Pathophysiological aspects of Aspergillus colonization in disease

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.

Comparative Cross-Kingdom DDA- and DIA-PASEF Proteomic Profiling Reveals Novel Determinants of Fungal Virulence and a Putative Druggable Target

Accurate and reliable detection of fungal pathogens presents an important hurdle to manage infections, especially considering that fungal pathogens, including the globally important human pathogen, Cryptococcus neoformans, have adapted diverse mechanisms to survive the hostile host environment and moderate virulence determinant production during coinfections. These pathogen adaptations present an opportunity for improvements (e.g., technological and computational) to better understand the interplay between a host and a pathogen during disease to uncover new strategies to overcome infection. In this study, we performed comparative proteomic profiling of an in vitro coinfection model across a range of fungal and bacterial burden loads in macrophages. Comparing data-dependent acquisition and data-independent acquisition enabled with parallel accumulation serial fragmentation technology, we quantified changes in dual-perspective proteome remodeling. We report enhanced and novel detection of pathogen proteins with data-independent acquisition-parallel accumulation serial fragmentation (DIA-PASEF), especially for fungal proteins during single and dual infection of macrophages. Further characterization of a fungal protein detected only with DIA-PASEF uncovered a novel determinant of fungal virulence, including altered capsule and melanin production, thermotolerance, and macrophage infectivity, supporting proteomics advances for the discovery of a novel putative druggable target to suppress C. neoformans pathogenicity.

Incidence and risk factors for coronavirus disease 2019-associated pulmonary aspergillosis using administrative claims data

BACKGROUND

Coronavirus disease 2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) is one of the noticeable complications of COVID-19 and its incidence varies widely. In Japan, research on the incidence, risk factors and mortality associated with CAPA is limited.

OBJECTIVES

This study aimed to explore the incidence and potential risk factors for CAPA in patients with severe or critical COVID-19 and evaluate the relationship between CAPA and mortality of patients with severe or critical COVID-19.

METHODS

We investigated the incidence of CAPA in patients with severe and critical COVID-19 using administrative claims data from acute care hospitals in Japan. We employed multivariable regression models to explore potential risk factors for CAPA and their contribution to mortality in patients with severe and critical COVID-19.

RESULTS

The incidence of CAPA was 0.4%-2.7% in 33,136 patients with severe to critical COVID-19. Age, male sex, chronic lung disease, steroids, immunosuppressants, intensive care unit admission, blood transfusion and dialysis were potential risk factors for CAPA in patients with severe to critical COVID-19. CAPA was an independent factor associated with mortality.

CONCLUSIONS

CAPA is a serious complication in patients with severe and critical COVID-19 and may increase mortality.

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.

Invasive aspergillosis in liver transplant recipients in the current era

Invasive aspergillosis (IA) is a rare but fatal disease among liver transplant recipients (LiTRs). We performed a multicenter 1:2 case-control study comparing LiTRs diagnosed with proven/probable IA and controls with no invasive fungal infection. We included 62 IA cases and 124 matched controls. Disseminated infection occurred only in 8 cases (13%). Twelve-week all-cause mortality of IA was 37%. In multivariate analyses, systemic antibiotic usage (adjusted odds ratio [aOR], 4.74; P = .03) and history of pneumonia (aOR, 48.7; P = .01) were identified as independent risk factors associated with the occurrence of IA. Moreover, reoperation (aOR, 5.99; P = .01), systemic antibiotic usage (aOR, 5.03; P = .04), and antimold prophylaxis (aOR, 11.9; P = .02) were identified as independent risk factors associated with the occurrence of early IA. Among IA cases, Aspergillus colonization (adjusted hazard ratio [aHR], 86.9; P < .001), intensive care unit stay (aHR, 3.67; P = .02), disseminated IA (aHR, 8.98; P < .001), and dialysis (aHR, 2.93; P = .001) were identified as independent risk factors associated with 12-week all-cause mortality, while recent receipt of tacrolimus (aHR, 0.11; P = .001) was protective. Mortality among LiTRs with IA remains high in the current era. The identified risk factors and protective factors may be useful for establishing robust targeted antimold prophylactic and appropriate treatment strategies against IA.

How I approach: the transplant recipient with fever and pulmonary infiltrates

Recipients of hematopoietic stem cell transplants and solid organ transplants frequently develop pulmonary infiltrates from both infectious and non-infectious etiologies. Differentiation and further characterization of microbiologic etiologies-viral, bacterial, and fungal-can be exceedingly challenging. Pediatric patients face unique challenges as confirmatory evaluations with bronchoscopy or lung biopsy may be limited. A generalizable approach to diagnosing and managing these conditions has not been well established. This paper aims to summarize our initial clinical approach while discussing the relative evidence informing our practices. A pediatric patient with characteristic infiltrates who has undergone HSCT is presented to facilitate the discussion. Generalizable approaches to similar patients are highlighted as appropriate while highlighting considerations based on clinical course and key risk factors.

Chronic pulmonary aspergillosis: comprehensive insights into epidemiology, treatment, and unresolved challenges

Chronic pulmonary aspergillosis (CPA) is a challenging respiratory infection caused by the environmental fungus Aspergillus. CPA has a poor prognosis, with reported 1-year mortality rates ranging from 7% to 32% and 5-year mortality rates ranging from 38% to 52%. A comprehensive understanding of the pathogen, pathophysiology, risk factors, diagnosis, surgery, hemoptysis treatment, pharmacological therapy, and prognosis is essential to manage CPA effectively. In particular, Aspergillus drug resistance and cryptic species pose significant challenges. CPA lacks tissue invasion and has specific features such as aspergilloma. The most critical risk factor for the development of CPA is pulmonary cavitation. Diagnostic approaches vary by CPA subtype, with computed tomography (CT) imaging and Aspergillus IgG antibodies being key. Treatment strategies include surgery, hemoptysis management, and antifungal therapy. Surgery is the curative option. However, reported postoperative mortality rates range from 0% to 5% and complications range from 11% to 63%. Simple aspergilloma generally has a low postoperative mortality rate, making surgery the first choice. Hemoptysis, observed in 50% of CPA patients, is a significant symptom and can be life-threatening. Bronchial artery embolization achieves hemostasis in 64% to 100% of cases, but 50% experience recurrent hemoptysis. The efficacy of antifungal therapy for CPA varies, with itraconazole reported to be 43-76%, voriconazole 32-80%, posaconazole 44-61%, isavuconazole 82.7%, echinocandins 42-77%, and liposomal amphotericin B 52-73%. Combinatorial treatments such as bronchoscopic triazole administration, inhalation, or direct injection of amphotericin B at the site of infection also show efficacy. A treatment duration of more than 6 months is recommended, with better efficacy reported for periods of more than 1 year. In anticipation of improvements in CPA management, ongoing advances in basic and clinical research are expected to contribute to the future of CPA management.

Pathogenicity and virulence of Aspergillus fumigatus

Pulmonary infections caused by the mould pathogen Aspergillus fumigatus are a major cause of morbidity and mortality globally. Compromised lung defences arising from immunosuppression, chronic respiratory conditions or more recently, concomitant viral or bacterial pulmonary infections are recognised risks factors for the development of pulmonary aspergillosis. In this review, we will summarise our current knowledge of the mechanistic basis of pulmonary aspergillosis with a focus on emerging at-risk populations.

Poorly controlled asthma - Easy wins and future prospects for addressing fungal allergy

Poorly controlled asthma is especially common in low resource countries. Aside from lack of access to, or poor technique with, inhaled beta-2 agonists and corticosteroids, the most problematic forms of asthma are frequently associated with both fungal allergy and exposure, especially in adults leading to more asthma exacerbations and worse asthma. The umbrella term 'fungal asthma' describes many disorders linked to fungal exposure and/or allergy to fungi. One fungal asthma endotype, ABPA, is usually marked by a very high IgE and its differential diagnosis is reviewed. Both ABPA and fungal bronchitis in bronchiectasis are marked by thick excess airway mucus production. Dermatophyte skin infection can worsen asthma and eradication of the skin infection improves asthma. Exposure to fungi in the workplace, home and schools, often in damp or water-damaged buildings worsens asthma, and remediation improves symptom control and reduces exacerbations. Antifungal therapy is beneficial for fungal asthma as demonstrated in nine of 13 randomised controlled studies, reducing symptoms, corticosteroid need and exacerbations while improving lung function. Other useful therapies include azithromycin and some biologics approved for the treatment of severe asthma. If all individuals with poorly controlled and severe asthma could be 'relieved' of their fungal allergy and infection through antifungal therapy without systemic corticosteroids, the health benefits would be enormous and relatively inexpensive, improving the long term health of over 20 million adults and many children. Antifungal therapy carries some toxicity, drug interactions and triazole resistance risks, and data are incomplete. Here we summarise what is known and what remains uncertain about this complex topic.

GEMA 5.3. Spanish Guideline on the Management of Asthma

The Spanish Guideline on the Management of Asthma, better known by its acronym in Spanish GEMA, has been available for more than 20 years. Twenty-one scientific societies or related groups both from Spain and internationally have participated in the preparation and development of the updated edition of GEMA, which in fact has been currently positioned as the reference guide on asthma in the Spanish language worldwide. Its objective is to prevent and improve the clinical situation of people with asthma by increasing the knowledge of healthcare professionals involved in their care. Its purpose is to convert scientific evidence into simple and easy-to-follow practical recommendations. Therefore, it is not a monograph that brings together all the scientific knowledge about the disease, but rather a brief document with the essentials, designed to be applied quickly in routine clinical practice. The guidelines are necessarily multidisciplinary, developed to be useful and an indispensable tool for physicians of different specialties, as well as nurses and pharmacists. Probably the most outstanding aspects of the guide are the recommendations to: establish the diagnosis of asthma using a sequential algorithm based on objective diagnostic tests; the follow-up of patients, preferably based on the strategy of achieving and maintaining control of the disease; treatment according to the level of severity of asthma, using six steps from least to greatest need of pharmaceutical drugs, and the treatment algorithm for the indication of biologics in patients with severe uncontrolled asthma based on phenotypes. And now, in addition to that, there is a novelty for easy use and follow-up through a computer application based on the chatbot-type conversational artificial intelligence (ia-GEMA).

Aspergillus colonisation in severe community-acquired pneumonia: not just a mere colonisation

In patients with severe community-acquired pneumonia, detection of Aspergillus is associated with a mortality rate surpassing 50%, irrespective of whether it is defined as invasion or colonisation https://bit.ly/46PMk1f.

Allergic bronchopulmonary aspergillosis: A multidisciplinary review

Allergic bronchopulmonary aspergillosis (ABPA) is a rare disease characterized by a complex allergic inflammatory reaction of airways against Aspergillus affecting patients with chronic respiratory diseases (asthma, cystic fibrosis). Exacerbation is often the way to diagnose ABPA and marks its evolution by its recurrent character leading to cortico-requirement or long-term antifungal treatment. Early diagnosis allows treatment of ABPA at an initial stage, preventing recurrence of exacerbations and long-term complications, mainly represented by bronchiectasis. This review of the literature aims to present the current state of the art in terms of diagnosis and treatment of ABPA from a multidisciplinary perspective. As there is no clinical, biological nor radiological specific sign, diagnostic criteria are regularly revised. They are mainly based on the elevation of total and specific IgE against Aspergillus fumigatus and the presence of suggestive CT abnormalities such as mucoid impaction and consolidations. ABPA management includes eviction of mold and pharmacological therapy. Exacerbations are treated in first line with a moderate dose of oral corticosteroids. Azole antifungal agents represent an alternative for the treatment of exacerbations and are the preferential strategy to reduce the future risk of exacerbations and for corticosteroids sparing. Asthma biologics may be of interest; however, their place remains to be determined. Avoiding complications of ABPA while limiting the side effects of systemic drugs remains a major challenge of ABPA management. Several drugs, including new antifungals and asthma biologics, are currently being tested and may be useful in the future.

Lung microbiota and potential treatment of respiratory diseases

The unique microbiome found in the lungs has been studied and shown to be associated with both pulmonary homeostasis and lung diseases. The lung microbiome has the potential to produce metabolites that modulate host-microbe interactions. Specifically, short-chain fatty acids (SCFAs) produced by certain strains of the lung microbiota have been shown to regulate immune function and maintain gut mucosal health. In response, this review described the distribution and composition of the microbiota in lung diseases and discussed the impact of the lung microbiota on health and lung disease. In addition, the review further elaborated on the mechanism of microbial metabolites in microbial-host interaction and their application in the treatment of lung diseases. A better understanding of the interaction between the microbiota, metabolites, and host will provide potential strategies for the development of novel methods for the treatment of pulmonary microbial induced lung diseases.

Coincidence of Candida Endophthalmitis, and Aspergillus and Pneumocystis jirovecii Pneumonia in a COVID-19 Patient: Case Report

INTRODUCTION

Coronavirus disease 2019 (COVID-19) is associated with immune system dysfunction and makes patients vulnerable to opportunistic infections. This report presents a patient with a history of COVID-19, suffering from opportunistic infections.

CASE DESCRIPTION

We reported a 64-year-old man complaining of progressive visual loss in his left eye, who had previously been hospitalized for three weeks due to COVID-19. In the ophthalmologic assessment, large foci of dense subretinal and intraretinal infiltrations involving the macula were observed (compatible with endogenous fungal endophthalmitis). Real-time PCR result of intraocular fluid was positive for Candida spp. During subsequent hospitalization, the patient also suffered from fever and productive coughs (manifestations of pneumonia caused by Aspergillus fumigatus and Pneumocystis jirovecii). In response to antibiotic therapy, the fever and coughs subsided, and the ocular examination revealed a dramatic decrease in the size of retinal infiltrations.

CONCLUSIONS

In patients with severe COVID-19, long-term ICU admission and immunosuppressive drugs lead to immune system dysfunction and make the patient more susceptible to opportunistic infections. Consequently, fungal pathogens such as Aspergillus, Pneumocystis jirovecii, and Candida spp. may cause infection in different body organs. Thus, clinicians should be alert and have clinical suspicion to diagnose accurately and manage patients accordingly.

Validity of Platelia Aspergillus IgG and Aspergillus Precipitin Test To Distinguish Pulmonary Aspergillosis from Colonization

When Aspergillus, an ubiquitous, saprophytic fungus, is detected in respiratory tract specimens collected from chronic respiratory disease patients, it is important to determine whether it is a true infection or colonization. We investigated the usefulness of the Bio-Rad Platelia Aspergillus IgG (Platelia Aspergillus IgG) enzyme-linked immunosorbent assay (ELISA) method and the Aspergillus precipitin test to distinguish pulmonary aspergillosis from colonization. Between January 2017 and November 2021, 51 confirmed, untreated pulmonary aspergillosis (33 chronic pulmonary aspergillosis [CPA] and 18 allergic bronchopulmonary aspergillosis [ABPA]) and 77 colonization patients were included in this study. At first, the conventional cutoff value was utilized in assessing the validity of the two antibody tests for distinguishing pulmonary aspergillosis from colonization. The Platelia Aspergillus IgG cutoff value was then reevaluated to fit this situation. Finally, differences in test accuracy dependent on Aspergillus species were assessed for both antibody tests by comparing cases with Aspergillus fumigatus complex and those with non-fumigatus Aspergillus complex. Both antibody tests demonstrated significantly higher positive rates for pulmonary aspergillosis (P < 0.0001) than colonization. The cutoff value should be 15.7 arbitrary units (AU)/mL to best distinguish infection from colonization, which was higher than the conventional value of 10 AU/mL. The diagnostic sensitivity of Platelia Aspergillus IgG for the non-fumigatus Aspergillus complex was inferior to the A. fumigatus complex (P = 0.019). In conclusion, both Aspergillus antibody tests were valid to distinguish infection from colonization, although we should note the higher cutoff value for Platelia Aspergillus IgG and the lower sensitivity in cases of non-fumigatus Aspergillus infection. IMPORTANCE Pulmonary aspergillosis is the most common pulmonary fungal infection. However, Aspergillus is a ubiquitous, saprophytic fungus; it can be detected in respiratory specimens even in the absence of infection. Especially since Aspergillus is detected in respiratory specimens collected from patients with chronic respiratory disease, it is important to determine whether it is true infection or colonization. We investigated the validity of the Platelia Aspergillus IgG ELISA method and the Aspergillus precipitin test to distinguish pulmonary aspergillosis from colonization. Both antibody tests were considered useful in differentiating true infection from colonization in respiratory practice. The appropriate cutoff value for Platelia Aspergillus IgG was higher than the conventional value, and it was also noted that the sensitivity of both antibody tests for non-fumigatus Aspergillus complex was low. This study will be significant in real-world clinical practice of pulmonary aspergillosis using antibody tests in respiratory care.

Invasive Pulmonary Aspergillosis: Not Only a Disease Affecting Immunosuppressed Patients

Fungal infections have become a common threat in Intensive Care Units (ICU). The epidemiology of invasive fungal diseases (IFD) has been extensively studied in patients severely immunosuppressed over the last 20-30 years, however, the type of patients that have been admitted to hospitals in the last decade has made the healthcare system and ICU a different setting with more vulnerable hosts. Patients admitted to an ICU tend to have older age and higher severity of disease. Moreover, the number of patients being treated in ICU are often immunosuppressed as a result of the widespread use of immunomodulatory agents, such as corticosteroids, chemotherapy, and biological agents. The development of Invasive Pulmonary aspergillosis (IPA) reflects a different clinical trajectory to affected patients. The increasing use of corticosteroids would probably explain the higher incidence of IPA especially in critically ill patients. In refractory septic shock, severe community-acquired pneumonia (SCAP), and acute respiratory distress syndrome (ARDS), the use of corticosteroids has re-emerged in order to decrease unacceptably high mortality rates associated with these clinical conditions. It is also pertinent to note that different reports have used different diagnosis criteria, and this might explain the different incidence rates. Another layer of complexity to better understand current IPA data is related to more aggressive acquisition of samples through invasive respiratory examinations.

The clinical significance of Aspergillus-positive respiratory samples

BACKGROUND

Aspergilli moulds are frequently detected in sputum and other respiratory samples. It is not known what the significance of these findings is, or how to differentiate contamination, temporary or persistent colonisation from clinical infection when Aspergilli are found in respiratory samples.

OBJECTIVES

In this study we studied the clinical significance of Aspergillus findings from respiratory samples.

METHODS

We retrospectively evaluated 299 patients who had provided Aspergillus-positive respiratory samples in 2007-2016, which provided a follow-up time of 3-13 years. Data were collected from laboratory registry and Helsinki University Hospital medical records. Underlying diseases, immunosuppression, reasons for sample collection, clinical significance of positive Aspergillus culture, antifungal medication, and patient survival were assessed.

RESULTS

Underlying pulmonary disease had 88% of patients, most commonly asthma (44%), bronchiectasis (30%) or COPD (21%). Corticosteroids (orally or inhalation therapy) prior to positive samples used 78%; the use of corticosteroids did not explain the development of Aspergillus disease. Pulmonary disease caused by Aspergillus was identified in 88 (29%) of the reviewed patients; remaining samples did not represent clinical disease. Chronic cavitary or fibrosing pulmonary aspergillosis (CCPA or CFPA) had 44 (49%) of the diseased. The probability of Aspergillus disease increased when Aspergillus-positive samples were given repeatedly within 1 year (p = .001). Mortality for all reasons was 45%. The repeated positive samples did not predict survival (p = .084), but the diagnosis of CPA did (p < .001).

CONCLUSIONS

The possibility of Aspergillus disease increases when Aspergilli are found repeatedly, collection of samples should be repeated due to method insensitivity. Diagnosis of CPA predicted significantly lower survival.

Upper respiratory tract mycobiome alterations in different kinds of pulmonary disease

Introduction

The human respiratory tract is considered to be a polymicrobial niche, and an imbalance in the microorganism composition is normally associated with several respiratory diseases. In addition to the well-studied bacteriome, the existence of fungal species in the respiratory tract has drawn increasing attention and has been suggested to have a significant clinical impact. However, the understanding of the respiratory fungal microbiota (mycobiome) in pulmonary diseases is still insufficient.

Methods

In this study, we investigated the fungal community composition of oropharynx swab (OS) samples from patients with five kinds of pulmonary disease, including interstitial lung disease (ILD), bacterial pneumonia (BP), fungal pneumonia (FP), asthma (AS) and lung cancer (LC), and compared them with healthy controls (HCs), based on high-throughput sequencing of the amplified fungal internal transcribed spacer (ITS) region.

Results

The results showed significant differences in fungal composition and abundance between disease groups and HCs. Malassezia was the most significant genus, which was much more abundant in pulmonary diseases than in the control. In addition, many common taxa were shared among different disease groups, but differences in taxa abundance and specific species in distinct disease groups were also observed. Based on linear discriminant analysis effect size (LefSe), each group had its characteristic species. Furthermore, some species showed a significant correlation with the patient clinical characteristics.

Discussion

Our study deepened our understanding of the respiratory tract mycobiome in some diseases that are less studied and identified the commonalities and differences among different kinds of pulmonary disease. These results would provide the solid basis for further investigation of the association between the mycobiome and pathogenicity of pulmonary diseases.

Effect of Flagellin Pre-Exposure on the Inflammatory and Antifungal Response of Bronchial Epithelial Cells to Fungal Pathogens

Bronchial epithelial cells (BEC) play a crucial role in innate immunity against inhaled fungi. Indeed, in response to microorganisms, BEC synthesize proinflammatory cytokines involved in the recruitment of neutrophils. We have recently shown that BEC exert antifungal activity against Aspergillus fumigatus by inhibiting filament growth. In the present study, we first analyzed the inflammatory and antifungal responses of BEC infected by several fungal species such as Aspergillus spp., Scedosporium apiospermum and Candida albicans, which are frequently isolated from the sputum of people with chronic pulmonary diseases. The airways of these patients, such as people with cystic fibrosis (pwCF), are mainly colonized by P. aeruginosa and secondary by fungal pathogens. We have previously demonstrated that BEC are capable of innate immune memory, allowing them to increase their inflammatory response against A. fumigatus following a previous contact with Pseudomonas aeruginosa flagellin. To identify the impact of bacteria exposure on BEC responses to other fungal infections, we extended the analysis of BEC innate immune memory to Aspergillus spp., Scedosporium apiospermum and Candida albicans infection. Our results show that BEC are able to recognize and respond to Aspergillus spp., S. apiospermum and C. albicans infection and that the modulation of BEC responses by pre-exposure to flagellin varies according to the fungal species encountered. Deepening our knowledge of the innate immune memory of BEC should open new therapeutic avenues to modulate the inflammatory response against polymicrobial infections observed in chronic pulmonary diseases such as CF.

Mortality and lung function decline in patients who develop chronic pulmonary aspergillosis after lung cancer surgery

BACKGROUND

Lung cancer surgery is reported as a risk factor for chronic pulmonary aspergillosis (CPA). However, limited data are available on its clinical impact. We aimed to determine the effect of developed CPA after lung cancer surgery on mortality and lung function decline.

METHODS

We retrospectively identified the development of CPA after lung cancer surgery between 2010 and 2016. The effect of CPA on mortality was evaluated using multivariable Cox proportional hazard analyses. The effect of CPA on lung function decline was evaluated using multiple linear regression analyses.

RESULTS

During a median follow-up duration of 5.01 (IQR, 3.41-6.70) years in 6777 patients, 93 developed CPA at a median of 3.01 (IQR, 1.60-4.64) years. The development of CPA did not affect mortality in multivariable analysis. However, the decline in forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV₁) were greater in patients with CPA than in those without (FVC, - 71.0 [- 272.9 to - 19.4] vs. - 10.9 [- 82.6 to 57.9] mL/year, p < 0.001; FEV₁, - 52.9 [- 192.2 to 3.9] vs. - 20.0 [- 72.6 to 28.6] mL/year, p = 0.010). After adjusting for confounding factors, patients with CPA had greater FVC decline (β coefficient, - 103.6; 95% CI - 179.2 to - 27.9; p = 0.007) than those without CPA. However, the FEV₁ decline (β coefficient, - 14.4; 95% CI - 72.1 to 43.4; p = 0.626) was not significantly different.

CONCLUSION

Although the development of CPA after lung cancer surgery did not increase mortality, the impact on restrictive lung function deterioration was profound.

Higher risk for influenza-associated pulmonary aspergillosis (IAPA) in asthmatic patients: A Swiss multicenter cohort study on IAPA in critically ill influenza patients

BACKGROUND

Influenza-associated pulmonary aspergillosis (IAPA) is an important complication of severe influenza with high morbidity and mortality.

METHODS

We conducted a retrospective multicenter study in tertiary hospitals in Switzerland during 2017/2018 and 2019/2020 influenza seasons. All adults with PCR-confirmed influenza infection and treatment on intensive-care unit (ICU) for >24 h were included. IAPA was diagnosed according to previously published clinical, radiological, and microbiological criteria. We assessed risk factors for IAPA and predictors for poor outcome, which was a composite of in-hospital mortality, ICU length of stay ≥7 days, mechanical ventilation ≥7 days, or extracorporeal membrane oxygenation.

RESULTS

One hundred fifty-eight patients (median age 64 years, 45% females) with influenza were included, of which 17 (10.8%) had IAPA. Asthma was more common in IAPA patients (17% vs. 4% in non-IAPA, P = 0.05). Asthma (OR 12.0 [95% CI 2.1-67.2]) and days of mechanical ventilation (OR 1.1 [1.1-1.2]) were associated with IAPA. IAPA patients frequently required organ supportive therapies including mechanical ventilation (88% in IAPA vs. 53% in non-IAPA, P = 0.001) and vasoactive support (75% vs. 45%, P = 0.03) and had more complications including ARDS (53% vs. 26%, P = 0.04), respiratory bacterial infections (65% vs. 37%, P = 0.04), and higher ICU-mortality (35% vs. 16.4%, P = 0.05). IAPA (OR 28.8 [3.3-253.4]), influenza A (OR 3.3 [1.4-7.8]), and higher SAPS II score (OR 1.07 [1.05-1.10]) were independent predictors of poor outcome.

INTERPRETATION

High clinical suspicion, early diagnostics, and therapy are indicated in IAPA because of high morbidity and mortality. Asthma is likely an underappreciated risk factor for IAPA.

The Toll pathway mediates Drosophila resilience to Aspergillus mycotoxins through specific Bomanins

Host defense against infections encompasses both resistance, which targets microorganisms for neutralization or elimination, and resilience/disease tolerance, which allows the host to withstand/tolerate pathogens and repair damages. In Drosophila, the Toll signaling pathway is thought to mediate resistance against fungal infections by regulating the secretion of antimicrobial peptides, potentially including Bomanins. We find that Aspergillus fumigatus kills Drosophila Toll pathway mutants without invasion because its dissemination is blocked by melanization, suggesting a role for Toll in host defense distinct from resistance. We report that mutants affecting the Toll pathway or the 55C Bomanin locus are susceptible to the injection of two Aspergillus mycotoxins, restrictocin and verruculogen. The vulnerability of 55C deletion mutants to these mycotoxins is rescued by the overexpression of Bomanins specific to each challenge. Mechanistically, flies in which BomS6 is expressed in the nervous system exhibit an enhanced recovery from the tremors induced by injected verruculogen and display improved survival. Thus, innate immunity also protects the host against the action of microbial toxins through secreted peptides and thereby increases its resilience to infection.

Breathing can be dangerous: Opportunistic fungal pathogens and the diverse community of the small mammal lung mycobiome

Human lung mycobiome studies typically sample bronchoalveolar lavage or sputum, potentially overlooking fungi embedded in tissues. Employing ultra-frozen lung tissues from biorepositories, we obtained fungal ribosomal RNA ITS2 sequences from 199 small mammals across 39 species. We documented diverse fungi, including common environmental fungi such as Penicillium and Aspergillus, associates of the human mycobiome such as Malassezia and Candida, and others specifically adapted for lungs (Coccidioides, Blastomyces, and Pneumocystis). Pneumocystis sequences were detected in 83% of the samples and generally exhibited phylogenetic congruence with hosts. Among sequences from diverse opportunistic pathogens in the Onygenales, species of Coccidioides occurred in 12% of samples and species of Blastomyces in 85% of samples. Coccidioides sequences occurred in 14 mammalian species. The presence of neither Coccidioides nor Aspergillus fumigatus correlated with substantial shifts in the overall mycobiome, although there was some indication that fungal communities might be influenced by high levels of A. fumigatus. Although members of the Onygenales were common in lung samples (92%), they are not common in environmental surveys. Our results indicate that Pneumocystis and certain Onygenales are common commensal members of the lung mycobiome. These results provide new insights into the biology of lung-inhabiting fungi and flag small mammals as potential reservoirs for emerging fungal pathogens.

Telomere-to-telomere genome sequence of the model mould pathogen Aspergillus fumigatus

The pathogenic fungus Aspergillus fumigatus is a major etiological agent of fungal invasive and chronic diseases affecting tens of millions of individuals worldwide. Draft genome sequences of two clinical isolates (Af293 and A1163) are commonly used as reference genomes for analyses of clinical and environmental strains. However, the reference sequences lack coverage of centromeres, an accurate sequence for ribosomal repeats, and a comprehensive annotation of chromosomal rearrangements such as translocations and inversions. Here, we used PacBio Single Molecule Real-Time (SMRT), Oxford Nanopore and Illumina HiSeq sequencing for de novo genome assembly and polishing of two laboratory reference strains of A. fumigatus, CEA10 (parental isolate of A1163) and its descendant A1160. We generated full length chromosome assemblies and a comprehensive telomere-to-telomere coverage for CEA10 and near complete assembly of A1160 including ribosomal repeats and the sequences of centromeres, which we discovered to be composed of long transposon elements. We envision these high-quality reference genomes will become fundamental resources to study A. fumigatus biology, pathogenicity and virulence, and to discover more effective treatments against diseases caused by this fungus.

The fungus Aspergillus fumigatus causes invasive and chronic diseases worldwide. Here, Bowyer et al. use long-read and short-read sequencing to generate complete chromosome assemblies and telomere-to-telomere coverage for two isolates, thus providing high-quality reference genomes as fundamental resources to study this pathogen.

Novel Treatment Approach for Aspergilloses by Targeting Germination

Germination of conidia is an essential process within the Aspergillus life cycle and plays a major role during the infection of hosts. Conidia are able to avoid detection by the majority of leukocytes when dormant. Germination can cause severe health problems, specifically in immunocompromised people. Aspergillosis is most often caused by Aspergillus fumigatus (A. fumigatus) and affects neutropenic patients, as well as people with cystic fibrosis (CF). These patients are often unable to effectively detect and clear the conidia or hyphae and can develop chronic non-invasive and/or invasive infections or allergic inflammatory responses. Current treatments with (tri)azoles can be very effective to combat a variety of fungal infections. However, resistance against current azoles has emerged and has been increasing since 1998. As a consequence, patients infected with resistant A. fumigatus have a reported mortality rate of 88% to 100%. Especially with the growing number of patients that harbor azole-resistant Aspergilli, novel antifungals could provide an alternative. Aspergilloses differ in defining characteristics, but germination of conidia is one of the few common denominators. By specifically targeting conidial germination with novel antifungals, early intervention might be possible. In this review, we propose several morphotypes to disrupt conidial germination, as well as potential targets. Hopefully, new antifungals against such targets could contribute to disturbing the ability of Aspergilli to germinate and grow, resulting in a decreased fungal burden on patients.

Increased susceptibility of irradiated mice to Aspergillus fumigatus infection via NLRP3/GSDMD pathway in pulmonary bronchial epithelia

Background

Aspergillus fumigatus infection is difficult to diagnose clinically and can develop into invasive pulmonary aspergillosis, which has a high fatality rate. The incidence of Aspergillus fumigatus infection has increased die to widespread application of radiotherapy technology. However, knowledge regarding A. fumigatus infection following radiation exposure is limited, and the underlying mechanism remains unclear. In this study, we established a mouse model to explore the effect of radiation on A. fumigatus infection and the associated mechanisms.

Methods

In this study, a mouse model of A. fumigatus infection after radiation was established by irradiating with 5 Gy on the chest and instilling 5 × 10⁷/ml Aspergillus fumigatus conidia into trachea after 24 h to explore the effect and study its function and mechanism. Mice were compared among the following groups: normal controls (CON), radiation only (RA), infection only (Af), and radiation + infection (RA + Af). Staining analyses were used to detect infection and damage in lung tissues. Changes in protein and mRNA levels of pyroptosis-related molecules were assessed by western blot analysis and quantitative reverse transcription polymerase chain reaction, respectively. Protein concentrations in the serum and alveolar lavage fluid were also measured. An immunofluorescence colocalization analysis was performed to confirm that NLRP3 inflammasomes activated pyroptosis.

Results

Radiation destroyed the pulmonary epithelial barrier and significantly increased the pulmonary fungal burden of A. fumigatus. The active end of caspase-1 and gasdermin D (GSDMD) were highly expressed even after infection. Release of interleukin-18 (IL-18) and interleukin-1β (IL-1β) provided further evidence of pyroptosis. NLRP3 knockout inhibited pyroptosis, which effectively attenuated damage to the pulmonary epithelial barrier and reduced the burden of A. fumigatus.

Conclusions

Our findings indicated that the activation of NLRP3 inflammasomes following radiation exposure increased susceptibility to A. fumigatus infection. Due to pyroptosis in lung epithelial cells, it resulted in the destruction of the lung epithelial barrier and further damage to lung tissue. Moreover, we found that NLRP3 knockout effectively inhibited the pyroptosis and reducing susceptibility to A. fumigatus infection and further lung damage. Overall, our results suggest that NLRP3/GSDMD pathway mediated-pyroptosis in the lungs may be a key event in this process and provide new insights into the underlying mechanism of infection.

Inhaled antifungal therapy: benefits, challenges, and clinical applications

INTRODUCTION

Disease due to pulmonary infection with Aspergillus, and other emerging opportunistic fungi remains a significant unmet need. Existing antifungal medicines are predominantly dosed either orally or systemically, but because of limited exposure to the lung lumen, adverse events, and problematic drug-drug interactions, inhaled treatment could provide an attractive option.

AREA COVERED

This review summarizes 1) the limitations of current antifungal therapy, 2) the beneficial effects of inhaled antifungal agents, 3) the clinical development of inhaled antifungal triazoles (repurposed with an innovative inhalation system or a novel inhaled agent) for the treatment of pulmonary fungal infections, and 4) the difficulties and challenges of inhaled antifungal agent development. Regrettably, details of novel inhaled devices or formulations were not covered.

EXPERT OPINION

Inhaled antifungal treatment could provide an attractive option by shifting the risk benefit ratio of treatment favorably. Preclinical and clinical studies with inhaled antifungal agents (off-label use) are encouraging so far. New inhaled antifungal triazoles are well tolerated in early clinical studies and warrant further clinical development. However, challenges remain and many unaddressed issues including required preclinical studies, appropriate clinical design, pharmacokinetics, delivery system(s) and regulatory process need to be resolved. Early communication with regulatory authorities is therefore recommended.

Entzündliche und infektiöse Erkrankungen der Lunge und Pleura bei Kindern und Jugendlichen

Entzündliche Erkrankungen der Lunge und Pleura bei Kindern und Jugendlichen umfassen ein weites Spektrum von der komplizierten Pneumonie, der Tuberkulose, Mykosen bis hin zur Echinokokkose. Die Häufigkeit hängt stark von der geografischen Herkunft ab. Diese Übersichtsarbeit gibt einen Überblick von der Diagnostik bis hin zur chirurgischen Therapie dieser Erkrankungen beim pädiatrischen Kollektiv.

Invasive mould infections in patients from floodwater-damaged areas after hurricane Harvey - a closer look at an immunocompromised cancer patient population

OBJECTIVES

Extensive floodwater damage following hurricane Harvey raised concerns of increase in invasive mould infections (IMIs), especially in immunocompromised patients. To more comprehensively characterize the IMI landscape pre- and post-Harvey, we used a modified, less restrictive clinical IMI (mcIMI) definition by incorporating therapeutic-intent antifungal drug prescriptions combined with an expanded list of host and clinical features.

METHODS

We reviewed 103 patients at MD Anderson Cancer Center (Houston, Texas), who lived in Harvey-affected counties and had mould-positive cultures within 12 months pre-/post-Harvey (36 and 67 patients, respectively). Cases were classified as proven or probable IMI (EORTC/MSG criteria), mcIMI, or colonization/contamination. We also compared in-hospital mortality and 42- day survival outcomes of patients with mcIMI pre-/post-Harvey.

RESULTS

The number of patients with mould- positive cultures from Harvey-affected counties almost doubled from 36 pre- Harvey to 67 post- Harvey (p < 0.01). In contrast, no significant changes in (mc)IMI incidence post-Harvey nor changes in the aetiological mould genera were noted. However, patients with mcIMIs from flood affected areas had significantly higher in-hospital mortality (p = 0.01).

CONCLUSIONS

We observed increased colonization but no excess cases of (mc)IMIs in immunosuppressed cancer patients from affected areas following a large flooding event such as hurricane Harvey.

Performance of the Euroimmun Aspergillus Antigen ELISA for the Diagnosis of Invasive Pulmonary Aspergillosis in Bronchoalveolar Lavage Fluid

Invasive pulmonary aspergillosis (IPA) is a life-threatening disease that affects mainly immunocompromised hosts. Galactomannan testing from serum and bronchoalveolar lavage fluid (BALF) represents a cornerstone in diagnosing the disease. Here, we evaluated the diagnostic performance of the novel Aspergillus-specific galactomannoprotein (GP) enzyme-linked immunosorbent assay (ELISA; Euroimmun Medizinische Labordiagnostika) compared with the established Platelia Aspergillus GM ELISA (GM; Bio-Rad Laboratories) for the detection of Aspergillus antigen in BALF. Using the GP ELISA, we retrospectively tested 115 BALF samples from 115 patients with clinical suspicion of IPA and GM analysis ordered in clinical routine. Spearman's correlation statistics and receiver operating characteristics (ROC) curve analysis were performed. Optimal cutoff values were determined using Youden's index. Of 115 patients, 1 patient fulfilled criteria for proven IPA, 42 for probable IPA, 15 for putative IPA, 10 for possible IPA, and 47 did not meet criteria for IPA. Sensitivities and specificities for differentiating proven/probable/putative versus no IPA (possible excluded) were 74% and 96% for BALF GP and 90% and 96% for BALF GM at the manufacturer-recommended cutoffs. Using the calculated optimal cutoff value of 12 pg/mL, sensitivity and specificity of the BALF GP were 90% and 96%, respectively. ROC curve analysis showed an area under the curve (AUC) of 0.959 (95% confidence interval [CI] of 0.923 to 0.995) for the GP ELISA and an AUC of 0.960 (95% CI of 0.921 to 0.999) for the GM ELISA for differentiating proven/probable/putative IPA versus no IPA. Spearman's correlation analysis showed a strong correlation between the ELISAs (rho = 0.809, P < 0.0001). The GP ELISA demonstrated strong correlation and test performance similar to that of the GM ELISA and could serve as an alternative test for BALF from patients at risk for IPA.

Characteristics and Outcomes of Patients with Invasive Pulmonary Aspergillosis and Respiratory Tract Aspergillus Colonization from a Tertiary University Hospital in Thailand

Positive culture for Aspergillus spp. from respiratory specimens needs to be interpreted together with relevant clinical conditions/settings to differentiate invasive infection from colonization. In this study, we aimed to investigate the association between positive culture for Aspergillus spp. from respiratory specimens and the presence of invasive pulmonary aspergillosis. Hospitalized patients with positive culture for Aspergillus spp. from any respiratory sample were retrospectively recruited. Patients were classified into two groups: those with invasive pulmonary aspergillosis and those with non-invasive aspergillosis/colonization. Two hundred and forty-one patients (48.1% male; mean age: 59.8 ± 14.5 years) were included. The most common Aspergillus spp. was A. fumigatus (21.0%). The most common underlying condition was chronic lung disease (23.7%), followed by solid tumor (22.4%). Myeloproliferative disease (aOR: 69.2, 95% CI: 2.4–1991.9), neutropenia ≥ 10 days (aOR: 31.8; 95% CI: 1.10–920.53), and corticosteroid treatment (aOR: 42.8, 95% CI: 6.5–281.3) were independent predictors of the invasive form. Chronic lung disease was independently inversely related to invasive form (OR: 0.04; 95% CI: 0.003–0.49). Serum galactomannan was positive in 69.2% of patients with invasive aspergillosis (OR: 25.9, 95% CI: 5.2–127.8). All inappropriately treated patients with invasive form died. In conclusion, positive culture for Aspergillus spp. from respiratory specimens with coexisting myeloproliferative disease, neutropenia ≥ 10 days, corticosteroid treatment, or positive serum galactomannan is highly suggestive of invasive pulmonary aspergillosis.

Recent Advances in Fungal Infections: From Lung Ecology to Therapeutic Strategies With a Focus on Aspergillus spp

Fungal infections are estimated to be the main cause of death for more than 1.5 million people worldwide annually. However, fungal pathogenicity has been largely neglected. This is notably the case for pulmonary fungal infections, which are difficult to diagnose and to treat. We are currently facing a global emergence of antifungal resistance, which decreases the chances of survival for affected patients. New therapeutic approaches are therefore needed to face these life-threatening fungal infections. In this review, we will provide a general overview on respiratory fungal infections, with a focus on fungi of the genus Aspergillus. Next, the immunological and microbiological mechanisms of fungal pathogenesis will be discussed. The role of the respiratory mycobiota and its interactions with the bacterial microbiota on lung fungal infections will be presented from an ecological perspective. Finally, we will focus on existing and future innovative approaches for the treatment of respiratory fungal infections.

Aspergillus-related lung disease in people with cystic fibrosis: can imaging help us to diagnose disease?

In people with cystic fibrosis (PwCF), viscous sputum and dysfunction of the mucociliary escalator leads to early and chronic infections. The prevalence of Aspergillus fumigatus in sputum is high in PwCF and the contribution of A. fumigatus to the progression of structural lung disease has been reported. However, overall, relatively little is known about the contribution of A. fumigatus to CF lung disease. More knowledge is needed to aid clinical decisions on whether to start antifungal treatment. In this review, we give an overview of A. fumigatus colonisation and infection in PwCF and the different types of pulmonary disease caused by it. Furthermore, we discuss the current evidence for structural lung damage associated with A. fumigatus in PwCF on chest computed tomography and magnetic resonance imaging. We conclude that radiological outcomes to identify disease caused by A. fumigatus can be important for clinical studies and management.

First Case Report of Aspergillary Rhinopharyngitis in a Foal From Chile

We present the first case of rhinopharyngitis due to Aspergillus fumigatus in a purebred Chilean horse. Clinically, manifested mucopurulent discharge from both nostrils, inflammation of the nasal, ocular, and ear mucosa; associated with decay and hyporexia. Based on the clinical signs and analysis of the mycological and molecular transtracheal aspirate sample, the present case was diagnosed as Aspergillus fumigatus rhinopharyngitis. After the antifungal susceptibility test, oral itraconazole treatment was maintained for 45 days, showing no clinical sign.

Differences in the clinical characteristics of chronic pulmonary aspergillosis according to spirometric impairment

The clinical features by declining lung function remain uncharacterized in chronic pulmonary aspergillosis (CPA) patients. We investigated the clinical characteristics of CPA patients based on spirometric impairments (restrictive spirometric pattern [RSP] and obstructive spirometric pattern [OSP]) and their severity. We retrospectively analyzed medical records of CPA patients who underwent pulmonary function tests from March 2017 to February 2020. We used Global Lung Initiative 2012 equations with lower limit of normal. The clinical characteristics of patients with RSP were compared to those with OSP. Additionally, RSP patients’ characteristics were analyzed according to forced vital capacity (FVC) tertile, and OSP patients’ characteristics were analyzed according to forced expiratory volume in 1 second (FEV₁) tertile. Among the 112 patients with CPA (52 [46%] with RSP and 60 [54%] with OSP), body mass index (BMI) was significantly lower in patients with RSP than in those with OSP (17.6 kg/m² versus 20.3 kg/m²; P = 0.003), and non-tuberculous mycobacterial disease was more frequently observed in patients with RSP than in those with OSP (28.8% versus 11.7%; P = 0.004). Additionally, for patients with RSP, younger age and bilateral pulmonary lesions were more frequently observed in the first tertile group than in the other groups (P for trend: 0.025 and 0.001, respectively). For patients with OSP, low BMI, paracavitary infiltrates, and elevated WBC count were more frequently observed in the first tertile group than in the other groups (P for trend: < 0.001, 0.011, and 0.041, respectively). Differences in the clinical features of CPA patients were identified according to heterogeneous spirometric patterns and their severity. Further studies are needed to investigate the clinical significance of these findings.

Prevalence of Fungal and Bacterial Co-Infection in Pulmonary Fungal Infections: A Metagenomic Next Generation Sequencing-Based Study

With the widespread use of antibacterial drugs and increasing number of immunocompromised patients, pulmonary fungal infections are becoming more common. However, the incidence of pulmonary fungal and bacterial co-infection is rarely reported. In this study, 119 patients definitively diagnosed with pulmonary fungal infections between July 2018 and March 2020 were assessed using metagenomic next-generation sequencing (mNGS) as well as traditional pathogen detection to gauge the incidence of fungal and bacterial co-infection and evaluate the associated risk factors. We found that of the 119 patients with fungal infections, 48 (40.3%) had pulmonary fungal and bacterial co-infection. We identified immunocompromised status and the presence of one or more pulmonary cavities as risk factors associated with fungal and bacterial co-infection. The most commonly isolated fungi species were Aspergillus, Pneumocystis, and Rhizopus. The most commonly isolated bacterial species were Pseudomonas aeruginosa, Acinetobacter baumannii, and Stenotrophomonas maltophilia. Seventy-nine (66.4%) patients had received empirical antibiotic treatment before their pathogenic test results became available, and 41.7% (fungal infection group) and 38.7% (fungal and bacterial co-infection group) of the patients had their antibacterial drug dosage changed accordingly. This mNGS-based study showed that the incidence of fungal and bacterial co-infection is significant. Our research outcomes can, thus, guide the use of antibacterial drugs in the treatment of clinical fungal infections.

Hsp90 interaction networks in fungi-tools and techniques

Heat-shock protein 90 (Hsp90) is a central regulator of cellular proteostasis. It stabilizes numerous proteins that are involved in fundamental processes of life, including cell growth, cell-cycle progression and the environmental response. In addition to stabilizing proteins, Hsp90 governs gene expression and controls the release of cryptic genetic variation. Given its central role in evolution and development, it is important to identify proteins and genes that interact with Hsp90. This requires sophisticated genetic and biochemical tools, including extensive mutant collections, suitable epitope tags, proteomics approaches and Hsp90-specific pharmacological inhibitors for chemogenomic screens. These usually only exist in model organisms, such as the yeast Saccharomyces cerevisiae. Yet, the importance of other fungal species, such as Candida albicans and Cryptococcus neoformans, as serious human pathogens accelerated the development of genetic tools to study their virulence and stress response pathways. These tools can also be exploited to map Hsp90 interaction networks. Here, we review tools and techniques for Hsp90 network mapping available in different fungi and provide a summary of existing mapping efforts. Mapping Hsp90 networks in fungal species spanning >500 million years of evolution provides a unique vantage point, allowing tracking of the evolutionary history of eukaryotic Hsp90 networks.

Review of current and future therapeutics in ABPA

Allergic bronchopulmonary aspergillosis is an allergic pulmonary condition caused by hypersensitivity to antigens of Aspergillus sp. found most commonly in patients with underlying asthma or cystic fibrosis. Host factors which alter the innate and adaptive immune responses to this abundant airborne fungus contribute to the development of chronic airway inflammation, bronchiectasis, and fibrosis. Traditionally, treatment has focussed on reducing fungal burden and immune response to fungal antigens. However, a significant proportion of patients continue to suffer recurrent exacerbations with progressive lung damage, and the side effect burden of existing treatments is high. New treatments including novel antifungal agents, monoclonal antibodies against aspects of the adaptive immune response as well as targeted immunotherapies may be better tolerated and achieve improved outcomes but have not yet been studied in large-scale randomised control trials.

Practice Guidelines for the Diagnosis of COVID-19-Associated Pulmonary Aspergillosis in an Intensive Care Setting

Coronavirus disease-2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) is a new disease characterized by secondary Aspergillus mold infection in patients with COVID-19. It primarily affects patients with COVID-19 in critical state with acute respiratory distress syndrome, requiring intensive care and mechanical ventilation. CAPA has a higher mortality rate than COVID-19, posing a serious threat to affected individuals. COVID-19 is a potential risk factor for CAPA and has already claimed a massive death toll worldwide since its outbreak in December 2019. Its second wave is currently progressing towards a peak, while the third wave of this devastating pandemic is expected to follow. Therefore, an early and accurate diagnosis of CAPA is of utmost importance for effective clinical management of this highly fatal disease. However, there are no uniform criteria for diagnosing CAPA in an intensive care setting. Therefore, based on a review of existing information and our own experience, we have proposed new criteria in the form of practice guidelines for diagnosing CAPA, focusing on the points relevant for intensivists and pulmonary and critical care physicians. The main highlights of these guidelines include the role of CAPA-appropriate test specimens, clinical risk factors, computed tomography of the thorax, and non-culture-based indirect and direct mycological evidence for diagnosing CAPA in the intensive care unit. These guidelines classify the diagnosis of CAPA into suspected, possible, and probable categories to facilitate clinical decision-making. We hope that these practice guidelines will adequately address the diagnostic challenges of CAPA, providing an easy-to-use and practical algorithm to clinicians for rapid diagnosis and clinical management of the disease.

Aspergillus fumigatus and aspergillosis: From basics to clinics

The airborne fungus Aspergillus fumigatus poses a serious health threat to humans by causing numerous invasive infections and a notable mortality in humans, especially in immunocompromised patients. Mould-active azoles are the frontline therapeutics employed to treat aspergillosis. The global emergence of azole-resistant A. fumigatus isolates in clinic and environment, however, notoriously limits the therapeutic options of mould-active antifungals and potentially can be attributed to a mortality rate reaching up to 100 %. Although specific mutations in CYP 51A are the main cause of azole resistance, there is a new wave of azole-resistant isolates with wild-type CYP 51A genotype challenging the efficacy of the current diagnostic tools. Therefore, applications of whole-genome sequencing are increasingly gaining popularity to overcome such challenges. Prominent echinocandin tolerance, as well as liver and kidney toxicity posed by amphotericin B, necessitate a continuous quest for novel antifungal drugs to combat emerging azole-resistant A. fumigatus isolates. Animal models and the tools used for genetic engineering require further refinement to facilitate a better understanding about the resistance mechanisms, virulence, and immune reactions orchestrated against A. fumigatus. This review paper comprehensively discusses the current clinical challenges caused by A. fumigatus and provides insights on how to address them.

Chronic pulmonary aspergillosis: prevalence, favouring pulmonary diseases and prognosis

Chronic pulmonary aspergillosis (CPA) is an emerging disease in patients with common chronic pulmonary diseases (CPDs). While its prevalence is linked to tuberculosis (TB) in endemic countries, epidemiological and prognostic data are lacking in low TB incidence countries. The aim of this study was to describe these features in CPA patients hospitalised in France between 2009 and 2018.We estimated the prevalence and mortality of hospitalised CPA patients using the French nationwide administrative hospital database. We also assessed the association with CPD, thoracic interventions and malnutrition.From 2009 to 2018, 17 290 patients were hospitalised in France for CPA, with an increasing prevalence during this period. Most patients were male (63.5%) with a median age of 65 years at CPA diagnosis, living in farming regions and large cities. The proportion of underlying chronic obstructive pulmonary disease (COPD) and emphysema during the previous 5 years was 44% and 22%, respectively, whereas it was only 3% for both TB and non-TB mycobacterial (NTM) infections. The mortality rates during the first hospitalisation, at 1 year and at 5 years were 17%, 32% and 45%, respectively. In multivariate analysis, mortality rates were increased in patients aged >65 years, male patients and patients with malnutrition, diabetes or lung cancer history. The risk of mortality in patients with COPD or emphysema was higher than in those with previous mycobacterial lung infection.In France, CPA is an emerging infection commonly associated with non-mycobacterial CPD. This shift in the distribution profile of underlying CPD will likely worsen CPA mortality.

fuPCR as diagnostic method for the detection of rare fungal pathogens, such as Trichosporon, Cryptococcus and Fusarium

Fungal respiratory tract colonisation is a common finding in patients with hematologic neoplasms due to immunosuppression inherent in the diseases and exacerbated by therapy. This greatly increases the risk of fungal infections of the lungs, which is associated with significant mortality. Therefore, reliable diagnostic methods with rapidly available results are needed to administer adequate antifungal therapy.We have established an improved method for fungal DNA extraction and amplification that allows simultaneous detection of fungal families based on a set of multiplexed real time PCR reactions (fuPCR). We analysed respiratory rinses and blood of 94 patients with haematological systemic diseases by fuPCR and compared it with the results of culture and serological diagnostic methods. 40 healthy subjects served as controls.Regarding Candida species, the highest prevalence resulted from microbiological culture of respiratory rinses and from detection of antibodies in blood serum in patients (61% and 47%, respectively) and in the control group (29% and 51%, respectively). Detection of other pathogenic yeasts, such as Cryptococcus and Trichosporon, and moulds, such as Fusarium, was only possible in patients by fuPCR from both respiratory rinses and whole blood and serum. These fungal species were found statistically significantly more frequent in respiratory rinses collected from patients after myeloablative therapy for stem cell transplantation compared to samples collected before treatment (p<<0.05i>).The results show that fuPCR is a valuable complement to culturing and its inclusion in routine mycological diagnostics might be helpful for early detection of pathophysiologically relevant respiratory colonisation for patients with hematologic neoplasms.

LAY ABSTRACT

We validated a set of PCR reactions (fuPCR) for use in routine diagnostic. In contrast to culture and serological methods, only by fuPCR pathogenic yeasts (Cryptococcus and Trichosporon) and moulds (Aspergillus and Fusarium) were detected in respiratory rinses and blood of haematological patients.

Biofilm formation in clinically relevant filamentous fungi: a therapeutic challenge

Biofilms are highly-organized microbial communities attached to a biotic or an abiotic surface, surrounded by an extracellular matrix secreted by the biofilm-forming cells. The majority of fungal pathogens contribute to biofilm formation within tissues or biomedical devices, leading to serious and persistent infections. The clinical significance of biofilms relies on the increased resistance to conventional antifungal therapies and suppression of the host immune system, which leads to invasive and recurrent fungal infections. While different features of yeast biofilms are well-described in the literature, the structural and molecular basis of biofilm formation of clinically related filamentous fungi has not been fully addressed. This review aimed to address biofilm formation in clinically relevant filamentous fungi.

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.

Nebulized Amphotericin B Dosing Regimen for Aspergillus Prevention After Lung Transplant

OBJECTIVES

Lung transplant guidelines recommend nebulized amphotericin B with or without systemic antifungal agents for fungal prophylaxis. However, amphotericin formulation, dosing, and frequency vary between studies. We assessed the safety and effectiveness of nebulized amphotericin B to prevent Aspergillus infection in 2 regimens, ie, twice daily compared with 3 times daily.

MATERIALS AND METHODS

This was a single-center retrospective cohort study. We included patients at least 14 years old who underwent lung transplant and received nebulized amphotericin B alone or in combination with another antifungal agent either twice daily or 3 times daily. The primary endpoint was the incidence of lung Aspergillus infection, and the secondary endpoints were nebulized amphotericin B side effects and breakthrough Aspergillus infection.

RESULTS

A total of 84 patients were included. The group given nebulized amphotericin twice daily had a higher rate of Aspergillus infection at 17% compared with 4% in the group treated 3 times daily (P = .24). No serious side effects were reported, but coughing and diarrhea were more common in patients who received amphotericin B 3 times daily.

CONCLUSIONS

A systemic antifungal agent combined with nebulized amphotericin either twice or 3 times daily has been effective to prevent Aspergillus infection. Nebulized amphotericin twice daily may be a more viable option to increase a patient's adherence and decrease medication cost and side effects. However, a larger randomized controlled trial is needed to determine the best dosing regimen for nebulized amphotericin B as a fungal prophylaxis after lung transplant.

Aspergillus Species in Lower Respiratory Tract of Hospitalized Patients from Shanghai, China: Species Diversity and Emerging Azole Resistance

Purpose

To investigate species diversity and prevalence of antifungal resistance among clinical isolates of Aspergillus spp. in Shanghai, China.

Patients and Methods

In this study, the Aspergillus spp. isolates were analyzed by multilocus sequence typing (MLST) targeting the internal transcribed spacer (ITS) regions, and partial β-tubulin (BenA) and calmodulin (CaM) genes. The susceptibilities of these isolates to nine antifungal agents were determined according to the protocol in document M38-A3 established by the Clinical and Laboratory Standards Institute (CLSI).

Results

The most common Aspergillus spp. was A. fumigatus (58.2%), followed by the A. flavus complex (23.5%), and A. niger complex (15.3%). Isolates belonging to A. tamarii and A. effusus of the A. flavus complex and A. tubingensis and A. awamori of the A. niger complex were identified. Moreover, several mutations were found in the azole target cyp51A gene (TR₄₆/Y121F/T289A and F46Y, G89G, M172V, N248T and D255E) in azole-resistant isolates of A. fumigatus.

Conclusion

The results of our study revealed a diversity of species in the lower respiratory tract of inpatients in Shanghai and approximately 9% of our isolates were resistant to at least one of the triazole antifungals. Formulation of local treatment strategies to combat emerging azole resistance and species diversity in clinically relevant Aspergillus spp. is needed.

Parasexual recombination enables Aspergillus fumigatus to persist in cystic fibrosis

Aspergillus fumigatus is a saprobic fungus that causes a range of pulmonary diseases, some of which are characterised by fungal persistence such as is observed in cystic fibrosis (CF) patients. Creation of genetic variation is critical for A. fumigatus to adapt to the lung environment, but biofilm formation, especially in CF patients, may preclude mutational supply in A. fumigatus due to its confinement to the hyphal morphotype. We tested our hypothesis that genetic variation is created through parasexual recombination in chronic biofilms by phenotypic and genetic analysis of A. fumigatus isolates cultured from different origins.

As diploids are the hallmark of parasex, we screened 799 A. fumigatus isolates obtained from patients with CF, chronic pulmonary lung disease and acute invasive aspergillosis, and from the environment for spore size. Benomyl sensitivity, nuclear content measurements through fluorescence-activated cell sorting and scanning electron microscopy were used to confirm the diploid state of large size spores. Whole genome sequencing was used to characterise diploid-associated genetic variation.

We identified 11 diploids in isolates recovered from six of 11 (55%) CF patients and from one of 24 (4%) chronic aspergillosis patients, but not in 368 isolates from patients with acute Aspergillus infection and the environment. Diploid formation was associated with accumulation of mutations and variable haploid offspring including a voriconazole-resistant isolate.

Parasexual recombination allows A. fumigatus to adapt and persist in CF patients, and plays a role in azole resistance development. Our findings are highly significant for understanding the genetics and biology of A. fumigatus in the human lung.

Aspergillus fumigatus can undergo parasexual recombination in the lungs of chronically colonised individuals. This is highly relevant, as the parasexual cycle can facilitate genetic variation and, consequently, in-host adaptation.https://bit.ly/3kAtrXd

A Critical Review on Emerging Trends in Dry Powder Inhaler Formulation for the Treatment of Pulmonary Aspergillosis

Pulmonary aspergillosis (PA), a pulmonary fungal infection caused by Aspergillus spp., is a concern for immunocompromised populations. Despite substantial research efforts, conventional treatments of PA using antifungal agents are associated with limitations such as excessive systemic exposure, serious side effects and limited availability of the therapeutics in the lungs for an adequate duration. To overcome the limitations associated with the conventional regimens, pulmonary delivery of antifungal agents has become a focal point of research because of the superiority of local and targeted drug delivery. Dry powder inhalers and nebulized formulations of antifungal agents have been developed and evaluated for their capability to effectively deliver antifungal agents to the lungs. Moreover, progress in nanotechnology and the utilization of nanocarriers in the development of pulmonary delivery formulations has allowed further augmentation of treatment capability and efficiency. Thus, the following review provides an insight into the advantages and therapeutic potential of the utilization of nanocarriers in pulmonary delivery of antifungal agents for the treatment of PA. In addition, discussions on formulation aspects and safety concerns together with the clinical and regulatory aspects of the formulations are presented, which suggest the possibility and desirability of utilization of nanocarriers in the treatment of PA.