Aspergillus fumigatus and aspergillosis: From basics to clinics

Antifungal Effects of the Phloroglucinol Derivative DPPG Against Pathogenic Aspergillus fumigatus

Background: Fungal infections pose an increasingly predominant threat to human and animal health. Modified compounds derived from chemo-diverse natural products offer enhanced therapeutic efficacies and promising approaches to combat life-threatening fungal pathogens. Methods: We performed biosynthetic gene clusters analysis of 2,4-diacetylchloroglucoside (DAPG) in 4292 shotgun metagenomes samples from the healthy and diseased skin. Then, we assessed the antifungal activity of DAPG and the derivative 2,4-diproylphloroglucinol (DPPG) against pathogenic fungi by minimum inhibitory concentrations. The inhibitory effects of DPPG were measured using hyphal growth assay and spore germination assay. Concurrently, the mechanism of DPPG on Aspergillus fumigatus was investigated in membrane permeability and fluidity. The therapeutic efficacy was evaluated in a Galleria mellonella infection model. Results: We observed a significantly higher abundance of bacteria harboring DAPG biosynthetic clusters on healthy skin compared to diseased skin. Further, we designed and synthesized a series of phloroglucinol derivatives based on DAPG and obtained an antifungal candidate DPPG. DPPG not only exhibited robust antifungal activity against Aspergillus spp. and Candida spp. but also impaired hyphal growth and spore germination of A. fumigatus in vitro. A mechanism study showed that DPPG reduced membrane fluidity and increased the leakage of cellular contents, resulting in membrane perturbation and fungal death. Lastly, the therapeutic efficacy of DPPG was confirmed in a G. mellonella infection model. Conclusions: Our study demonstrates that DPPG is a potent scaffold to combat invasive fungal infections.

Aspergillus fumigatus biology, immunopathogenicity and drug resistance

Aspergillus fumigatus is a saprophytic fungus prevalent in the environment and capable of causing severe invasive infection in humans. This organism can use strategies such as molecule masking, immune response manipulation and gene expression alteration to evade host defences. Understanding these mechanisms is essential for developing effective diagnostics and therapies to improve patient outcomes in Aspergillus-related diseases. In this Review, we explore the biology and pathogenesis of A. fumigatus in the context of host biology and disease, highlighting virus-associated pulmonary aspergillosis, a newly identified condition that arises in patients with severe pulmonary viral infections. In the post-pandemic landscape, in which immunotherapy is gaining attention for managing severe infections, we examine the host immune responses that are critical for controlling invasive aspergillosis and how A. fumigatus circumvents these defences. Additionally, we address the emerging issue of azole resistance in A. fumigatus, emphasizing the urgent need for greater understanding in an era marked by increasing antimicrobial resistance. This Review provides timely insights necessary for developing new immunotherapeutic strategies against invasive aspergillosis.

Distribution characteristics of aerosol microorganisms in bronchoscopy room and the risk assessment of nosocomial infection

Objective

A large number of aerosols containing pathogenic microorganisms can be produced during bronchoscopy. The aim of the study is to evaluate the risk of nosocomial infection by pathogenic microorganisms after bronchoscopy. The distribution characteristics of aerosol microorganisms were detected before and after bronchoscopy, and then compared with the distribution characteristics of the patients' respiratory pathogens.

Methods

A total of 152 patients underwent bronchoscopy in the bronchoscopy room from May 06, 2024 to June 30, 2024. Airborne microorganisms were collected in the bronchoscopy room before and after the bronchoscopy, then cultured, counted and identified, to analyze the species, numbers and changes of microorganisms. At the same time, the data of respiratory pathogens and nosocomial infection of all patients were collected to evaluate the correlation between air microorganisms and respiratory pathogens, and the risk of nosocomial infection.

Results

(1) The concentration of air microorganisms after bronchoscopy was 89.60 ± 63.52 CFU/m3, significantly higher than 43.80 ± 26.70 CFU/m3 before bronchoscopy (p < 0.001). The increase in air microorganism concentration was in accordance with the total number of patients and the number of patients with respiratory infectious diseases on the same day (p < 0.001). After bronchoscopy for patients with infectious diseases, the concentration was significantly higher than that for patients with non-infectious diseases (p < 0.05). (2) The bacteria accounted for 75.34, 70.35% of the total aerosol microorganisms, fungi 22.17, 26.80% before and after bronchoscopy. The bacteria mainly included Micrococcus luteus, Staphylococcus epidermidis, Staphylococcus hominis, Haemophilus influenzae, Neisseria faunalis, Staphylococcus capitis, etc. The fungi mainly included Aspergillus flavus, Aspergillus niger, Saccharomyces albicans, Penicillium spp., etc. (3) The increase in air microorganisms after bronchoscopy was consistent with the distribution of pathogens causing respiratory infections in patients (p < 0.001). The increased pathogens were mainly composed of common respiratory pathogens, but it did not increase the risk of nosocomial respiratory infections in patients (p = 0.735).

Conclusion

Bronchoscopy can increase the concentration of aerosol microorganisms. The increased microorganisms are related to the respiratory pathogens of patients, which are mainly the common pathogens of pulmonary infection. This, however, does not increase the risk of nosocomial respiratory infection.

Occurrence of Moulds and Yeasts in the Slaughterhouse: The Underestimated Role of Fungi in Meat Safety and Occupational Health

Despite their potential impact on meat safety and occupational health, fungi are often underestimated contaminants in slaughterhouses. Moulds and yeasts may be associated with meat contamination in multiple processing stages, and mycotoxigenic species, such as Aspergillus, Fusarium, and Penicillium, pose food safety concerns. Bioaerosols may carry infectious fungi at the slaughterhouse that are capable of causing respiratory conditions and allergies. Chronic exposure to mycotoxins can have hepatotoxic, nephrotoxic, and carcinogenic effects in humans. While bacterial contamination in meat has been widely studied, fungal contamination remains overlooked due to limited evidence of immediate disease and the perception that its risks are lower than those of bacteria, which may contribute to insufficient research, awareness, and standardised surveillance protocols. This review compiles published data on the occurrence of fungi in slaughterhouses over the past twenty-five years. It highlights the primary mould and yeast isolated species, mainly identified based on morphological and microscopic characteristics, providing context for their role in meat safety and occupational health. The findings emphasise the need for improved risk assessment and fungal monitoring in meat plants. Standardised fungal detection and control protocols are also suggested for implementation to enhance meat safety and workplace conditions.

Nanoparticle-based antifungal therapies innovations mechanisms and future prospects

Fungal infections present an increasing global health challenge, with a substantial annual mortality rate of 1.6 million deaths each year in certain situations. The emergence of antifungal resistance has further complicated treatment strategies, underscoring the urgent need for novel therapeutic approaches. This review explores recent advances in nanoparticle-based therapies targeting fungal infections, emphasizing their unique potential to enhance drug solubility, bioavailability, and targeted delivery. Nanoparticles offer the ability to penetrate biological barriers, improve drug stability, and act as direct antifungal agents by disrupting fungal cell walls and generating reactive oxygen species. Despite their promising applications, challenges such as potential toxicity, scalability of production, and the need for controlled drug release remain. Future research should focus on optimizing nanoparticle properties, evaluating long-term safety profiles, developing environmentally sustainable synthesis methods, and exploring synergistic approaches with existing antifungal drugs. Nanotechnology offers a transformative opportunity in the management of fungal diseases, paving the way for more effective and targeted treatments.

Static and Dynamic Assessments of a Sulfur-Triglyceride Composite for Antimicrobial Surface Applications

Over 80 MT of elemental sulfur, a byproduct of fossil fuel desulfurization, are generated annually. This has spurred the development of high sulfur content materials (HSMs) via inverse vulcanization as a productive pathway towards sulfur utilization. In this study, we evaluate the antimicrobial performance of SunBG90, an HSM made from brown grease and sulfur, as tiles or infused into fabric squares. The static antimicrobial activity of SunBG90 tiles was assessed, revealing excellent efficacy against Gram-positive bacteria, with reductions of 96.84% for Staphylococcus aureus and 91.52% for Listeria monocytogenes. The tiles also exhibited strong antifungal activity, reducing Candida auris by 96.20% and mold (fumigatus) by 83.77%. In contrast, efficacy against Gram-negative bacteria was more variable, with moderate reductions for Escherichia coli (61.10%) and Salmonella enteritidis (62.15%), lower activity against Campylobacter jejuni and Salmonella typhi, and no effect on Clostridium perfringens. Under dynamic conditions, SunBG90-infused fabrics achieved a near-complete inhibition of L. monocytogenes (99.91%) and high reduction of E. coli (98.49%), along with a 96.24% inhibition of Candida auris. These results highlight the potential and limitations of SunBG90 for antimicrobial applications, emphasizing the need for further optimization to achieve consistent broad-spectrum activity.

Molecular docking and MD simulations reveal protease inhibitors block the catalytic residues in Prp8 intein of Aspergillus fumigatus: a potential target for antimycotics

Resistance to azoles and amphotericin B especially in Aspergillus fumigatus is a growing concern towards the treatment of invasive fungal infection. At this critical juncture, intein splicing would be a productive, and innovative target to establish therapies against resistant strains. Intein splicing is the central event for the activation of host protein, essential for the growth and survival of various microorganisms including A. fumigatus. The splicing process is a four-step protease-like nucleophilic cascade. Thus, we hypothesise that protease inhibitors would successfully halt intein splicing and potentially restrict the growth of the aforementioned pathogen. Using Rosetta Fold and molecular dynamics simulations, we modelled Prp8 intein structure; resembling classic intein fold with horse shoe shaped splicing domain. To fully comprehend the active site of Afu Prp8 intein, C1, T62, H65, H818, N819 from intein sequences and S820, the first C-extein residue are selected. Molecular docking shows that two FDA-approved drugs, i.e. Lufotrelvir and Remdesivir triphosphate efficiently interact with Prp8 intein from the assortment of 212 protease inhibitors. MD simulation portrayed that Prp8 undergoes conformational change upon ligand binding, and inferred the molecular recognition and stability of the docked complexes. Per-residue decomposition analysis confirms the importance of F: block R802, V803, and Q807 binding pocket in intein splicing domain towards recognition of inhibitors, along with active site residues through strong hydrogen bonds and hydrophobic contacts. However, in vitro and in vivo assays are required to confirm the inhibitory action on Prp8 intein splicing; which may pave the way for the development of new antifungals for A. fumigatus.

Antifungal Resistance in Non-fumigatus Aspergillus Species

This review provides an in-depth exploration of antifungal resistance in non-fumigatus Aspergillus species, mainly focusing on acquired resistance. The available data have been compiled and sometimes re-analysed. It highlights the increasing prevalence of resistance in non-fumigatus species belonging to Flavi, Terrei, Nigri, and Nidulantes Aspergillus sections, offering a detailed analysis of resistance detection methods and the global distribution of resistant strains. The review also thoroughly examines the molecular mechanisms behind resistance and raises key unresolved issues, such as the factors contributing to resistance selection and the clinical implications of in vitro resistance. Additionally, it addresses the challenges of treating infections caused by resistant Aspergillus species and cryptic species and discusses current and future strategies relying on combination therapy and newly developed antifungals. The conclusion emphasises the need for further research into resistance mechanisms and alternative treatments to address the rising threat of antifungal resistance in Aspergillus species.

Aspergillus fumigatus in the Food Production Chain and Azole Resistance: A Growing Concern for Consumers

Aspergillosis is a fungal disease caused by the inhalation of Aspergillus spores, with Aspergillus fumigatus being the primary causative agent. This thermotolerant fungus affects both immunocompetent and immunocompromised individuals, posing a significant public health concern. In recent years, the detection of A. fumigatus in food products and production environments has raised questions about its potential role as an additional route of exposure. Furthermore, the emergence of azole-resistant strains in agricultural settings highlights the need to better understand its transmission dynamics and implications for food safety. This review explores the occurrence of A. fumigatus in crops and food products, its possible routes of contamination, and the potential link between environmental exposure to azole fungicides and resistance development. Additionally, it identifies knowledge gaps and proposes future research directions to improve risk assessment and mitigation strategies within the food production chain.

Clinical aspects and recent advances in fungal diseases impacting human health

Fungal diseases are of growing clinical concern in human medicine as the result of changes in the epidemiology, diversity in clinical presentation, emergence of new pathogens, difficulties in diagnosis and increasing resistance to antifungals of current available classes. There is a need for high disease awareness among the public and healthcare physicians, improvement in diagnostic methods and the development of drugs from new therapeutic classes with an improved resistance profile. In this article, we will explore some key aspects of fungal diseases in humans and provide a general overview of this important topic.

Aspergillus fumigatus from Pathogenic Fungus to Unexplored Natural Treasure: Changing the Concept

The Aspergillus genus is one of the oldest known fungal genera. Its species can survive in extremely difficult environmental conditions and can affect plants, animals, and human health due to their pathogenic characteristics. Also, they represent an enormous chemical and biological repertoire. A. fumigatus is a fungal pathogen that has been thoroughly investigated due to its medical significance. Additionally, A. fumigatus has revealed a capacity to biosynthesize different classes of secondary metabolites such as alkaloids, terpenes, sterols, quinones, peptides, and benzophenones. Alkaloids are the most common type of secondary metabolites that A. fumigatus produces, and they have a variety of biological functions. This current study aimed to highlight the positive aspects of this fungus. The published research on the structures, biological functions, and biosynthesis of A. fumigatus's isolated metabolites were emphasized in this work. The current review comprised more than 400 compounds, with more than 145 references that were published between 1965 and August 2024. This review underscores the role of this fungus as a reservoir of bioactive compounds with antimicrobial, anticancer, anti-inflammatory, and agricultural applications.

Climate Change and Medical Mycology

This review explores how climate change influences fungal disease dynamics, focusing on emergence of new fungal pathogens, increased antifungal resistance, expanding geographic ranges of fungal pathogens, and heightened host susceptibility. Rising temperatures and altered precipitation patterns enhance fungal growth and resistance mechanisms, complicating treatment efforts. Climate-driven geographic shifts are expanding the range of diseases like Valley fever, histoplasmosis, and blastomycosis. Additionally, natural disasters exacerbated by climate change increase exposure to fungal pathogens through environmental disruptions and trauma. Many of those impacts affect primarily those already disadvantaged by social determinants of health putting them at increased risk for fungal diseases.

Pathogenic Aspergillus spp. and Candida spp. in coastal waters from southern Brazil: an one health approach

Aspergillus and Candida are ubiquitous fungi included in the group of high priority in the World Health Organization list of fungal pathogens. They are found in various ecosystems and the environmental role in increasing the resistance to antifungals has been shown. Thus, we aimed to determine the occurrence of Aspergillus spp. and Candida spp. pathogenic species in water samples from a coastal ecosystem from southern Brazil, and its antifungal susceptibility profile. Water samples were collected monthly at three environmental sites, over 25 months. Abiotic parameters of the water samples were analyzed as well as antifungal susceptibility. Aspergillus spp. and Candida spp. were detected in 44% (n = 33/75) and 40% (n = 30/75) respectively of the samples, totaling 67 and 96 isolates. Section Fumigati and C. parapsilosis were the most section/species isolated. Triazole resistance was detected in 3% of the Aspergillus spp. (2/67) and in 1% of the Candida spp. (1/96) isolates. Our study contributes with data showing that coastal aquatic environments can serve as a source of infection of resistant fungal isolates, proving the need for environmental surveillance and monitoring of fungal resistance in the One Health perspective.

Distribution and Epidemiological Characteristics of Clinical Isolates of A. fumigatus in a Hospital from 2021 to 2023: A Retrospective Study

Objective

The distribution characteristics of clinical isolates of A. fumigatus were analyzed to provide the basis for the prevention and control of A. fumigatus infection.

Methods

From January 2021 to December 2023, the First Affiliated Hospital of Nanjing Medical University collected clinical isolates of A. fumigatus from hospitalized patients for study. Duplicate strains from the same patient in the same area were eliminated, and community-, hospital-, and colonization infections were grouped.

Results

A total of 561 clinical isolates of A. fumigatus were identified, with 402 (82.35%) originating from male patients and 159 (17.65%) from female patients. The percentage of individuals aged 51 to 90 years was 78.97% (443/561). With the exception of surgery, which predominantly involved colonization, other departments mainly exhibited community-acquired infections (CAI) (P=0.002). The length of hospital stay was less than <15-30 days for most cases in the healthcare-associated infection group (HAI) (P<0.001). Lower respiratory tract infection accounted for the main site of infection across all three groups (95.37%), with ventilator-associated pneumonia being most prevalent in the HAI group (P<0.001). The detection rates of A. fumigatus from 2021 to 2023 were 3.89‱, 7.15‱, and 12.50‱, respectively. The detection frequencies of A. fumigatus throughout the three groups exhibited a year-on-year increase (P<0.001). Sputum samples constituted the main source of clinical isolates for all three groups, accounting for 61 strains (89.71%), 277 strains (78.69%), and 122 strains (86.52%) respectively, followed by bronchoalveolar lavage fluid samples.

Conclusion

The detection rate of A. fumigatus has exhibited a consistent upward trend over the past three years, with varying epidemiological characteristics observed across different infection types. It is recommended that medical institutions develop targeted prevention and control measures for A. fumigatus infections based on these unique characteristics.

Comprehensive Review of Environmental Surveillance for Azole-Resistant Aspergillus fumigatus: A Practical Roadmap for Hospital Clinicians and Infection Control Teams

As azole-resistant Aspergillus fumigatus emerges globally, healthcare facilities face mounting challenges in managing invasive aspergillosis. This review synthesizes worldwide azole resistance data to reveal profound regional variability, demonstrating that findings from other regions cannot be directly extrapolated to local settings. Consequently, hospital-level environmental surveillance is crucial for tailoring interventions to local epidemiology and detecting resistant strains in real-time. We outline practical approaches-encompassing sampling site prioritization, diagnostic workflows (culture-based and molecular), and PDCA-driven continuous improvement-so that even resource-limited facilities can manage resistant isolates more effectively. By linking real-time surveillance findings with clinical decisions, hospitals can tailor antifungal stewardship programs and swiftly adjust prophylaxis or treatment regimens. Our approach aims to enable accurate, ongoing evaluations of emerging resistance patterns, ensuring that institutions maintain efficient and adaptive programs. Ultimately, we advocate for sustained, collaborative efforts worldwide, where facilities adapt protocols to local conditions, share data through international networks, and contribute to a global knowledge base on resistance mechanisms. Through consistent application of these recommendations, healthcare systems can better preserve azole efficacy, safeguard immunocompromised populations, and refine infection control practices in the face of evolving challenges.

Exploring immunotherapy to control human infectious diseases

Infectious diseases continue to pose significant challenges to global health, especially with the rise of antibiotic resistance and emerging pathogens. Traditional treatments, while effective, are often limited in the face of rapidly evolving pathogens. Immunotherapy, which harnesses and enhances the body's immune response, offers a promising alternative to conventional approaches for the treatment of infectious diseases. By employing use of monoclonal antibodies, vaccines, cytokine therapies, and immune checkpoint inhibitors, immunotherapy has demonstrated considerable potential in overcoming treatment resistance and improving patient outcomes. Key innovations, including the development of mRNA vaccines, use of immune modulators, adoptive cell transfer, and chimeric antigen receptor (CAR)-T cell therapy are paving the way for more targeted pathogen clearance. Further, combining immunotherapy with conventional antibiotic treatment has demonstrated effectiveness against drug-resistant strains, but this chapter explores the evolving field of immunotherapy for the treatment of bacterial, viral, fungal, and parasitic infections. The chapter also explores the recent breakthroughs and ongoing clinical trials in infectious disease immunotherapy.

Elements of dissemination in cryptococcosis

As healthcare improves and our ability to support patients with compromised immune systems increases, such patients become more vulnerable to microbes in the environment. These include fungal pathogens such as Cryptococcus neoformans, the primary cause of fungal meningitis and a top priority pathogen on the World Health Organization fungal pathogen list. Like many other environmental pathogens, C. neoformans must adapt to and thrive in diverse environments in order to cause disease: (i) the environmental niche, (ii) the lungs following inhalation of infectious particles, (iii) the bloodstream and/or lymphatic system during dissemination, and (iv) the central nervous system (CNS), where it causes a deadly cryptococcal meningoencephalitis. Because CNS infection is the driver of mortality and the presenting illness, understanding the dissemination process from both host and fungal perspectives is important for treating these infections. In this review, we discuss the different stages of dissemination, how fungal cells interact with host cells during disease, and the ability to adapt to different environments within hosts.

Epidemiology and Antifungal Susceptibilities of Clinically Isolated Aspergillus Species in Tertiary Hospital of Southeast China

Background and Aim

Infection caused by Aspergillus species poses a growing global concern, yet their prevalence in Southeast China lacks comprehensive documentation. This retrospective analysis aims to elucidate the epidemiological role and antifungal susceptibilities of Aspergillus species at Huashan Hospital of Fudan University, Shanghai, China.

Methods

Data spanning from 2018 to 2022, encompassing demographic, clinical, and laboratory information on Aspergillus species isolates were analyzed. The isolates were subjected to susceptibility testing using YeastOneTM broth microdilution system.

Results

A total of 253 Aspergillus isolates were identified, with A. fumigatus (57.71%) being the predominant species, followed by A. niger (26.88%), A. flavus (10.67%), and A. terreus (3.95%). Notably, the highest number of isolates originated from the Department of Infectious Disease (28.06%), with sputum (54.94%) being the primary source of isolation, where A. fumigatus was the dominant species. Gastrointestinal disorder (23.90%), hepatic disorder (9.09%), and diabetes (8.30%) were identified as the most prevalent underlying conditions, with A. fumigatus being the most abundant species in each case, accounting for 65.08%, 82.60%, and 73.91%, respectively, followed by A. flavus. Non-wild-type (NWT) Aspergillus isolates exhibited higher resistance against amphotericin B (AMB) compared to triazoles. Specifically, A. fumigatus showed greater resistance to AMB, with only 23.28% of isolates being susceptible, while the majority of isolates were susceptible to triazoles like itraconazole (ITR) and posaconazole (POS). POS demonstrated the highest efficacy against all species. Sequencing revealed mutations in the promoter region of the cyp51A gene and at positions Y121F and E247K in A, fumigatus which confer resistance to ITR, voriconazole (VRC), and POS.

Conclusion

These findings contribute to a better understanding of the epidemiology and antifungal resistance pattern of Aspergillus species in the region, providing valuable insights for the management of Aspergillus-related infections.

The proteomic response of Aspergillus fumigatus to amphotericin B (AmB) reveals the involvement of the RTA-like protein RtaA in AmB resistance

The polyene antimycotic amphotericin B (AmB) and its liposomal formulation AmBisome belong to the treatment options of invasive aspergillosis caused by Aspergillus fumigatus. Increasing resistance to AmB in clinical isolates of Aspergillus species is a growing concern, but mechanisms of AmB resistance remain unclear. In this study, we conducted a proteomic analysis of A. fumigatus exposed to sublethal concentrations of AmB and AmBisome. Both antifungals induced significantly increased levels of proteins involved in aromatic acid metabolism, transmembrane transport, and secondary metabolite biosynthesis. One of the most upregulated proteins was RtaA, a member of the RTA-like protein family, which includes conserved fungal membrane proteins with putative functions as transporters or translocases. Accordingly, we found that RtaA is mainly located in the cytoplasmic membrane and to a minor extent in vacuolar-like structures. Deletion of rtaA led to increased polyene sensitivity and its overexpression resulted in modest resistance. Interestingly, rtaA expression was only induced by exposure to the polyenes AmB and nystatin, but not by itraconazole and caspofungin. Orthologues of rtaA were also induced by AmB exposure in A. lentulus and A. terreus. Deletion of rtaA did not significantly change the ergosterol content of A. fumigatus, but decreased fluorescence intensity of the sterol-binding stain filipin. This suggests that RtaA is involved in sterol and lipid trafficking, possibly by transporting the target ergosterol to or from lipid droplets. These findings reveal the contribution of RtaA to polyene resistance in A. fumigatus, and thus provide a new putative target for antifungal drug development.

Spatiotemporal modeling quantifies cellular contributions to uptake of Aspergillus fumigatus in the human lung

The human lung is confronted daily with thousands of microbial invaders reaching the lower respiratory tract. An efficient response by the resident type 1 and type 2 alveolar epithelial cells (AECs) and alveolar macrophages (AMs) cells during the early hours of innate immunity is a prerequisite to maintain a non-inflammatory state, but foremost to rapidly remove harmful substances. One such human-pathogenic invader is the opportunistic fungus Aspergillus fumigatus. If the spherical conidia are not cleared in time, they swell reaching approximately twice of their initial size and germinate to develop hyphae around six hours post-infection. This process of morphological change is crucial as it enables the pathogen to invade the alveolar epithelium and to reach the bloodstream, but also makes it conspicuous for the immune system. During this process, conidia are first in contact with AECs then with migrating AMs, both attempting to internalize and clear the fungus. However, the relative contribution of AMs and AECs to uptake of A. fumigatus remains an open question, especially the capabilities of the barely investigated type 1 AECs. In this study, we present a bottom-up modeling approach to incorporate experimental data on the dynamic increase of the conidial diameter and A. fumigatus uptake by AECs and AMs in a hybrid agent-based model (hABM) for the to-scale simulation of virtual infection scenarios in the human alveolus. By screening a wide range of parameters, we found that type 1 AECs, which cover approximately 95% of the alveolar surface, are likely to have a greater impact on uptake than type 2 AECs. Moreover, the majority of infection scenarios across the regime of tested parameters were cleared through uptake by AMs, whereas the contribution to conidial uptake by AECs was observed to be limited, indicating that their crucial support might mostly consist in mediating chemokine secretion for AM recruitment. Regardless, as the first host cell being confronted with A. fumigatus conidia, our results evidence the large potential impact of type 1 AECs antimicrobial activities, underlining the requirement of increasing experimental efforts on this alveolar constituent.

PHGDH/SYK: a hub integrating anti-fungal immunity and serine metabolism

Immune cells modify their metabolic pathways in response to fungal infections. Nevertheless, the biochemical underpinnings need to be better understood. This study reports that fungal infection drives a switch from glycolysis to the serine synthesis pathway (SSP) and one-carbon metabolism by inducing the interaction of spleen tyrosine kinase (SYK) and phosphoglycerate dehydrogenase (PHGDH). As a result, PHGDH promotes SYK phosphorylation, leading to the recruitment of SYK to C-type lectin receptors (CLRs). The CLR/SYK complex initiates signaling cascades that lead to transcription factor activation and pro-inflammatory cytokine production. SYK activates SSP and one-carbon metabolism by inducing PHGDH activity. Then, one-carbon metabolism supports S-adenosylmethionine and histone H3 lysine 36 trimethylation to drive the production of pro-inflammatory cytokines and chemokines. These findings reveal the crosstalk between amino acid metabolism, epigenetic modification, and CLR signaling during fungal infection.

Aspergillus fumigatus escape mechanisms from its harsh survival environments

Aspergillus fumigatus is a ubiquitous pathogenic mold and causes several diseases, including mycotoxicosis, allergic reactions, and systemic diseases (invasive aspergillosis), with high mortality rates. In its ecological niche, the fungus has evolved and mastered many reply strategies to resist and survive against negative threats, including harsh environmental stress and deficiency of essential nutrients from natural environments, immunity responses and drug treatments in host, and competition from symbiotic microorganisms. Hence, treating A. fumigatus infection is a growing challenge. In this review, we summarized A. fumigatus reply strategies and escape mechanisms and clarified the main competitive or symbiotic relationships between A. fumigatus, viruses, bacteria, or fungi in host microecology. Additionally, we discussed the contemporary drug repertoire used to treat A. fumigatus and the latest evidence of potential resistance mechanisms. This review provides valuable knowledge which will stimulate further investigations and clinical applications for treating and preventing A. fumigatus infections. KEY POINTS: • Harsh living environment was a great challenge for A. fumigatus survival. • A. fumigatus has evolved multiple strategies to escape host immune responses. • A. fumigatus withstands antifungal drugs via intrinsic escape mechanisms.

A ubiquitin-mediated post-translational degradation of Cyp51A contributes to a novel azole resistance mode in Aspergillus fumigatus

The airborne fungus Aspergillus fumigatus is a major pathogen that poses a serious health threat to humans by causing aspergillosis. Azole antifungals inhibit sterol 14-demethylase (encoded by cyp51A), an enzyme crucial for fungal cell survival. However, the most common mechanism of azole resistance in A. fumigatus is associated with the mutations in cyp51A and tandem repeats in its promoter, leading to reduced drug-enzyme interaction and overexpression of cyp51A. It remains unknown whether post-translational modifications of Cyp51A contribute to azole resistance. In this study, we report that the Cyp51A expression is highly induced upon exposure to itraconazole, while its ubiquitination level is significantly reduced by itraconazole. Loss of the ubiquitin-conjugating enzyme Ubc7 confers resistance to multiple azole antifungals but hinders hyphal growth, conidiation, and virulence. Western blot and immunoprecipitation assays show that deletion of ubc7 reduces Cyp51A degradation by impairing its ubiquitination, thereby leading to drug resistance. Most importantly, the overexpression of ubc7 in common environmental and clinical azole-resistant cyp51A isolates partially restores azole sensitivity. Our findings demonstrate a non-cyp51A mutation-based resistance mechanism and uncover a novel role of post-translational modification in contributing to azole resistance in A. fumigatus.

Starships: a new frontier for fungal biology

Transposable elements (TEs) are semiautonomous genetic entities that proliferate in genomes. We recently discovered the Starships, a previously hidden superfamily of giant TEs found in a diverse subphylum of filamentous fungi, the Pezizomycotina. Starships are unlike other eukaryotic TEs because they have evolved mechanisms for both mobilizing entire genes, including those encoding conditionally beneficial phenotypes, and for horizontally transferring between individuals. We argue that Starships have unrivaled capacity to engage their fungal hosts as genetic parasites and mutualists, revealing unexplored terrain for investigating the ecoevolutionary dynamics of TE-eukaryote interactions. We build on existing models of fungal genome evolution by conceptualizing Starships as a distinct genomic compartment whose dynamics profoundly shape fungal biology.

Synergistic effects of putative Ca2+-binding sites of calmodulin in fungal development, temperature stress and virulence of Aspergillus fumigatus

In pathogenic fungi, calcium-calmodulin-dependent serine-threonine-specific phosphatase calcineurin is involved in morphogenesis and virulence. Therefore, calcineurin and its tightly related protein complexes are attractive antifungal drug targets. However, there is limited knowledge available on the relationship between in vivo Ca2+-binding sites of calmodulin (CaM) and its functions in regulating stress responses, morphogenesis, and pathogenesis. In the current study, we demonstrated that calmodulin is required for hyphal growth, conidiation, and virulence in the human fungal pathogen, Aspergillus fumigatus. Site-directed mutations of calmodulin revealed that a single Ca2+-binding site mutation had no significant effect on A. fumigatus hyphal development, but multiple Ca2+-binding site mutations exhibited synergistic effects, especially when cultured at 42 °C, indicating that calmodulin function in response to temperature stress depends on its Ca2+-binding sites. Western blotting implied that mutations in Ca2+-binding sites caused highly degraded calmodulin fragments, suggesting that the loss of Ca2+-binding sites results in reduced protein stability. Moreover, normal intracellular calcium homeostasis and the nuclear translocation of the transcriptional factor CrzA are dependent on Ca2+-binding sites of AfCaM, demonstrating that Ca2+-binding sites of calmodulin are required for calcium signalling and its major transcription factor CrzA. Importantly, in situ mutations for four Ca2+-binding sites of calmodulin resulted in an almost complete loss of virulence in the Galleria mellonella wax moth model. This study shed more light on the functional characterization of putative calcium-binding sites of calmodulin in the morphogenesis and virulence of A. fumigatus, which enhances our understanding of calmodulin biological functions in cells of opportunistic fungal pathogens.

The epidemiological characteristics of invasive pulmonary aspergillosis and risk factors for treatment failure: a retrospective study

OBJECTIVE

The incidence of invasive pulmonary aspergillosis (IPA) is increasing gradually. This study analysed the epidemiological characteristics and prognostic factors of patients with IPA and explored the risk factors affecting prognosis.

MATERIALS AND METHODS

The clinical data and treatment of 92 patients with IPA were retrospectively analysed, and the patients were followed for 12 weeks. Patients were divided into an effective treatment group and an ineffective treatment group, and the risk factors affecting prognosis were discussed.

RESULTS

A total of 92 patients met the IPA inclusion criteria, and the most common genus of Aspergillus was Aspergillus fumigatus. The incidence of IPA was highest in patients with malignant tumours. IPA often coexisted with infections caused by other pathogens. We divided the patients into an effective treatment group and an ineffective treatment group according to prognosis. Compared with those in the effective treatment group, the procalcitonin (PCT) level, lactate dehydrogenase-to-albumin ratio (LDH/ALB) and neutrophil-to-lymphocyte ratio (NLR) in the ineffective treatment group were greater, the serum albumin level was lower, and the imaging findings revealed less nodules and bronchial wall thickening (P < 0.05). Among these factors, a decrease in the serum albumin concentration, an increase in the PCT level, coinfection and less bronchial wall thickening on imaging were independent risk factors for aspergillosis treatment failure.

CONCLUSION

A decreased albumin level, an elevated PCT level, coinfection, and less bronchial wall thickening were independent risk factors for treatment failure in patients with IPA. Attention should be given to the albumin level, coinfection status and imaging findings of patients.

Diagnosing fungal infections in clinical practice: a narrative review

BACKGROUND

Invasive fungal infections (IFI) present a major medical challenge, with an estimated 6.5 million cases annually, resulting in 3.8 million deaths. Pathogens such as Aspergillus spp. Candida spp. Mucorales spp. Cryptococcus spp. and other fungi species contribute to these infections, posing risks to immunocompromised individuals. Early and accurate diagnosis is crucial for effective treatment and better patient outcomes.

AREAS COVERED

This narrative review provides an overview of the current methods and challenges associated with diagnosing fungal diseases, including invasive aspergillosis and invasive candidiasis, as well as rare and endemic fungal infections. Various diagnostic techniques, including microscopy, culture, molecular diagnostics, and serological tests, are reviewed, highlighting their respective advantages and limitations and role in clinical guidelines. To illustrate, the need for improved diagnostic strategies to overcome existing challenges, such as the low sensitivity and specificity of current tests and the time-consuming nature of traditional culture-based methods, is addressed.

EXPERT OPINION

Current advancements in fungal infection diagnostics have significant implications for healthcare outcomes. Improved strategies like molecular testing and antigen detection promise early detection of fungal pathogens, enhancing patient management. Challenges include global access to advanced technologies and the need for standardized, user-friendly point-of-care diagnostics to improve diagnosis of fungal infections globally.

Application and antagonistic mechanisms of atoxigenic Aspergillus strains for the management of fungal plant diseases

This review covers, for the first time, all methods based on the use of Aspergillus strains as biocontrol agents for the management of plant diseases caused by fungi and oomycetes. Atoxigenic Aspergillus strains have been screened in a variety of hosts, such as peanuts, maize kernels, and legumes, during the preharvest and postharvest stages. These strains have been screened against a wide range of pathogens, such as Fusarium, Phytophthora, and Pythium species, suggesting a broad applicability spectrum. The highest efficacies were generally observed when using non-toxigenic Aspergillus strains for the management of mycotoxin-producing Aspergillus strains. The modes of action included the synthesis of antifungal metabolites, such as kojic acid and volatile organic compounds (VOCs), secretion of hydrolytic enzymes, competition for space and nutrients, and induction of disease resistance. Aspergillus strains degraded Sclerotinia sclerotiorum sclerotia, showing high control efficacy against this pathogen. Collectively, although two Aspergillus strains have been commercialized for aflatoxin degradation, a new application of Aspergillus strains is emerging and needs to be optimized.

One-Step Soft Agar Enrichment and Isolation of Human Lung Bacteria Inhibiting the Germination of Aspergillus fumigatus Conidia

Fungi of the genus Aspergillus are widespread in the environment, where they produce large quantities of airborne conidia. Inhalation of Aspergillus spp. conidia in immunocompromised individuals can cause a wide spectrum of diseases, ranging from hypersensitivity responses to lethal invasive infections. Upon deposition in the lung epithelial surface, conidia encounter and interact with complex microbial communities that constitute the lung microbiota. The lung microbiota has been suggested to influence the establishment and growth of Aspergillus spp. in the human airways. However, the mechanisms underlying this interaction have not yet been sufficiently investigated. In this study, we aimed to enrich and isolate bacterial strains capable of inhibiting the germination and growth of A. fumigatus conidia from bronchoalveolar lavage fluid (BALF) samples of lung transplant recipients using a novel enrichment method. This method is based on a soft agar overlay plate assay in which bacteria are directly in contact with conidia, allowing inhibition to be readily observed during enrichment. We isolated a total of five clonal bacterial strains with identical genotypic fingerprints, as shown by random amplified polymorphic DNA PCR (RAPD-PCR). All strains were identified as Pseudomonas aeruginosa (strains b1-b5). The strains were able to inhibit the germination and growth of Aspergillus fumigatus in a soft agar confrontation assay, as well as in a germination multiplate assay. Moreover, when compared with ten P. aeruginosa strains isolated from expectoration through standard methods, no significant differences in inhibitory potential were observed. Additionally, we showed inhibition of A. fumigatus growth on Calu-3 cell culture monolayers. However, the isolated P. aeruginosa strains were shown to cause significant damage to the cell monolayers. Overall, although P. aeruginosa is a known opportunistic lung pathogen and antagonist of A. fumigatus, we validated this novel one-step enrichment approach for the isolation of bacterial strains antagonistic to A. fumigatus from BALF samples as a proof-of-concept. This opens up a new venue for the targeted enrichment of antagonistic bacterial strains against specific fungal pathogens.

In vitro activity of olorofim against 507 filamentous fungi including antifungal drug-resistant strains at a tertiary laboratory in Australia: 2020-2023

BACKGROUND

New antifungal agents are required to mitigate against azole-resistant Aspergillus and drug-resistant non-Aspergillus moulds. The novel orotomide, olorofim (F2G, Manchester, UK), has potent fungicidal activity against Aspergillus including azole-resistant Aspergillus fumigatus, Lomentospora prolificans and Scedosporium spp. Development of olorofim-specific clinical breakpoints/epidemiological cut-off values requires reliable MIC data.

OBJECTIVES

Determine the in vitro activity of olorofim compared with standard antifungals against mould pathogens at an Australian hospital.

MATERIALS AND METHODS

Olorofim MICs were determined for 507 clinical mould isolates using the CLSI M38-A3 standard. MICs of amphotericin B, anidulafungin, posaconazole, voriconazole and isavuconazole were obtained using Sensititre™ YeastOne YO10 and AUSNMRCI panels (Thermo-Fisher Scientific).

RESULTS

A. fumigatus sensu stricto was the commonest species (33.3%) followed by L. prolificans (18.3%), Scedosporium (11.4%) and Fusarium (6%) species. Olorofim modal MICs were ≤0.25 mg/L (MIC90 0.25 mg/L) for all Aspergillus except Aspergillus Section Usti (1 mg/L); MICs for nine azole-resistant/non-wild-type A. fumigatus ranged from 0.008 to 0.125 mg/L. The MIC90 of olorofim for L. prolificans was 0.5 mg/L, 0.25-0.5 mg/L for Scedosporium spp. and 8 mg/L for the F. solani complex but with modal MICs of 0.25 and 0.008 mg/L for F. oxysporum and F. proliferatum complexes, respectively. For Verruconis gallopava (n = 10), the olorofim MIC90 was 0.06 mg/L (voriconazole MIC90 2 mg/L, isavuconazole MICs of 4->8 mg/L). Olorofim had little activity against other dematiaceous moulds including Exophiala species.

CONCLUSIONS

Olorofim was highly active against Aspergillus spp. including azole-resistant A. fumigatus, L. prolificans, Scedosporium spp. and some Fusarium species with the new finding of potent activity against V. gallopava.

Antifungal pipeline: New tools for the treatment of mycoses

Fungal infections are becoming an escalating public health challenge, particularly among immunocompromised individuals. The partially limited efficacy of current antifungal treatments, their potential adverse effects, and the increasing problem of resistance emphasize the need for new treatment options. Existing antifungal classes-allylamines, azoles, echinocandins, polyenes, and pyrimidine analogs-face challenges due to their similarity with human cells and rising resistance. New antifungal agents, such as ibrexafungerp, rezafungin, oteseconazole, and miltefosine, offer novel mechanisms of action along with reduced toxicity. While antifungal resistance is a growing global concern, fungal infections in low- and middle-income countries (LMICs) present specific challenges with high rates of opportunistic infections like cryptococcosis and endemic mycoses such as histoplasmosis. The World Health Organization's fungal priority pathogens list highlights the prevalence of these infections in LMICs, where limited access to antifungal drugs and misuse are common. This review provides a comprehensive overview of these new agents and their mechanisms, and explores the challenges and roles of antifungal drugs in LMICs, where the burden of fungal infections is high. Continued research and development are essential to address the rising incidence and resistance of fungal infections globally.

Metabolic regulation of the host-fungus interaction: from biological principles to therapeutic opportunities

Fungal infections present a significant global public health concern, impacting over 1 billion individuals worldwide and resulting in more than 3 million deaths annually. Despite considerable progress in recent years, the management of fungal infections remains challenging. The limited development of novel diagnostic and therapeutic approaches is largely attributed to our incomplete understanding of the pathogenetic mechanisms involved in these diseases. Recent research has highlighted the pivotal role of cellular metabolism in regulating the interaction between fungi and their hosts. In response to fungal infection, immune cells undergo complex metabolic adjustments to meet the energy demands necessary for an effective immune response. A comprehensive understanding of the metabolic circuits governing antifungal immunity, combined with the integration of individual host traits, holds the potential to inform novel medical interventions for fungal infections. This review explores recent insights into the immunometabolic regulation of host-fungal interactions and the infection outcome and discusses how the metabolic repurposing of immune cell function could be exploited in innovative and personalized therapeutic approaches.

MicroRNA expression profile of alveolar epithelial cells infected with Aspergillus fumigatus

There are limited number of studies investigating the role of microRNAs (miRNAs) in Aspergillus infections. In this study, we designed an in vitro aspergillosis model to identify differentially expressed Aspergillus-related miRNAs. For this purpose, carcinoma cell lines "A549" and "Calu-3" were infected with Aspergillus fumigatus. Total miRNA was isolated at 0, 1, 6, and 24 h post-infection. Quantitative real-time PCR assay was conducted to screen 31 human miRNAs that were possibly related to aspergillosis. Up- and downregulated miRNAs were detected in the infected cells. Highest level of miRNA expression was detected at 6 h post-infection. miR-21, hsa-miR-186-5p, hsa-miR-490-5p, miR-26a-5p, miR-26b-5p, hsa-miR-424-5p, hsa-miR-548d-3p, hsa-miR-196a-5p, miR-150-5p, miR-17-5p, and hsa-miR-99b-5p were found to be significantly upregulated (p < 0.001) at 6 h after A. fumigatus infection compared with the controls. Among the screened miRNAs, hsa-miR-145-5p (p < 0.001); hsa-miR-583 and hsa-miR-3978 (p < 0.01); and miR-21-5p, hsa-miR-4488, and hsa-miR-4454 (p < 0.05) were found to be downregulated compared with the controls. In conclusion, screening the identified miRNAs may reveal the personal predisposition to aspergillosis, which might be valuable from the perspective of personalized medicine.

Influenza-associated and COVID-19-associated pulmonary aspergillosis in critically ill patients

Influenza-associated pulmonary aspergillosis (IAPA) and COVID-19-associated pulmonary aspergillosis (CAPA) are increasingly recognised as important complications in patients requiring intensive care for severe viral pneumonia. The diagnosis can typically be made in 10-20% of patients with severe influenza or COVID-19, but only when appropriate diagnostic tools are used. Bronchoalveolar lavage sampling for culture, galactomannan testing, and PCR forms the cornerstone of diagnosis, whereas visual examination of the tracheobronchial tract during bronchoscopy is required to detect invasive Aspergillus tracheobronchitis. Azoles are the first-choice antifungal drugs, with liposomal amphotericin B as an alternative in settings where azole resistance is prevalent. Despite antifungal therapy, IAPA and CAPA are associated with poor outcomes, with fatality rates often exceeding 50%. In this Review, we discuss the mechanistic and clinical aspects of IAPA and CAPA. Moreover, we identify crucial knowledge gaps and formulate directions for future research.

Constraint on boric acid resistance and tolerance evolvability in Candida albicans

Boric acid is a broad-spectrum antimicrobial used to treat vulvovaginal candidiasis when patients relapse on the primary azole drug fluconazole. Candida albicans is the most common cause of vulvovaginal candidiasis, colloquially referred to as a "vaginal yeast infection". Little is known about the propensity of C. albicans to develop BA resistance or tolerance (the ability of a subpopulation to grow slowly in high levels of drug). We evolved 96 replicates from eight diverse C. albicans strains to increasing BA concentrations to test the evolvability of BA resistance and tolerance. Replicate growth was individually assessed daily, with replicates passaged when they had reached an optical density consistent with exponential growth. Many replicates went extinct quickly. Although some replicates could grow in much higher levels of BA than the ancestral strains, evolved populations isolated from the highest terminal BA levels (after 11 weeks of passages) surprisingly showed only modest growth improvements and only at low levels of BA. No large increases in resistance or tolerance were observed in the evolved replicates. Overall, our findings illustrate that there may be evolutionary constraints limiting the emergence of BA resistance and tolerance, which could explain why it remains an effective treatment for recurrent yeast infections.

Development of a Multiplex Real-Time PCR Assay for the Simultaneous Detection of Two Fungal Pathogens Causing Pneumonia

Infectious diseases caused by fungal sources are of great interest owing to their increasing prevalence. Invasive fungal infections, including invasive pulmonary aspergillosis caused by Aspergillus fumigatus, and Pneumocystis pneumonia caused by Pneumocystis jirovecii, are significant causes of morbidity and mortality among immunocompromised patients. The accurate and timely detection of these pathogens in this high-risk population is crucial for effective patient management. We developed a multiplex real-time polymerase chain reaction (PCR) assay, RF2 mRT-PCR, specifically designed to detect two respiratory fungi, P. jirovecii and A. fumigatus, and evaluated its performance in specimens of patients with lower respiratory tract infection. The performance was evaluated using 731 clinical samples, 55 reference species, and one synthetic DNA. The reproducibility test yielded a probit curve with a lower limit of detection of 19.82 copies/reaction for P. jirovecii and 64.20 copies/reaction for A. fumigatus. The RF2 mRT-PCR assay did not cross-react with non-A. fumigatus Aspergillus species or other common bacterial and viral species, and showed 100% in vitro sensitivity and specificity with reference assays. Additionally, it simultaneously detected A. fumigatus and P. jirovecii in co-infected samples. Therefore, the RF2 mRT-PCR assay is an efficient and reliable tool for in vitro diagnosis of A. fumigatus and P. jirovecii pulmonary infections.

Chiral Fluorescent Antifungal Azole Probes Detect Resistance, Uptake Dynamics, and Subcellular Distribution in Candida Species

Azoles are essential for fungal infection treatment, yet the increasing resistance highlights the need for innovative diagnostic tools and strategies to revitalize this class of antifungals. We developed two enantiomers of a fluorescent antifungal azole probe (1 S and 1 R ), analyzing 60 Candida strains via live-cell microscopy. A database of azole distribution images in strains of Candida albicans, Candida glabrata, and Candida parapsilosis, among the most important pathogenic Candida species, was established and analyzed. This analysis revealed distinct populations of yeast cells based on the correlation between fluorescent probe uptake and cell diameter. Varied uptake levels and subcellular distribution patterns were observed in C. albicans, C. glabrata, and C. parapsilosis, with the latter displaying increased localization to lipid droplets. Comparison of the more potent fluorescent antifungal azole probe enantiomer 1 S with the moderately potent enantiomer 1 R highlighted time-dependent differences in the uptake profiles. The former displayed a marked elevation in uptake after approximately 150 min, indicating the time required for significant cell permeabilization to occur and its association with the azole's antifungal activity potency. Divergent uptake levels between susceptible and high efflux-based azole-resistant strains were detected, offering a rapid diagnostic approach for identifying azole resistance. This study highlights unique insights achievable through fluorescent antifungal azole probes, unraveling the complexities of azole resistance, subcellular dynamics, and uptake within fungal pathogens.

Application of microbial agents in organic solid waste composting: a review

The rapid growth of organic solid waste has recently exacerbated environmental pollution problems, and its improper treatment has led to the loss of a large number of biomass resources. Here, we expound the advantages of microbial agents composting compared with conventional organic solid waste treatment technology, and review the important role of microbial agents composting in organic solid waste composting from the aspects of screening and identification, optimization of conditions, mechanism of action, combination with other technologies and ultra-high-temperature and ultra-low-temperature microbial composting. We discuss the value of microorganisms with different growth conditions in organic solid waste composting, and put forward a seasonal multi-temperature composite microbial composting technology. Provide new ideas for the all-round treatment of microbial agents in organic solid waste in the future. © 2024 Society of Chemical Industry.

Comparative Analysis of the Clarus Aspergillus Galactomannan Enzyme Immunoassay Prototype for the Diagnosis of Invasive Pulmonary Aspergillosis in Bronchoalveolar Lavage Fluid

BACKGROUND

Galactomannan (GM) testing using Platelia Aspergillus enzyme immunoassay (Platelia AGM) from bronchoalveolar lavage fluid (BALF) aids in early diagnosis of invasive pulmonary aspergillosis (IPA). Globally, only a minority of laboratories have the capability to perform on-site GM testing, necessitating accessible and affordable alternatives. Hence, we conducted a comparative evaluation of the new clarus Aspergillus GM enzyme immunoassay prototype (clarus AGM prototype) with Platelia AGM using BALF samples.

METHODS

This is a single-center, prospective, cross-sectional study, where Platelia AGM testing was routinely performed followed by clarus AGM prototype testing in those with true positive or true negative AGM test results according to the 2020 EORTC/MSG and the 2024 FUNDICU consensus definitions. Descriptive statistics, ROC curve analysis, and Spearman's correlation analysis were used to evaluate analytical performance of the clarus AGM prototype assay.

RESULTS

This study enrolled 259 adult patients, of which 53 (20%) were classified as probable IPA, while 206 did not fulfill IPA-criteria. Spearman's correlation analysis revealed a strong correlation between the two assays (rho = 0.727, p < 0.001). The clarus AGM prototype had a sensitivity of 96% (51/53) and a specificity of 74% (153/206) for differentiating probable versus no IPA when using the manufacturer recommended cut-off. ROC curve analysis showed an AUC of 0.936 (95% CI 0.901-0.971) for the clarus AGM prototype, while the Platelia AGM yielded an AUC of 0.918 (95% CI 0.876-0.959).

CONCLUSIONS

Clarus AGM prototype demonstrated a strong correlation and promising test performance, comparable to Platelia AGM, rendering it a viable alternative in patients at risk of IPA.

Unveiling Moroccan Nature's Arsenal: A Computational Molecular Docking, Density Functional Theory, and Molecular Dynamics Study of Natural Compounds against Drug-Resistant Fungal Infections

Candida albicans and Aspergillus fumigatus are recognized as significant fungal pathogens, responsible for various human infections. The rapid emergence of drug-resistant strains among these fungi requires the identification and development of innovative antifungal therapies. We undertook a comprehensive screening of 297 naturally occurring compounds to address this challenge. Using computational docking techniques, we systematically analyzed the binding affinity of each compound to key proteins from Candida albicans (PDB ID: 1EAG) and Aspergillus fumigatus (PDB ID: 3DJE). This rigorous in silico examination aimed to unveil compounds that could potentially inhibit the activity of these fungal infections. This was followed by an ADMET analysis of the top-ranked compound, providing valuable insights into the pharmacokinetic properties and potential toxicological profiles. To further validate our findings, the molecular reactivity and stability were computed using the DFT calculation and molecular dynamics simulation, providing a deeper understanding of the stability and behavior of the top-ranking compounds in a biological environment. The outcomes of our study identified a subset of natural compounds that, based on our analysis, demonstrate notable potential as antifungal candidates. With further experimental validation, these compounds could pave the way for new therapeutic strategies against drug-resistant fungal pathogens.

Azole resistance in Aspergillus fumigatus- comprehensive review

Aspergillus fumigatus is a ubiquitous filamentous fungus commonly found in the environment. It is also an opportunistic human pathogen known to cause a range of respiratory infections, such as invasive aspergillosis, particularly in immunocompromised individuals. Azole antifungal agents are widely used for the treatment and prophylaxis of Aspergillus infections due to their efficacy and tolerability. However, the emergence of azole resistance in A. fumigatus has become a major concern in recent years due to their association with increased treatment failures and mortality rates. The development of azole resistance in A. fumigatus can occur through both acquired and intrinsic mechanisms. Acquired resistance typically arises from mutations in the target enzyme, lanosterol 14-α-demethylase (Cyp51A), reduces the affinity of azole antifungal agents for the enzyme, rendering them less effective, while intrinsic resistance refers to a natural resistance of certain A. fumigatus isolates to azole antifungals due to inherent genetic characteristics. The current review aims to provide a comprehensive overview of azole antifungal resistance in A. fumigatus, discusses underlying resistance mechanisms, including alterations in the target enzyme, Cyp51A, and the involvement of efflux pumps in drug efflux. Impact of azole fungicide uses in the environment and the spread of resistant strains is also explored.

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.

A Simulation Study to Reveal the Epidemiology and Aerosol Transmission Characteristics of Botrytis cinerea in Grape Greenhouses

Most previously studies had considered that plant fungal disease spread widely and quickly by airborne fungi spore. However, little is known about the release dynamics, aerodynamic diameter, and pathogenicity threshold of fungi spore in air of the greenhouse environment. Grape gray mold is caused by Botrytis cinerea; the disease spreads in greenhouses by spores in the air and the spore attaches to the leaf and infects plant through the orifice. In this study, 120 μmol/L propidium monoazide (PMA) were suitable for treatment and quantitation viable spore by quantitative real-time PCR, with a limit detection of 8 spores/mL in spore suspension. In total, 93 strains of B. cinerea with high pathogenicity were isolated and identified from the air samples of grapevines greenhouses by a portable sampler. The particle size of B. cinerea aerosol ranged predominately from 0.65-3.3 μm, accounting for 71.77% of the total amount. The B. cinerea spore aerosols were infective to healthy grape plants, with the lowest concentration that could cause disease being 42 spores/m3. Botrytis cinerea spores collected form six greenhouse in Shandong Province were quantified by PMA-qPCR, with a higher concentration (1182.89 spores/m3) in May and June and a lower concentration in July and August (6.30 spores/m3). This study suggested that spore dispersal in aerosol is an important route for the epidemiology of plant fungal disease, and these data will contribute to the development of new strategies for the effective alleviation and control of plant diseases.

Rethinking Aspergillosis in the Era of Microbiota and Mycobiota

Aspergillosis encompasses a wide range of clinical conditions based on the interaction between Aspergillus and the host. It ranges from colonization to invasive aspergillosis. The human lung provides an entry door for Aspergillus. Aspergillus has virulence characteristics such as conidia, rapid growth at body temperature, and the production of specific proteins, carbohydrates, and secondary metabolites that allow A. fumigatus to infiltrate the lung's alveoli and cause invasive aspergillosis. Alveolar epithelial cells play an important role in both fungus clearance and immune cell recruitment via cytokine release. Although the innate immune system quickly clears conidia in immunocompetent hosts, A. fumigatus has evolved multiple virulence factors in order to escape immune response such as ROS detoxifying enzymes, the rodlet layer, DHN-melanin and toxins. Bacterial co-infections or interactions can alter the immune response, impact Aspergillus growth and virulence, enhance biofilm formation, confound diagnosis, and reduce treatment efficacy. The gut microbiome's makeup influences pulmonary immune responses generated by A. fumigatus infection and vice versa. The real-time PCR for Aspergillus DNA detection might be a particularly useful tool to diagnose pulmonary aspergillosis. Metagenomics analyses allow quick and easy detection and identification of a great variety of fungi in different clinical samples, although optimization is still required particularly for the use of NGS techniques. This review will analyze the current state of aspergillosis in light of recent discoveries in the microbiota and mycobiota.

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.

Impact of climate change and natural disasters on fungal infections

The effects of climate change and natural disasters on fungal pathogens and the risks for fungal diseases remain incompletely understood. In this literature review, we examined how fungi are adapting to an increase in the Earth's temperature and are becoming more thermotolerant, which is enhancing fungal fitness and virulence. Climate change is creating conditions conducive to the emergence of new fungal pathogens and is priming fungi to adapt to previously inhospitable environments, such as polluted habitats and urban areas, leading to the geographical spread of some fungi to traditionally non-endemic areas. Climate change is also contributing to increases in the frequency and severity of natural disasters, which can trigger outbreaks of fungal diseases and increase the spread of fungal pathogens. The populations mostly affected are the socially vulnerable. More awareness, research, funding, and policies on the part of key stakeholders are needed to mitigate the effects of climate change and disaster-related fungal diseases.

CNS Aspergillosis: A Downside of Corticosteroid Use

Glucocorticoids are ubiquitously used by physicians for a myriad of diseases. Though powerful and potentially lifesaving, sometimes the dangerous side effects are not at the forefront of our medical decision-making. By immunosuppressing patients, glucocorticoids can place patients at increased risk for not only the metabolic effects of chronic glucocorticoid use but also increased risk for opportunistic infections. Patients at increased risk include those on prolonged courses or those that require high doses. We report a case of a 34-year-old man who was initiated on glucocorticoids for an unknown rheumatologic disease and presented with generalized weakness, fatigue, nausea, and vomiting. The patient experienced a seizure, which prompted head imaging. A mass was found and eventually biopsied, which was notable for Aspergillus fumigatus. The patient was initiated on antifungals for CNS aspergillosis and recovered.

Time-resolved fluoroimmunoassay for Aspergillus detection based on anti-galactomannan monoclonal antibody from stable cell line

Invasive Aspergillosis is a high-risk illness with a high death rate in immunocompromised people due to a lack of early detection and timely treatment. Based on immunology study, we achieved an efficient production of anti-galactomannan antibody by Chinese hamster ovary (CHO) cells and applied it to time-resolved fluoroimmunoassay for Aspergillus galactomannan detection. We first introduced dual promoter expression vector into CHO host cells, and then applied a two-step screening strategy to screen the stable cell line by methionine sulfoximine pressurization. After amplification and fermentation, antibody yield reached 4500 mg/L. Then we conjugated the antibodies with fluorescent microspheres to establish a double antibody sandwich time-resolved fluoroimmunoassay, which was compared with the commercial Platelia™ Aspergillus Ag by clinical serum samples. The preformed assay could obtain the results in less than 25 min, with a limit of detection for galactomannan of approximately 1 ng/mL. Clinical results of the two methods showed that the overall percent agreement was 97.7% (95% CI: 96.6%-98.4%) and Cohen's kappa coefficient was 0.94. Overall, the assay is highly consistent with commercial detection, providing a more sensitive and effective method for the rapid diagnosis of invasive aspergillosis.

The Inflammatory Response Induced by Aspergillus fumigatus Conidia Is Dependent on Complement Activation: Insight from a Whole Blood Model

INTRODUCTION

We aimed to elucidate the inflammatory response of Aspergillus fumigatus conidia in a whole-blood model of innate immune activation and to compare it with the well-characterized inflammatory reaction to Escherichia coli.

METHODS

Employing a human lepirudin whole-blood model, we analyzed complement and leukocyte activation by measuring the sC5b-9 complex and assessing CD11b expression. A 27-multiplex system was used for quantification of cytokines. Selective cell removal from whole blood and inhibition of C3, C5, and CD14 were also applied.

RESULTS

Our findings demonstrated a marked elevation in sC5b-9 and CD11b post-A. fumigatus incubation. Thirteen cytokines (TNF, IL-1β, IL-1ra, IL-4, IL-6, IL-8, IL-17, IFNγ, MCP-1, MIP-1α, MIP-1β, FGF-basic, and G-CSF) showed increased levels. A generally lower level of cytokine release and CD11b expression was observed with A. fumigatus conidia than with E. coli. Notably, monocytes were instrumental in releasing all cytokines except MCP-1. IL-1ra was found to be both monocyte and granulocyte-dependent. Pre-inhibiting with C3 and CD14 inhibitors resulted in decreased release patterns for six cytokines (TNF, IL-1β, IL-6, IL-8, MIP-1α, and MIP-1β), with minimal effects by C5-inhibition.

CONCLUSION

A. fumigatus conidia induced complement activation comparable to E. coli, whereas CD11b expression and cytokine release were lower, underscoring distinct inflammatory responses between these pathogens. Complement C3 inhibition attenuated cytokine release indicating a C3-level role of complement in A. fumigatus immunity.

The Narrow Footprint of Ancient Balancing Selection Revealed by Heterokaryon Incompatibility Genes in Aspergillus fumigatus

In fungi, fusion between individuals leads to localized cell death, a phenomenon termed heterokaryon incompatibility. Generally, the genes responsible for this incompatibility are observed to be under balancing selection resulting from negative frequency-dependent selection. Here, we assess this phenomenon in Aspergillus fumigatus, a human pathogenic fungus with a very low level of linkage disequilibrium as well as an extremely high crossover rate. Using complementation of auxotrophic mutations as an assay for hyphal compatibility, we screened sexual progeny for compatibility to identify genes involved in this process, called het genes. In total, 5/148 (3.4%) offspring were compatible with a parent and 166/2,142 (7.7%) sibling pairs were compatible, consistent with several segregating incompatibility loci. Genetic mapping identified five loci, four of which could be fine mapped to individual genes, of which we tested three through heterologous expression, confirming their causal relationship. Consistent with long-term balancing selection, trans-species polymorphisms were apparent across several sister species, as well as equal allele frequencies within A. fumigatus. Surprisingly, a sliding window genome-wide population-level analysis of an independent dataset did not show increased Tajima's D near these loci, in contrast to what is often found surrounding loci under balancing selection. Using available de novo assemblies, we show that these balanced polymorphisms are restricted to several hundred base pairs flanking the coding sequence. In addition to identifying the first het genes in an Aspergillus species, this work highlights the interaction of long-term balancing selection with rapid linkage disequilibrium decay.