Total Spore Research Articles

On the use of total aerobic spore bacteria to make treatment decisions due to Cryptosporidium risk at public water system wells.

Spore reduction can be used as a surrogate measure of Cryptosporidium natural filtration efficiency. Estimates of log10 (log) reduction were derived from spore measurements in paired surface and well water samples in Casper Wyoming and Kearney Nebraska. We found that these data were suitable for testing the hypothesis (H0) that the average reduction at each site was 2 log or less, using a one-sided Student's t-test. After establishing data quality objectives for the test (expressed as tolerable Type I and Type II error rates), we evaluated the test's performance as a function of the (a) true log reduction, (b) number of paired samples assayed and (c) variance of observed log reductions. We found that 36 paired spore samples are sufficient to achieve the objectives over a wide range of variance, including the variances observed in the two data sets. We also explored the feasibility of using smaller numbers of paired spore samples to supplement bioparticle counts for screening purposes in alluvial aquifers, to differentiate wells with large volume surface water induced recharge from wells with negligible surface water induced recharge. With key assumptions, we propose a normal statistical test of the same hypothesis (H0), but with different performance objectives. As few as six paired spore samples appear adequate as a screening metric to supplement bioparticle counts to differentiate wells in alluvial aquifers with large volume surface water induced recharge. For the case when all available information (including failure to reject H0 based on the limited paired spore data) leads to the conclusion that wells have large surface water induced recharge, we recommend further evaluation using additional paired biweekly spore samples.

English

The overuse of chemical fertilizers in agriculture remains an environmental concern, especially in sub-Saharan areas of Africa where soil degradation lead to low crop yield. Crop inoculation with beneficial microorganisms appears a good alternative to reduce chemical substances and improve yield. In this regard, studies on soil biological activities and inoculation experiments on maize (Zea mays L.) and peanut (Arachis hypogaea L.) crops were conducted. The aim of this work was to evaluate the effect of these crops on soil microbial activities and to assess their response to inoculation with two fungi (Glomus aggregatum and Glomus etunicatum) alone or in combination. Rhizospheric and non rhizospheric soils were collected in peanut and maize fields at Takali in northern Côte d’Ivoire. Soil enzymes activities, total microbial biomass, AMF spore and rhizobia densities were determined in these soils. Then, mycorrhizal inoculation experiment of these plant species was conducted in a greenhouse located at Nangui Abrogoua University, Abidjan, Côte d’Ivoire. After three months, plant growth and yield, mycorrhizal and nodulation parameters were measured. Results showed that maize has significantly improved enzymes activities, spore density and total microbial biomass of soil. Effect of peanut was only significant on chitinase. Moreover, soil rhizobia density was reduced under this crop effect. Maize significantly improved these parameters more than peanut. Inoculation results showed a significant enhancement of the height and shoot dry weight of maize with single inoculation with G. aggregatum or G. etunicatum even if a low mycorrhization rate was observed. However, in peanut, the mixed inoculants (G. aggregatum + G. etunicatum) significantly increased the pod weight and nodulation parameters. Results showed the importance of plant cover in the improvement of soil biological quality including enzymes activities and microbial community and suggested that the effect of mycorrhizal inoculation is influenced by many factors as plant species, AMF and soil environment characteristics.   Key words: A. hypogaea, Z. mays, soil enzyme activities, microbial biomass, soil microorganisms’ density, mycorrhizal inoculation. &nbsp

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.

Stoichiometry, Absolute Abundance, and Localization of Proteins in the Bacillus cereus Spore Coat Insoluble Fraction Determined Using a QconCAT Approach.

Spores of Bacillus cereus pose a threat to food safety due to their high resistance to the heat or acid treatments commonly used to make food microbiologically safe. Spores may survive these treatments and later resume growth either on foodstuffs or, after ingestion, upon entering the gut they are capable of producing toxins, which cause either vomiting or diarrhea. The outer layers of the spore, the spore coat and exosporium, consist primarily of proteins that may serve as potential biomarkers for detection. The major morphogenetic protein CotE is important for correct assembly and attachment of the outermost layer, the exosporium, and by extension retention of many proteins. However, characterization of the proteins affected by deletion of CotE has been limited to electrophoretic patterns. Here we report the effect of CotE deletion on the insoluble fraction of the spore proteome through liquid chromatography–Fourier transform tandem mass spectrometry (LC–FTMS/MS) analysis. A total of 560 proteins have been identified in both mutant and wild-type spore coat isolates. A further 163 proteins were identified exclusively in wild-type spore isolates indicating that they are dependent on CotE for their association with the spore. Several of these are newly confirmed as associated with the exosporium, namely BC_2569 (BclF), BC_3345, BC_2427, BC_2878, BC_0666, BC_2984, BC_3481, and BC_2570. A total of 153 proteins were only identified in ΔCotE spore isolates. This was observed for proteins that are known or likely to be interacting with or are encased by CotE. Crucial spore proteins were quantified using a QconCAT reference standard, the first time this was used in a biochemically heterogeneous system. This allowed us to determine the absolute abundance of 21 proteins, which spanned across three orders of magnitude and together covered 5.66% ± 0.51 of the total spore weight. Applying the QconCAT methodology to the ΔCotE mutant allowed us to quantify 4.13% ± 0.14 of the spore total weight and revealed a reduction in abundance for most known exosporium associated proteins upon CotE deletion. In contrast, several proteins, either known or likely to be interacting with or encased by CotE (i.e., GerQ), were more abundant. The results obtained provide deeper insight into the layered spore structure such as which proteins are exposed on the outside of the spore. This information is important for developing detection methods for targeting spores in a food safety setting. Furthermore, protein stoichiometry and determination of the abundance of germination mediating enzymes provides useful information for germination and outgrowth model development.

Does Over-Dominance of Bambusa bambos alter the Abundance and Composition of Arbuscular Mycorrhizal Fungal Community?

Plants have the potential to modify soil biological properties through root exudates and litter inputs. Bambusa bambos (L) Voss., a native bamboo, has been expanding its range in Intermediate and dry zone forests in Sri Lanka. With synchronised flowering and death cycles, bamboos have shown the potential to modify forest dynamics. No study has been attempted so far to evaluate its impacts on biological properties of forest soils. The current study assessed the impacts of population expansion of B. bambos on arbuscular mycorrhizal fungi (AMF) by conducting a comparative study with the help of bamboo-dominated (BD) and non-bamboo (NB) forest patches in the Intermediate Zone, Sri Lanka. The study sites are located in Moragahakanda in the Central Province of Sri Lanka. Two sites (located 4 km apart from each other) were selected; one dominated by bamboo (BD) and the other with no bamboo (NB). Eight composite soil samples (from a depth of 0-20 cm) were analysed for soil moisture content (%) and microbial biomass Carbon (MBC %). Wet sieving and decanting method was used to quantify the AMF spores. Different morphotypes were identified using spore wall characteristics. The results revealed significantly higher soil moisture in BD than in NB while MBC% showed no significant difference. A relatively higher total spore count (2,923) was reported in BD compared to NB (2,776). BD forests also demonstrated significantly higher mean spore abundance (≈ 500/100g soil) compared to that in NB forests (≈100/100g soil), with higher relative contribution from largest spores (125 μm). The AMF richness was relatively low in BD forest (15) than in NB (18), with 14 morphotypes present in both forest types. Shannon-Wiener index and evenness were relatively higher in NB (2.38 and 0.3) in comparison to BD (2.24 and 0.28). B. bambos has shown the potential to increase the AMF abundance with no impact on its richness and composition. Higher AMF abundance may possibly due to favourable micro-habitat conditions at BD compared to NB. Identification of such changes is crucial to introduce measures for conservation and restoration of these sensitive forests.Keywords: Native bamboos, AMF, Rapid spread, Bambusa bambos, Sri Lanka

Henneguya ovata n. sp. (Myxosporea: Bivalvulida), causing severe enteric henneguyosis of net-cage-cultured ovate pompano, Trachinotus ovatus in China

High diversity of fish myxosporeans was reported in China, but less concerns in species from marine environment, especially in South China Sea. Increasing myxosporidiosis of cultured marine fish expedite us to initiate a project of investigating the myxosporean diversity of marine fish in China. As a part of this project, a new myxosporean species, named as Henneguya ovata n. sp. was described here which intensively infected the internal wall of intestinal tract of net-cage-cultured ovate pompano, Trachinotus ovatus Linnaeus (1758) (Perciformes: Carangidae) off the coast of Huidong country, Guangdong Province, South China. The parasite generally produced white and usually round plasmodia, up to 3mm in diameter. Mature spores with a bifurcated equal caudal appendage were elongated ellipsoidal in frontal view, with blunted round anterior end, measuring 15.8±0.9 (14.7–17.1)μm in total spore length, 6.9±0.3 (6.1–7.1)μm in spore body length, 3.3±0.2 (2.9–4.1)μm in width, 2.9±0.1 (2.8–3.3)μm in thickness. The caudal appendages were 8.9±0.3 (8.1–9.6)μm in length. Two equal pyriform polar capsules situated in the plane of the suture line at the anterior end of spores, measuring 2.7±0.1 (2.6–2.9)μm in length and 1.2±0.1 (0.9–1.3)μm in width and occupied about half of the spore body length. Polar filaments wounded in 3 to 4 coils and situated perpendicularly of the longitudinal axis of the polar capsules. Morphological comparisons showed that the present species was smaller than most of reported Henneguya species. Under ultrastructural observations, numerous projections could be seen in the plasmodial wall toward host tissue. The obtained partial 18S rDNA gene sequences, 1675bp in length, did not match any of myxosporeans available in the GenBank, but was most similar to two Trachinotus-infecting Henneguya species (about 91%). Phylogenetic analysis revealed that the parasite clustered within the marine Henneguya-Myxobolus clade infecting fish of the order Perciformes. Therefore, our results strengthened again the contention that the host affinity was the strongest among evolutionary signals to infer the phylogeny of myxosporeans of the family Myxobolidae. However, spore morphology and tissue tropism could represent well phylogenetic relationships among species of myxobolid group of within a short evolutionary history. Taking into account the high infection intensity and caused remarkable thin and transparent intestinal wall, the detrimental effects of infection of this myxosporean on cultured T. ovatus deserve more attentions in future.

One year of temporal characterization of fungal spore concentration in São Paulo metropolitan area, Brazil

There are very few studies related to the characterization of biological components, especially fungal ones, present in the particulate matter (PM) of atmospheric aerosols in Brazil. The biogenic components of PM can have a direct relationship with respiratory diseases outbreaks and can also be linked to climate processes. Studies indicate that fungal spores constitute one of the major biological components present in the atmosphere and can be responsible for a significant amount of particulate mass concentration. This work aims to (i) identify the main fungal types in the atmosphere of São Paulo; (ii) estimate the fungal type concentrations and variations in the atmosphere; (iii) investigate the fungal spore seasonality; and (iv)estimate their diurnal behavior. In order to achieve that, a "Burkard 7-day Recording" air sampler operating at 10L/min was used to collect spore samples on a 24/7 basis, from September 2013 to September 2014, at the main campus of the University of São Paulo, an area mostly impacted by vehicular emission and characterized by the presence of green areas. Fungal types were grouped considering their morphological similarity (i.e., cell number, coloration, shape and size) and predetermined taxonomic group (phylum, family and genus). After this initial classification, fungal types were grouped in three main groups, Ascomycota and Basidiomycota, which included only the teleomorph form of the fungi, and Deuteromycota, which includes the anamorph form of both phyla. Fungal types were characterized using an optical microscope, and 45 major fungal types were found, with Basidiomycota being the main phylum. The average concentration was 5736 (± 2459) spores/m³ per day, with the highest concentration at 23780 spores/m³ in autumn at night and the lowest concentration at 567 spores/m³ in autumn in the morning. Higher concentrations of Ascospores (AS) and Basidiospores (BS) occurred in spring and summer, whereas Mitospores presented the highest concentration in winter and autumn. In addition, spore concentrations presented different profiles according to hourly variation, with the highest concentration of Total spores occurring at dawn. However, the concentration of Mitospores was higher during the afternoon, probably due to spore releasing mechanisms or to their transport. Ascomycota and Deuteromycota presented an antagonistic behavior in most situations.

Monitoring of airborne fungal spore load in relation to meteorological factors, air pollutants and allergic symptoms in Farakka, an unexplored biozone of eastern India.

Fungi are important components of atmosphere which play a major role in causing respiratory allergy upon inhalation. An airborne fungal spore survey was carried out in two outdoor environments in Farakka-an unexplored township covering the National Thermal Power Station, West Bengal, India for a period of 2years (October 2013 to September 2015). A Burkard personal volumetric air sampler was used at 15days interval to collect the total fungal spore load. A fungal spore calendar has been prepared depicting monthly average spore concentration in the air. The relationships between fungal spore concentration and different climatic factors were analysed statistically. Higher concentration levels of aerospora and pollutants were recorded during winter season. A detailed questionnaire was used to obtain medical history data of 523 local patients visiting the outpatients department of Farakka NTPC (National Thermal Power Station) hospital. A significant positive correlation was found between fungal spore concentration, atmospheric pollutants and allergic manifestation. The dominant fungal spores were isolated, sub-cultured and tested for allergenic potential by skin prick tests (SPTs) among subjects with clinical history of respiratory allergy, which evoked ˃45.0% skin reactivity upon individuals.

Crop Fertilization Impacts Epidemics and Optimal Latent Period of Biotrophic Fungal Pathogens.

Crop pathogens are known to rapidly adapt to agricultural practices. Although cultivar resistance breakdown and resistance to pesticides have been broadly studied, little is known about the adaptation of crop pathogens to fertilization regimes and no epidemiological model has addressed that question. However, this is a critical issue for developing sustainable low-input agriculture. In this article, we use a model of life history evolution of biotrophic wheat fungal pathogens in order to understand how they could adapt to changes in fertilization practices. We focus on a single pathogen life history trait, the latent period, which directly determines the amount of resources allocated to growth and reproduction along with the speed of canopy colonization. We implemented three fertilization scenarios, corresponding to major effects of increased nitrogen fertilization on crops: (i) increase in nutrient concentration in leaves, (ii) increase of leaf lifespan, and (iii) increase of leaf number (tillering) and size that leads to a bigger canopy size. For every scenario, we used two different fitness measures to identify putative evolutionary responses of latent period to changes in fertilization level. We observed that annual spore production increases with fertilization, because it results in more resources available to the pathogens. Thus, diminishing the use of fertilizers could reduce biotrophic fungal epidemics. We found a positive relationship between the optimal latent period and fertilization when maximizing total spore production over an entire season. In contrast, we found a negative relationship between the optimal latent period and fertilization when maximizing the within-season exponential growth rate of the pathogen. These contrasting results were consistent over the three tested fertilization scenarios. They suggest that between-strain diversity in the latent period, as has been observed in the field, may be due to diversifying selection in different cultural environments.

Pilot-scale biopesticide production by Bacillus thuringiensis subsp. kurstaki using starch industry wastewater as raw material

ABSTRACTPilot-scale Bacillus thuringiensis based biopesticide production (2000 L bioreactor) was conducted using starch industry wastewater (SIW) as a raw material using optimized operational parameters obtained in 15 L and 150 L fermenters. In pilot scale fermentation process the oxygen transfer rate is a major limiting factor for high product yield. Thus, the volumetric mass transfer coefficient (KLa) remains a tool to determine the oxygen transfer capacity [oxygen utilization rate (OUR) and oxygen transfer rate (OTR)] to obtain better bacterial growth rate and entomotoxicity in new bioreactor process optimization and scale-up. This study results demonstrated that the oxygen transfer rate in 2000 L bioreactor was better than 15 L and 150 L fermenters. The better oxygen transfer in 2000 L bioreactor augmented the bacterial growth [total cell (TC) and viable spore count (SC)] and delta-endotoxin yield. Prepared a stable biopesticide formulation for field use and its entomotoxicity was also evaluated. This study result corroborates the feasibility of industrial scale operation of biopesticide production using starch industry wastewater as raw material.

Meteorological factors associated with abundance of airborne fungal spores over natural vegetation

The abundance of airborne fungal spores in agricultural and urban settings increases with greater air temperature, relative humidity, or precipitation. The same meteorological factors that affect temporal patterns in spore abundance in managed environments also vary spatially across natural habitats in association with differences in vegetation structure. Here we investigated how temporal and spatial variation in aerial spore abundance is affected by abiotic (weather) and biotic (vegetation) factors as a foundation for predicting how fungi may respond to changes in weather and land-use patterns. We measured the phenology of airborne fungal spores across a mosaic of naturally occurring vegetation types at different time scales to describe (1) how spore abundance changes over time, (2) which local meteorological variables are good predictors for airborne spore density, and (3) whether spore abundance differs across vegetation types. Using an air volumetric vacuum sampler, we collected spore samples at 3-h intervals over a 120-h period in a mixed-evergreen forest and coastal prairie to measure diurnal, nocturnal, and total airborne spore abundance across vegetation types. Spore samples were also collected at weekly and monthly intervals in mixed-evergreen forest, redwood forest, and maritime chaparral vegetation types from 12 field sites across two years. We found greater airborne spore densities during the wetter winter months compared to the drier summer months. Mean total spore abundance in the mixed-evergreen forest was twice than in the coastal prairie, but there were no significant differences in total airborne spore abundance among mixed-evergreen forest, redwood forest, and maritime chaparral vegetation types. Weekly and monthly peaks in airborne spore abundance corresponded with rain events and peaks in soil moisture. Overall, temporal patterns in meteorological factors were much more important in determining airborne fungal spore abundance than the vegetation type. This suggests that overall patterns of fungal spore dynamics may be predictable across heterogeneous landscapes based on local weather patterns.

Prevalence and Characterization of Aerobic Spore Forming Bacteria in Raw Milk and Some Cheeses

Prevalence of aerobic spore forming bacteria in raw milk, Ras cheese and Domiati cheese was investigated. Total bacterial and total aerobic spore forming counts were enumerated by using tryptone soy agar medium. All isolated aerobic sporeformers were identified on genus and species levels. The minimum, maximum and the means of total aerobic sporeformers counts in raw milk samples were 3.2×103, 2.7×104 and 1.5×104 cfu/ml, respectively. Counts in Ras cheese samples were, 2×102, 3.5×104 and 1.8×104 cfu/g, and in Domiati cheese samples being, 1.2×103, 2.3×104 and 1.2×104 cfu/g, in the same order. A total of 60 B. cereus group of bacterial cultures isolated from market dairy products were identified as B. anthracis 39(65%), B. cereus 6(10%), B. mycoides 13(21.7%) and B. thuringiensis 2(3.3%). Results also show that all tested 60 isolates could be plotted in different patterns from A to G, e.g. B. cereus (A), B. mycoides (B, C and D), B. thuringiensis (E) and B. anthracis (F and G).

Changes in farming practices impact on spore release patterns of the blackleg pathogen, Leptosphaeria maculans

Blackleg disease is caused by the stubble-borne pathogen Leptosphaeria maculans and results in significant yield losses in canola (Brassica napus) worldwide. Control of this disease includes breeding for resistance, fungicides and cultural practices including stubble management. In recent years, cropping systems have changed with the introduction of no-till farming and inter-row sowing, and it is unknown what impact these changes have had on stubble retention. The aim of this study is to investigate the impact of inter-row sowing on stubble retention and spore release. The use of inter-row sowing resulted in 25–48% of stubble remaining standing (vertical) in fields after 1 year. Furthermore, spore release was significantly (P < 0.05) delayed in stubble that remained vertical in the field compared with stubble lying down, with total spore release from vertical stubble 66% less than from horizontal stubble. The impact these changes have on the epidemiology of blackleg disease remains unknown.

Execution of Enriched Rice Bran Medium in Hyper Production of Penicillin V by Penicillium chrysogenum

The antibiotic penicillin is being a major pharmaceutical compound after several years of use. The present research work focuses on the selection of suitable low cost substrate from rice based residues like grains, husk and bran for the seed culturing of Penicillium chrysogenum by solid state fermentation (SSF) and optimization of medium for hyper production of penicillin V (Pen V) by P. chrysogenum under submerged fermentation (SmF). In SSF, significantly highest number of total spores and viable spores were augmented in rice bran media than the rest. The effect of different carbon, nitrogen sources, pH, temperature, incubation time and various concentrations of precursor amino acid (l-valine) were studied for hyper production of Pen V by P. chrysogenum. The results revealed that in SmF, the enriched rice bran medium has had increased the production yield of Pen V at a highest level of 22.1 g/L than the synthetic production medium 19.8 g/L. Hence, the Pen V produced from the enriched low cost rice based substrate is being an alternate for next generation production.

The Occurrence and Infectivity of Arbuscular Mycorrhizal Fungi in Inoculated and Uninoculated Rhizosphere Soils of Two-year-old Commercial Grapevines

Arbuscular mycorrhizal (AM) fungal populations present in the rhizosphere of vine roots in the vineyards of a commercial farm in the Stellenbosch Region were investigated using microscopic analyses. AM root colonisation levels of between 70% and 90% were found in both grapevine roots that were previously artificially inoculated with commercial AM inocula, and in uninoculated (control) grapevine roots. The AM fungal isolates in the rhizosphere soil, identified using morphological criteria, belonged to the genera Acaulospora, Gigaspora, Glomus, Sclerocystis and Scutellospora. The majority of species found was not present in the commercial inocula and was either indigenous to the vineyard or originated from the nursery where the vines were obtained. Isolates of Glomus and Acaulospora appeared to be the most abundant. The AM fungal species occurred at a soil phosphorus (P) concentration of up to 80 mg/kg P and a soil pH (KCl) that ranged between 5.63 and 6.10. Total spore counts ranged between 1 000 and 3 779 spores/100 g dry soil. In accordance with literature, lower spore concentrations were recorded for the heavier soil types with no cover crop system, compared with the sandy soil type on which cover crops were sown annually.

Relation of indoor and outdoor airborne fungal spore levels in the Kansas City metropolitan area.

Environmental control is an important component of asthma management for persons with asthma. A damp indoor environment and elevated airborne spore levels are factors in housing environmental control. We investigated if indoor airborne fungal spore levels correlated with outdoor ground-level airborne fungal spores or outdoor centrally collected spore levels as to types and abundance. Air collections were taken from home interiors, outdoor areas adjacent to the homes, and at a central location in the metropolitan area at the approximate same time. All air collections were examined and enumerated microscopically, and airborne spore estimates per cubic meter of air were reported for total fungal spores and for 11 identifiable spore groups. The 244 homes in the study were typical of the North American Midwest. The overall mean total spore counts in spores per cubic meter of air was indoors (4076 spores/m3), outdoors at ground level (8899 spores/m3), and outdoor metropolitan area (8342 spores/m3). All of the major indoor taxa were strongly correlated with the mean total spores present in the home. Total outdoor ground spore levels were highly correlated with levels of major outdoor taxa, such as ascospores and Cladosporium. Correlations of indoor spore levels with outdoor spore levels are strong for most major outdoor taxa. Indoor Aspergillus-Penicillium and Chaetomium are significantly correlated between indoor and local ground-level outdoor air. Although conditions may exist where indoor or outdoor spore levels were not well aligned, in most circumstances, the outdoor airborne spore community was reflected in the indoor airborne spore community.

Occupational exposure and respiratory health problems among nutmeg production workers in Grenada, the Caribbean.

The nutmeg industry is a major contributor to the Grenadian economy. However, workers in the industry face many environmental and occupational health risks. The goal of this study was to investigate respiratory health problems and possible related occupational exposures among nutmeg production workers. A questionnaire, spirometry and allergen skin-prick test was given to 92 nutmeg workers. Samples for measurement of airborne dust, mold, and phosphine were also collected from work environments. Approximately half of the workers with lower respiratory symptoms such as dry cough (49.4%) and shortness of breath (42.9%) reported that their symptoms were work related. Spirometry results showed that 18.8% of workers had obstruction. Area geometric mean (GM) inhalable dust concentrations, GM personal concentrations, and total mold spores during work activities were found to be high. High prevalence of respiratory symptoms among workers in this facility was consistent with measured levels of dust and mold, and was widespread over all work areas.

Ambient Fungal Spore Concentration in a Subtropical Metropolis: Temporal Distributions and Meteorological Determinants

ABSTRACTAmbient particles comprise approximately 25% of fungal spores, which cause adverse health outcomes such as respiratory diseases, allergy, and infection. In this study, we investigated temporal variations and distributions of ambient fungal spores in an urban area of the Taipei metropolis for over 1 year. A Burkard 7-day volumetric spore trap was used to collect air samples. Samples collected daily were stained, counted, and identified on the basis of morphological characteristics. The associations between fungal spores and environmental parameters were then evaluated through multiple regression analysis. Daily monitoring data revealed a large variation in fungal spore concentrations. Specifically, fungal spores peaked during summer months (June–August) and declined during winter months (December–early March); moreover, the average concentration of total fungal spores was 3,607.97 ± 3,181.81 spores m–3. Ascospores were the most prevalent taxon that was recovered from the samples, followed by basidiospores, Aspergillus/Penicillium, and Cladosporium. Multiple regression analysis revealed that meteorological parameters were the main predictors of fungal concentrations. Temperature, wind speed, and humidity were consistently correlated with total fungi and major fungal taxa, and sunlight had a negative association with ascospores. Among the atmospheric pollutants, particulate matter with an aerodynamic diameter ≤ 10 µm (PM10) and ozone were positively associated with fungal spores. Carbon monoxide (CO) at lag day 1 had a negative association with basidiospores. This is the first study to characterize daily concentrations and determinants of ambient fungal spores in an urban area of Taipei metropolis. The obtained data can be used to evaluate the health impact of fungal spore exposure on the residents of the Taipei metropolitan area.

Fungal Bioaerosol Exposure and its Effects on the Health of Mushroom and Vegetable Farm Workers in Taiwan

ABSTRACTWorkers from specific occupational settings may be exposed to high fungal bioaerosol concentrations, causing detrimental health effects. Therefore, we conducted a study to evaluate the characteristics and health effects of fungal bioaerosols present on agricultural farms. By using IOM inhalable dust samplers, personal and area samples of airborne fungi were collected from five agricultural farms—two mushroom and three vegetable farms. A standardized questionnaire and spirometry were used to evaluate workers’ health. The Kruskal–Wallis test was used to examine the distributions of fungal and environmental factors among the different farms, and regression analyses were performed to evaluate the effects of personal bioaerosol exposure on workers’ health. In the personal samples, the geometric mean concentrations ranged from 4.3 × 103 to 3.0 × 104 CFU m–3 for total culturable fungi and from 4.2 × 103 to 1.2 × 105 spores m–3 for total fungal spores. The total fungal spore concentrations differed significantly among the personal samples (p = 0.026), but not among the area samples, from the five farms. The culturable fungal concentrations among the five farms did not differ significantly in the personal or area samples. Decreased lung functions of the workers were significantly associated with the concentrations of total fungi and several fungal taxa such as Ascospores, Fusarium, and Periconia. This study demonstrated that exposure to high fungal bioaerosol concentrations reduced the lung functions of the mushroom and vegetable farm workers. Superior ventilation and appropriate personal protection equipment are required to reduce occupational biohazards.

Functional Processed Cheese Spreads with High Nutritional Value as Supplemented with Fresh and Dried Mushrooms

In this study processed cheese was supplemented with either fresh or dried edible mushroom (Pleurotus ostreatus Hk 35), to improve its nutritional value, functional and sensory properties, chemical composition, amino acids content, and microbiological quality. Fresh mushroom was added to cheese blend in pieces and smashed form at levels of 0, 5, 10 and 15%, while dried mushroom was added at levels of 0, 1, 1.5 and 2%. Among all processed cheese treatments obvious differences (P≤0.01) were noticed in the organoleptic scores; the highest flavor scores (37.4, 37.3) were recorded for processed cheese supplemented with 1% and 1.5% mushroom powder, respectively. Significant differences (P≤0.01) were also recorded among chemical composition of the resulted processed cheese spreads. Moisture, ash and protein recorded the highest values in processed cheese supplemented with mushrooms compared to control. Moisture content in processed cheese control was 46.26%, while ranged from 47.39 to 53.72% in cheese spread supplemented with mushrooms. There was a significant difference (P≤0.001) in ash content of processed cheese spreads; the highest ash content (5.4%) was for processed cheese spread supplemented with 2% dried mushroom. Cheese spreads that contain mushrooms was high in protein/DM (31.20-36.36%) comparing to the spread of control (30.88%). There was also a significant difference (P ≤ 0.001) in the contents of all tested minerals in processed cheeses. The highest mean values of Ca, P, Mg and Zn was observed in control and processed cheese that contain mushroom powder. Regarding the pH values; processed cheese spreads that contain mushrooms have pH values ranged from 5.39-5.78, while in control ranged from 5.47-5.63. Microbiological investigation showed that the total viable counts and spore former bacteria was lower in processed cheese supplemented with mushrooms than in cheese control. On the other hand, an increase in lipolytic and proteolytic bacteria was noticed during storage period. No yeast and molds were detected in the first month of storage for all processed cheese treatments.