Fungal Spore Counts Research Articles

Initial study of trap and identification of environmental pollens and fungi spores in Samborondon, Ecuador

Initial study of trap and identification of environmental pollens and fungi spores in Samborondon, Ecuador Introduction: The identification of local aeroallergens in any geographical area is essential for the specific diagnosis and treatment of allergic diseases. Our objective was to identify and registry the most important aeroallergens trapped at the aerobiology station in the city of Samborondon, Ecuador.Material and methods:Pollen grains and fungal spore counts were performed according to the standardized technique with a Hirst-type collection equipment, Burkard spore trap for seven days, following the recommendations of the National Allergy Bureau (NAB) of the American Academy of Allergy Asthma and Immunology (AAAAI). The equipment was installed on the roof of the Universidad de Especialidades Espiritu Santo (UEES), 25 m above ground level, coordinates: 2°07 ́57 ́ ́S 79°52 ́06 ́ ́W, in the city of Samborondon. The sampling period was performed from November 2022 to April 2023.Results:We identified the following pollen families: Poaceae (258 grains/m3), Apocynaceae (Plumeria rubra pc) 214 grains/m3, Lamiaceae (180 grains/m3), Asteraceae - Ambrosía spp.- (60 grains/m3), Chenopodiacea (27 grains/m3), Myrtaceae (17 grains/m3), Pinaceae (11 grains/m3), Betulaceae (7 grains/m3).Also identified fungical spores: Fuzariella spp./Leptosphaeria spp. (1899/m3), Cladosporium spp. (1407/m3), Nigrospora spp. (1183/m3), Dreschlera/Helmintosporum spp. (329/m3), Alternaria spp. (98/m3), Pithomyces spp. (79/m3), Curvularia spp. (48/m3), Stemphylium spp. (46/m3).Conclusions:We reported the first study of aerobiology (capture and identification of environmental pollens and fungi) in the city of Samborondon. The inhabitants of this area are exposed to different aeroallergens with a predominance of Poaceaes pollen and Fuzzariella spp./Leptosphaeria spp. spores. The identified allergens should be part of the usual allergy studies. The results of this first preliminary study should be compared with information from the forthcoming years, which will help to identify variations in the concentration of seasonal aeroallergens, annual fluctuations, and extend the traps to other parts of the city.Key words: aerobiology, allergic rhinitis, allergic conjunctivitis, pollens.

Initial study of trap and identification of environmental pollens and fungi spores in Samborondon, Ecuador

To identify and registry the most important aeroallergens trapped at the aerobiology station in the city of Samborondon, Ecuador. Pollen grains and fungal spore counts were performed according to the standardized technique with a Hirst-type collection equipment, Burkard spore trap for seven days, following the recommendations of the National Allergy Bureau (NAB) of the American Academy of Allergy Asthma and Immunology (AAAAI). The equipment was installed on the roof of the Universidad de Especialidades Espiritu Santo (UEES), 25 m above ground level, coordinates: 2°07 ́57 ́ ́S 79°52 ́06 ́ ́W, in the city of Samborondon. The sampling period was performed from November 2022 to April 2023. We identified the following pollen families: Poaceae (258 grains/m3), Apocynaceae (Plumeria rubra pc) (214 grains/m3), Lamiaceae (180 grains/m3), Asteraceae Ambrosía spp.- (60 grains/m3), Chenopodiacea (27 grains/m3), Myrtaceae (17 grains/m3), Pinaceae (11 grains/m3), Betulaceae (7 grains/m3). Also identified fungical spores: Fuzariella spp./Leptosphaeria spp. (1899/m3), Cladosporium spp. (1407/m3), Nigrospora spp. (1183/m3), Dreschlera/Helmintosporum spp. (329/m3), Alternaria spp. (98/m3), Pithomyces spp. (79/m3), Curvularia spp. (48/m3), Stemphylium spp. (46/m3). We reported the first study of aerobiology (capture and identification of environmental pollens and fungi) in the city of Samborondon. The inhabitants of this area are exposed to different aeroallergens with a predominance of Poaceaes pollen and Fuzzariella spp./Leptosphaeria spp. spores. The identified allergens should be part of the usual allergy studies. The results of this first preliminary study should be compared with information from the forthcoming years, which will help to identify variations in the concentration of seasonal aeroallergens, annual fluctuations, and extend the traps to other parts of the city.

Meteorological influences on airborne pollen and spores in Johannesburg (Gauteng), South Africa

Airborne fungal spores and pollen (aerospora), synergistic with air pollution, are key triggers of allergic respiratory diseases. Effective diagnosis and treatment requires up-to-date location-specific knowledge on the temporal variability of aerospora types and levels. Johannesburg is the largest city in South Africa and has grown substantially in three decades, with changes in ground cover, population density and air pollution, yet until now, no continuous aerospora sampling has occurred. We present a daily two-year (August 2019–July 2021) aerospora assemblage for Johannesburg and explore temporal characteristics of 13 dominant aerospora in relation to daily meteorological variables (pressure, rainfall, relative humidity, temperature and wind characteristics). February–July, July–September and January-July represent high-risk periods for fungal spores [(Alternaria alternata (Fries. ex Keissler), Ascospores, Aspergillus niger (Van Tieghem), Penicillium chrysogenum (Thom), Cladosporium graminum (Corda), Epicoccum nigrum (Link), Helminthosporium solani (Durieu and Montagne) Nigrospora sphaerica (Saccardo ex. Mason), Smuts Ustilago nuda (Jensen ex. Rostrup) and Torula herbarum (Link)], trees (Cupressus, Morus and Platanus) and grass (Poaceae), respectively. Using a generalised additive model, results show that daily meteorological characteristics explained 7–32% of daily aerospora variability, with the largest effect on tree pollen. Rainfall, relative humidity and temperature influenced daily fungal spore and Poaceae counts, with moderate/low rainfall (< 20 mm), higher/mid-ranging relative humidity (~ 40–60%) and temperatures of ~ 15–20 °C associated with higher counts during high-risk periods. Rainfall predominantly influenced tree counts during high-risk periods, with higher counts occurring on low rainfall (<10 mm) days. These results update the aerospora profile of Johannesburg, South Africa, providing important information to inform allergy care.

Co-Application of Silver Nanoparticles and Symbiotic Fungus Piriformospora indica Improves Secondary Metabolite Production in Black Rice

In the current research, unique Nano-Embedded Fungus (NEF), made by the synergic association of silver nanoparticles (AgNPs) and endophytic fungus (Piriformospora indica), is studied, and the impact of NEF on black rice secondary metabolites is reported. AgNPs were synthesized by chemical reduction process using the temperature-dependent method and characterized for morphological and structural features through UV visible absorption spectroscopy, zeta potential, XRD, SEM-EDX, and FTIR spectroscopy. The NEF, prepared by optimizing the AgNPs concentration (300 ppm) in agar and broth media, showed better fungal biomass, colony diameter, spore count, and spore size than the control P. indica. Treatment with AgNPs, P. indica, and NEF resulted in growth enhancement in black rice. NEF and AgNPs stimulated the production of secondary metabolites in its leaves. The concentrations of chlorophyll, carotenoids, flavonoids, and terpenoids were increased in plants inoculated with P. indica and AgNPs. The findings of the study highlight the synergistic effect of AgNPs and the fungal symbionts in augmenting the secondary metabolites in leaves of black rice.

P154 Fungal spore count in a tertiary care hospital in Mumbai, India

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PM ObjectivesFungal spores are ubiquitously present in the environment. Appropriate temperature and humidity can lead to fungal growth. It is of concern in a hospital environment. Diabetic and immunosuppressed persons are more vulnerable to such infections. The fairly humid and slightly warm climate of Mumbai is ideal for fungal growth. According to an article released in March 2021, the total fungal count in Mumbai was 16.2 CFUs. Here is a brief gist of how fungal spores were controlled within a tertiary hospital in Mumbai, India which is located near sea by simple but effective methods.MethodsAir sampling of the Operation Theatre (OT), Central Sterile Supply Department (CSSD), Bone marrow transplant (BMT) areas is done on weekly basis in the hospital and for areas such as ICU (Intensive Care Unit), Oncology (ONCO) Ward, Cardiac Catheterization (Cath) lab and Digital subtraction angiography (DSA) lab monthly air sampling is done to check for bacterial and fungal load. Two types of air samplers are used: Heico air sampler from HiMedia and Dyanamicro air sampler. OT, BMT, CSSD have HEPA (high efficiency particulate air) filters installed for filtration of air. The other areas like ICU, ONCO ward, Cath lab, and DSA lab do not have HEPA filters.ResultsIn the last 4 years there were two instances where fungal growth was observed once in BMT and once in ICU. In ICU Aspergillus niger growth was observed and in BMT there was a growth of multiple Aspergillus spp. It took nearly 3-4 months for the eradication of the fungus in BMT and 2 months to clear the fungus from ICU. Due to strict engineering control, we were able to restrict the spread within hospital.In BMT unit the growth was observed during rainy season when because of heavy rain there was seepage in one wall of the unit and also there was a leakage of sink in the ante-room area. When these repairs were done the fungal growth was not observed afterward.In ICU thorough cleaning of the Air Handling Unit (AHU) filter leads to resolution of the issue.Both these episodes were uneventful as no patient had any infection due to these.Factors that helped in controlling the fungal spores spread are:Controlled temperatureHumidityAC duct cleaningRegular AHU filter cleaningDifferent sizes of filters used for filtration of circulating air in hospitalNumber of air changesUse of antifungal paints in the hospitalRegular checks in hospital for any leakage or seepage issues.Monitoring of constructional activities in the hospital with appropriate measures to control fungal spore disseminationConclusionEven though the hospital is situated near sea and the outside air has high humidity and high microbial load, effective engineering measures and close monitoring of the areas can help in controlling the spread of fungus within the hospital. Routine periodic checks of the air for fungal spores can also help prevent nosocomial infections.

Exploring 50-years of fungal spore counts and GP consultation rates for asthma to explore their potential association

Exploring 50-years of fungal spore counts and GP consultation rates for asthma to explore their potential association

Meteorological Factors Influence the Presence of Fungi in the Air; A 14-Month Surveillance Study at an Adult Cystic Fibrosis Center.

BackgroundCystic fibrosis is an inherited disease that predisposes to progressive lung damage. Cystic fibrosis patients are particularly prone to developing pulmonary infections. Fungal species are commonly isolated in lower airway samples from patients with cystic fibrosis. Fungal spores are prevalent in the air.MethodsWe performed environmental air sampling surveillance at the Manchester Adult Cystic Fibrosis Centre, UK (MACFC) over a 14-month period to assess fungal growth inside and outside the CF center.ResultsAirborne counts of fungal spores peaked from May to October, both in outdoor and indoor samples. Collection of meteorological data allowed us to correlate fungal presence in the air with elevated temperatures and low wind speeds. Additionally, we demonstrated patient rooms containing windows had elevated fungal counts compared to rooms not directly connected to the outdoors.ConclusionsThis study suggests that airborne Aspergillus fumigatus spores were more abundant during the summer months of the survey period, which appeared to be driven by increased temperatures and lower wind speeds. Indoor counts directly correlated to outdoor A. fumigatus levels and were elevated in patient rooms that were directly connected to the outdoor environment via an openable window designed for ventilation purposes. Further studies are required to determine the clinical implications of these findings for cystic fibrosis patients who are predisposed to Aspergillus related diseases, and in particular whether there is seasonal influence on incidence of Aspergillus related conditions and if screening for such complications such be increased during summer months and precautions intensified for those with a known history of Aspergillus related disease.

Estimation of Possible Primary Biological Particle Emissions and Rupture Events at the Southern Great Plains ARM Site

AbstractWe use 10 years of data from the Department of Energy (DoE) Atmospheric Radiation Measurements (ARM) United States Southern Great Plains (SGP) site with nearby regional pollen and fungal spore measurements to indirectly estimate the seasonal influence of these two primary biological aerosol particles (PBAP). We estimate possible primary emissions of larger PBAP and PBAP rupture events, which form submicron organic aerosol during precipitation or high relative humidity. High pollen counts at two urban stations near SGP occur during late winter/early spring (day of year (DOY) 50–120) and late summer (DOY 240–310). Around 4–19 days per year show possible pollen events (PPE) when near‐surface lidar observations of daily linear particle depolarization ratio &gt;0.1 are coincident with high organic aerosol fraction. For PPE days with rainfall, aerosol size distribution observations show enhanced submicron particle concentrations consistent with pollen rupture events. For fungal spores, high fungal spore counts occur during late spring/early summer (DOY 110–195) and late summer/autumn (DOY 220–340). Based on size distribution observations, up to 7% of days have possible fungal spore rupture events (PFE) with higher aerosol number count specifically over the range expected for fungal spore fragment mobility diameter (20–50 nm). These short‐lived PFE correlate with rainfall or occur after prolonged exposure to rainfall (e.g., &gt;10 h). While the SGP site lacks direct measurements of bioaerosol and large particle sizes, this analysis suggests that PBAP primary emissions and rupture events could occur about 32 days per year, representing an important component of the aerosol budget during seasonal emissions.

Do Airborne Mold Counts Predict Asthma Exacerbations?

Airborne fungal spore counts including Alternaria, Cladiosporium, Ascospores, Aspergillus, Epicoccum, Agrocybe and Basidiospores have been correlated with asthma exacerbation requiring ER visits and hospitalizations in children and adults with asthma, particularly those sensitized to mold. Airborne fungi have also been suggested as a possible etiology for “thunderstorm asthma” driven more commonly by grass pollen. We hypothesized there would be a correlation between airborne mold and asthma exacerbations reflected in ER visits, nonurgent outpatient visits and hospitalization.

Mucormycosis in COVID-19

Mucormycosis has emerged as a disease of immense importance, especially owing to the surge of cases during the second wave of COVID pandemic. Various factors are being attributed to the sudden burst of cases in our country, such as higher fungal spore counts in tropical climate, uncontrolled diabetes mellitus, prolonged steroid therapy, contamination of oxygen facilities, respiratory equipment, reused face mask, and zinc supplements. The need of the hour is to emphasize on awareness of early warning signs, as the benefits appear to be time sensitive.

Diversity, Concentration and Dynamics of Culturable Fungal Bioaerosols at Doha, Qatar.

This research was conducted to investigate the dynamics of airborne fungi using viable culture collection and in respect to different abiotic variables, including seasonal and intra-diurnal variations. A gravimetric method was used to sample airborne fungal deposition on potato dextrose agar plates on alternate days, for a year between April 2015 to March 2016. From 176 settle plate exposures, a total of 1197 mould and 283 yeast colony-forming units (CFU), 21 genera and 62 species were retrieved. The highest fungal spore count was recorded in February 2016, whereas the lowest count occurred in August 2015. The main constituents of the fungal airspora were attributed to Cladosporium (60.2%), Aspergillus (10.4%), Fusarium (9.4%), Alternaria (8.5%), and Ganoderma spp. (2.3%). Temperature was negatively correlated with total colony count (r = −0.231, p ≤ 0.05) or species richness (r = −0.267, p ≤ 0.001), while wind speed was positively correlated with total colony count (r = 0.484, p ≤ 0.001) or species richness (r = 0.257, p ≤ −0.001). The highest dispersal of fungal spores was obtained at 18:00, whereas the lowest fungal spores release was recorded at 00:00 (midnight). There were no significant differences in species composition and richness of the airborne fungal population between two study sites, the Industrial area and Qatar University Campus. The count of Alternaria spp. and Fusarium spp. were significantly higher at the Industrial area site, which corresponds to a higher CO2 level than the Qatar University site. This study lays the foundation for future work to assess the implications of such aeromycological data on public health.

Isolation of citric acid-producing Aspergillus niger from soil and organic wastes

Introduction of new Aspergillus niger strains that are more productive than those currently in use is one of the important steps in promoting more effective commercial citric acid production. The present study was conducted to isolate and characterise indigenous A. niger from selected soil and organic wastes such as soil with buried bamboo, soil with bamboo on the surface, soil under cattle grazing, mango orchard soil, rotting plum fruit and rotting bread. Morphological identification of A. niger was based on the length and width of the conidiophores, vesicles, phialides, and spores. Citric acid-producing Aspergillus isolates were screened based on the citric acid production index. The present study found that the highest fungal spore counts (3.35±0.15 x 107 spores/g sample) were obtained from soil under cattle grazing, as were the highest A. niger counts (7.25±0.05 x 106 spores/g sample). The lowest total fungal counts came from rotting plum fruit (4.70±0.10 x 105 spores/g sample). A total of 14 isolates were collected, with five (NSA03, NSA06, NSA09, NSA12, and NSA14) showing morphological similarities with the reference isolate, A. niger Tiegh. All isolates were able to produce citric acid, but with varying efficiencies according to their citric acid production indices. The soil under cattle grazing area found to be the best site for sampling and isolation for citric acid-producing A. niger by using Czapek-Dox as a medium of isolation.

Airborne fungal spore relationships with meteorological parameters and skin prick test results in Elazig, Turkey.

Since fungi spores have high concentrations in the atmosphere during most of the year, they have an important place in respiratory allergies. In this regard, the preparation of calendars showing fungi spore loads for residential areas has much importance in the treatment of the patients. The first aim of this study was to present the airborne fungal spore research results from Eastern Anatolia in Turkey. Then, the mold spores' relationships with the meteorological parameters and skin prick test results were also evaluated. The presence of fungal spores was investigated using a volumetric spore trap in 2018year. In this study, fungal spores within the atmosphere of the Elazığ city of Turkey was measured through the volumetric method, using a Lanzoni VPPS 2000 device (VPPS 2000 Lanzoni, Bologna, Italy), in 2018year. Annual data of temperature, humidity, precipitation and wind speed were used for comparing meteorological data with airborne fungal spore counts. In addition, 637 children who were admitted to a pediatric allergy clinic with allergic complaints were enrolled in the study. A total of 145,099 spores/m3 and 20 fungal taxa belonging to the molds were recorded. Ustilago was the predominant genus (18.10%), followed by Oidium (18.01%), Drechslera (12.82%), and Fusarium (11.60%), which were the most common fungal spores found in Elazig's atmosphere. The total mold spores in the atmosphere reached the highest level, with 28,153 spores/m3, in July (mid-summer). Moreover, we found a positive correlation between the mold spores and the temperature, but negative correlations with the humidity and wind speed. In the skin prick tests in the children with allergic complaints, we detected sensitization to Alternaria alternata in 4.4%, Cladosporium herbarum in 3.0%, Penicillium notatum in 1.4%, and Aspergillus fumigatus in 1.1%. Additionally, there was no correlation between fungal spore concentration in the atmosphere with fungal spores sensitization in the skin prick test. This study was the first aerofungal survey of the Eastern Anatolia region in Turkey; therefore, new information has been introduced in the field of aerobiology in Turkey.

Seasonal and vertical variability of saccharides and other organic tracers of PM10 in relation to weather conditions in an urban environment of Upper Silesia, Poland

Abstract PM10 samples collected over one year from the city of Sosnowiec, part of the Upper Silesia metropolis were studied. The locale was a gradient meteorological station, 4 m and 100 m above ground. The dominant compounds identified were anhydro-, mono- and disaccharides which were divided into three groups of organic tracers (OT): biomass burning (BB) including low-rank coal burning, pollen grains (PG) and fungal spores (FS). The BB group included: levoglucosan, mannosan and galactosan, complemented with vanillic and dehydroabietic acids. The PG group included: fructose, glucose and sucrose, supplemented with D-pinitol, and the FS tracers included: arabitol, mannitol and trehalose. Levoglucosan reached 1503 ng/m3 in heating season at 4 m and 983 ng/m3 at 100 m. These values are among the highest mean concentrations of levoglucosan reported in Europe, confirming severe pollution of the Upper Silesian urban environment. We also suggest that the significant levoglucosan levels during the non-heating seasons could be from wind advected polluted soil and dust. All FS tracers correlate well with fungal spore counts, while the correlation of pollen numbers with their typical molecular tracers is statistically less significant. Weather conditions significantly influence the concentration of OT in aerosols. Among these, air temperature is a factor that affects the occurrence/existence of OT in the atmosphere, while temperature inversions are the main phenomenon which determines elevated concentrations of pollutants and their vertical variation in ambient air. For example, the concentration of BB tracers can be twice as high at 4 m as at 100 m under moderate to strong temperature inversions associated with low wind speed. Water vapor pressure and sun irradiation are also important factors controlling OT concentrations. This is one of the first studies of vertical differences in organic tracers which presents the variability and complexity of the processes affecting their concentrations in ambient air.

Influence of spore morphology on spectrophotometric quantification of Trichoderma inocula.

Species of the genus Trichoderma are filamentous fungi commonly used in research, industry and agriculture. Trichoderma reesei strains are prominent producers of cellulolytic and hemicellulolytic enzymes as well as being expression hosts; several other species such as T. atroviride might be exploited as biocontrol agents. A careful preparation of Trichoderma inocula, which consists mainly of conidia (asexual spores), is of immense importance. Conidia concentration is still mostly determined with the help of a hemocytometer; however, as a more accurate and time-saving alternative, absorbance can be used to estimate fungal spore counts. We established a spectrophotometric method for fast and reliable preparation of Trichoderma inocula by evaluating the effect of size, shape and pigmentation of the conidia at different wavelengths.

Achilles’ Heel

S18: Landmarks of Air Pollution Epidemiology: Legacy of Douglas Dockery, Beatrix Theater, August 27, 2019, 1:30 PM - 3:00 PM In the early 1970’s, criticisms were raised regarding the limited exposure assessment in U.S. Environmental Protection Agency’s (EPA’s) Community Health and Environmental Surveillance System study in Chattanooga, TN. Subsequently, after the 1974 oil embargo, the Harvard Six Cities Study was proposed by Drs. Ferris and Speizer as an intervention study to assess the health impact of an anticipated increase in coal-related air pollution. As implemented by Drs. Dockery and Spengler, this was the first multi-city study with 1-in-2-day, central site measurements of ambient fine particulate matter (PM2.5) using the Harvard Impactor along with indoor measurements of PM2.5 and nitrogen dioxide in children’s homes. Although the anticipated increases in air pollution did not occur, time-series analysis of the impact of PM2.5 on daily mortality in these six cites made a major contribution to setting EPA’s 1997 daily National Ambient Air Quality Standard (NAAQS) for PM2.5 and a subsequent survival analysis was supportive of the annual PM2.5 NAAQS. In a joint Harvard-EPA component, the ambient PM2.5 filters were assessed with X-ray fluorescence to measure the elemental composition of particles and thereby assess the health impact of specific sources of fine particles. The subsequent Harvard-Health Canada 24-Cities Study was the first multi-city study with daily measurements of PM2.5 particle acidity using an annular denuder and, in State College, PA, daily counts of speciated fungal spores. Subsequently, in a series of intervention studies in multiple countries, Dr. Dockery has assessed the health benefits of specific control measures for particulate pollution. These studies were groundbreaking at the time and have informed design of future epidemiologic research with an emphasis on high quality exposure assessment. The views expressed in this presentation are those of the authors and do not necessarily represent the views or policies of the U.S. Environmental Protection Agency.

Variation in airborne fungal spore concentrations among five monitoring locations in a desert urban environment

Fungal spores are biological particles that are ubiquitous in the outdoor air. Spores of several very common fungal species are known allergens, with the potential to cause respiratory illnesses by exacerbating asthma and allergic rhinitis. The National Allergy Bureau typically has one monitoring station established per city to determine fungal spore counts for an entire metropolitan area. However, variations in fungal spore concentrations could occur among different locations. The objective of this study was to measure and compare airborne fungal spore concentrations in five locations in Las Vegas for the year 2015 to determine if there are differences among microenvironments in the city. Twenty-four-hour or 7-day air samples were collected from five sites across the Las Vegas Valley. Samples were analyzed with a light microscope for fungal spores and counts were converted to concentrations of spores per volume of air. Mixed-model methods were used to evaluate mean differences. Results showed that smuts (basidiomycetes) were the dominant spore type for all five sites during the spring season. Cladosporium species were responsible for the second most dominant spore type with the highest concentrations occurring during the summer and fall months. Results obtained from the five stations established in Las Vegas show that there are important variations among the sites regarding fungal spore concentrations. The data suggest that more sites and additional monitoring of outdoor allergens are needed to provide information necessary to inform the community of outdoor air quality conditions and their potential effects on public health. This study presents new outdoor fungal spore data for the southwest region of the USA, focused in the Las Vegas Valley.

RNAi-based management for Fusarium wilt of banana

Banana is an important tropical crop and trading commodity in the world. However, Fusarium wilt is a severe risk for the world banana industry. Caused by the soil-borne fungal pathogen, Fusarium oxysporum f. sp. cubense (Foc), the disease is spreading insidiously and has been a source of enormous losses worldwide since the 1800s. Unfortunately, effective control methods are not available yet. The current study used an RNAi strategy, referred to as host-induced gene silencing (HIGS), to confer durable resistance against Fusarium by inhibiting in planta expression of Foc essential genes that are conserved in all Foc races and crucial for fungal virulence. In order to find efficient target genes, a wide search of literature has been conducted and four conserved target regions have been chosen after bioinformatics analysis. Preliminary findings from in vitro fungal inhibition assays showed significant reductions in fungal spore count, germination rate and mycelia growth after treating fungal cultures with double-stranded RNA (dsRNA) targeting four Foc genes, suggesting silencing of these genes was effective to reduce fungal growth. Intron hairpin constructs encoding dsRNA targeting selected Foc genes are in the process of being transformed into Arabidopsis thaliana for proof-of-concept of in planta fungal resistance.

Outpatient Visits for Allergic Diseases are Associated with Exposure to Ambient Fungal Spores in the Greater Taipei Area

Allergic diseases are prevalent worldwide and may result from exposure to various substances. Exposure to ambient bioaerosols is a potential risk factor for allergic diseases; however, accurate exposure assessment is challenging due to the limited number of outdoor monitoring stations. In this study, the relationships between ambient bioaerosol exposure and allergic diseases (viz., acute conjunctivitis, allergic rhinitis, and asthma) were evaluated using validated land-use regression (LUR) models to estimate the exposure levels. Data on the daily outpatient visits were retrieved from the Taiwan National Health Insurance Research Database. The total fungal spore count was associated with acute conjunctivitis in males at the second and third quartiles with relative risks (RRs) of 1.75 (95% confidence interval [CI] = 1.24, 2.48) and 1.32 (95% CI = 1.03, 1.70), respectively. It was also associated with asthma in both sexes when the concentration ≥ 95^(th) percentile with RRs = 3.06 (95% CI = 1.89, 4.95) in males and 1.73 (95% CI = 1.08, 2.76) in females. Cladosporium was correlated with acute conjunctivitis in females at a concentration ≥ 95^(th) percentile with RR = 2.90 (95% CI = 1.40, 6.04). Basidiospores were associated with allergic rhinitis in males at the third and fourth quartiles with RRs = 1.88 (95% CI = 1.44, 2.45) and 1.49 (95% CI = 1.20, 1.84), respectively. Meteorological parameters, including relative humidity and rainfall, were also crucial factors associated with the number of outpatient visits. Our results revealed that ambient fungal spores are critical determinants of allergic diseases. In addition, using LUR models to assess exposure to ambient bioaerosols is feasible.

Protective role of biosynthesized silver nanoparticles against early blight disease in Solanum lycopersicum

Tomato suffers a huge loss every year because of early blight disease. This study focuses on efficient inhibition of Alternaria solani, the causative agent of early blight disease in tomato in vitro and in vivo. Foliar spray of 5 μg/mL of biosynthesized silver nanoparticles in A. solani infected plants resulted in significant increase of 32.58% in fresh weight and 23.52% in total chlorophyll content of tomato as compared to A. solani infected plants. A decrease of 48.57, 30, 39.59 and 28.57% was observed in fungal spore count, lipid peroxidation, proline content and superoxide dismutase respectively in infected tomato plants after treatment with synthesized silver nanoparticles as compared to A. solani infected plants. No significant variation in terms of soil pH, cultured population, carbon source utilization pattern and soil enzymes including dehydrogenase, urease, protenase and β-glucosidase was observed after foliar spray of nanoparticles. It was revealed that direct killing of pathogens, increased photosynthetic efficiencies, increased plant resistance and decrease in stress parameters and stress enzymes are the mechanisms employed by plants and nanoparticles simultaneously to combat the biotic stress. Biosynthesized silver nanoparticles bear the potential to revolutionize plant disease management, though the molecular aspects of increased resistance must be looked upon.