The incidence of fungal spores in the ambient air and inside homes: Evidence from London

Little research has been carried out in London concerning fungal spore prevalence yet this information may help to elucidate geographical patterns of asthma and hay fever. Although many types of spore reach peak concentrations outdoors in late-summer, the incidences in the indoor environment may be more important through the winter because of heating and poor ventilation. Daily average concentrations of fungal spores in the ambient atmosphere were monitored with a Burkard volumetric spore trap on an exposed roof in North London from autumn 1991 until the summer of 1992. Indoor spore measurements were taken in 19 homes in the vicinity through the winter months, both by direct air sampling using a portable Burkard sampler and by dust culture. Trends in the occurrence and concentrations of fungal spores indoors and outdoors were examined. Relationships between the abundance of selected allergenic fungi and features of the houses were analysed including age of dwelling, dampness, cleanliness and presence of pets.Aspergillus andPenicillium were the most frequently occurring spore types in the homes. Overall, high spore incidence was associated with dampness and dust accumulation. The outdoor spore samples revealed generally low concentrations through the winter until March when concentrations of many types includingCladosporium, Epicoccum andAlternaria increased in abundance in response to the warmer weather. Even during the late-spring and early-summer, concentrations of most fungal spores were notably below those reported for rural sites.     

Application of electronic nose technology for the detection of fungal contamination in library paper

Studies were carried out in vitro on a cellulose based agar at two water activities (a_w,0.975,0.995) and on three types of paper at two relative humidities (75, 100% RH) for the potential for differentiation of contamination and colonisation by Aspergillus terreus, A. holandicus and Eurotium chevalieri. In vitro studies showed that conducting polymer sensor array gave different responses to each of these species when grown on cellulose agar at both a_w levels. Discriminant function analyses of the data showed differentiation of the controls from the spoilage fungi. Cluster analysis gave a significant (P=0.05) separation of the control and each spoilage fungus. In situ studies on three types of paper showed that using natural substrates the volatile patterns produced by each of these fungi was different from each other and from the control. The results obtained were better at the higher humidity. The three paper types could be successfully differentiated into clusters. For a single paper type, differentiation of controls from spoilage fungal treatments was better at the higher humidity. This study has shown that this technology has potential for the early detection of fungal contamination in library materials and archives for the improved protection of cultural heritage.     

Fungal spores are an important component of library air

The airborne fungal spore types were studied in different libraries in Delhi, using an Andersen sampler and a Burkard personal sampler, for culturable and non-culturable fungi respectively. The concentration inside the libraries, before and after the agitation of books, were compared with outside air. The major contributors to the library air areCladosporium, aspergilli/penicillia, smuts andAlternaria, varying from 50 to 14%. Some fungi (Cladosporium, Alternaria, smut,Penicillium chrysogenum andnigricans) showed seasonal occurrence, corresponding to their occurrence in the extramural environment. Aspergilli/penicillia,Drechslera, Curvularia andAspergillus flavus had a significantly higher concentration (P<0.01) inside the library, and recorded a significant increase in concentration after agitation of books. Air-conditioned libraries have low fungal spore concentrations, as compared to naturally ventilated libraries.     

Effects of weather conditions on selected airborne fungal spores in the southern part of the state of Enugu,Nigeria

A study of airborne fungal spore was carried out at nine locations in the southern part of the state of Enugu, Nigeria, from March 2005 to February 2006. The aim of the study was to ascertain the variations in selected fungal spore types at the sites owing to weather conditions. The variation in airborne fungal spores of 14 taxa was studied using modified Tauber pollen traps including Alternaria, Corynespora, Curvularia, Drechslera type, Endophragmiella, Botryodiplodia, Ganoderma, Gliomastrix, Nigrospora, Pithomyces, Spegazzinia, Sporidesmium, Tetraploa and Ustilago. The frequency of the spore types recorded showed considerable variation. The highest spore counts were recorded in July, June and October. The highest numbers of fungal spores were recorded during the rainy season (June–October) to early dry season (November–December). The peak of occurrence of most selected fungal spore types was July. The highest percentages of fungal spores were documented at the recording stations Mgbowo Junction, UNTH Ituku Ozalla and Oji River Express Junction. Spearman’s correlation analyses were performed for the monthly amounts of the fungal spore types and monthly meteorological factors. The numbers of Curvularia, Nigrospora and Sporidesmium was significantly correlated with relative humidity, while those of Endophragmiella, Pithomyces and Nigrospora were significantly correlated with temperature. A significant correlation was also found between the number of Nigrospora spores and light intensity and Sporidesmium spores and wind velocity. Relative humidity and temperature seem to be the most important weather conditions affecting the frequency of the selected spore types in the atmosphere.     

An assessment of the air quality in indoor and outdoor air with reference to fungal spores and pollen grains in four working environments in Kerala, India

Qualitative and quantitative analyses of airborne fungal spores and pollen grains in four working environments (market, saw mill, poultry and cow sheds) in Thiruvananthapuram, the capital city of Kerala, India, were carried out for 2 years using Burkard Personal Slide Sampler and Andersen Two-Stage Sampler. Total spore concentration in these sites was always higher in indoor environments than in outdoor environments. Difference in concentration was not statistically significant in any of these work places except in saw mill (t test, p < 0.05). The highest spore concentration was recorded here followed by market, poultry and cow sheds. A total of 32 fungal spore types from indoor environments and 33 spore types from outdoor environments were recorded. Of them, 16 spore types were common to all the sites. Ameropsores, Cladosporium, other basidiospores, Ganoderma and Nigrospora were the dominant spore types in both indoor and outdoor environments. A total of 27 species of viable fungi from indoor and 24 species from outdoor environments were identified. Penicillium citrinum, Aspergillus flavus and Aspergillus niger were the most dominant viable fungi isolated. In contrast, total pollen concentration was always higher in outdoor environments than in indoor environments. Twenty-nine pollen types from indoor and 32 pollen types from outdoor were captured during the sampling. Poaceae, Cocos, Artocarpus, Amaranthus/Chenopodium and Tridax were the common and dominant pollen types observed in all the sites. Peak spore and pollen incidence were recorded during the late rainy and dry seasons (October–February) in both indoor and outdoor environments. The study revealed high prevalence of predominantly allergenic fungal spores and pollen grains in all the four work places. Workers/visitors are at potential risk of susceptibility to respiratory/allergic disorders.     

Status of airborne spores and pollen in a coir factory in Kerala,India

The prevalence of airborne fungal spores and pollen grains in the indoor and outdoor environments of a coir factory in Thiruvananthapuram district of Kerala state, India was studied using the Burkard Personal Sampler and the Andersen 2-stage Sampler for 2 years (September 1997 to August 1999). The concentration of pollen grains was remarkably lower than that of fungal spores (ratio of 1:28). There was no large difference in the concentrations and types of fungal spores between the indoor and outdoor environments, with 26 spore types found to be present indoors and 27 types outdoors; of these, 22 were common to both the environments. Aspergillus/Penicillium, Cladosporium, ‘other basidiospores’ and ascospores were the dominant spore types. The total spore concentration was highest in February and lowest in September, and it was significantly higher in 1998–1999 than in 1997–1998. Twenty viable colony-forming types were isolated from inside the coir factory. The most dominant viable fungi isolated were Penicillium citrinum, Aspergillus flavus and Aspergillus niger. The total pollen concentration was higher in the outdoor environment of the coir factory than indoors, with 15 and 17 pollen types, respectively. Grass and Cocos nucifera pollen types were dominant. The dominant spore and pollen types trapped in the two environments of the coir factory are reportedly allergenic and, consequently, workers are at risk of catching respiratory/allergic diseases.     

Pollen and Mould Allergy in Southern Sardinia (Italy): Comparison of Skin-Test Frequencies and Air Sampling Data

A study was carried out to investigate the influence of atmospheric pollen and fungi in determining allergic diseases by comparing the frequency of skin reactions to air sampling data over a 6-year period.

48% of our population reacted to at least one of the pollen and fungal extracts used. Among pollen, Gramineae gave the most frequent positive reactions, followed by Parietaria, Olea and Compositae. The most common positive skin tests in fungus sensitive patients were by extracts of Alternaria, Cladosporium, Aspergillus and Candida

As for the aerobiological survey, the general trend of pollen and molds was similar during the sampling period. The annual pollen catch did not show remarkable differences during the years sampled, whereas the total fungal spore count was highest in 1988 and 1990.

A comparison between aerobiological and clinical data revealed a good degree of concordance between total pollen counts and positive skin test frequencies for Urticaceae, Gramineae and Oleaceae but not for Compositae (high positive skin reactions and very low counts) and Cupressaceae (high counts and few skin reactions).

A less marked correlation has been found between fungal spore counts and positive skin-test frequencies as compared to pollen. Spores such as Cladosporium, which are present in large number in the air, appear to be less sensitizing, while certain spore types (e.g. Alternaria), seem to be able to sensitize patients in spite of their low atmospheric concentrations.     

Contribution of leaf surface fungi to the air spora

High concentrations of airborne fungal spores frequently occur from spring through fall in temperate areas of the world. Although it is generally assumed that fungi on leaf surfaces are contributors to the air spora, little data are available comparing the types of fungi found on leaf surfaces with those in the atmosphere. Air sampling was carried out with a Burkard Spore Trap located on the roof of a building on the University of Tulsa campus using standard methods. Leaf samples were aseptically collected from Ulmus americana and Quercus palustris trees on campus, placed in sterile plastic bags, and brought to the lab. For each leaf, 4 cm² areas of both upper and lower leaf surfaces were swabbed and plated on malt extract agar with streptomycin. Cultures were incubated at room temperature for 5–7 days and then examined microscopically. Results were expressed as colony forming units (CFU)/cm². Twenty-one fungal taxa were identified from the air samples. The most abundant taxa were Cladosporium, ascospores, basidiospores, and Alternaria; together these four spore types comprised over 90% of the yearly total. Yeasts were the most abundant fungi isolated from both leaf types. Among the mycelial fungi were Phoma species, followed by Cladosporium and Alternaria. Overall twenty genera of filamentous fungi were identified. Yeasts and Phoma are normally splash dispersed and were not identified in the Burkard air samples. However, 10 taxa isolated from leaf surfaces were registered in air samples. Crude estimates of the leaf surface area of each tree suggest that the total fungal load was approximately 5.04×10⁸ CFU for Ulmus and 2.71×10⁸ CFU for Quercus. Of these levels, 19% were from fungi also detected in air samples. The data suggest that some leaf-surface fungi are major contributors to the air spora.     

Ten types of microscopically identifiable airborne fungal spores at Leiden,The Netherlands

A universal method for the complete assessment of atmospheric fungal spores does not exist, which is continuous, volumetric and non-selective, and offers at the same time reliable identification of the collected spores. To perform a survey of airborne fungal spores, a choice has to be made between a viable and non-viable method. For the study carried out in Leiden, the non-viable, continuous volumetric method has been employed, showing the results over a period of 10 years, for 10 microscopically identifiable fungal spore types. Of this selection,Cladosporium spores have by far the highest airborne quantities, with an average annual total of the daily averages of over 700 000.Botrytis, Ustilago andAlternaria follow with much lower spore concentrations of between 20 000 and 30 000 as annual totals. The spore types ofEpicoccum, Erysiphe, Entomophthora, Torula, Stemphylium, andPolythrincium are represented with annual sums lower than 10 000. A spore calendar shows the overall seasonal appearance of the 10 selected types.     

Fungal spores prevalent in the aerosol of the city of Caxias do Sul, Rio Grande do Sul, Brazil, over a 2-year period (2001–2002)

This study was carried out over a 2-year period (2001 and 2002) with the aim of identifying the fungal population in the aerosol of the Southern city of Caxias do Sul, RS, Brazil. Sampling was performed using Hirstȁ9s non-viable volumetric method. Our results show the presence of a large number of fungal spore types, a total of 41. Three groups were predominant: Deuteromycotina, Ascomycotina and Basidiomycotina. In 2001, Deuteromycotina taxa represented 44.61% of the total annual spore counts, with the largest concentration occurring in the fall (58,637 spores); in 2002, it represented 40.03% of the total annual spore counts, and the largest concentration was obtained in the summer (68,317 spores). Ascomycotina was present at the same level (24.5%) in both years of sampling, and the highest concentrations were found out in the summer (2001: 42,183 spores; 2002: 29,461 spores). Basidiomycotina represented 22.37% of the total annual spore counts in 2001, and 20.41% in 2002, with the largest concentrations found in the summer (2001: 35,988 spores; 2002: 30,212 spores). The most frequent fungi found during the study period were Cladosporium, Coprinus, Leptosphaeria, Aspergillus/Penicillium and Ganoderma. Permanent aerobiological monitoring would be necessary to detect associated environmental variations.     

Prevalence of culturable and non-culturable airborne fungi in a grain store in Delhi

Fungal spores are important aeroallergens and proper knowledge of their qualitative and quantitative prevalence in indoor and outdoor environments is of paramount importance in the study of allergic disorders. The present investigation was aimed at the study of seasonal and annual prevalence of fungi inside a large grain storage facility. Sampling was carried out from September 1989 to August 1991. Although fungal spores occurred throughout the year there was seasonal variation.Aspergillus flavus. Cladosporium spp.Epicoccum nigrum and basidiospores had a definite seasonal pattern.Aspergillus flavus andUstilago (smuts) were the most predominant fungi in the facility. Their concentration was significantly higher (P<0.05) than in outside air. The need to reduce fungal concentration in grain storage is emphasised.     

Arbuscular mycorrhizal dynamics in a chronosequence of Caragana korshinskii plantations

Arbuscular mycorrhizal (AM) fungi in a chronosequence of 5–42-year-old Caragana korshinskii plantations in the semi-arid Loess Plateau region of northwestern China were investigated. AM fungi colonization, spore diversity and PCR-denatured gradient gel electrophoresis-based AM fungal SSU rRNA gene sequences were analyzed. AM fungi colonization [measured as the percent of root length (%RLC), vesicular (%VC) and arbuscular (%AC) colonization] and spore density were significantly correlated with sampling month, but not with plant age, except for %RLC. The percent of vesicular colonization was negatively correlated with soil total nitrogen and organic carbon, and spore density was negatively correlated with soil moisture and available phosphorus. Ten distinguishable AM fungal spore morphotypes, nine Glomus and one Scutellospora species, were found. Nine AM fungal Glomus phylotypes were identified by sequencing, but at each sampling time only four to six AM fungal phylotypes were detected. The AM fungal community was significantly seasonal, whereas the AM fungal species richness did not increase with plantation age. A significant change in AM fungal colonization and community composition over an annual cycle was observed in this study, and our results suggest that the changes of AM are the product of the interaction between host phenology, soil characteristics and habitat. Understanding these interactions is essential if habitat restoration is to be effective.     

泰山丛枝菌根真菌群落结构特征

2007年对泰山植被根围内丛枝菌根(arbuscular mycorrhiza,AM)真菌群落组成、数量、分布及其与植物多样性的关系进行了研究。从泰山傲徕峰、黑龙潭库区等样地共分离出4属16种AM真菌:球囊霉属Glomus 9种、无梗囊霉属Acaulospora 4种、巨孢囊霉属Gigaspora 2种和盾巨孢囊霉属Scutellospora1种。其中,球囊霉属Glomus及聚球囊霉Glomus fasciculatum的孢子密度、相对多度、分布频度和重要值均最高,分别为泰山植被区根围内AM真菌优势属和优势种。各样地之间Sorenson相似系数在0.60和0.85之间。植被数量与孢子密度(r=0.80,p0.01)、植物种的丰富度与AM真菌种的丰富度(r=0.77,p0.01)以及与孢子密度(r=0.59,p0.01)均呈极显著正相关关系。研究结果表明植物多样性对于提高AM真菌多样性发挥极为重要的作用。     

Ten types of microscopically identifiable airborne fungal spores at Leiden,The Netherlands

A universal method for the complete assessment of atmospheric fungal spores does not exist, which is continuous, volumetric and non-selective, and offers at the same time reliable identification of the collected spores. To perform a survey of airborne fungal spores, a choice has to be made between a viable and non-viable method. For the study carried out in Leiden, the non-viable, continuous volumetric method has been employed, showing the results over a period of 10 years, for 10 microscopically identifiable fungal spore types. Of this selection,Cladosporium spores have by far the highest airborne quantities, with an average annual total of the daily averages of over 700 000.Botrytis, Ustilago andAlternaria follow with much lower spore concentrations of between 20 000 and 30 000 as annual totals. The spore types ofEpicoccum, Erysiphe, Entomophthora, Torula, Stemphylium, andPolythrincium are represented with annual sums lower than 10 000. A spore calendar shows the overall seasonal appearance of the 10 selected types.     

Organic Matter Stimulates Bacteria and Arbuscular Mycorrhizal Fungi in Bauhinia purpurea and Leucaena diversifolia Plantations on Eroded Slopes in Nepal

Erosion resulting from landslides is a serious problem in mountainous countries such as Nepal. To restore such sites it is essential to establish plant cover that protects the soil and reduces surface erosion. Mycorrhizal fungi growing in symbiosis with plants are essential in this respect because they improve both plant nutrient uptake and soil structure. We investigated the influence of organic matter and P amendment on recently produced biomass of bacteria and arbuscular mycorrhizal (AM) fungi in eroded slopes in Nepal. Eroded soil mixed with different types of organic matter or P was placed in mesh bags, which were buried around trees of Bauhinia purpurea and Leucaena diversifolia between June 2003 and December 2003 (the wet season) or between December 2003 and June 2004 (the dry season). Signature fatty acids were used to determine bacterial and AM fungal biomass after the 6‐month intervals. The amount and composition of AM fungal spores were analyzed in the mesh bags from the dry season. More microbial biomass was produced during the wet season than during the dry season. Furthermore, organic matter addition enhanced the production of AM fungal and bacterial biomass during both periods. The positive influence of organic matter addition on AM fungi could be an important contribution to plant survival in plantations on eroded slopes. Different AM spore communities and bacterial profiles were obtained with different organic amendments and this suggests a possible way of selecting for specific microbial communities in the management of eroded sites.     

The variation in spore concentrations of selected fungal taxa associated with weather conditions in Szczecin,Poland, 2004–2006

The investigation of airborne fungal spore concentrations was carried out in Szczecin, Poland between 2004 and 2006. The objective of the studies was to determine a seasonal variation in concentrations of selected fungal spore types due to meteorological parameters. The presence of spores of ten taxa: Cladosporium, Ganoderma, Alternaria, Epicoccum, Didymella, Torula, Dreschlera‐type, Polythrincium, Stemphylium and Pithomyces was recorded in Szczecin using a volumetric method (Hirst type). Fungal spores were present in the air in large numbers in summer. The highest concentrations were noted in June, July and August. The peak period was recorded in August for most of the studied spore types: Ganoderma, Alternaria, Epicoccum, Dreschlera‐type, Polythrincium and Stemphylium. Cladosporium and Didymella spores reached their highest concentrations in July while concentrations of Torula were highest in May and Pithomyces in September. Multiple regression analysis was performed for three fungal seasons: 2004, 2005, and 2006. Spore concentrations were positively correlated with minimum temperature for seven spore types in 2004, for five spore types in 2005, and for eight spore types in 2006 (significance level of α = 0.05). Some spore types are also significantly correlation among their concentrations, pressure, relative humidity and rain. Minimum temperature appeared to be the most influential factor for most spore types.     

Literature on Basic Palynology

The occurrence of airborne fungi at an urban coastal site was compared with that at a rural inland site in the South of Sardinia. Spore concentrations at the two sites differed markedly with lower concentrations at the urban site but the spore types found were similar. The general trend of the fungal airspores was also very similar at both sites as a result of the similar climatic conditions.

Mould spore concentrations were greatest in late spring (May-June) and autumn (October-November) with a decrease during summer months at both sites sampled. Cladosporium was the most common spore type identified followed by Basidiomycetes, Alternaria, Fusarium. These taxa are well known as allergens. It is recommended that further aeromycological surveys should be performed in different areas to determine the clinical importance of fungi as allergens in Sardinia.     

A viscometric study of the biodegradation of photographic gelatin by fungi isolated from cinematographic films

The biodegradation of photographic gelatin grade (Bloom 225) material was studied by viscometry in aqueous solution (at 37 °C, 6.67% w/w) using filamentous fungi isolated and identified from cinematographic film stored in different Spanish archives. From viscosity data, different variables such as molecular weight and chain scission were calculated. To ensure initial spore suspension concentration was standardized for all the biodegradation experiments, a correlation between transmittance at 530 nm of fungal spore suspensions and the corresponding cytometric determination of populations was established for all the fungal strains studied in this work. The bioassay experiments were carried out at 25 and 4 °C using an initial concentration of fungi of 4.5×10⁵ conidia/mL except in the case of the genus Alternaria, where the concentration was 10 times lower. The fungal strains were three species of Aspergillus, i.e., A .ustus, A. nidulans var. nidulans, A. versicolor, seven Penicillium chrysogenum strains, and Cladosporium cladosporioides, Alternaria alternata, Mucor racemosus, Phoma glomerata, and Trichoderma longibrachiatum. All were gelatinase positive. Through the viscosity decay profiles with bioassay-time and the corresponding calculated chain scission, the relative quantitative gelatinase efficiency of these fungi has been evaluated.     

Large‐scale fungal diversity assessment in the Andean Yungas forests reveals strong community turnover among forest types along an altitudinal gradient

The Yungas, a system of tropical and subtropical montane forests on the eastern slopes of the Andes, are extremely diverse and severely threatened by anthropogenic pressure and climate change. Previous mycological works focused on macrofungi (e.g. agarics, polypores) and mycorrhizae in Alnus acuminata forests, while fungal diversity in other parts of the Yungas has remained mostly unexplored. We carried out Ion Torrent sequencing of ITS2 rDNA from soil samples taken at 24 sites along the entire latitudinal extent of the Yungas in Argentina. The sampled sites represent the three altitudinal forest types: the piedmont (400–700 m a.s.l.), montane (700–1500 m a.s.l.) and montane cloud (1500–3000 m a.s.l.) forests. The deep sequence data presented here (i.e. 4 108 126 quality‐filtered sequences) indicate that fungal community composition correlates most strongly with elevation, with many fungi showing preference for a certain altitudinal forest type. For example, ectomycorrhizal and root endophytic fungi were most diverse in the montane cloud forests, particularly at sites dominated by Alnus acuminata, while the diversity values of various saprobic groups were highest at lower elevations. Despite the strong altitudinal community turnover, fungal diversity was comparable across the different zonal forest types. Besides elevation, soil pH, N, P, and organic matter contents correlated with fungal community structure as well, although most of these variables were co‐correlated with elevation. Our data provide an unprecedented insight into the high diversity and spatial distribution of fungi in the Yungas forests.     

Airborne Fungi Survey of Some Residences in Durham,North Carolina,USA

Gravity settling culture (GSC) plate collections of endogenous fungi were made at four homes in Durham, North Carolina. During frost-free periods (May-August), the most frequently isolated genera included Mucor, Cladosporium (Hormodendrum), Aspergillus, Penicillium, Rhizopus, Alternaria, Cunninghamella, Aureobasidium, Fusarium, Heterosporium, Amblyosporium, and other (unidentified) fungi. Higher numbers of mold isolates were associated with high shade and high levels of organic debris near the home and poor landscaping and landscape maintenance. Lower concentrations of mold isolates were associated with the presence of a central electrostatic filtration system and good compliance with dust controls. The viable mold spore levels were lower in homes where the electrostatic filtration unit was operated continuously rather than intermittently. These findings reflect the ease with which outdoor spore clouds may penetrate structures and obscure evidence of internal fungus source. The data also imply that because of size-related undersampling, open plates can exclude abundant types of recovery. No statistically significant correlations could be made between indoor mold isolates and any of the following: number and age of the occupants, age and size of home, month of survey or the presence of plants. Attempts have been made to facilitate the diagnosis of fungal allergy by gathering together examples of places and materials which are most likely to be a risk for mold sensitive patients.