Aspergillus colonization in patients with chronic obstructive pulmonary disease

Fungal lung disease

Fungal lung disease encompasses a wide spectrum of organisms and associated clinical conditions, presenting a significant global health challenge. The type and severity of disease are determined by underlying host immunity and infecting fungal strain. The most common group of diseases are associated with the filamentous fungus Aspergillus species and include allergic bronchopulmonary aspergillosis, sensitisation, aspergilloma and chronic and invasive pulmonary aspergillosis. Fungal lung disease remains epidemiologically heterogenous and is influenced by geography, environment and host comorbidities. Diagnostic modalities continue to evolve and now include novel molecular assays and biomarkers; however, persisting challenges include achieving rapid and accurate diagnosis, particularly in resource-limited settings, and in differentiating fungal infection from other pulmonary conditions. Treatment strategies for fungal lung diseases rely mainly on antifungal agents but the emergence of drug-resistant strains poses a substantial global threat and adds complexity to existing therapeutic challenges. Emerging antifungal agents and increasing insight into the lung mycobiome may offer fresh and personalised approaches to diagnosis and treatment. Innovative methodologies are required to mitigate drug resistance and the adverse effects of treatment. This state-of-the-art review describes the current landscape of fungal lung disease, highlighting key clinical insights, current challenges and emerging approaches for its diagnosis and treatment.

Computed Tomography-Based Quantitative Texture Analysis and Gut Microbial Community Signatures Predict Survival in Non-Small Cell Lung Cancer

This study aims to combine computed tomography (CT)-based texture analysis (QTA) and a microbiome-based biomarker signature to predict the overall survival (OS) of immune checkpoint inhibitor (ICI)-treated non-small cell lung cancer (NSCLC) patients by analyzing their CT scans (n = 129) and fecal microbiome (n = 58). One hundred and five continuous CT parameters were obtained, where principal component analysis (PCA) identified seven major components that explained 80% of the data variation. Shotgun metagenomics (MG) and ITS analysis were performed to reveal the abundance of bacterial and fungal species. The relative abundance of Bacteroides dorei and Parabacteroides distasonis was associated with long OS (>6 mo), whereas the bacteria Clostridium perfringens and Enterococcus faecium and the fungal taxa Cortinarius davemallochii, Helotiales, Chaetosphaeriales, and Tremellomycetes were associated with short OS (≤6 mo). Hymenoscyphus immutabilis and Clavulinopsis fusiformis were more abundant in patients with high (≥50%) PD-L1-expressing tumors, whereas Thelephoraceae and Lachnospiraceae bacterium were enriched in patients with ICI-related toxicities. An artificial intelligence (AI) approach based on extreme gradient boosting evaluated the associations between the outcomes and various clinicopathological parameters. AI identified MG signatures for patients with a favorable ICI response and high PD-L1 expression, with 84% and 79% accuracy, respectively. The combination of QTA parameters and MG had a positive predictive value of 90% for both therapeutic response and OS. According to our hypothesis, the QTA parameters and gut microbiome signatures can predict OS, the response to therapy, the PD-L1 expression, and toxicity in NSCLC patients treated with ICI, and a machine learning approach can combine these variables to create a reliable predictive model, as we suggest in this research.

Infection, Allergy, and Inflammation: The Role of Aspergillus fumigatus in Cystic Fibrosis

Aspergillus fumigatus (Af) is a mold frequently detected in airway samples from people with cystic fibrosis (pwCF). Abnormal airway mucus may allow Af to germinate, resulting in airway infection or an allergic response. While Af is known to increase morbidity in pwCF, individual responses and the degree of impact on lung disease vary. Improved approaches to diagnosis, treatment, and prevention of Af, particularly the persistent Af infection, are needed. This update highlights our current understanding of Af pathophysiology in the CF airway, the effects of Af on pwCF, and areas of research needed to improve clinical outcomes.

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.

Assessing Differences between Clinical Isolates of Aspergillus fumigatus from Cases of Proven Invasive Aspergillosis and Colonizing Isolates with Respect to Phenotype (Virulence in Tenebrio molitor Larvae) and Genotype

The fungus Aspergillus fumigatus, the cause of invasive aspergillosis (IA), is a serious risk to transplant patients and those with respiratory diseases. Host immune suppression is considered the most important factor for the development of IA. Less is known about the importance of fungal virulence in the development of IA including the significance of variation between isolates. In this study, isolates of A. fumigatus from cases diagnosed as having proven IA or colonisation (no evidence of IA) were compared in assays to measure isolate virulence. These assays included the measurement of radial growth and protease production on agar, sensitivity to UV light and oxidative stressors, and virulence in Tenebrio molitor (mealworm) larvae. These assays did not reveal obvious differences in virulence between the two groups of isolates; this provided the impetus to conduct genomic analysis. Whole genome sequencing and analysis did not allow grouping into coloniser or IA isolates. However, focused analysis of single nucleotide polymorphisms revealed variation in three putative genes: AFUA_5G09420 (ccg-8), AFUA_4G00330, and AFUA_4G00350. These are known to be responsive to azole exposure, and ccg-8 deletion leads to azole hypersensitivity in other fungi. A. fumigatus virulence is challenging, but the findings of this study indicate that further research into the response to oxidative stress and azole exposure are required to understand the development of IA.

Invasive pulmonary aspergillosis/pseudomonas

A 47-year-old Caucasian man on long-standing antifungal therapy for chronic necrotising aspergillosis and a history of recurrent pseudomonas pneumonias presented to the outpatient pulmonary clinic with dyspnoea and chest discomfort for 3 days. A CT angiography of the chest demonstrated angioinvasion from the previously noted left upper lobe cavitary lesion into the left main pulmonary artery, along with new consolidating lesions. Due to the high risk for massive haemoptysis, he was evaluated by thoracic surgery and underwent a successful left pneumonectomy. As invasive pulmonary aspergillosis is associated with high mortality, surgical intervention should always be considered, especially in those who develop extensive disease, despite being on aggressive antifungal therapy. Though minimally described in literature, invasive pulmonary pseudomonas also carries a high mortality risk. In our patient, cultures from the resected lung only demonstrated Pseudomonas aeruginosa.

Increased Incidence and Associated Risk Factors of Aspergillosis in Patients with Bronchiectasis

There are insufficient data regarding the relationship between non-cystic fibrosis bronchiectasis and incident aspergillosis. We performed a population-based, matched cohort study using data from the Korean National Health Insurance database between 2003 and 2013. The incidence of aspergillosis was 50/100,000 person-years in the bronchiectasis cohort and 11/100,000 person-years in the matched cohort (subdistribution hazard ratio, 4.53; 95% confidence interval (CI), 3.25–6.32). Among the bronchiectasis cohort, chronic obstructive pulmonary disease (adjusted HR, 1.95; 95% CI, 1.07–3.57), previous pulmonary tuberculosis (adjusted HR, 3.67; 95% CI, 2.03–6.64), and non-tuberculous mycobacterial pulmonary disease (adjusted HR, 11.25; 95% CI, 1.49–85.18) increased the risk of incident aspergillosis. The incidence of aspergillosis in patients with bronchiectasis was approximately 4.5-fold that in those without bronchiectasis. Comorbid pulmonary diseases—chronic obstructive pulmonary disease, previous pulmonary tuberculosis, and non-tuberculous mycobacterial pulmonary disease—significantly increased the risk of aspergillosis in patients with bronchiectasis. Our study indicates that close monitoring is warranted for aspergillosis in patients with bronchiectasis.

Investigation of feedstuff contaminated with aflatoxigenic fungi species in the semi-arid region in northeast of Iran

There is a close relationship between human health and the quality of the ration used by domestic animals. Also, molds, like genus of Aspergillus, infect animal and human food products with dangerous toxic substances, i.e., aflatoxins that are causing primary and secondary mycotoxicosis in animals and human. The aim of this study was to compare fungal species that contaminated and produced aflatoxin in livestock and poultry feed in Gonabad that is a semi-arid city in northeast of Iran. Sampling was randomly performed three times from two livestock feed mills and two poultry feed mills during summer and autumn. Samples were cultured in two forms of solid and suspension in Sabouraud dextrose agar with chloramphenicol medium (SC) for 5 days in 28 °C. Microscopic diagnostic test and also molecular diagnostic test were used to determine fungal species in culture based on β-tubulin gene sequencing. A total of 27.25% and 31.7% of two livestock feed and two poultry feed samples were contaminated with Aspergillus, respectively. Aspergillus flavus (n = 4), Aspergillus Fumigatus (n = 2), Aspergillus versicolor (n = 2), Aspergillus niger (n = 2), Aspergillus parasiticus (n = 1), Aspergillus ochraceus (n = 1), and Aspergillus terreus (n = 1) were detected by molecular PCR test. The rate of contamination to genus of Aspergillus in autumn was higher than summer (P value = 0.008). Poultry feed sample showed more contamination to Aspergillus species compared with livestock feed.

Invasive Aspergillosis After Non-Fatal Drowning

Background

Pneumonitis and pneumonia after non-fatal drowning are common and the pathogens involved are numerous. However, invasive aspergillosis after non-fatal drowning in immunocompetent individuals is relatively rare. Here, we report a case of invasive aspergillosis complicated by pulmonary embolism after non-fatal drowning that proved fatal.

Case Presentation

A 75-year-old Japanese man accidentally fell into a creek and was brought to a local hospital. His oxygenation steadily deteriorated to the point that he required intubation and mechanical ventilation. He was then transferred to the emergency department at our hospital. On arrival, he had severe respiratory dysfunction with diminished breath sounds. Radiography of the chest and computed tomography of the lungs showed diffuse bilateral infiltrates. The diagnosis was acute respiratory distress syndrome caused by aspiration pneumonitis as a result of non-fatal drowning and septic shock. Despite intensive care, the patient’s hypoxia continued to worsen and he died on day 7. Computed tomography scans obtained at autopsy showed that both lungs were extensively infiltrated with effusion. An embolus was also detected in the right pulmonary artery. Microscopic analysis revealed diffuse filamentous fungi throughout the lungs, heart, stomach, thyroid gland, and the pulmonary embolus, which were identified as Aspergillus fumigatus by culture.

Conclusion

Invasive aspergillosis should also be considered in immunocompetent patients with severe respiratory failure after non-fatal drowning who do not respond to broad-spectrum antibiotics. Angioinvasive aspergillosis can even result in fatal pulmonary embolism; hence, early targeted testing for Aspergillus species and empiric intravenous voriconazole should be considered in such cases.

Blood Aspergillus PCR: The Good, the Bad, and the Ugly

Invasive Aspergillosis (IA) is one of the most common invasive fungal diseases and is accompanied by high morbidity and mortality. In order to maximize patient outcomes and survival, early and rapid diagnosis has been shown to be pivotal. Hence, diagnostic tools aiding and improving the diagnostic process are ambitiously searched for. In this context, polymerase chain reaction (PCR) may represent a potential candidate. Its additional value and benefits in diagnosis have been demonstrated and are scientifically established. Nevertheless, standardized and widespread usage is sparse because several factors influence diagnostic quality and need to be considered in order to optimize diagnostic performance and outcome. In the following review, the current role of PCR in the diagnosis of IA is explored, with special focus on the strengths and limitations of PCR in different settings.

How Environmental Fungi Cause a Range of Clinical Outcomes in Susceptible Hosts

Environmental fungi are globally ubiquitous and human exposure is near universal. However, relatively few fungal species are capable of infecting humans, and among fungi, few exposure events lead to severe systemic infections. Systemic infections have mortality rates of up to 90%, cost the US healthcare system $7.2 billion annually, and are typically associated with immunocompromised patients. Despite this reputation, exposure to environmental fungi results in a range of outcomes, from asymptomatic latent infections to severe systemic infection. Here we discuss different exposure outcomes for five major fungal pathogens: Aspergillus, Blastomyces, Coccidioides, Cryptococcus, and Histoplasma species. These fungi include a mold, a budding yeast, and thermal dimorphic fungi. All of these species must adapt to dramatically changing environments over the course of disease. These dynamic environments include the human lung, which is the first exposure site for these organisms. Fungi must defend themselves against host immune cells while germinating and growing, which risks further exposing microbe-associated molecular patterns to the host. We discuss immune evasion strategies during early infection, from disruption of host immune cells to major changes in fungal cell morphology.

A Higher Rate of Pulmonary Fungal Infection in Chronic Obstructive Pulmonary Disease Patients with Influenza in a Large Tertiary Hospital

BACKGROUND

Influenza is considered a self-limiting disease. However, in patients with chronic obstructive pulmonary disease (COPD), it may result in serious outcomes during the flu season.

OBJECTIVES

The aims of this retrospective study were to explore the characteristics of hospitalized patients with COPD complicated by influenza and determine the factors affecting the prognosis of these patients.

METHOD

Demographic and clinical data were collected for 278 patients totally from the West China Hospital between January 1, 2016 and February 28, 2018.

RESULTS

Among the patients with influenza, the positive fungal culture rate, and the rates of antifungal drug and systemic corticosteroids use were higher for those with COPD than for those without COPD. Respiratory failure was more common in patients with influenza and COPD than in patients with influenza only, while the proportion of severe cases was higher among the former than among the latter. Among the patients with COPD, the positive fungal culture rate, particularly for Aspergillus, and the rate of systemic corticosteroids use were higher for those with influenza than for those without influenza. Multivariate analysis revealed that a COPD history of >20 years and smoking for >20 pack-years were independent factors for susceptibility of COPD patients to influenza.

CONCLUSIONS

Aspergillus infection seems to be more common in patients with influenza and COPD. In addition, COPD complicated by influenza during the seasonal outbreak can easily progress to a severe disease state. Heavy smokers and patients with a prolonged COPD history are more likely to be infected by influenza.

Chronic Pulmonary Aspergillosis in Patients with Underlying Respiratory Disorders in Cuba-A Pilot Study

Chronic pulmonary aspergillosis (CPA) is a fungal infection with high mortality and morbidity rates. This disease is caused by several Aspergillus species and affects patients with an underlying respiratory condition. This pilot study aims to recognize CPA among patients with different respiratory diseases. Twenty-one out of 47 patients were classified as CPA based on the examination of clinical signs and symptoms, radiological findings, mycological culture of respiratory samples and analysis of Aspergillus IgG antibodies. There was a close association between high levels of Aspergillus IgG antibodies and the presence of cavities. Although Aspergillus flavus was the predominant species among clinical isolates, the number of isolates was small to reach conclusions on the prevalence of this species as main cause of CPA in Cuba. From the eleven evaluable patients for the treatment with itraconazole (Lozartil®), nine improved their health status while two did not show any recovery. This drug is included in the therapy schemes for aspergillosis in Cuba.

High burden of Aspergillus fumigatus infection among chronic respiratory diseases

Aspergillus fumigatus (AF) is a ubiquitous fungus in our environment and causes severe airway disorders. Chronic respiratory diseases (CRDs) are a series of chronic airway and lung diseases. Although both are chronic disorders, however, the relationships between AF and CRDs are still unclear. Therefore, we examined 104 Aspergillus species (spp.) isolated samples in our hospital during three consecutive years to further elucidate the relationships between Aspergillus spp. and CRDs. Based on sample isolates, we then grouped these into two groups, AF and non-AF, to retrospectively analyse the clinical features and to clarify the relationships between AF and CRDs. Importantly, the manifestation of CRD was more frequent in the AF group than in the non-AF group (p = 0.035). Among CRDs, lung fibrosis was more evident in the AF group (p = 0.025). Moreover, diabetes mellitus was tended to be evident in AF group than non-AF group (p = 0.035). In conclusion, CRDs, especially lung fibrosis, were highly prevalent in AF group than non-AF group.