Search Results (103)

Powdery mildew, caused by Erysiphe quercicola, is one of the primary diseases responsible for the reduction in natural rubber production in China. This disease is a typical airborne pathogen, characterized by its ability to spread via air currents and rapidly escalate into an epidemic under favorable environmental conditions. Accurate prediction and determination of the prevention and control period represent both a critical challenge and key focus area in managing rubber-tree powdery mildew. This study investigates the effects of spore concentration, environmental factors, and infection time on the progression of powdery mildew in rubber trees. By employing six distinct machine learning model construction methods, with the disease index of powdery mildew in rubber trees as the response variable and spore concentration, temperature, humidity, and infection time as predictive variables, a preliminary predictive model for the disease index of rubber-tree powdery mildew was developed. Results from indoor inoculation experiments indicate that spore concentration directly influences disease progression and severity. Higher spore concentrations lead to faster disease development and increased severity. The optimal relative humidity for powdery mildew development in rubber trees is 80% RH. At varying temperatures, the influence of humidity on the disease index differs across spore concentration, exhibiting distinct trends. Each model effectively simulates the progression of powdery mildew in rubber trees, with predicted values closely aligning with observed data. Among the models, the Kernel Ridge Regression (KRR) model demonstrates the highest accuracy, the R² values for the training set and test set were 0.978 and 0.964, respectively, while the RMSE values were 4.037 and 4.926, respectively. This research provides a robust technical foundation for reducing the labor intensity of traditional prediction methods and offers valuable insights for forecasting airborne forest diseases. Full article

Spores of filamentous fungi are common biological particles in indoor air that can negatively impact human health, particularly among immunocompromised individuals and patients with chronic respiratory conditions. Airborne viruses represent an equally pervasive threat, with some carrying the potential for pandemic spread, affecting both healthy individuals and the immunosuppressed alike. This study investigated the abundance and diversity of airborne fungal spores in both hospital and residential environments, using custom designed air samplers with or without the presence of negative air ions (NAIs) inside the sampler. The main purpose of investigation was the assessment of biological effects of NAIs on fungal spore viability, deposition, mycelial growth, and sporulation, as well as airborne viral load. The precise assessment of mentioned biological effects is otherwise difficult to carry out due to low concentrations of studied specimens; therefore, specially devised and designed, ion-bioaerosol interaction air samplers were used for prolonged collection of specimens of interest. The total fungal spore concentrations were quantified, and fungal isolates were identified using cultural and microscopic methods, complemented by MALDI-TOF mass spectrometry. Results indicated no significant difference in overall spore concentration between environments or treatments; however, presence of NAIs induced a delay in the sporulation process of Cladosporium herbarum, Aspergillus flavus, and Aspergillus niger within 72 h. These effects of NAIs are for the first time demonstrated in this work; most likely, they are mediated by oxidative stress mechanisms. A parallel experiment demonstrated a substantially reduced concentration of aerosolized equine herpesvirus 1 (EHV-1) DNA within 10–30 min of exposure to NAIs, with more than 98% genomic load reduction beyond natural decay. These new results on the NAIs interaction with a virus, as well as new findings regarding the fungal sporulation, resulted in part from a novel interaction setup designed for experiments with the bioaerosols. Our findings highlight the potential of NAIs as a possible approach for controlling fungal sporulation and reducing airborne viral particle quantities in indoor environments. Full article

This study investigates the composition, abundance, and seasonal variability of airborne pollen in Siirt, a transitional region between the Irano-Turanian and Mediterranean phytogeographical zones in southeastern Türkiye. The main objective was to assess pollen diversity and its relationship with meteorological parameters over a two-year period (2022–2023). Airborne pollen was collected using a Hirst-type volumetric pollen and spore trap; a total of 18,666 pollen grains/m³ belonging to 37 taxa were identified. Of these, 70.67% originated from woody taxa and 29.33% from herbaceous taxa. Peak concentrations occurred in April, with the lowest levels in December. The dominant taxa, all exceeding 1% of the total, were Pinaceae (31.00%); Cupressaceae/Taxaceae (27.79%); Poaceae (18.42%); Moraceae (4.23%); Amaranthaceae (2.42%); Urticaceae (2.13%); Quercus (1.55%); Fabaceae (1.29%); and Rumex (1.02%). Spearman’s correlation analysis revealed significant relationships between daily pollen concentrations and meteorological variables such as temperature, humidity, precipitation, and wind speed. These findings highlight that both climatic conditions and the surrounding vegetation, shaped by regional land cover, play a crucial role in determining pollen dynamics. In conclusion, this study provides the first aerobiological baseline for Siirt and contributes valuable data for allergy-risk forecasting and long-term ecological monitoring in southeastern Türkiye. Full article

Avocado, a fruit consumed worldwide and essential for countries like Mexico and Chile, faces significant postharvest challenges, particularly during prolonged storage and transportation periods, where Botryosphaeriaceae and Glomerellaceae genera cause fruit rots that can generate substantial economic losses. This study investigated three Hass avocado orchards in the Valparaíso region of Chile to identify spore dispersion peaks, analyze the aerial dynamics of fungal inoculum, and evaluate the association with climatic conditions, as well as the incidence (I) and damage index (DI) of fruit rots. Spore traps were installed in symptomatic trees and monitored weekly over 13 months. Meteorological data were collected in parallel. Fruits from these orchards were sampled to evaluate postharvest rots, physiological maturity, and disease severity using molecular techniques, including DNA sequencing and phylogenetic analysis of isolated pathogens. The results revealed that spore peaks for both fungal families were closely associated with increased rainfall and high relative humidity, particularly from June to mid-September (winter season). The Santo Domingo orchard exhibited the highest disease pressure, with stem-end rot reaching an I of 44% and a DI of 17.25%, and anthracnose reaching an I of 23% and a DI of 12.25%. This study provides the first long-term, field-based evidence of airborne spore dynamics of Botryosphaeriaceae and Glomerellaceae in Chilean avocado orchards and their statistical relationship with environmental variables. These findings highlight the potential of incorporating climatic indicators—such as rainfall thresholds and humidity levels—into monitoring and early-warning systems to optimize fungicide application timing, reduce unnecessary chemical use, and improve postharvest disease management in avocado production. Full article

This study investigated the potential of Tillandsia plants, which can be arranged as a soil-free living green panel, and Banksia flower spikes, which could be arranged as a non-living natural panel, to filter particulate matter (PM) and airborne microorganisms. The Tillandsia panels demonstrated superior PM filtration, achieving up to 74% efficiency for large particles (>10 μm) at air velocities of 1.0 and 1.5 m/s without increasing pressure drop substantially. Conversely, Banksia performed better at 0.5 m/s, filtering up to 53% of PM compared to Tillandsia’s 13%. Notably, both panel types demonstrated significant fungal filtration, removing over 50% of airborne spores at 1.5 m/s. These findings suggest that incorporating plant-based panels into urban environments can enhance air quality and public health especially for allergenic particles and microorganisms. Full article

Cave environments represent extreme and underexplored ecosystems wherein fungi play a crucial role in nutrient cycling and ecological dynamics. This study provides the first comprehensive assessment of fungal diversity in air samples from caves across Portugal, with six samples from five locations being assessed through culture-dependent and metabarcoding approaches. From the five bat roosts studied, eleven morphologically distinct fungal colonies were isolated, with genera such as Aspergillus, Penicillium, and Chaetomium identified. Concurrently, Oxford Nanopore sequencing of the internal transcribed spacer (ITS) region of fungal rDNA revealed 286 genera, with Aspergillus, Candida, and Calyptella dominating across the sites. Diversity indices and community composition analyses, including Principal Coordinate Analysis (PCoA) and hierarchical clustering, highlighted distinct fungal profiles influenced by site-specific environmental factors and human activity. The data underscores the dual role of fungi in bat roosts as essential decomposers, emphasizing their adaptability to oligotrophic conditions. These findings advance our understanding of subterranean fungal ecology and emphasize the need for targeted conservation efforts to protect cave ecosystems from anthropogenic impacts. Full article

Several studies have reported the incidence of fungi and mycotoxins in coffee beans; however, there are few reports related to occupational exposure to these agents at coffee dry milling industries. The aim of this review was to identify and to analyze studies assessing occupational exposure to fungi and mycotoxins in coffee industries. Therefore, a systematic literature search was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology and focusing on the assessment of occupational exposure to fungi and mycotoxins in the coffee industry. In these papers, different environmental matrices were considered in evaluating occupational exposure, but the most used matrix was airborne dust (four of the five studies). Airborne fungi were sampled using active (four of the five studies) and passive sampling. Only the most recent of the studies (2022) identified microorganisms by their genera and species, and only two groups of mycotoxins were analyzed in the studies considered, namely, Ochratoxin A and Aflatoxins. None of the studies reported data on both fungi and mycotoxins. The fungal genera identified in these occupational environments included Cladosporium, Paecilomyces, Aspergillus, Penicillium, and other genera. Among the mycotoxins, only aflatoxins and ochratoxin A were investigated. Occupational exposure to these biological agents may lead to several health effects. Fungal spores and fragments can cause respiratory diseases such as asthma, allergic rhinitis, bronchitis, and hypersensitivity pneumonitis. Additionally, the mycotoxins studied—particularly Aflatoxins and Ochratoxin A—are associated with serious toxicological effects. Coexposure to both fungi and mycotoxins may enhance health risks and should be carefully considered in occupational risk assessments. Considering the possible effects related to exposure to fungi and mycotoxins and the number of workers involved in this type of industry in the world, more studies should be developed. This is the first review to systematically consolidate data on occupational exposure to both fungi and mycotoxins specifically within the coffee industry, highlighting existing knowledge gaps and the need for targeted risk assessments in coffee-producing settings. Full article

Molds are frequent indoor contaminants, where they can colonize many materials. The subsequent aerosolization of fungal spores from moldy surfaces can strongly impact indoor air quality and the health of occupants. The investigation of fungal contamination of habitations is a key point in evaluating sanitary risks and understanding the relationship that may exist between the fungal presence on surfaces and air contamination. However, to date there is no “gold standard” of sampling indoor air for such investigations. Among various air sampling methods, impingement can be used for capturing fungal spores, as it enables real-time sampling and preserves analytical follow-up. Its efficiency varies depending on several factors, such as spore hydrophobicity, sampling conditions, etc. Sampling devices may also impact the results, with recovery rates sometimes lower than filtration-based methods. The Coriolis µ air sampler, an impingement-based device, utilizes centrifugal force to concentrate airborne particles into a liquid medium, offering flexibility for molecular analysis. Several studies have used this device for air sampling, demonstrating its application in detecting pollen, fungal spores, bacteria, and viruses, but it is most often used in laboratory conditions. The present case study, conducted in a moldy house, aims to investigate the efficiency of this device in sampling fungal spores for DNA analysis in indoor environments. The results obtained suggest that the use of this device requires an optimized methodology to enhance its efficiency and reliability in bioaerosol research. Full article

Analyzing the transmission dynamics of airborne disease spores is crucial for advancing early warning and control strategies for crop diseases. This study introduces a novel approach utilizing the HYSPLIT-5 model to investigate the spore transmission patterns and pathways of airborne crop diseases. By employing the Lagrangian particle trajectory method of HYSPLIT-5 in conjunction with MeteInfoMap 3.5, the spatiotemporal frequency of cucumber downy mildew spore trajectories over extended periods was examined. The results indicate that the transmission trajectory of cucumber downy mildew spores is heavily influenced by atmospheric circulation, with spores spreading along air currents to surrounding areas. These trajectories frequently intersect, resulting in a broad transmission range, and the observed transmission patterns exhibit a degree of universality. Which provided a basis for the subsequent study of a large-scale prediction model of cucumber downy mildew. Full article

Airborne pollen monitoring in the city of Vukovar (Northeastern Croatia) was carried out using a Hirst-type spore trap, which was placed on the roof of a building at a height of 15 m above ground level. Over 5 consecutive years of airborne pollen monitoring, 76 pollen types from 45 plant families were identified. Of these, 29 pollen types belonged to arboreal species and 47 to non-arboreal species. Sixty-two percent of the total pollen was non-arboreal pollen. The main pollen types present in the airborne spectrum were Ambrosia artemisiifolia, Betula, Urtica, and Poaceae. Among the arboreal types, the genus Betula is the only taxon producing a high percentage in the pollen spectrum. Regarding allergenicity, A. artemisifolia, Betula, and Poaceae pose the highest allergy risk, while Urtica has a low risk of pollen allergy. Large differences in annual pollen sum and the seasonal dynamics of these dominant taxa during the study period were verified. The presence of the pollen in the air was influenced by weather conditions, showing in particular a positive correlation with the minimum air temperature for Betula and mean air temperature for Urtica, Poaceae, and A. artemisiifolia. However, the pollen concentration in the air was negatively correlated with precipitation for Betula, Urtica, and Poaceae and with humidity for A. artemisiifolia. Full article

Fungal spore calendars for Mexico are non-existent. This research represents the first fungal spore concentration data in the atmosphere of Hermosillo, Mexico, a city in the Sonoran Desert with high rates of allergies and public health problems. We used standardized sampling techniques frequently used by aerobiologists, including a Burkard spore trap to monitor airborne fungal spores daily for 2016–2019 and 2022–2023. Results are expressed as daily fungal spore concentrations in air (spores/m³ air). The most common fungal outdoor spores corresponded to Cladosporium (44%), Ascospora (17%), Smut (14%), Alternaria (12%), and Diatrypaceae (7%) of the total 6-year data. High minimum temperatures produce an increase in the most important spores in the air (Cladosporium and Alternaria), whereas precipitation increases Ascospore concentrations. The most important peak of fungal spore concentration in the air is recorded during summer–fall in all cases. Airborne fungal spores at Hermosillo had a greater impact on human health. These data will be of great help for the prevention, diagnostics, and treatment of seasonal allergies in the population and for the agricultural sector that has problems with some pathogens of their crops caused by fungus. Full article

The lettuce drop or white mold is an economically important disease as the causal fungus Sclerotinia sclerotiorum can infect the lettuce at any stage of plant development. Polyphagous nature of S. sclerotiorum, the longevity of soil-borne sclerotia and air-borne ascospores makes the control difficult. Chemical fungicides are available only for foliar application against infections by ascospores so, the development of bio-control is of great importance. We tested antagonism of native isolate T. koningiopsis agg. (Hypocreales) (STP8) under laboratory and greenhouse environments. In vitro tests showed excellent STP8 antagonisms to S. sclerotiorum evidencing hyperparasitic activity on mycelia and sclerotia as well as antibiosis. The sclerotia were completely degraded after two months. In the greenhouse, infection of lettuce with S. sclerotiorum was reduced by treating the seedlings with an STP8 spore suspension. Uninfected plants treated with STP8 were of the best quality based on morphological parameters, confirming the ability of STP8 to promote lettuce growth. Even the infected lettuce treated with STP8 were healthier and in better condition than the control lettuce, suggesting that STP8 was also enhancing plant defense system. Full article

Airborne fungi are widely distributed in the environment and originate from various sources like soil, plants, decaying organic matter, and even indoor environments. Exposure to airborne fungal spores can cause allergic reactions, asthma, and respiratory infections. Certain fungi can cause serious infections, particularly in individuals with weakened immune systems. An aerobiological study was conducted to detect airborne fungi using metagenomics in three areas of Mexico City, each representing different degrees of urbanization, during the dry and rainy seasons of 2017. Seasonality showed a significant role in the composition of airborne fungi. Ascomycota predominated in the three areas sampled during dry and rainy seasons, with the genera Cladosporium and Penicillium presenting the highest relative abundances across seasons. The Agaromycetes showed an increase during the rainy season. Regarding the areas, the north and center sites showed similar meteorological conditions and fungal community composition patterns. According to the Shannon and Simpson indices, the south area showed a greater species diversity during the dry season. These insights into the interactions between urbanization, seasonality, and airborne microbial communities could contribute to more effective urban management, reduced health risks, and the promotion of sustainable development. Full article

Basidiomycetes produce huge numbers of spores that can disperse over various distances. High spore concentrations are typically observed near the fruiting bodies, with their abundance in the air influenced by the specific habitat in which the fungi grow. The aim of this study was to investigate the concentration of airborne Boletus-type spores in a forest environment and evaluate the thesis that their dispersion beyond the forest is limited. Fungal spores were sampled in the summer and fall of 2022 in the forest, at its edge, and 1500 m away from the forest. The highest spore concentration was recorded in the forest interior, where approximately 76% of the total spores were detected. A noticeable decline in spore concentrations was observed at the forest edge, with a further significant reduction in open areas, including arable fields and mosaics of crops and heterogeneous plots, where spore presence accounted for only 12.1% of the total. During mushroom picking, airborne Boletus-type spores in the forest were unexpectedly high, so they could pose a threat to sensitized people. Full article

Polarization optics, which characterize the orientation of the electromagnetic field through Stokes vectors formalism, have been effectively used in lidar remote sensing to detect particles that differ in shape, such as mineral dust or pollen. In this study, for the first time, we explore the capability of polarization optics to distinguish the light-backscattering patterns of pollen and fungal spores, two complex-shaped particles that vary significantly in surface structure. A unique laboratory polarimeter operating at lidar backscattering at 180.0° was conducted to assess their light depolarization property in laboratory ambient air. If, at the precise lidar backscattering angle of 180.0°, the depolarization ratios of pollen and fungal spores were difficult to differentiate, slight deviations from 180.0° allowed us to reveal separate scattering matrices for pollen and fungal spores. This demonstrates that polarization optics can unambiguously differentiate these particles based on their light-(back)scattering properties. These findings are consistent at both 532 and 1064 nm. This non-invasive, real-time technique is valuable for environmental monitoring, where rapid identification of airborne allergens is essential, as well as in agricultural and health sectors. Polarization-based light scattering thus offers a valuable method for characterizing such atmospheric particles, aiding in managing airborne contaminants. Full article