Fungal Particles Research Articles

Assessment of the microbial contamination in "Do It Yourself" (DIY) stores - a holistic approach to protect workers' and consumers' health.

In "Do-It-Yourself" (DIY) stores, workers from the wood department are considered woodworkers. Given the health risks associated with woodworking, particularly from fungi and their metabolites, this study aims to assess microbial contamination and health risks for both workers and customers. The study was developed in 13 DIY stores in Lisbon Metropolitan Area, Portugal. It employed a comprehensive sampling approach combining active (MAS-100, Andersen six-stage, Coriolis μ, and SKC Button Aerosol Sampler) and passive (electrostatic dust collectors, surface swabs, e-cloths, settled dust, filters from vacuumed dust, filtering respiratory protection devices, and mechanical protection gloves) methods to assess microbial contamination. A Lighthouse Handheld Particle Counter HH3016- IAQ was used to monitor the particulate matter size, temperature, and humidity. The wood exhibition area presented the highest fungal load, while the payment area exhibited the highest bacterial load. MAS-100 detected the highest fungal load, and surface swabs had the highest bacterial load. Penicillium sp. was the most frequently observed fungal species, followed by Aspergillus sp. Mycotoxins, namely mycophenolic acid, griseofulvin, and aflatoxin G1, were detected in settled dust samples and one filter from the vacuum cleaner from the wood exhibition area. Cytotoxicity evaluation indicates the wood-cutting area has the highest cytotoxic potential. Correlation analysis highlights relationships between fungal contamination and particle size and biodiversity differences among sampling methods. The comprehensive approach applied, integrating numerous sampling methods and laboratory assays, facilitated a thorough holistic analysis of this specific environment, enabling Occupational and Public Health Services to prioritize interventions for accurate exposure assessment and detailed risk management.

Distribution characteristics and analysis of fungal aerosol concentration and particle size in air-conditioned wards in Wuhan, China

Distribution characteristics and analysis of fungal aerosol concentration and particle size in air-conditioned wards in Wuhan, China

Airborne fungal concentrations around the Modelo Callao Landfill

Non-hazardous waste generated in Metropolitan Lima and Callao is transported to the Modelo Callao landfill for safe disposal. The accumulation of waste constitutes a significant source of fungal particles released into the atmosphere, posing a potential health risk to nearby populations. The aim of this research was to evaluate the concentration of outdoor fungal particles, considering environmental conditions (temperature, relative humidity, wind speed, and direction) during summer and winter seasons in the 18 de octubre settlement and Chillón Avenue, areas located in the vicinity of the Modelo Callao Landfill in Ventanilla during 2022. The gravitational method was used for sampling. The highest concentrations were detected at 150 and 200 m from the landfill, where a kindergarten and a local park are located. Fifteen fungal genera were identified in both seasons. The predominant fungi were Aspergillus spp. (46.09 %), Penicillium spp. (23.29 %) and Alternaria spp. (11.33 %). The average concentrations during summer and winter were 297.21 CFU/m3 and 471.69 CFU/m3, respectively. Based on these findings, we recommend that residential areas be located beyond 200 m from the landfill to minimize exposure to fungal aerosols. Additionally, we propose the implementation of an action plan to improve air quality in the areas surrounding the final disposal infrastructure.

Molecular mechanisms of zymosan-induced inflammasome activation in macrophages

Zymosan is a β-glucan-rich component derived from the cell walls of Saccharomyces cerevisiae extensively used in research for its potent immunomodulatory properties. It can prompt inflammatory responses such as peritonitis and arthritis, and is particularly used to study the immune response to fungal particles. Although the zymosan induced-release of the proinflammatory cytokine IL-1β by macrophages is an essential mechanism for combating fungal infection and inducing inflammation, the exact processes leading to its release remain not well understood. In this study, we uncover the intracellular mechanisms involved in zymosan induced-release of active IL-1β by peritoneal macrophages. Zymosan initiates pro-IL-1β formation through TLR2/MyD88 activation; however, Dectin-1 activation only amplify the conversion of pro-IL-1β into its active form. The conversion of inactive to active IL-1β upon zymosan stimulation depends on the NLRP3, ASC, and caspase-1 driven by the decrease in intracellular potassium ions. Notably, zymosan-induced activation of caspase-1 does not require phagocytosis. Instead, zymosan induces a rapid drop in the intracellular ATP concentration, which occurs concomitant with caspase-1 and IL-1β activation. Accordingly, disruption of glycolytic flux during zymosan stimulation promotes an additional reduction of intracellular ATP and concurrently amplifies the activation of caspase-1 and IL-1β. These results reveal that fungal recognition by macrophages results in a metabolic dysfunction, leading to a decrease of intracellular ATP associated with inflammasome activation.

Investigating Pulmonary Neutrophil Responses to Inflammation in Mice via Flow Cytometry.

Neutrophils play a crucial role in maintaining lung health by defending against infections and participating in inflammation processes. Here we describe a detailed protocol for evaluating pulmonary neutrophil phenotype using a murine model of sterile inflammation induced by the fungal cell wall particle zymosan. We provide step-by-step instructions for the isolation of single cells from both lung tissues and airspaces, followed by comprehensive staining techniques for both cell surface markers and intracellular components. This protocol facilitates the sorting and detailed characterization of lung neutrophils via flow cytometry, making it suitable for downstream applications such as mRNA extraction, single-cell sequencing, and analysis of neutrophil heterogeneity. We also identify and discuss essential considerations for conducting successful neutrophil flow cytometry experiments. This work is aimed at researchers exploring the intricate functions of neutrophils in the lung under physiological and pathological conditions with the aid of flow cytometry.

The influence of car traffic on airborne fungal diversity in Tianjin, China

ABSTRACT Little is known about the effect of car traffic on airborne fungal communities. We investigated the environmental factors affecting the diversity and concentration of airborne fungi at high-traffic density junctions, in Tianjin, China. A total of 244 fungal strains belonging to 78 species and 45 genera of Ascomycota (78.69%) and Basidiomycota (21.31%) were isolated and identified using morphological and molecular analysis. Aspergillus was the species-richest genus, with 9 recorded species, followed by Alternaria and Cladosporium, both with 8 species. Coprinellus radians was the most abundant fungal species, with 31 isolated strains, followed by Alternaria alternata (26 strains), Cladosporium cladosporioides (21), Alternaria compacta (13), and Cladosporium tenuissimum (11). We found a higher diversity and concentration of airborne fungi in the analysed urban air environments when the road traffic was at its highest intensity. Higher level of car traffic resulted in higher concentrations of fungal particles in the air for various taxa, including Alternaria, Aspergillus, and Cladosporium, which are known to cause respiratory allergies and infections. This result suggests that reducing vehicular traffic could be an effective measure to control airborne fungal exposure and microbial pollution.

Land-use patterns and fungal bioaerosols in the Brazilian Atlantic Forest biome

Whilst the importance of fungal primary biological aerosol particles (PBAPs) has been recognised, few studies have empirically assessed how land-use patterns influence them. Here, we show the impacts of different land-use patterns on fungal PBAPs within the Brazilian Atlantic Forest biodiversity hotspot. Spanning a distance of ca. 600 km within this biome, we collected fungal bioaerosols in the following land-use patterns: a 25-year-old coffee plantation, a 2.5-year-old Eucalyptus plantation, a 3-months-old maize crop, a 2-year-old and another 7-year-old native forest reforestation area, and a native forest fragment. Using the portable Burkard air sampler, a total of 14 morphotype-species were found. Cladosporium sp. comprised as much as about 95% of all fungal spores collected, being present in all samples (frequency of 100%). Forest systems had as much as 5-to-19-fold more fungal spores in the air than maize crops. Sampling height and time (morning vs. afternoon) did not influence fungal concentration and number of species. In addition, using data derived from an eddy covariance tower in the Eucalyptus site, we estimated the emission rate to be 6649 spores m−2 s−1. Our study confirms that land-use patterns affect fungal PBAPs, and that replacing large areas of native Atlantic Forest by monospecific stands, a homogenisation of airborne fungi is occurring, with unknown consequences for climate regulation.

Biosensors for detection of airborne pathogenic fungal spores: a review.

The excessive presence of airborne fungal spores presents major concerns with potential adverse impacts on public health and food safety. These spores are recognized as pathogens and allergens prevalent in both outdoor and indoor environments, particularly in public spaces such as hospitals, schools, offices and hotels. Indoor environments pose a heightened risk of pulmonary diseases due to continuous exposure to airborne fungal spore particles through constant inhalation, especially in those individuals with weakened immunity and immunocompromised conditions. Detection methods for airborne fungal spores are often expensive, time-consuming, and lack sensitivity, making them unsuitable for indoor/outdoor monitoring. However, the emergence of micro-nano biosensor systems offers promising solutions with miniaturized designs, nanomaterial integration, and microfluidic systems. This review provides a comprehensive overview of recent advancements in bio-nano-sensor system technology for detecting airborne fungal spores, while also discussing future trends in biosensor device development aimed at achieving rapid and selective identification of pathogenic airborne fungi.

Pleiotropic functions of SscA on the asexual spore of the human pathogenic fungus Aspergillus fumigatus

ABSTRACT Asexual spores, called conidia, are key reproductive fungal particles that enable survival in harsh environmental conditions or host systems. The conidia can infect humans, animals, and plants to cause various fungal diseases. Transcription factors, including VosA, WetA, and SscA, have key roles in conidia formation and long-term survival in Aspergillus nidulans. Herein, we report the pleiotropic functions of SscA in the conidia of the human pathogen A. fumigatus. The deletion of sscA increased conidia formation despite decreased fungal growth. Absence of sscA impaired long-term survival and reduced spore resistance to various stresses, including heat, UV, and oxidation. Transcriptomic analyses showed that SscA involved the mRNA expression of cell wall organisation-related genes. Importantly, the sscA deletion mutant conidia contained an increased amount of β-glucan and chitin compared to wild type conidia. In addition, conidial gliotoxin production was decreased in the sscA deletion strain. Overall, SscA has pleiotropic roles in conidia formation, maturation and dormancy and mycotoxin production in A. fumigatus.

Dectin-1 multimerization and signaling depends on fungal β-glucan structure and exposure

Dectin-1A is a C-type lectin innate immunoreceptor that recognizes β-(1,3;1,6)-glucan, a structural component of Candida species cell walls. β-Glucans can adopt solution structures ranging from random coil to insoluble fiber due to tertiary (helical) and quaternary structure. Fungal β-glucans of medium and high molecular weight are highly structured, but low molecular weight glucan is much less structured. Despite similar affinity for Dectin-1, the ability of glucans to induce Dectin-1A-mediated signaling correlates with degree of structure. Glucan denaturation experiments showed that glucan structure determines agonistic potential, but not receptor binding affinity. We explored the impact of glucan structure on molecular aggregation of Dectin-1A. Stimulation with glucan signaling decreased Dectin-1A diffusion coefficient. Fluorescence measurements provided direct evidence of ligation-induced Dectin-1A aggregation, which positively correlated with increasing glucan structure content. In contrast, Dectin-1A is predominantly in a low aggregation state in resting cells. Molecular aggregates formed during interaction with highly structured, agonistic glucans did not exceed relatively small (<15 nm) clusters of a few engaged receptors. Finally, we observed increased molecular aggregation of Dectin-1A at fungal particle contact sites in a manner that positively correlated with the degree of exposed glucan on the particle surface. These results indicate that Dectin-1A senses the solution conformation of β-glucans through their varying ability to drive receptor dimer/oligomer formation and activation of membrane proximal signaling events.

Aspergillus Conidia and Allergens in Outdoor Environment: A Health Hazard?

Aspergillus is a genus of saprophytic fungus widely distributed in the environment and associated with soil, decaying vegetation, or seeds. However, some species, such as A. fumigatus, are considered opportunistic pathogens in humans. Their conidia (asexual spores) and mycelia are associated with clinical diseases known as invasive aspergillosis (IA), mainly related to the respiratory tract, such as allergic asthma, allergic bronchopulmonary aspergillosis (ABPA), or hypersensitivity. However, they can also disseminate to other organs, particularly the central nervous system. Due to the dispersal mechanism of the conidia through the air, airborne fungal particle measurement should be used to prevent and control this mold. This study aims to measure the outdoor airborne concentration of Aspergillus conidia and the Asp f 1 allergen concentration in Bellaterra (Barcelona, Spain) during 2021 and 2022, and to compare their dynamics to improve the understanding of the biology of this genus and contribute to a better diagnosis, prevention, and therapeutic measures in the face of possible health problems. The results show that both particles were airborne nearly all year round, but their concentrations showed no correlation. Due to Asp f 1 not being present in the conidia itself but being detectable during their germination and in hyphal fragments, we report the relevance of the aero-immunological analysis as a methodology to detect the potential pathogenic hazard of this fungus.

90 Bioaerosol Exposure in Automated and Traditional Waste Sorting Plants

Abstract The waste management sector takes a central part in the transition towards circular economy and is subject to technological progress and the implementation of new work operations. Traditional waste collection and processing systems are characterized by numerous tasks that favour waste workers’ exposure to bioaerosols, whereas exposure in modern automated waste sorting plants remains elusive. Moreover, there is still a lack of health-risk based exposure limits for most components contained in bioaerosols. We investigated occupational exposure to bioaerosols in traditional and automated waste sorting plants. The results revealed significant differences in various exposure levels, such as total dust (GM automated: 0.34 mg/m3, GM manual: 0.66 mg/m3), endotoxins (GM automated: 51 EU/m3, GM manual: 32 EU/m3) and microorganisms between and within type of plant. An assessment of the composition of air-borne fungal particles (FESEM based immunodetection method) showed significantly increased levels of fungal spores at automated waste sorting plants (GM automated: 1.2 × 105 spores/m3, GM manual: 2.1 × 104 spores/m3). Elevated total dust levels and concentrations of submicronic fungal fragments were significantly correlated to the occurrence of symptoms of the extrathoracic region, such as congested nose, in exposed workers. The results of this study showed high variation in exposure levels between and within type of waste sorting plant, as well as seasonal variation for some parameters, such as total dust and endotoxins. This indicates that Norwegian waste workers are potentially exposed to high levels of dust and microorganisms that may cause adverse health effects in receptible individuals.

Encapsulation of entomopathogenic fungal conidia: evaluation of stability and control potential of Rhipicephalus microplus

The use of chemical acaricides is the primary strategy to control tick infestations. Nonetheless, chemical resistance in ticks has been reported. Thus, complementary methods such as biological control using entomopathogenic fungi (EPF) have been investigated. EPF, although efficient, have their viability compromised when applied under natural conditions, which indicates that formulation development is essential. Some researchers have demonstrated the efficacy of ionic gelation in protecting EPF against deleterious abiotic factors. In the present study, we conducted the ionic gelation technique to encapsulate Metarhizium anisopliae (Metschn.) Sorokin (Hypocreales: Clavicipitaceae) conidia in 2% (EC 2%) and 3% (EC 3%) sodium alginate. Next, the quantity and viability of encapsulated conidia (EC) were determined. The morphology of particles was characterized by using Scanning Electron Microscopy (SEM). EC and non-encapsulated conidia (NEC) were stored at room temperature (26.8 °C) and in the freezer (-11.9 °C) to shelf-life testing. For UV-B irradiance tolerance and thermotolerance tests, EC and NEC were exposed to UV-B (6.0 or 8.0 kJ m − 2) and heat (42 ºC). In addition, biological parameters of Rhipicephalus microplus Canestrini (Acari: Ixodidae) engorged females exposed to EC were evaluated. The particles presented a spherical shape, more homogeneous (EC 2%) or heterogeneous (EC 3%). Encapsulation decreased (4.8×) the conidial concentration and did not affect their viability. On the other hand, encapsulation increased the shelf life of conidia at room temperature as well as their UV-B tolerance and thermotolerance (6 h). The fungal particles decreased the biological parameters of females more significantly than the NEC. As far as we know, we reported for the first time the use of the ionic gelation to encapsulate entomopathogenic fungi toward controlling R. microplus.

NADPH oxidase 2 limits amplification of IL-1β-G-CSF axis and animmature neutrophil subset in murine lung inflammation.

The leukocyte NADPH oxidase 2 (NOX2) regulates inflammation independent of its antimicrobial activity. Inherited defects in NOX2 lead to chronic granulomatous disease (CGD), associated with recurrent bacterial and fungal infections, often with excessive neutrophilic inflammation that results in significant inflammatory burden and tissue damage. We previously showed that excessive leukotriene B4 (LTB4) production by NOX2-deficient mouse neutrophils was a key driver of elevated lung neutrophil infiltration in the initial response to pulmonary challenge with the model fungal particle zymosan. We now identify interleukin-1β (IL-1β) and downstream granulocyte colony-stimulating factor (G-CSF) as critical amplifying signals that augment and sustain neutrophil accrual in CGD mice. Neutrophils, delivered into the lung via LTB4, were the primary source of IL-1β within the airways, and their increased numbers in CGD lungs led to significantly elevated local and plasma G-CSF. Elevated G-CSF simultaneously promoted increased granulopoiesis and mobilized the release of higher numbers of an immature CD101- neutrophil subset from the marrow, which trafficked to the lung and acquired a significantly more proinflammatory transcriptome in CGD mice compared with wild-type mice. Thus, neutrophil-produced IL-1β and downstream G-CSF act sequentially but nonredundantly with LTB4 to deploy neutrophils and amplify inflammation in CGD mice after inhalation of zymosan. NOX2 plays a critical role in dampening multiple components of a feed-forward pipeline for neutrophil recruitment, and these findings highlight NOX2 as a key regulator of neutrophil number, subsets, and function at inflamed sites.

Clinical Manifestations of Human Exposure to Fungi

Biological particles, along with inorganic gaseous and particulate pollutants, constitute an ever-present component of the atmosphere and surfaces. Among these particles are fungal species colonizing almost all ecosystems, including the human body. Although inoffensive to most people, fungi can be responsible for several health problems, such as allergic fungal diseases and fungal infections. Worldwide fungal disease incidence is increasing, with new emerging fungal diseases appearing yearly. Reasons for this increase are the expansion of life expectancy, the number of immunocompromised patients (immunosuppressive treatments for transplantation, autoimmune diseases, and immunodeficiency diseases), the number of uncontrolled underlying conditions (e.g., diabetes mellitus), and the misusage of medication (e.g., corticosteroids and broad-spectrum antibiotics). Managing fungal diseases is challenging; only four classes of antifungal drugs are available, resistance to these drugs is increasing, and no vaccines have been approved. The present work reviews the implications of fungal particles in human health from allergic diseases (i.e., allergic bronchopulmonary aspergillosis, severe asthma with fungal sensitization, thunderstorm asthma, allergic fungal rhinosinusitis, and occupational lung diseases) to infections (i.e., superficial, subcutaneous, and systemic infections). Topics such as the etiological agent, risk factors, clinical manifestations, diagnosis, and treatment will be revised to improve the knowledge of this growing health concern.

Human intestinal epithelial cells can internalize luminal fungi via LC3-associated phagocytosis.

Intestinal epithelial cells (IECs) are the first to encounter luminal microorganisms and actively participate in intestinal immunity. We reported that IECs express the β-glucan receptor Dectin-1, and respond to commensal fungi and β-glucans. In phagocytes, Dectin-1 mediates LC3-associated phagocytosis (LAP) utilizing autophagy components to process extracellular cargo. Dectin-1 can mediate phagocytosis of β-glucan-containing particles by non-phagocytic cells. We aimed to determine whether human IECs phagocytose β-glucan-containing fungal particles via LAP. Colonic (n=18) and ileal (n=4) organoids from individuals undergoing bowel resection were grown as monolayers. Fluorescent-dye conjugated zymosan (β-glucan particle), heat-killed- and UV inactivated C. albicans were applied to differentiated organoids and to human IEC lines. Confocal microscopy was used for live imaging and immuno-fluorescence. Quantification of phagocytosis was carried out with a fluorescence plate-reader. zymosan and C. albicans particles were phagocytosed by monolayers of human colonic and ileal organoids and IEC lines. LAP was identified by LC3 and Rubicon recruitment to phagosomes and lysosomal processing of internalized particles was demonstrated by co-localization with lysosomal dyes and LAMP2. Phagocytosis was significantly diminished by blockade of Dectin-1, actin polymerization and NAPDH oxidases. Our results show that human IECs sense luminal fungal particles and internalize them via LAP. This novel mechanism of luminal sampling suggests that IECs may contribute to the maintenance of mucosal tolerance towards commensal fungi.

Features of the seasonal dynamics of airborne fungal spore concentrations in Ukraine

Fungi represent a distinct kingdom of ubiquitous living beings. Most other organisms are constantly in contact with elements of the fungal body. In particular, the widespread vegetation of fungi in the environment, their sporulation and the further spread of spores and mycelia by air currents make the contact of fungal particles with human respiratory organs inevitable. This can lead to the development of sensitization and allergies. Therefore, the aim of the presented study was to determine the taxonomy of airborne fungal spores, the qualitative and quantitative changes in this composition at different times of the year compared with previous sporulation seasons, as well as the prevention of allergic diseases. The study of fungal sporulation was carried out from 2011 to 2021 by volumetric method using Burkard trap of a Hirst type in a 24-hour mode (from February to November). The device was installed on the roof of the chemical building of the National Pirogov Memorial Medical University, Vinnytsya. Reading of the microscopic slides obtained from air samples was carried out using light microscopes with a magnification of 400 and 1000 by the method of 12 vertical transects. It was found that spores of various taxonomic groups of fungi, namely, of Asco- and Basidiomycetes were observed throughout the growing season from March to October with the highest concentrations in mid and late summer. Thus, in June, July and August, peak concentrations of spores of the fungi Ganoderma, Coprinus, Cladosporium were observed; in July, September and October – of Ustilaginales; from July to November – of Alternaria, Epicoccum; in October – of different Basidiospores, and also Periconia, Stemphylium and Uredinales; in September – of Agrocybe. Among all studied micromycetes, concentrations of Cladosporium spores were the highest. However, significant sporulation persisted even in the autumn period, which made fungal spores a specific causative agent of airborne respiratory diseases at this time, especially against the background of low pollen concentrations. Climate change can lead to modification in the length of the fungal growing season. This information should be taken into account when predicting the symptoms of seasonal allergies in the population.

Fungal Contamination of Building Materials and the Aerosolization of Particles and Toxins in Indoor Air and Their Associated Risks to Health: A Review.

It is now well established that biological pollution is a major cause of the degradation of indoor air quality. It has been shown that microbial communities from the outdoors may significantly impact the communities detected indoors. One can reasonably assume that the fungal contamination of the surfaces of building materials and their release into indoor air may also significantly impact indoor air quality. Fungi are well known as common contaminants of the indoor environment with the ability to grow on many types of building materials and to subsequently release biological particles into the indoor air. The aerosolization of allergenic compounds or mycotoxins borne by fungal particles or vehiculated by dust may have a direct impact on the occupant's health. However, to date, very few studies have investigated such an impact. The present paper reviewed the available data on indoor fungal contamination in different types of buildings with the aim of highlighting the direct connections between the growth on indoor building materials and the degradation of indoor air quality through the aerosolization of mycotoxins. Some studies showed that average airborne fungal spore concentrations were higher in buildings where mould was a contaminant than in normal buildings and that there was a strong association between fungal contamination and health problems for occupants. In addition, the most frequent fungal species on surfaces are also those most commonly identified in indoor air, regardless the geographical location in Europe or the USA. Some fungal species contaminating the indoors may be dangerous for human health as they produce mycotoxins. These contaminants, when aerosolized with fungal particles, can be inhaled and may endanger human health. However, it appears that more work is needed to characterize the direct impact of surface contamination on the airborne fungal particle concentration. In addition, fungal species growing in buildings and their known mycotoxins are different from those contaminating foods. This is why further in situ studies to identify fungal contaminants at the species level and to quantify their average concentration on both surfaces and in the air are needed to be better predict health risks due to mycotoxin aerosolization.

Determination of the mycobiome in the lower respiratory tract of horses with equine asthma

Fungal particles are important allergenic components involved in the development of equine asthma. The aim of this study was to evaluate the mycobiome composition of the lower respiratory tract in asthmatic horses using fungal culture, quantitative multiplex real-time PCR analysis (FungiMultiPlex) and Next-Generation Sequencing approach. Bronchoalveolar lavage fluid (BALF) samples obtained from 45 client-owned horses diagnosed with equine asthma were analysed by fungal culture (19 samples), FungiMultiPlex (34 samples), and Next-Generation Sequencing (14 samples). The fungal culture was positive in 11/19 (58%) cases, and FungiMultiPlex was positive in 19/34 (56%) cases. No fungal PCR product was detected by Next-Generation Sequencing analysis. Fungal culture and FungiMultiPlex methods were performed simultaneously on eight horses only. Association of results of these methods was calculated using Phi coefficient (φ= 0.333), and concordance between the methods was not confirmed (P = 0.420). The results of this study suggest that the fungal culture and quantitative multiplex real-time PCR might be considered diagnostically useful to assess the presence of fungi in BALF in a semiquantitative and quantitative manner, respectively. The Next-Generation Sequencing method seems to be less diagnostically suitable due to technical obstacles pertinent to both the low concentration of microbial agents in the rather diluted BALF samples, and, also, due to the relatively high environmental background contamination of the collected material. Based on our data, we advocate the use of the combination of quantitative multiplex real-time PCR and fungal culture in a routine clinical diagnostic setting.

1378. Fungal infections in burn patients during Northern California wildfires

Abstract Background Wildfires are an increasing human health concern. In 2020 there were nearly 10,000 fires in California including 5 of the 6 largest wildfires recorded in the state, burning 4.1million acres. In addition to the known risks of direct burn and inhalation injury, extreme heat exposure, and psychological stress, there are unrecognized infection risks associated with smoke exposure. Fungal elements travel great distances in the air, and smoke significantly alters the number and diversity of fungal particles in affected geographical regions. Aims: To analyze the incidence and contributing factors for mould infections in hospitalized burn patients in the fall of 2020, during the peak of wildfire season. Methods We reviewed the electronic medical records for all patients admitted with burns in the fall of 2020 and recorded demographics, treatment, and outcomes. Data was stored in a secure electronic database. Results Of the 10 patients admitted with wildfire related burns, 4 developed mould infections. Two additional cases were diagnosed in patients burned in a plane crash and one in a house fire. Five of the 7 patients (71%) were men; patients had a mean age of 37.7 years (range 24-56 years); mechanism in 4 of the 7 was direct wildfire exposure (57.1%); mean total body surface area (TBSA) burned was 69% (range 44-90%). Mould infection was identified on or after hospital day 14 in all patients. A total of 5 mould genera were isolated, with Aspergillus mould genus isolated from 6 patients (85.7%). All 7 patients (100%) were treated with at least 2 days of antibacterials before identification of mould infection; 4 (57.1%) of the patients died before leaving the hospital. Following this period, mould cases decreased to baseline low levels of &amp;lt; 10% for all burn sizes. Conclusion Wildfires in the western United States have had a devastating effect on the ecosystem and human health. We suspect that wildfires may increase the risk of invasive mold infections in burn patients with ambient wildfire smoke exposure. We observed a disproportionate number of invasive mould infections in hospitalized burn patients during large wildfires, which may have a significant impact on the seasonal treatment of burn patients. The relationship between wildfires and fungal infection warrants future investigation. Disclosures All Authors: No reported disclosures.