Role of molds in farmer's lung disease in Eastern France

Risk of hypersensitivity pneumonitis and other interstitial lung diseases following organic dust exposure

BACKGROUND

Organic dust is associated with hypersensitivity pneumonitis, and associations with other types of interstitial lung disease (ILD) have been suggested. We examined the association between occupational organic dust exposure and hypersensitivity pneumonitis and other ILDs in a cohort study.

METHODS

The study population included all residents of Denmark born in 1956 or later with at least 1 year of gainful employment since 1976. Incident cases of hypersensitivity pneumonitis and other ILDs were identified in the Danish National Patient Register 1994-2015. Job exposure matrices were used to assign individual annual levels of exposure to organic dust, endotoxin and wood dust from 1976 to 2015. We analysed exposure-response relations by different exposure metrics using a discrete-time hazard model.

RESULTS

For organic dust, we observed increasing risk with increasing cumulative exposure with incidence rate ratios (IRR) per 10 unit-years of 1.19 (95% CI 1.12 to 1.27) for hypersensitivity pneumonitis and 1.04 (95% CI 1.02 to 1.06) for other ILDs. We found increasing risk with increasing cumulative endotoxin exposure for hypersensitivity pneumonitis and other ILDs with IRRs per 5000 endotoxin units/m3-years of 1.55 (95% CI 1.38 to 1.73) and 1.09 (95% CI 1.00 to 1.19), respectively. For both exposures, risk also increased with increasing duration of exposure and recent exposure. No increased risks were observed for wood dust exposure.

CONCLUSION

Exposure-response relations were observed between organic dust and endotoxin exposure and hypersensitivity pneumonitis and other ILDs, with lower risk estimates for the latter. The findings indicate that organic dust should be considered a possible cause of any ILD.

TRIAL REGISTRATION NUMBER

j.no.: 1-16-02-196-17.

Japanese clinical practice guide 2022 for hypersensitivity pneumonitis

Considering recently published two guidelines for the diagnosis of hypersensitivity pneumonitis (HP), the Japanese Respiratory Society (JRS) has now published its own Japanese clinical practice guide for HP. Major types of HP in Japan include summer-type, home-related, bird-related, farmer's lung, painter's lung, humidifier lung, and mushroom grower's lung. Identifying causative antigens is critical for increasing diagnostic confidence, as well as improving prognosis through appropriate antigen avoidance. This guide proposes a comprehensive antigen questionnaire including the outbreak sources reported in Japan. Drawing on the 2021 CHEST guideline, this guide highlights the antigen identification confidence level and adaptations for environmental surveys. The detection of specific antibodies against causative antigens is an important diagnostic predictor of HP. In Japan, the assessments of bird-specific IgG (pigeons, budgerigars) and the Trichosporon asahii antibody are covered by medical insurance. Although this guide adopts the 2020 ATS/JRS/ALAT guideline diagnostic criteria based on the combination of imaging findings, exposure assessment, bronchoalveolar lavage lymphocytosis, and histopathological findings, it added some annotations to facilitate the interpretation of the content and correlate the medical situation in Japan. It recommends checking biomarkers; seasonal changes in the KL-6 concentration (increase in winter for bird-related HP/humidifier lung and in summer for summer-type HP) and high KL-6 concentrations providing a basis for the suspicion of HP. Antigen avoidance is critical for disease management of HP. This guide also addresses the pharmacological management of HP, highlighting the treatment strategy for fibrotic HP including combination therapies with anti-inflammatory/immunosuppressive and antifibrotic drugs.

Functional Clustering of Metabolically Related Genes Is Conserved across Dikarya

Transcriptional regulation is vital for organismal survival, with many layers and mechanisms collaborating to balance gene expression. One layer of this regulation is genome organization, specifically the clustering of functionally related, co-expressed genes along the chromosomes. Spatial organization allows for position effects to stabilize RNA expression and balance transcription, which can be advantageous for a number of reasons, including reductions in stochastic influences between the gene products. The organization of co-regulated gene families into functional clusters occurs extensively in Ascomycota fungi. However, this is less characterized within the related Basidiomycota fungi despite the many uses and applications for the species within this clade. This review will provide insight into the prevalence, purpose, and significance of the clustering of functionally related genes across Dikarya, including foundational studies from Ascomycetes and the current state of our understanding throughout representative Basidiomycete species.

Diurnal Variations of Size-Resolved Bioaerosols During Autumn and Winter Over a Semi-Arid Megacity in Northwest China

Bioaerosols have a major negative effect on air quality and on public health by causing the spread of diseases. This study evaluated the bioaerosol composition and variation in a semi-arid megacity of northwest China from October 2019 to January 2020 using an Andersen six-stage impactor sampler. The size distribution, diurnal variations of the concentrations of airborne bacteria, airborne fungi, and total airborne microbes (TAM) were investigated in autumn and winter. The mean concentrations of airborne bacteria, fungi, and TAM were 523.5 ± 301.1 colony-forming units (CFU)/m3, 1318.9 ± 447.8 CFU/m3, and (7.25 ± 1.90) × 106 cells/m3, respectively, in autumn and 581 ± 305.4 CFU/m3, 1234.4 ± 519.9 CFU/m3, and (5.96 ± 1.65) × 106 cells/m3, respectively, in winter. The mean bioaerosol concentrations were slightly higher on nonhaze days than on haze days, but the difference was not statistically significant. Higher ambient particulate matter levels and atmospheric oxidation capacity inhibited bacteria survival. The diurnal maximum bioaerosol concentration was observed in the morning in autumn, whereas in winter, bioaerosols did not exhibit such a distribution, the impact of human activities on bioaerosols was still uncertain. The size of airborne bacteria exhibited a bimodal distribution, whereas a unimodal pattern was observed for fungi and TAM. Most bacteria, fungi, and TAM were distributed in the respirable ranges from trachea and primary bronchi to alveoli, indicating that bioaerosols have a high risk of being inhaled and causing respiratory diseases in Xi'an.

Exposure assessment in hypersensitivity pneumonitis: a comprehensive review and proposed screening questionnaire

Hypersensitivity pneumonitis is an immune-mediated inflammatory lung disease characterised by the inhalation of environmental antigens leading to acute and chronic lung injury. Along with suggestive clinical and radiological findings, history and timing of suspected antigen exposure are important elements for diagnostic confidence. Unfortunately, many diagnoses remain tentative and based on vague and imprecise environmental or material exposure histories. To date, there has not been a comprehensive report highlighting the frequency and type of environmental exposure that might lead to or support a more systematic approach to antigen identification. We performed a comprehensive literature review to identify and classify causative antigens and their associated environmental contexts or source materials, with emphasis on the extent of the supportive literature for each exposure type. Eligible publications were those that reported unique inciting antigens and their respective environments or contexts. A clinical questionnaire was then proposed based on this review to better support diagnosis of hypersensitivity pneumonitis when antigen testing or other clinical and radiological variables are inconclusive or incomplete.

Diagnosis of Hypersensitivity Pneumonitis in Adults. An Official ATS/JRS/ALAT Clinical Practice Guideline

Background: This guideline addresses the diagnosis of hypersensitivity pneumonitis (HP). It represents a collaborative effort among the American Thoracic Society, Japanese Respiratory Society, and Asociación Latinoamericana del Tórax.Methods: Systematic reviews were performed for six questions. The evidence was discussed, and then recommendations were formulated by a multidisciplinary committee of experts in the field of interstitial lung disease and HP using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach.Results: The guideline committee defined HP, and clinical, radiographic, and pathological features were described. HP was classified into nonfibrotic and fibrotic phenotypes. There was limited evidence that was directly applicable to all questions. The need for a thorough history and a validated questionnaire to identify potential exposures was agreed on. Serum IgG testing against potential antigens associated with HP was suggested to identify potential exposures. For patients with nonfibrotic HP, a recommendation was made in favor of obtaining bronchoalveolar lavage (BAL) fluid for lymphocyte cellular analysis, and suggestions for transbronchial lung biopsy and surgical lung biopsy were also made. For patients with fibrotic HP, suggestions were made in favor of obtaining BAL for lymphocyte cellular analysis, transbronchial lung cryobiopsy, and surgical lung biopsy. Diagnostic criteria were established, and a diagnostic algorithm was created by expert consensus. Knowledge gaps were identified as future research directions.Conclusions: The guideline committee developed a systematic approach to the diagnosis of HP. The approach should be reevaluated as new evidence accumulates.

Metagenomic analysis reveals antibiotic resistance genes in the bovine rumen

Metagenomics and network analysis were used to profile antibiotic resistance genes (ARGs) and their cooccurrence patterns in bovine rumen microbes. A total of 4941 ruminal microbial genomes and 20 metagenome samples were used in this study. In general, 103 ARG subtypes belonging to 20 ARG types in 79 candidate genomes were identified, showing the broad-spectrum profiles of ARGs in the bovine rumen environment. A wide distribution of genes encoding bacitracin resistance was found among the candidate genomes, suggesting the possibility that bovines might be one of the sources of bacitracin resistance genes. Cooccurrence patterns were found within or between the ARG types, and a positive correlation was found between some ARGs and bacteria, which revealed potential dominant hosts of ARGs. The investigation showed that bovine rumen systems are important ARG reservoirs, and our research might provide a theoretical basis for the evaluation of the harmfulness of ARGs and antibiotic-resistant bacteria (ARB) to food safety and human health.

Seasonal variations of microbial assemblage in fine particulate matter from a nursery pig house

The microorganisms contained in PM_2.5 from livestock houses can spread over long distances through airborne transmission. As such, the potential bacterial pathogens and fungal allergens within can pose a formidable threat to nearby residents' health and the overall environment. However, little is known about the microbial assemblage contained in PM_2.5 from pig houses. In this study, 16S and 18S rRNA gene sequencing was employed to analyze the bacterial and fungal assemblage contained in PM_2.5 from a nursery pig house across four seasons, respectively. The results showed that alpha diversity was higher in summer and autumn compared to the spring and winter. The bacterial and fungal assemblage varied according to season. At the phylum level, the dominant bacteria and fungi were Firmicutes and Basidiomycota, respectively, across the four seasons. At the genus level, a total of five potential bacterial pathogen and 20 potential fungal allergen genera were identified across the samples. The most abundant bacterial pathogen and fungal allergen genera were observed in summer and autumn, respectively, but neither had a significant correlation with PM_2.5 concentration. Moreover, microbial diversity and the relative abundance of fungal allergen genera were positively correlated with temperature and relative humidity. It can be concluded that microbial diversity and assemblage varied significantly among the seasons in a nursery pig house, and this can be useful in exploring the potential risks of PM_2.5 from pig houses across all four seasons.

PM2.5 from a broiler breeding production system: The characteristics and microbial community analysis

Particulate matter (PM) released from the processes of livestock production has a negative impact on the health of animals and workers. Herein, the concentration, major chemical components, morphology and microbiological compositions of particulate matter 2.5 (PM_2.5, particles with aerodynamic diameter less than 2.5 μm) in a broiler breeding house were investigated. The results showed that the PM_2.5 distribution in the chicken house was affected by the illumination, draught fans, chicken frame structure and activity of the chickens in the broiler breeding house. Component analysis showed that organic carbon (OC) accounted for the largest proportion, and followed by element carbon (EC), SO₄^2-, NO₃^-, NH₄⁺, Na⁺, K⁺ and Ca²⁺. Ultrastructural observations revealed that the shape of PM_2.5 had a round, rectangular, chain-like and irregular shape. The concentration of endotoxin was approximately 0.3 EU/m³. Microbiological analysis showed that at the genus level, the pathogenic bacteria included Staphylococcus, Corynebacterium, Enterococcus, Parabacteroides, Escherichia and Megamonas. The abundant harmful fungi were Aspergillus, Scopulariopsis, Wallemia, and Fusarium. Through redundancy analysis (RDA) analysis, we determined that OC, EC, Na⁺, K⁺, and NH₄⁺ had strong correlations with Brachybacterium, Brevibacterium, Corynebacterium, Escherichia, Scopulariopsis and Microascus. SO₄^2- was closely related to Scopulariopsis and Salinicoccus. Salinicoccus was also strongly correlated with NO₃^-. Our results indicated that feed, faeces, and outside soot are contributed to the increase in PM_2.5 concentration in the chicken house, while the sources of the dominant bacterial and fungi might be feed, faeces, suspended outside soil and cereal crops.

Microbial exposure to dairy farmers' dwellings and COPD occurrence

Dairy farming is a risk factor for chronic obstructive pulmonary disease (COPD). The aim was to determine predictive markers either in blood samples or in dwelling dust samples by comparing COPD and healthy controls with or without farming activity. Dust was collected and analyzed by real-time quantitative PCR. ELISA and DELFIA® were performed to assay the level of specific IgG and IgE of 10 targeted microorganisms. The dwelling exposure of farmers was higher than in the non-farmers (Especially Eurotium amstelodami and Lichtheimia corymbifera). The IgG response against Wallemia sebi and Saccharopolyspora rectivirgula was more often higher in the farmers than the non-farmers. However, exposure and sensitization to the microorganisms tested cannot explain the occurrence of COPD in the dairy farmers' population. COPD development is probably caused by multiple factors associated with exposure over a period of several years.

Hypersensitivity pneumonitis: A new strategy for serodiagnosis and environmental surveys

We propose a strategy for serodiagnosis of hypersensitivity pneumonitis (HP): 1) question patients about their private or occupational activity, or visit him on site; 2) select panels of six somatic specific antigens appropriate for each type of exposure; 3) and use ELISA to test concomitantly two recombinant antigens highly specific to Farmer's lung, Metalworking-fluid HP, and for Bird fancier's lung. The serodiagnosis provides an immunological argument that may complete radiological, functional lung exploration and clinical features; 4) If the serodiagnosis is negative but the suspicion of HP is strong, a microbial analysis of the patient's specific exposure is conducted; 5) "A la carte" antigens are produced from the microorganisms isolated in the patient's environment sample and tested; 6) Finally, the patient may be asked to undergo a specific inhalation challenge with the offending antigens in a safety cabin, or to avoid his usual environment for a few days.

Fungal aerosols at dairy farms using molecular and culture techniques

Occupational exposure to harmful bioaerosols in industrial environments is a real threat to the workers. In particular, dairy-farm workers are exposed to high levels of fungal bioaerosols on a daily basis. Associating bioaerosol exposure and health problems is challenging and adequate exposure monitoring is a top priority for aerosol scientists. Using only culture-based tools does not express the overall microbial diversity and underestimate the large spectrum of microbes in bioaerosols and therefore the extended fungal profile that farmers are exposed to. The aim of this study was to provide an in-depth characterization of fungal exposure at Eastern Canadian dairy farms using qPCR and high-throughput sequencing methods. Specific primers were used for the quantification of Penicillium/Aspergillus and Aspergillus fumigatus in dairy farms air samples. Illumina Miseq sequencing of the ITS1 region provided sequences for the diversity analyses. The minimum and maximum concentration of Penicillium/Aspergillus ranged from 4.6 × 10⁶ to 9.4 × 10⁶ gene copies/m³ and from 1 × 10⁴ gene copies/m³ to 4.8 × 10⁵ gene copies/m³ for Aspergillus fumigatus, respectively. Differences in the diversity profiles of the five dairy farms support the idea that the novel approach identifies a large number of fungal taxa. The most striking differences include Microascus, Piptoporus, Parastagonospora, Dissoconium, Microdochium, Tubilicrinis, Ganoderma, Ustilago, Phlebia and Wickerhamomyces. The presence of a diverse portrait of fungi in air may represent a health risk for workers who are exposed on a daily basis. The broad spectrum of fungi detected in this study includes many known pathogens like Aspergillus, Acremonium, Alternaria and Fusarium. Adequate monitoring of bioaerosol exposure is necessary to evaluate and minimize risks.

Fungal contamination of wind instruments: Immunological and clinical consequences for musicians

INTRODUCTION

Playing a wind instrument is an increasingly reported cause of hypersensitivity pneumonitis. However, current knowledge about contamination of wind instruments by fungi and specific fungal sensitization is scarce. Therefore, we aimed: (i) to assess the current prevalence and type of fungal contamination of wind instruments, (ii) to identify potential risk factors associated with instrument contamination, and (iii) to evaluate the prevalence of sensitization to these fungi among musicians.

MATERIAL AND METHODS

Musicians from music schools in eastern France and who played a wind instrument were prospectively recruited (NCT01487850). The mouthpiece and the reed of their instrument were sampled to quantify the magnitude and type of fungi. Each subject had a physical examination, a mycological analysis of saliva and a blood sample in search of serum precipitins against the most frequent fungi isolated from instruments. The results were compared with those of 40 healthy non-exposed controls.

RESULTS

Forty musicians playing a wind instrument (bassoon, clarinet, oboe, saxophone) were included. (i) 95% of wind instruments were colonized by fungi, mainly with Phoma spp., Penicillium spp. and Rhodotorula mucilaginosa; (ii) absence of systematic drying of the instrument was a main contributing factor; (iii) serum precipitins were significantly more present in the musicians' sera than in control sera and were consistent with the fungi present in their instrument.

CONCLUSION

This study reveals a constant and specific fungal contamination among wind reed instruments with a significant sensitization among musicians, pleading in favour of regular instrument cleaning. Physicians should be aware of this possible source of antigenic exposure.

Species of Aspergillus section Aspergillus from clinical samples in the United States

The diversity of Aspergillus species in clinical samples is continuously increasing. Species under the former name Eurotium, currently accommodated in section Aspergillus of the genus Aspergillus, are xerophilic fungi widely found in the human environment and able to grow on substrates with low water activity. However, their prevalence in the clinical setting is poorly known. We have studied the presence of these species in a set of clinical samples from the United States using a multilocus sequence analysis based on the internal transcribed spacer (ITS) region of the rRNA, and fragments of the genes β-tubulin (BenA), calmodulin (CaM), and polymerase II second largest subunit (RPB2). A total of 25 isolates were studied and identified as follows: A. montevidensis (44%), A. chevalieri (36%), A. pseudoglaucus (8%), and A. costiformis (4%). A new species Aspergillus microperforatus is also proposed, which represented 8% of the isolates studied and is characterized by uniseriate conidial heads, subglobose to pyriform vesicles, rough conidia, globose to subglobose cleistothecia, and lenticular and smooth ascospores. The in vitro antifungal activity of eight clinically available antifungals was also determined against these isolates, with the echinocandins and posaconazole having the most potent activity.

The Genus Wallemia—From Contamination of Food to Health Threat

The fungal genus Wallemia of the order Wallemiales (Wallemiomycotina, Basidiomycota) comprises the most xerotolerant, xerophilic and also halophilic species worldwide. Wallemia spp. are found in various osmotically challenged environments, such as dry, salted, or highly sugared foods, dry feed, hypersaline waters of solar salterns, salt crystals, indoor and outdoor air, and agriculture aerosols. Recently, eight species were recognized for the genus Wallemia, among which four are commonly associated with foods: W. sebi, W. mellicola, W. muriae and W. ichthyophaga. To date, only strains of W. sebi, W. mellicola and W. muriae have been reported to be related to human health problems, as either allergological conditions (e.g., farmer’s lung disease) or rare subcutaneous/cutaneous infections. Therefore, this allergological and infective potential, together with the toxins that the majority of Wallemia spp. produce even under saline conditions, defines these fungi as filamentous food-borne pathogenic fungi.

Differentiated surface fungal communities at point of harvest on apple fruits from rural and peri-urban orchards

The diverse fungal communities that colonize fruit surfaces are closely associated with fruit development, preservation and quality control. However, the overall fungi adhering to the fruit surface and the inference of environmental factors are still unknown. Here, we characterized the fungal signatures on apple surfaces by sequencing internal transcribed spacer 1 (ITS1) region. We collected the surface fungal communities from apple fruits cultivated in rural and peri-urban orchards. A total of 111 fungal genera belonging to 4 phyla were identified, showing remarkable fungal diversity on the apple surface. Comparative analysis of rural samples harboured higher fungal diversity than those from peri-urban orchards. In addition, fungal composition varied significantly across apple samples. At the genus level, the protective genera Coniothyrium, Paraphaeosphaeria and Periconia were enriched in rural samples. The pathogenic genera Acremonium, Aspergillus, Penicillium and Tilletiposis were enriched in peri-urban samples. Our findings indicate that rural samples maintained more diverse fungal communities on apple surfaces, whereas peri-urban-planted apple carried potential pathogenic risks. This study sheds light on ways to improve fruit cultivation and disease prevention practices.

Bioaerosols concentrations in working areas in biomethanization facilities

This study sought to fill the gap in information about the type and the concentration of bioaerosols present in the air of biomethanization facilities (BF). Evaluation of bioaerosol composition and concentration was achieved in two biomethanization facilities located in Eastern Canada, during summer and winter. In order to have a thorough understanding of the studied environment, the methodology combined culture of bacteria and molds, qualitiative polymerase chain reaction (qPCR) for specific microorganisms, endotoxin quantification, and next-generation sequencing (NGS) for bacterial diversity. Results revealed that workers in biomethanization facilities are exposed to bioaerosols and pathogenic microorganisms similar to those found in composting plants. However, human exposure levels to bioaerosols are lower in BF than in composting plants. Despite these differences, use of personal protective equipment is recommended to lower the risks of health problems.

IMPLICATIONS

Biomethanization is a new technology used in eastern Canada for waste management. In the next few years, it is expected that there will be an expansion of facilities in response of tight governmental regulations. Workers in biomethanization facilities are exposed to various amounts of bioaerosols composed of some harmful microorganisms. Therefore, monitoring this occupational exposure could be an interesting tool for improving worker's health.

Granulometry, microbial composition and biological activity of dusts collected in French dairy farms

BACKGROUND

Dairy working increases the prevalence of lower airway respiratory diseases, especially COPD and asthma. Epidemiological studies have reported that chronic inhalation of organic dusts released during specific daily tasks could represent a major risk factor for development of these pathologies in dairy workers. Knowledge on size, nature and biological activity of such organic dusts remain however limited.

OBJECTIVE

To compare size distribution, microbial composition and cellular effects of dusts liberated by the spreading of straw bedding in five French dairy farms located in Brittany.

RESULTS

Mechanized distribution of straw bedding generated a cloud of inhalable dusts in the five dairy farms' barns. Thoracic particles having a 3-7.5µm size constituted 58.9-68.3% of these dusts. Analyses of thoracic dusts by next generation sequencing showed that the microbial dust composition differed between the five French farms, although Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria represent more than 97.5% of the bacterial phyla detected in each sample. Several bacteria genera comprising of human pathogenic species, such as Pseudomonas, Staphylococcus, Thermoactinomyces or Saccharopolyspora were identified. Cladosporium and Alternaria fungal genera, which are potent environmental determinants of respiratory symptoms, were detected in dusts collected in the five farms and their levels reached 15.5-51.1% and 9-24.7% of assignable fungal sequences in each sample, respectively. Finally, all dust samples significantly and strongly increased the expression of the pro-inflammatory TNF-α, IL-1β, IL-6 and IL-8 cytokines at both mRNA and protein levels in human monocyte-derived macrophages. Their effects were dose-dependent and detectable from 1µg/ml. The intensity of the macrophage responses however differed according to the samples.

CONCLUSIONS

Our results strengthen the hypothesis that organic dusts released during the distribution of straw bedding are mainly constituted of thoracic particles which are small enough to deposit on lower bronchial epithelium of dairy farmers and induce inflammation.

Polyphasic taxonomy of Aspergillus section Aspergillus (formerly Eurotium), and its occurrence in indoor environments and food

Aspergillus section Aspergillus (formerly the genus Eurotium) includes xerophilic species with uniseriate conidiophores, globose to subglobose vesicles, green conidia and yellow, thin walled eurotium-like ascomata with hyaline, lenticular ascospores. In the present study, a polyphasic approach using morphological characters, extrolites, physiological characters and phylogeny was applied to investigate the taxonomy of this section. Over 500 strains from various culture collections and new isolates obtained from indoor environments and a wide range of substrates all over the world were identified using calmodulin gene sequencing. Of these, 163 isolates were subjected to molecular phylogenetic analyses using sequences of ITS rDNA, partial β-tubulin (BenA), calmodulin (CaM) and RNA polymerase II second largest subunit (RPB2) genes. Colony characteristics were documented on eight cultivation media, growth parameters at three incubation temperatures were recorded and micromorphology was examined using light microscopy as well as scanning electron microscopy to illustrate and characterize each species. Many specific extrolites were extracted and identified from cultures, including echinulins, epiheveadrides, auroglaucins and anthraquinone bisanthrons, and to be consistent in strains of nearly all species. Other extrolites are species-specific, and thus valuable for identification. Several extrolites show antioxidant effects, which may be nutritionally beneficial in food and beverages. Important mycotoxins in the strict sense, such as sterigmatocystin, aflatoxins, ochratoxins, citrinin were not detected despite previous reports on their production in this section. Adopting a polyphasic approach, 31 species are recognized, including nine new species. ITS is highly conserved in this section and does not distinguish species. All species can be differentiated using CaM or RPB2 sequences. For BenA, Aspergillus brunneus and A. niveoglaucus share identical sequences. Ascospores and conidia morphology, growth rates at different temperatures are most useful characters for phenotypic species identification.

Impact of Mycotoxins Secreted by Aspergillus Molds on the Inflammatory Response of Human Corneal Epithelial Cells

Exposure to molds and mycotoxins not only contributes to the onset of respiratory disease, it also affects the ocular surface. Very few published studies concern the evaluation of the effect of mycotoxin exposure on ocular cells. The present study investigates the effects of aflatoxin B₁ (AFB₁) and gliotoxin, two mycotoxins secreted by Aspergillus molds, on the biological activity of the human corneal epithelial (HCE) cells. After 24, 48, and 72 h of exposure, cellular viability and inflammatory response were assessed. Both endpoint cell viability colorimetric assays and continuous cell impedance measurements, providing noninvasive real-time assessment of the effect on cells, were performed. Cytokine gene expression and interleukin-8 release were quantified. Gliotoxin appeared more cytotoxic than AFB₁ but, at the same time, led to a lower increase of the inflammatory response reflecting its immunosuppressive properties. Real-time cell impedance measurement showed a distinct profile of cytotoxicity for both mycotoxins. HCE cells appeared to be a well-suited in vitro model to study ocular surface reactivity following biological contaminant exposure. Low, but persistent inflammation, caused by environmental factors, such as fungal toxins, leads to irritation and sensitization, and could be responsible for allergic manifestations which, in turn, could lead to mucosal hyper-reactivity.

Emphysema in active farmer's lung disease

BACKGROUND

Farmer's lung (FL) is a common type of hypersensitivity pneumonitis. It is often considered that fibrosis is the most frequent finding in chronic FL. Nevertheless, three cohort studies have suggested that some patients with chronic FL may develop emphysema. We aimed to evaluate the current prevalence of emphysema in active FL, to describe the radiological and functional features of emphysema in active FL, and to identify risk factors associated with emphysema in this population.

METHODS

Patients aged over 18 years with active FL were prospectively recruited through the SOPHIA study (CPP Est; P-2009-521), between 2007 and 2015. Each patient had complete medical history screening, clinical examination, high resolution computed tomodensitometry, bronchoalveolar lavage, pulmonary function tests and serum precipitins.

RESULTS

Among 33 patients with active FL, the prevalence of emphysema in this series of incident active FL cases was higher (48.5%) than that of fibrosis (12%) and was not dependent on smoking habits. Most patients with emphysema did not have lung hyperinflation. The possible risk factors for emphysema in active FL were a longer duration of exposure to organic dusts, and at a higher level.

CONCLUSION

Emphysema is found in half of patients with active FL and may be influenced by exposure patterns.

Fungal peptides from pneumonitis hypersensitivity etiologic agents are able to induce specific cellular immune response

PURPOSE

Hypersensitivity pneumonitis (HP) is an immunoallergic disease due to chronic exposure to high quantities of different microorganisms such as Mycobacterium immunogenum (Mi), a mycobacterium, and Lichtheimia corymbifera (Lc), a filamentous fungus. It has recently been demonstrated that the protein DLDH (dihydrolipoyl dehydrogenase), is common to these microorganisms. This study aimed to investigate the immune potential of overlapping peptide pools covering the MiDLDH and LcDLDH.

EXPERIMENTAL DESIGN

A selection of 34 peptides, from the MiDLDH and LcDLDH, able to interact with Major Histocompatibility Complex (MHC) 1 and MHC 2, was obtained using three different epitope prediction websites. By means of ELISPOT assays, we compared the frequency of Interferon gamma (IFNγ) secreting peripheral blood mononuclear cells (PBMC) after stimulation with overlapping peptide pools. Tests were performed using cells from 35 healthy blood donors.

RESULTS

One peptide pool containing five peptides from MiDLDH and able to interact with MHC 2 induced a marked IFNγ specific immune response (Pool F, p<0.001, Wilcoxon signed-rank test).

CONCLUSION

This study demonstrated that peptides from microorganisms involved in HP were able to induce a high IFNγ specific immune response after stimulation of PBMCs from healthy blood donors which could be useful to develop an effective prevention strategy.

Identification of Antigenic Proteins from Lichtheimia corymbifera for Farmer's Lung Disease Diagnosis

The use of recombinant antigens has been shown to improve both the sensitivity and the standardization of the serological diagnosis of Farmer’s lung disease (FLD). The aim of this study was to complete the panel of recombinant antigens available for FLD serodiagnosis with antigens of Lichtheimia corymbifera, known to be involved in FLD. L. corymbifera proteins were thus separated by 2D electrophoresis and subjected to western blotting with sera from 7 patients with FLD and 9 healthy exposed controls (HEC). FLD-associated immunoreactive proteins were identified by mass spectrometry based on a protein database specifically created for this study and subsequently produced as recombinant antigens. The ability of recombinant antigens to discriminate patients with FLD from controls was assessed by ELISA performed with sera from FLD patients (n = 41) and controls (n = 43) recruited from five university hospital pneumology departments of France and Switzerland. Forty-one FLD-associated immunoreactive proteins from L. corymbifera were identified. Six of them were produced as recombinant antigens. With a sensitivity and specificity of 81.4 and 77.3% respectively, dihydrolipoyl dehydrogenase was the most effective antigen for discriminating FLD patients from HEC. ELISA performed with the putative proteasome subunit alpha type as an antigen was especially specific (88.6%) and could thus be used for FLD confirmation. The production of recombinant antigens from L. corymbifera represents an additional step towards the development of a standardized ELISA kit for FLD diagnosis.

Occupational exposure to mould and microbial metabolites during onion sorting--insights into an overlooked workplace

Manual sorting of onions is known to be associated with a bioaerosol exposure. The study aimed to gain an initial indication as to what extent manual sorting of onions is also associated with mycotoxin exposure. Twelve representative samples of outer onion skins from different onion origins were sampled and analyzed with a multimycotoxin method comprising 40 mycotoxins using a single extraction step followed by liquid chromatography with electrospray ionization and triple quadrupole mass spectrometry. Six of the 12 samples were positive for mycotoxins. In those samples, deoxynivalenol, fumonisin B1, and B2 were observed in quantitatively detectable amounts of 3940 ng/g for fumonisin B1 and in the range of 126-587 ng/g for deoxynivalenol and 55-554 ng/g for fumonisin B2. Although the results point to a lower risk due to mycotoxins, the risk should not be completely neglected and has to be considered in the risk assessment.

Review of bioaerosols in indoor environment with special reference to sampling, analysis and control mechanisms

Several tiny organisms of various size ranges present in air are called airborne particles or bioaerosol which mainly includes live or dead fungi and bacteria, their secondary metabolites, viruses, pollens, etc. which have been related to health issues of human beings and other life stocks. Bio-terror attacks in 2001 as well as pandemic outbreak of flue due to influenza A H1N1 virus in 2009 have alarmed us about the importance of bioaerosol research. Hence characterization i.e. identification and quantification of different airborne microorganisms in various indoor environments is necessary to identify the associated risks and to establish exposure threshold. Along with the bioaerosol sampling and their analytical techniques, various literatures revealing the concentration levels of bioaerosol have been mentioned in this review thereby contributing to the knowledge of identification and quantification of bioaerosols and their different constituents in various indoor environments (both occupational and non-occupational sections). Apart from recognition of bioaerosol, developments of their control mechanisms also play an important role. Hence several control methods have also been briefly reviewed. However, several individual levels of efforts such as periodic cleaning operations, maintenance activities and proper ventilation system also serve in their best way to improve indoor air quality.

A Taxonomic Revision of the Wallemia sebi Species Complex

Wallemia sebi is a xerophilic food- and air-borne fungus. The name has been used for strains that prevail in cold, temperate and tropical climates. In this study, multi-locus phylogenetic analyses, using the internal transcribed spacer (ITS) regions, DNA replication licensing factor (MCM7), pre-rRNA processing protein (TSR1), RNA polymerase II largest subunit (RPB1), RNA polymerase II second largest subunit (RPB2) and a new marker 3´-phosphoadenosine-5´-phosphatase (HAL2), confirmed the previous hypothesis that W. sebi presents a complex of at least four species. Here, we confirm and apply the phylogenetic analyses based species hypotheses from a companion study to guide phenotypic assessment of W. sebi like strains from a wide range of substrates, climates and continents allowed the recognition of W. sebi sensu stricto and three new species described as W. mellicola, W. Canadensis, and W. tropicalis. The species differ in their conidial size, xerotolerance, halotolerance, chaotolerance, growth temperature regimes, extracellular enzyme activity profiles, and secondary metabolite patterns. A key to all currently accepted Wallemia species is provided that allow their identification on the basis of physiological, micromorphological and culture characters.

Application of the phylogenetic species concept to Wallemia sebi from house dust and indoor air revealed by multi-locus genealogical concordance

A worldwide survey of Wallemia occurring in house dust and indoor air was conducted. The isolated strains were identified as W. sebi and W. muriae. Previous studies suggested that the W. sebi phylogenetic clade contained cryptic species but conclusive evidence was lacking because only the internal transcribed spacer (ITS) marker was analyzed. The ITS and four protein-coding genes (MCM7, RPB1, RPB2, and TSR1) were sequenced for 85 isolates. Based on an initial neighbor joining analysis of the concatenated genes, W. muriae remained monophyletic but four clades were found in W. sebi, which we designated as W. sebi clades 1, 2, 3, and 4. We hypothesized that these clades represent distinct phylogenetic species within the Wallemia sebi species complex (WSSC). We then conducted multiple phylogenetic analyses and demonstrated genealogical concordance, which supports the existence of four phylogenetic species within the WSSC. Geographically, W. muriae was only found in Europe, W. sebi clade 3 was only found in Canada, W. sebi clade 4 was found in subtropical regions, while W. sebi clade 1 and 2 were found worldwide. Haplotype analysis showed that W. sebi clades 1 and 2 had multiple haplotypes while W. sebi clades 3 and 4 had one haplotype and may have been under sampled. We describe W. sebi clades 2, 3, and 4 as new species in a companion study.

Working with argan cake: a new etiology for hypersensitivity pneumonitis

Background

Argan is now used worldwide in numerous cosmetic products. Nine workers from a cosmetic factory were examined in our occupational medicine department, following the diagnosis of a case of hypersensitivity pneumonitis (HP) related to handling of argan cakes.

Methods

Operators were exposed to three forms of argan (crude granulates, powder or liquid) depending on the step of the process. All workers systematically completed standardized questionnaires on occupational and medical history, followed by medical investigations, comprising, in particular, physical examination and chest X-rays, total IgE and a systematic screening for specific serum antibodies directed against the usual microbial agents of domestic and farmer’s HP and antigens derived from microbiological culture and extracts of various argan products. Subjects with episodes of flu-like syndrome several hours after handling argan cakes, were submitted to a one-hour challenge to argan cakes followed by physical examination, determination of Carbon Monoxide Diffusing Capacity (DLCO) and chest CT-scan on day 2, and, when necessary, bronchoalveolar lavage on day 4.

Results

Six of the nine workers experienced flu-like symptoms within 8 hours after argan handling. After challenge, two subjects presented a significant decrease of DLCO and alveolitis with mild lymphocytosis, and one presented ground glass opacities. These two patients and another patient presented significant arcs to both granulates and non-sterile powder. No reactivity was observed to sterile argan finished product, antigens derived from argan cultures (various species of Bacillus) and Streptomyces marokkonensis (reported in the literature to contaminate argan roots).

Conclusions

We report the first evidence of hypersensitivity pneumonitis related to argan powder in two patients. This implies preventive measures to reduce their exposure and clinical survey to diagnose early symptoms. As exposure routes are different and antibodies were observed against argan powder and not the sterile form, consumers using argan-based cosmetics should not be concerned.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-015-0013-3) contains supplementary material, which is available to authorized users.

Western blotting as a tool for the serodiagnosis of farmer's lung disease: validation with Lichtheimia corymbifera protein extracts

Electrosyneresis and double diffusion are immunoprecipitation techniques commonly used in the serological diagnosis of Farmer's lung disease (FLD). These techniques are reliable but lack standardization. The aim of this study was to evaluate Western blotting for the serodiagnosis of FLD. We carried out Western blotting with an antigenic extract of Lichtheimia corymbifera, an important aetiological agent of the disease. The membranes were probed with sera from 21 patients with FLD and 21 healthy exposed controls to examine the IgG antibody responses against purified somatic antigens. Given the low prevalence of the disease, 21 patients could be considered as a relevant series. Four bands were significantly more frequently represented in membranes probed with FLD sera (bands at 27.7, 40.5, 44.0 and 50.5 kDa) than those probed with control sera. We assessed the diagnostic value of different criteria alone or in combination. The diagnostic accuracy of the test was highest with the inclusion of at least two of the following criteria: at least five bands on the strip and the presence of one band at 40.5 or 44.0 kDa. Sensitivity, specificity and positive and negative predictive values were all 81%, and the odds ratio was 18.06. Inclusion of bands of high intensity diminished rather than improved the diagnostic value of the test. We concluded that Western blotting is a valuable technique for the serodiagnosis of FLD. The industrial production of ready-to-use membranes would enable the routine use of this technique in laboratories, and provide reliable and standardized diagnostic results within a few hours.

Immunoreactive proteins of Saccharopolyspora rectivirgula for farmer's lung serodiagnosis

PURPOSE

Saccharopolyspora rectivirgula is the principal cause of farmer's lung disease (FLD). Serodiagnosis is based on immunoprecipitation techniques or enzyme immunoassays with homemade crude antigens and is not standardized. We aimed to produce specific recombinant antigens for the development of a standardized ELISA.

EXPERIMENTAL DESIGN

We recruited 41 patients and 43 healthy exposed controls from five university hospital pneumology departments in France and Switzerland. S. rectivirgula proteins were extracted, separated by 2D electrophoresis, and subjected to Western blotting, with sera from FLD patients or controls. FLD-specific proteins were identified by MS and were produced as recombinant antigens. The diagnostic performance of ELISA tests using the recombinant antigens was assessed with all the sera from FLD patients and controls.

RESULTS

We identified 25 FLD-specific proteins, some of which play important roles in transport, nutrition, or virulence. We produced 17 of these proteins as recombinant antigens and assessed their suitability for inclusion in the ELISA test. A combination of three of these proteins (SR1FA, SR17, and SR22) proved remarkably effective at discriminating between patients and controls, with a sensitivity of 83% and a specificity of 77%.

CONCLUSIONS AND CLINICAL RELEVANCE

The recombinant antigens produced in this study constitute a major step toward the improvement of diagnostic performance and the standardization of FLD serodiagnosis.

Extrolites of Wallemia sebi, a very common fungus in the built environment

Wallemia sebi has been primarily known as a spoilage fungus of dried, salted fish and other foods that are salty or sweet. However, this fungus is also very common in house dust. The health effects of chronic exposure to mold and dampness are known to be associated with both allergens and various inflammatory compounds, including the secondary metabolites of building associated fungi and their allergens. IgE sensitization to W. sebi has been long reported from housing and occupational exposures. However, its allergens have not been described previously. Strains from food have been reported to produce a number of compounds with modest toxicity. Strains from the built environment in Canada produced a number of metabolites including the known compound walleminone and a new compound 1-benzylhexahydroimidazo [1,5-α] pyridine-3,5-dione which we call wallimidione. Based on an in silico analysis, wallimidione is likely the most toxic of the metabolites reported to date from W. sebi. We found that the primary human antigen of W. sebi is a 47 kDa excreted cellulase present in high concentrations in W. sebi arthrospores. This species is a basidiomycete and, unsurprisingly, the antigen was not found in extracts of other fungi common in the built environment, all ascomycetes.

Mucormycoses caused by Lichtheimia species

Mucormycoses are life-threatening infections with fungi from the order Mucorales (Mucoromycotina). Although mucormycoses are uncommon compared to other fungal infections, e.g. aspergillosis and candidiasis, the number of cases is increasing especially in immunocompromised patients. Lichtheimia (formerly Absidia) species represent the second to third most common cause of mucormycoses in Europe. This mini review presents current knowledge about taxonomy and clinical relevance of Lichtheimia species. In addition, clinical presentation and risk factors will be discussed. Proper animal infection models are essential for the understanding of the pathogenesis and the identification of virulence factors of fungal pathogens. To date, several animal models have been used to study Lichtheimia infection. A brief overview of the different models and the main conclusions from the infection experiments is summarised in this review.

External validation of recombinant antigens for serodiagnosis of machine operator's lung

BACKGROUND

Machine operator's lung (MOL) is a hypersensitivity pneumonitis the diagnosis of which is difficult. Our laboratory previously developed an ELISA test using recombinant antigens from Mycobacterium immunogenum isolated in French plant. The objective was to validate the previous ELISA results with ten new suspected cases from Germany.

METHODS

Two serological analyses were performed: ELISA with the six recombinant antigens, and electrosyneresis with crude antigens of M. immunogenum and three other main species isolated from contaminated metalworking fluids.

RESULTS

The two recombinant antigens acyl-CoA dehydrogenase and dihydrolipoyl dehydrogenase, combined together, and electrosyneresis are useful in making the diagnosis regardless of the clinical and radiological data. Finally 9 out of the 10 suspected cases were declared as MOL.

CONCLUSIONS

Despite the geographical distance, the crude and recombinant antigens produced to investigate the clustered French cases also proved to be useful in diagnosing the suspected cases in Germany.

First report of mycophenolic acid production by Eurotium repens isolated from agricultural and indoor environments

Mycophenolic acid is considered as an immunosuppressive pharmaceutical drug, but also as a mycotoxin due to its undesirable presence in various feedstuffs. Although Penicillium brevicompactum has been historically identified as the major producer of mycophenolic acid, this study reports for the first time the production of mycophenolic acid by isolates of Eurotium repens collected from agricultural and indoor environments. Fungal identification was achieved by scanning electron microscopy and molecular techniques, and mycophenolic acid production was confirmed by two analytical methods (gas and liquid chromatography coupled to mass spectrometry). These findings suggest that mycophenolic acid production and immunosuppressive properties of other closely related Eurotium should be evaluated in future studies.

Internal transcribed spacer rRNA gene sequencing analysis of fungal diversity in Kansas City indoor environments

Compared to traditional methods of fungal exposure assessment, molecular methods have provided new insight into the richness of fungal communities present in both indoor and outdoor environments. In this study, we describe the diversity of fungi in the homes of asthmatic children located in Kansas City. Fungal diversity was determined by sequencing the internal transcribed spacer (ITS) regions of ribosomal RNA derived from fungi collected in air and dust samples from 31 homes participating in the Kansas City Safe and Healthy Homes Program (KCSHHP). Sequencing results were then compared to data obtained using viable and non-viable fungal exposure assessment methods. ITS clone libraries were predominantly derived from the phylum Ascomycota in both air (68%) and dust (92%) samples and followed by the Basidiomycota and Zygomycota. The majority of Ascomycota clones belonged to four orders including the Pleosporales, Eurotiales, Capnodiales, and Dothideales. ITS sequencing revealed the presence of a number of rarely documented fungal species placed in the Pleosporales. Several species placed in the Basidiomycota were detected in ITS clone libraries but not by viable or non-viable methods. The prevalence of organizational taxonomic units (OTUs) was significantly higher in air than in dust samples (p < 0.0001); however, no differences between OTUs in air samples collected in the subjects' room and basement were observed. These sequencing results demonstrate a much broader diversity of Ascomycota and Basidiomycota communities in KCSHHP indoor environments than previously estimated using traditional methods of assessment.

[Hypersensitivity pneumonitis related to Penicillium chrysogenum and mesophilic Streptomyces: the usefulness of the Medical Indoor Environment Councelor (MIEC)]

Hypersensitivity pneumonitis (HP) occurred after organic antigens inhalation at home is rare and the diagnosis is very often difficult. We report the case of a 55-year male patient with allergic asthma since childhood, well controlled with inhaled corticosteroids, twice hospitalized for respiratory distresses. The patient presented fever (39°C), dry cough, rapidly progressive dyspnea, chest pain and crackles. Blood gas analysis found a hypoxemia of 52 mmHg, and CT-scan showed ground glass images in the upper lobes. Respiratory function tests showed severe obstructive syndrome and a decrease of diffusion test. HP was suspected because the symptoms were triggered by domestic environmental. The Medical Indoor Environment Councelor (MIEC) visited the patient's house and camper and performed air and dust samples. Moldy walnuts were found in the camper. The identification of microorganisms present in the air and on the surfaces in the camper was used for serum precipitins research by double diffusion (DD) and electrosyneresis (E) methods. From the 14 antigens tested, serological tests were considered significant for mesophilic Streptomyces (five arcs DD, six arcs E) and Penicillium chrysogenum (one arc DD, four arcs E). After removal from the camper of the objects suspected to be contaminated, the patient's symptoms regressed. This is a typical case of domestic HP to mesophilic Streptomyces and P. chrysogenum. The MIEC's intervention was useful in both diagnosis and treatment.

Human monocyte-derived dendritic cells exposed to microorganisms involved in hypersensitivity pneumonitis induce a Th1-polarized immune response

Hypersensitivity pneumonitis (HP) is an immunoallergic disease characterized by a prominent interstitial infiltrate composed predominantly of lymphocytes secreting inflammatory cytokines. Dendritic cells (DCs) are known to play a pivotal role in the lymphocytic response. However, their cross talk with microorganisms that cause HP has yet to be elucidated. This study aimed to investigate the initial interactions between human monocyte-derived DCs (MoDCs) and four microorganisms that are different in nature (Saccharopolyspora rectivirgula [actinomycetes], Mycobacterium immunogenum [mycobacteria], and Wallemia sebi and Eurotium amstelodami [filamentous fungi]) and are involved in HP. Our objectives were to determine the cross talk between MoDCs and HP-causative agents and to determine whether the resulting immune response varied according to the microbial extract tested. The phenotypic activation of MoDCs was measured by the increased expression of costimulatory molecules and levels of cytokines in supernatants. The functional activation of MoDCs was measured by the ability of MoDCs to induce lymphocytic proliferation and differentiation in a mixed lymphocytic reaction (MLR). E. amstelodami-exposed (EA) MoDCs expressed higher percentages of costimulatory molecules than did W. sebi-exposed (WS), S. rectivirgula-exposed (SR), or M. immunogenum-exposed (MI) MoDCs (P < 0.05, Wilcoxon signed-rank test). EA-MoDCs, WS-MoDCs, SR-MoDCs, and MI-MoDCs induced CD4(+) T cell proliferation and a Th1-polarized immune response. The present study provides evidence that, although differences were initially observed between MoDCs exposed to filamentous fungi and MoDCs exposed to bacteria, a Th1 response was ultimately promoted by DCs regardless of the microbial extract tested.

Indoor fungal contamination: health risks and measurement methods in hospitals, homes and workplaces

Indoor fungal contamination has been associated with a wide range of adverse health effects, including infectious diseases, toxic effects and allergies. The diversity of fungi contributes to the complex role that they play in indoor environments and human diseases. Molds have a major impact on public health, and can cause different consequences in hospitals, homes and workplaces. This review presents the methods used to assess fungal contamination in these various environments, and discusses advantages and disadvantages for each method in consideration with different health risks. Air, dust and surface sampling strategies are compared, as well as the limits of various methods are used to detect and quantify fungal particles and fungal compounds. In addition to conventional microscopic and culture approaches, more recent chemical, immunoassay and polymerase chain reaction (PCR)-based methods are described. This article also identifies common needs for future multidisciplinary research and development projects in this field, with specific interests on viable fungi and fungal fragment detections. The determination of fungal load and the detection of species in environmental samples greatly depend on the strategy of sampling and analysis. Quantitative PCR was found useful to identify associations between specific fungi and common diseases. The next-generation sequencing methods may afford new perspectives in this area.

Quantitative polymerase chain reaction detection of circulating DNA in serum for early diagnosis of mucormycosis in immunocompromised patients

BACKGROUND

The aim of our study was to assess the detection of circulating DNA from the most common species of Mucorales for early diagnosis of mucormycosis in at-risk patients.

METHODS

We retrospectively evaluated a combination of 3 quantitative polymerase chain reaction (qPCR) assays using hydrolysis probes targeting Mucor/Rhizopus, Lichtheimia (formerly Absidia), and Rhizomucor for circulating Mucorales detection. Serial serum samples from 10 patients diagnosed with proven mucormycosis (2-9 samples per patient) were analyzed.

RESULTS

No cross-reactivity was detected in the 3 qPCR assays using 19 reference strains of opportunistic fungi, and the limit of detection ranged from 3.7 to 15 femtograms/10 µL, depending on the species. DNA from Mucorales was detected in the serum of 9 of 10 patients between 68 and 3 days before mucormycosis diagnosis was confirmed by histopathological examination and/or positive culture. All the qPCR results were concordant with culture and/or PCR-based identification of the causing agents in tissue (Lichtheimia species, Rhizomucor species, and Mucor/Rhizopus species in 4, 3, and 2 patients, respectively). Quantitative PCR was negative in only 1 patient with proven disseminated mucormycosis caused by Lichtheimia species.

CONCLUSION

Our study suggests that using specific qPCR targeting several species of Mucorales according to local ecology to screen at-risk patients could be useful in a clinical setting. The cost and efficacy of this strategy should be evaluated. However, given the human and economic cost of mucormycosis and the need for rapid diagnosis to initiate prompt directed antifungal therapy, this strategy could be highly attractive.

Management of hypersensivity pneumonitis

Hypersensitivity pneumonitis (HP) is an interstitial lung disease due to a combined type III and IV reaction with a granulomatous inflammation, caused by cytotoxic delayed hypersensitivity lymphocytes, in a Th1/Th17 milieu, chaperoned by a deficient suppressor function of T regulatory cells. Skewing toward a Th2 phenotype is reported for chronic HP. Phenotypic expression and severity depends on environmental and/or host genetic and immune co-factors. The wide spectrum of causative antigens is continuously up-dated with new sources of airborne organic particles and drug-induced HP. The diagnosis requires a detailed history, measurement of environmental exposure, pulmonary function tests, imaging, detection of serum specific antibodies, broncho-alveolar lavage, antigen-induced lymphocyte proliferation, environmental or laboratory-controlled inhalation challenge and lung biopsy. Complete antigen avoidance is the best therapeutic measure, although very difficult to achieve in some cases. Systemic steroids are of value for subacute and chronic forms of HP, but do not influence long term outcome. Manipulation of the immune response in HP holds future promise.

Health effects of occupational exposure in a dairy food industry, with a specific assessment of exposure to airborne lactic acid bacteria

OBJECTIVE

Lactic acid bacteria (LAB) are used in food industries as probiotic agents. The aim of this study is to assess the potential health effects of airborne exposure to a mix of preblend (LAB and carbohydrate) and milk powder in workers.

METHODS

A medical questionnaire, lung function tests, and immunologic tests were carried out on 50 workers. Occupational exposure to inhalable dust and airborne LAB was measured.

RESULTS

Workers not using respiratory masks reported more symptoms of irritation than workers using protection. Workers from areas with higher levels of airborne LAB reported the most health symptoms and the immune responses of workers to LAB was higher than the immune responses of a control population.

CONCLUSIONS

Measures to reduce exposure to airborne LAB and milk powder in food industries are recommended.

How to improve the hygienic quality of forages for horse feeding

BACKGROUND

Improving the hygienic quality of forages for horse nutrition seems to be a reasonable target for decreasing the prevalence of pulmonary diseases. The aim of the experiment was to study the effects of different agricultural practices on the main aero-allergens contained in forages, including breathable dust, fungi, mycotoxins and pollens.

RESULTS

Results showed that the late harvest of hay, a second crop or a haylage production provides a good alternative to increase hygienic quality by reducing fungi contamination and breathable dust content. Barn drying of hay, while having no effect on breathable dust, similarly reduced fungi contamination. In contrast, when hay was harvested at a lower dry mass content (750 g DM kg⁻¹ versus 850 g DM kg⁻¹), both breathable dust and fungi contaminations were increased, which could at least be reversed by adding propionic acid just before baling. Zearalenone was detected in different hays, and even in one case, in breathable dust.

CONCLUSION

Overall, our data suggest that different approaches can be used to increase forage hygienic quality for horse feeding and thus reduce their exposure to factors involved in equine pulmonary disease.

Exposure to moulds and actinomycetes in Alpine farms: a nested environmental study of the PASTURE cohort

Several studies have suggested that children exposed to a farm environment are protected against allergies and asthma. The present work is an environmental study nested within the PASTURE cohort and includes 97 farmers and 74 non-farmers in three regions of the Alpine Arc (Switzerland, France and Germany). The objectives were to determine and compare the fungi and actinomycetes present in farming and non-farming environments (children's bedrooms and cowsheds), and to identify the agricultural practices associated with an increase in airborne fungi and actinomycetes in cowsheds. Air samples were collected by air pump and were analysed by culture and by direct counting of spores on membranes. During their stay in bedrooms, children living on farms were exposed to significantly greater amounts of Absidia spp., Eurotium spp., Cladosporium spp., Penicillium spp. and mesophilic actinomycetes than children who did not live on farms. Depending on the season, the levels of moulds, yeasts and actinomycetes were from 14 to 82 times higher in cowsheds before feeding the cattle than in children's bedrooms, and from 12 to 464 times higher in cowsheds after feeding than in children's bedrooms. Feeding cattle in cowsheds was associated with a significant peak in airborne moulds and actinomycetes, and this peak was higher in winter than in summer. Silage distribution was associated with low amounts of moulds and actinomycetes. Other significant agricultural factors were the type of cowshed, cowshed volume, method of food distribution to cattle and use of fresh grass. An assessment of the microbiological diversity on farms and in children's rooms may help to determine the factors protecting children from asthma and atopic diseases.

Primary in vitro culture of porcine tracheal epithelial cells in an air-liquid interface as a model to study airway epithelium and Aspergillus fumigatus interactions

Since the airway epithelium is the first tissue encountered by airborne fungal spores, specific models are needed to study this interaction. We developed such a model using primary porcine tracheal epithelial cells (PTEC) as a possible alternative to the use of primary human cells. PTEC were obtained from pigs and were cultivated in an air-liquid interface. Fluorescent brightener was employed to quantify the internalization of Aspergillus fumigatus conidia. Potential differences (Vt) and transepithelial resistances (Rt) after challenge with the mycotoxin, verruculogen, were studied. Primers for porcine inflammatory mediator genes IL-8, TNF-alpha, and GM-CSF were designed for a quantitative real-time PCR procedure to study cellular responses to challenges with A. fumigatus conidia. TEM showed the differentiation of ciliated cells and the PTEC ability to internalize conidia. The internalization rate was 21.9 ± 1.4% after 8 h of incubation. Verruculogen (10(-6) M) significantly increased Vt without having an effect on the Rt. Exposure of PTEC to live A. fumigatus conidia for 24 h induced a 10- to 40-fold increase in the mRNA levels of inflammatory mediator genes. PTEC behave similarly to human cells and are therefore a suitable alternative to human cells for studying interaction between airway epithelium and A. fumigatus.

Characterization of cultivated fungi isolated from grape marc wastes through the use of amplified rDNA restriction analysis and sequencing

Microbial assessment of grape marc wastes, the residual solid by-product of the wine-industry, was performed by identifying phylogenetically the fungal culturable diversity in order to evaluate environmental and disposal safety issues and to discuss ecological considerations of applications on agricultural land. Fungal spores in grape marc were estimated to 4.7 x 10(6) per g dry weight. Fifty six fungal isolates were classified into eight operational taxonomic units (OTUs) following amplified ribosomal DNA restriction analysis (ARDRA) and colony morphology. Based on 18S rRNA gene and 5.8S rRNA gene-ITS sequencing, the isolates representing OTUs #1, #2, #3, and #4, which comprised 44.6%, 26.8%, 12.5%, and 5.3%, respectively, of the number of the total isolates, were identified as Aspergillus fumigatus, Bionectria ochroleuca, Haematonectria haematococca, and Trichosporon mycotoxinivorans. The isolates of OTU#5 demonstrated high phylogenetic affinity with Penicillium spp., while members of OTUs #6 and #7 were closer linked with Geotrichum candidum var. citri-aurantii and Mycocladus corymbifer, respectively (95.4 and 97.9% similarities in respect to their 5.8S rRNA gene-ITS sequences). The OTU#8 with a single isolate was related with Aspergillus strains. It appears that most of the fungal isolates are associated with the initial raw material. Despite the fact that some of the species identified may potentially act as pathogens, measures such as the avoidance of maintaining large and unprocessed quantities of grape marc wastes in premises without adequate aeration, together with its suitable biological treatment (e.g., composting) prior to any agriculture-related application, could eliminate any pertinent health risks.