was well tolerated, with limited systemic exposure and an apparently long lung residency time. In two lung transplant patients, PC945 treated an invasive pulmonary Aspergillus infection that had been unresponsive to multiple antifungal agents (systemic ± inhaled) without systemic side effects or detected drug–drug interactions.

The Fungal Microbiome and Asthma

Asthma is a group of inflammatory conditions that compromises the airways of a continuously increasing number of people around the globe. Its complex etiology comprises both genetic and environmental aspects, with the intestinal and lung microbiomes emerging as newly implicated factors that can drive and aggravate asthma. Longitudinal infant cohort studies combined with mechanistic studies in animal models have identified microbial signatures causally associated with subsequent asthma risk. The recent inclusion of fungi in human microbiome surveys has revealed that microbiome signatures associated with asthma risk are not limited to bacteria, and that fungi are also implicated in asthma development in susceptible individuals. In this review, we examine the unique properties of human-associated and environmental fungi, which confer them the ability to influence immune development and allergic responses. The important contribution of fungi to asthma development and exacerbations prompts for their inclusion in current and future asthma studies in humans and animal models.

Diversity of Bioaerosols in Selected Rooms of Two Schools and Antibiotic Resistance of Isolated Staphylococcal Strains (Bydgoszcz, Poland): A Case Study

The present study is aimed at evaluating microbiological air pollution in libraries, cafeterias and selected classrooms of two schools in Bydgoszcz city, northern Poland and determining the antibiotic resistance of Staphylococcal strains isolated from the indoor air. One of the investigated schools (School A) is located in the very center of the city, in the vicinity of a park, among old houses and stone-lined streets, while the other (School B), among modern residential buildings, close to a street with heavy traffic. In each school, air samples were collected in the morning, always from all three sampling sites, using the MAS-100 sampler. Selective growth media were used for bacteria and mold isolation and quantifying analysis. The antibiotic resistance of the isolated mannitol-positive staphylococci was assessed using the disc diffusion method in accordance with EUCAST recommendations. The highest mean concentration of heterotrophic bacteria was recorded in the cafeterias: 884 CFU m−3 in School A and 1906 CFU m−3 in School B. Molds were the most abundant in the library and cafeteria in School B, where their average concentration exceeded 300 CFU m−3. Cladosporium and Penicillium species prevailed, while Fusarium, Acremonium and Aspergillus were less abundant. Airborne mannitol-positive staphylococci were recorded at low concentrations, ranging from 6 to 11 CFU m−3 on average. According to the taxonomic analysis, Staphylococcus aureus isolates were the most abundant in both schools, followed by S. xylosus, S. haemolyticus and S. saprophyticus. The antibiograms indicated that resistance to erythromycin was common in 62.5% of the isolated staphylococcal strains. Levofloxacin and gentamicin were the most effective antibiotics. No multidrug-resistant strains were identified.

Preliminary Studies on Fungal Contamination of Two Rupestrian Churches from Matera (Southern Italy)

The Sassi, a UNESCO World Heritage Site and its rupestrian churches, are richly decorated and visited by thousands of visitors every year. It is important to preserve this heritage which shows signs of deterioration due to abiotic and/or biotic factors. Aiming to carry out in the future an environmental-friendly restoration, a screening of the fungi present on walls and frescoes of two rupestrian churches “Santa Lucia alle Malve” and “La Madonna dei derelitti” located, respectively, in the “Sasso Caveoso” and in the “Sasso Barisano” was performed. Isolation and characterization of fungal species from investigated sites was carried out. Total genomic DNA (gDNA) was extracted from pure fungal cultures and subsequently utilized in PCRs using primers that amplify a portion of the ribosomal DNA (ITS5/ITS4) or the β-tubulin gene (Bt2a/Bt2b). The amplicons were directly sequenced. Obtained nucleotide sequences were compared to those present in the GenBank (NCBI) showing a very high similarity (99–100%) with the following species: Parengyodontium album, Alternaria alternata, Cladosporium cladosporioides, Lecanicillium psalliotae, Meyerozyma guilliermondii and Botryotrichum atrogriseum. All sequences from this study were deposited in the EMBL database. Detailed knowledge about fungi isolated from stone is indispensable not only to counter/reduce the structural and aesthetic damage but also to protect the health of both guardians and visitors who may develop different pathologies due to the spores diffused in the environment.