Airborne fungal spores in 80 homes in the Latrobe Valley, Australia: levels, seasonality and indoor-outdoor relationship

Airborne viable and total fungal spores were sampled inside and outside 80 houses in the Latrobe Valley, Victoria, Australia as part of a larger indoor environmental study. Each residence was visited six times over a period of 1 year for sample collection, and fungal spore samples were collected from at least three indoor sites and from an outdoor site. Viable spores were sampled using an Andersen sampler, while total spores were assessed using a Burkard spore trap. Identification of fungal colonies to genera level was performed in two seasons; winter and late spring. The most common fungal genera/groups wereCladosporium, Penicillium, and yeasts, both indoors and outdoors in winter and late spring. Outdoor levels were higher than those indoors throughout the year, and a significant seasonal variation in spore levels was seen both indoors and outdoors with overall maxima in summer. Contrary to this trend, the levels ofAspergillus, yeasts,Cephalosporium andGliocladium were higher in winter. Most fungal genera were found in greater concentrations outdoors compared to indoors, butPenicillium was more common indoors. Outdoor spore levels were a significant influence on indoor levels, but seasonal differences suggest that other influences are important.     

Vegetation: A source of air fungal bio-contaminant

Airborne fungal counts and types were examined in three selected regions in Egypt. Two of the sampling sites are rural areas, one cultivated with chamomile and the second with vegetable. The third site is located in an urban area. A sedimentation method was used to isolate airborne fungal spores. Airborne fungal spore counts averaged 71\pm 19, 64\pm 14 and 175\pm 79 cfu/p/h in the urban, vegetable and chamomile growing areas, respectively. A total of 1486 fungal colonies belonging to 32 genera were identified. Alternaria (7.5–59.9%), Aspergillus (11.2–38.9%), Penicillium (9.5–15%) and Cladosporium (7.78–17.5%) were the predominant fungal genera found in all sampling sites. Alternaria (42–59.9%) and Aspergillus (38.9%) were the common fungal genera in the cultivated and urban areas, respectively. Vegetation is considered the main source of Alternaria, whereas Aspergillus, Penicillium and Cladosporium are related to local microenvironments and urbanization. Acremonium, Aureobasidium, Botrytis, Beauveria, Chlamydomyces, Chalara, Curvularia, Fusarium, Geotrichum, Trichothecium, Oidiodendron, Scopulariopsis, Spicaria, Stachybotrys chartarum, Torula and Thamnidium, were only detected in low percentages (0.11–1.8%) in the cultivated areas. Vegetation adds different fungal types into the air and their numbers vary according to vegetation type and weather conditions. Airborne fungal counts increased with temperature and decreased with rainfall and relative humidity. Airborne fungal spores have many implications in the spread of human and plant diseases. The presence of fungal spores in air, in spite of their counts, may raise arguments about their role in health complaints in a particular region, „i.e., the fungal concentration may be low but the predominant aeroallergen may be dangerous”.     

An aerobiological study of pollen grains and fungal spores of Barcelona (Spain)

Summary A study of concentration of airborne pollen grains and fungal spores has been carried out in Barcelona (Spain) during 1989–90. The volumetric method of filtration, previously described for airborne pollen analysis (Suarez-Cervera and Seoane-Camba, 1983) has been used. In this case, the filters have also been cultivated in Czapecdox-agar, Sabouraud-agar and Sabouraud-agar with streptomycin for the identification of the fungal colonies. Analysis of the number of fungal spores growing on the filter shows that the maxima of colonies of spores developed in culture per m³ of air filtered, correspond to September–December. Pollen and spore concentrations start from November–December, reach a maximum in March–April and decline progressively until September–October. Therefore, in the city of Barcelona, the greatest concentration occurs in spring and the lowest in autumn.     

Paleobotanical remains from the Paleocene–lower Eocene Vagadkhol Formation, western India and their paleoclimatic and phytogeographic implications

A small assemblage of macro- and micro floral remains comprising fossil leaf impressions, silicified wood, spores, and pollen grains is reported from the Paleocene–lower Eocene Vagadkhol Formation (=Olpad Formation) exposed around Vagadkhol village in the Bharuch District of Gujarat, western India. The fossil leaves are represented by five genera and six species, namely, Polyalthia palaeosimiarum (Annonaceae), Acronychia siwalica (Rutaceae), Terminalia palaeocatapa and T. panandhroensis (Combretaceae), Lagerstroemia patelii (Lythraceae), and a new species, Gardenia vagadkholia (Rubiaceae). The lone fossil wood has been attributed to a new species, Schleicheroxylon bharuchense (Sapindaceae). The palynological assemblage, consisting of pollen grains and spores, comprises eleven taxa with more or less equal representation of pteridophytes, gymnosperms, and angiosperms. Angiospermous pollen grains include a new species Palmidites magnus. Spores are mostly pteridophytic but some fungal spores were also recovered. All the fossil species have been identified in the extant genera. The present day distribution of modern taxa comparable to the fossil assemblage recorded from the Vagadkhol area mostly indicate terrestrial lowland environment. Low frequency of pollen of two highland temperate taxa (Pinaceae) in the assemblage suggests that they may have been transported from a distant source. The wood and leaf taxa in the fossil assemblage are suggestive of tropical moist or wet forest with some deciduousness during the Paleocene–early Eocene. The presence of many fungal taxa further suggests the prevalence of enough humidity at the time of sedimentation.     

Fertile fungal spores collected on different faced surfaces in the atmosphere of Giza,Egypt

A quantitative and qualitative survey was carried out for airborne fungus spores coming into contact with horizontally and vertically gravitation sampling oriented surfaces in the atmosphere of Giza city. Czapek Dox agar, malt extract agar, potato dextrose agar and Sabouraud dextrose agar Petri dishes were exposed monthly to the five oriented surfaces of a polystyrene cube, throughout a one-year period. Significant differences (P < 0.01) were observed between the total counts of caught airborne fungi contacting with the horizontal compared to other vertically oriented surfaces. Conversely, there were no significant differences observed between the total catch of airborne fungi using the various sampling media. The results revealed that vertical sampling provides valuable information that may be lost from horizontal sampling alone. A total of 5,053 colonies belonging to 40 fungal organisms were identified. Alternaria (24.26%), Aspergillus (19.2%), Cladosporium (14.5%) and Penicillium (11.43%) were the most predominant fungal genera. Collected fungi were grouped into high, medium, low and rare components depending upon their frequency in the studied atmosphere. Aspergillus niger, Aspergillus parasiticus, Alternaria, Cladosporium and Penicillium were regularly found on all oriented surfaces. However, Arthrobotrys, Biospora, Chaetomium, Pleospora, Trichothecium and Verticillium were rarely found in the air. Positive and/or negative correlations were observed between the total fungal counts and the predominant fungal types with meteorological parameters during sampling days.     

A study of fungal spore poupulations in the atmosphere of Kuwait

The fungal air-spora of Kuwait was investigated using the Petri-dish trapping technique. During the period from 1st April, 1974 to 30th June, 1975, a total of 3685 colonies were recorded from 2 % malt agar plates. Fifty-five genera and 116 species were identified. Alternaria occupied the first place in the order of percentage incidence, being represented by 18.3% of the entire catch, followed by Aspergillus (17.1%), Penicillium (14%), Cladosporium (13.6%), Drechslera (13.3%), and Ulocladium (7.1%). The widest spectrum of species was displayed by Aspergillus (possessed 19 species) followed by Penicillium (17 species), Alternaria (6 species), Drechslera (5 species), and Ulocladium (4 species). The monthly total number of fungi showed marked seasonal periodicity with the greatest number of colonies occurring in March–April and November. The lowest counts were recorded in mid-summer (July) and mid-winter (January). Only 220 colonies and 17 species of thermophilous fungi were reported from plates incubated at 45 °C. The most common species were Aspergillus fumigatus and A. terreus.     

Airborne concentrations ofBotrytis, Uncinula andPlasmopara spores in a vineyard in Leiro-Ourense (N.W. Spain)

Three important phytopathogenic spores which cause serious fungal diseases on vines (Botrytis, Uncinula andPlasmopara) were monitored from June 2, 1994 to September 21, 1994, in vineyards belonging to ‘Estación de Enoloxía e Viticultura’ of Ponte San Clodio-Leiro (Ourense), one of the most important vine growing areas of northwest of Spain. The concentrations for each of the genera were correlated with rainfall, humidity, maximum, minimum and average temperatures. These meteorological parameters are currently used to determine chemical sprays to be applied to the vines. The aim was to establish the behaviour of airborne concentrations of spores of these taxa during the period from the flowering to harvest because these are the periods of greatest susceptibility to attack by these pathogens.     

Airborne fungi monitoring in Santiago, Chile

Fungal airborne spores were studied from September 1996throughout August 1997 in Santiago, Chile. Total concentrationsfluctuated between 308 and 10,334 spores/m³/day withan annual mean of 2,154 per m³, the highest dispersion beingduring April and May. Forty-five percent of total fungal content wasfound in autumn. Thirteen genera and 3 other spore types wereidentified. Cladosporium, the most abundant genera in ouratmosphere, contributed with 70.9% of the total fungi counts andreached an annual mean of 1,527 spores/m³/day, itshighest frequency being in autumn. Alternaria appeared as thesecond most frequent genera, with an annual mean of 40spores/m³/day, representing a 1.9% of theannual fungal catch. Altogether, Stemphylium, Torula, Epicoccum,Ganoderma, Helminthosporium, Chaetomiun, Pleospora and othersreached relative frequencies of 0.5% or less. It is concludedthat fungi are present in Santiago's atmosphere all year round, some ofthem with a clear seasonality.     

Study of airborne fungal spores in Madrid, Spain

The concentration of fungal spores in the atmosphere of Madrid was recorded and analyzed for the year 2003. Airborne spores were sampled continuously with a Hirst-type spore trap located on the roof of a building of the School of Pharmacy, at about 8 m above ground level. Correlation between the mean daily spore concentrations and meteorological variables were explored by means of Spearman’s correlation analyses. Seventy spore types were identified, of which the most numerous were Cladosporium, Aspergillaceae (conidia), Coprinus, Agaricales (basidiospores), Ustilago (teliospores) and Pleospora (ascospores). These six types of spores represented more than 70% of the total. Cladosporium represented 41% of the total fungal spores, while Ustilago spores, the concentrations of which in May and June exceeded 47% of the monthly total spore count, constituted the second most important group. Spores reached their highest concentrations in the spring months, and in the autumn, mainly in October. A␣positive significant correlation was found between airborne spore counts and temperature and relative humidity. The results provide a picture of the spectrum of airborne fungal spores present in the atmosphere of Madrid and of the `peak' periods of their presence. Future studies will provide more detailed information on the seasonal dynamics of the spores most frequently found in the air as well as on the extent to which atmospheric conditions influence their release, dispersion and sedimentation processes.     

Fungal biodiversity,pollen morphology and leaf surface of some native species in Egypt

Five native species of the flora of Egypt: Adonis dentata Delile, Ranunculaceae; Papaver dubium L., Papaveraceae; Matthiola longipetala (Vent.) DC., Brassicaceae; Malva parviflora L., Malvaceae; and Erodium laciniatum (Cav.) Willd., Geraniaceae have been investigated morphologically, palynologically and mycologically. The total counts of phyllosphere fungi fluctuated between 223 and 388 colonies/100 leaf segments giving maximum on Malva parviflora followed by Matthiola longipetala, Erodium laciniatum, Papaver dubium and Adonis dentata. The widest spectrum of genera (20) and species (39 and l variety) was recorded on Malva parviflora and the narrowest on Adonis dentata (9, 14). Sixty species and one variety belonging to 27 genera were collected from leaves (24 genera and 56 species and 1 variety) and anthers/pollen (16 genera and 27 species) of the five studied plants with the most frequently species were some members of Alternaria, Cladosporium, Fusarium and Mucor. Members of Aspergillus and Penicillium were prevalent only on leaves of Matthiola longipetala and Malva parviflora, while these members were infrequently recorded on leaf surfaces of Adonis dentata and Papaver dubium. Results revealed that density of hairs on the leaf surface and size of leaf blade, almost seem to be the most reliable factors of the biodiversity of the fungal spores on the studied taxa. On the other hand, reticulate or striate pollen surface had a wider spectrum of fungal biodiversity and higher densities of spores compared with echinate and scabrate surface.     

Fungi in healthy and diseased sea fans (<Emphasis Type="Italic">Gorgonia ventalina)</Emphasis>: is <Emphasis Type="Italic">Aspergillus sydowii</Emphasis> always the pathogen?

Caribbean corals, including sea fans (Gorgonia spp.), are being affected by severe and apparently new diseases. In the case of sea fans, the pathogen is reported to be the fungus Aspergillus sydowii, and the disease is named aspergillosis. In order to understand coral diseases and pathogens, knowledge of the microbes associated with healthy corals is also necessary. In this study the fungal community of healthy Gorgonia ventalina colonies was contrasted with that of diseased colonies. In addition, the fungal community of healthy and diseased tissue within colonies with aspergillosis was contrasted. Fungi were isolated from healthy and diseased fans from 15 reefs around Puerto Rico, and identified by sequencing the nuclear ribosomal ITS region and by morphology. Thirty fungal species belonging to 15 genera were isolated from 203 G. ventalina colonies. Penicillum and Aspergillus were the most common genera isolated from both healthy and diseased fans. However, the fungal community of healthy fans was distinct and more diverse than that of diseased ones. Within diseased fans, fungal communities from diseased tissues were distinct and more diverse than from healthy tissue. The reduction of fungi in diseased colonies may occur prior to infection due to environmental changes affecting the host, or after infection due to increase in dominance of the pathogen, or because of host responses to infection. Data also indicate that the fungal community of an entire sea fan colony is affected even when only a small portion of the colony suffers from aspergillosis. An unexpected result was that A. sydowii was found in healthy sea fans but never in diseased ones. This result suggests that A. sydowii is not the pathogen causing aspergillosis in the studied colonies, and suggests several fungi common to healthy and diseased colonies as opportunistic pathogens. Given that it is not clear that Aspergillus is the sole pathogen, calling this disease aspergillosis is an oversimplification at best. Communicated by Biology Editor Dr Michael Lesser     

Airborne fungi in an Italian rice mill

Summary Studies employing volumetric spore trap (VSP) and gravity settling culture plates (GSC) were conducted in order to analyse the air spora of a rice mill at Pavia, Italy, from October-December 1988. Results revealed a variety of fungal spores belonging to different genera and including recognized rice pathogenic fungi. The most frequent genera by GSC method includedAcremonium, Alternaria, Aspergillus, Aureobasidium, Cladosporium, Epicoccum, Fusarium, Helminthosporium, Mucor, Nigrospora, Penicillium, Rhizopus, Trichoderma, Trichothecium, and some unidentified fungi. Environmental assessment of fungal spores by VSP revealed that the most prevalent fungi were:Alternaria, Cladosporium, Epicoccum, Helminthosporium, Nigrospora, Pyricularia, Tilletia and hyaline, dark and coloured types of ascospores and basidiospores. Airborne fungal spore concentrations were particularly high (5,000–6,000 spores/m³) in the rooms of the rice mill where the initial stages of rough rice transformation take place, and dropped to 2,500 spores/m³ in the last room, where workers are. During a temporary interruption of the working processes, air spora concentration dropped below 1,000 spores/m³.Cladosporium, Epicoccum andNigrospora spores were predominant in all subdivisions of the indoor environments of the rice mill.     

Development of a user-friendly delivery method for the fungus Metarhiziumanisopliae to control the ectoparasitic mite Varroa destructor in honey bee, Apis mellifera, colonies

A user-friendly method to deliver Metarhizium spores to honey bee colonies for control of Varroa mites was developed and tested. Patty blend formulations protected the fungal spores at brood nest temperatures and served as an improved delivery system of the fungus to bee hives. Field trials conducted in 2006 in Texas using freshly harvested spores indicated that patty blend formulations of 10 g of conidia per hive (applied twice) significantly reduced the numbers of mites per adult bee, mites in sealed brood cells, and residual mites at the end of the 47-day experimental period. Colony development in terms of adult bee populations and brood production also improved. Field trials conducted in 2007 in Florida using less virulent spores produced mixed results. Patty blends of 10 g of conidia per hive (applied twice) were less successful in significantly reducing the number of mites per adult bee. However, hive survivorship and colony strength were improved, and the numbers of residual mites were significantly reduced at the end of the 42-day experimental period. The overall results from 2003 to 2008 field trials indicated that it was critical to have fungal spores with good germination, pathogenicity and virulence. We determined that fungal spores (1 × 10¹⁰ viable spores per gram) with 98% germination and high pathogenicity (95% mite mortality at day 7) provided successful control of mite populations in established honey bee colonies at 10 g of conidia per hive (applied twice). Overall, microbial control of Varroa mite with M. anisopliae is feasible and could be a useful component of an integrated pest management program.     

Seasonal and Diurnal Variation of Airborne Basidiomycete Spore Concentrations in Mexico City

Seasonal and diurnal changes in concentrations of airborne basidiomycete spores (basidiospores, rusts, smuts) were studied, using Burkard volumetric spore traps, in two areas of Mexico City with different degrees of urbanization and related to changes in climatic variables through 1991. Basidiomycete spores formed a large component of the total airborne fungal spore load in the atmosphere of Mexico City. They were the second most abundant spore type after Deuteromycotina (Hyphomycetes), forming 32% of the total fungal spores trapped in an urban-residential area and 28% in an urban-commercial area. The most abundant basidiomycete spores were basidiospores although smut-type spores were trapped on more days than basidiospores and rusts on fewer. Basidiospores occurred in concentrations up to 2,000 spores m-3 in the urban-residential area. Basidiospores showed a marked seasonal distribution, especially in the southern area, with their greatest abundance during the wet season. The correlation coefficients associated with regressions between basidiospore concentration and some environmental factors were increased when a lag period of 2 to 4 days was used between environmental measurements and the day of spore collection. Basidiospore concentrations exceeded the 75 percentile concentration (>400 spores m^-3) most often when rainfall was up to 6 mm and relative humidity was >70%. Basidiospores showed a diurnal periodicity with greatest concentrations in the early morning. The most common basidiospore type was Coprinus which formed 67% of basidiospores trapped in the southern area and 63% in the central area. Smut spores were trapped on 87% of days through the year while rust spores occurred in only 35%. Both rusts and smuts were present in only small concentrations.     

Characterization of the physiological state of fungi by dynamics of colony emergence on solid media

Poisson distribution was shown to be applicable to the dynamics of emergence of fungal colonies on plates inoculated with pure cultures or environmental samples, indicating the possibility for application of Hattori approach for assessment of the physiological state of fungi. The differences in physiological activity of different fungal species and genera, between spores and mycelia, or between the fungal populations from different environments, were revealed using the t _r (delay time for colony emergence) and λ (potential capacity for growth) parameters.     

Airborne fungal spores in an industrial area: seasonal and diurnal periodicity

Qualitative and quantitative studies of atmospheric fungal spores at a chloralkali factory, Jayashree Chemicals. were made during 1993 employing culture plate and rotorod methods. A total of 57 sporulating fungal types, including three sterile mycelial forms, were recorded by the culture plate method and 51 spore types, including the hyphal fragments and unidentified spores, were recorded by the rotorod method. As to the seasonal variation, winter was found to be the greatest contributor of fungal spores as compared to the summer and rainy season. Instead, when considering the hour of the day, the peak number of fungal propagules was recorded at noon (12.00 h) followed by evening and morning values, an exception being recorded in winter months, when maximum CFUs ofCladosporium were monitored in the morning. The seasonal variation in fungal concentration and composition was found to be influenced by temperature, rainfall and relative humidity, whereas diurnal incidence was the effect of varying temperature and relative humidity during day time only. Moderate temperature and relative humidity favoured the maximum fungal spore load in the atmosphere.Cladosporium, Nigrospora, Alternaria, Lasiodiplodia, Drechslera, Pestalotia, Curvularia, Epicoccum, Aspergillus, Penicillium andChaetomium were the commonest fungal spores in the factory area.     

Fungi in the indoor environment of flour mill in Lucknow

Forty species of fungi were recovered from the indoor air of flour mills by exposing petri plates containing potato dextrose, czapek-dox, and sabouraud agar media for 5 minutes. A rotorod sampler was used. The fungal flora of the nearby outdoor environment was also studied for comparison. Species of genus Aspergillus dominated in the mills, being represented by 16 species including one ascosporic species. Other species were of genera Cladosporium and Fusarium. Variations in the fungal population in different months of the survey year were also observed.

Identifiable fungal spores recovered using the rotorod sampler were Alternaria (17% occurrence), Curvularia lunata (10.6%), C. letramera (10%), Cladosporium (19%), Drechslera sp. (9%), Epicoccum sp. (5%), Pithomyces sp. (3%), Nigrospora sp. (10.5%), Stemphylium sp. (4.5%) and Torula sp. (4.5%). Mycelial fragments and unidentifiable spores were also seen in abundance.

Varying allergic responses of patients tested intradermally for the antigens of six Aspergilli, viz., Aspergillus flavus, A. fumigatus, A. melleus, A. niger, A. niveus, and A. terreus were also recorded.     

Summer airborne mycoflora of Timişoara (Romania) and relationship to meteorological parameters

The present aeromycological investigation was undertaken to study atmospheric fungal spores in Timi?oara (western Romania). This study was carried out using a Hirst type volumetric sampler. The study revealed the existence of a rich airborne mycoflora. The atmospheric fungal spores were classified and evaluated into three groups (‘major’, ‘minor’ and ‘sporadic’) depending upon their catch percentage in the air. Cladosporium/Fusarium/Leptosphaeria-group, Alternaria, Helminthosporium airborne fungal spores and airborne fungal fragments regularly recorded (frequency 100% of days). Cladosporium accounted for 81.09% of the outdoor fungal spores. The airborne fungal fragments have been identified as abundant in our geographic area. Spearman’s correlations were applied to meteorological parameters and airborne fungal spore concentrations. In addition, correlations were calculated between the fungal spore concentrations and the meteorological variables from the previous day. A total of eleven weather factors were selected for this investigation. Following Spearman’s correlations, I identified two patterns of behaviour: most of the airborne fungal spores prefer cloudiness, lower near-surface soil temperature, lower atmospheric pressure, higher relative humidity and precipitation (pattern A) while other spore concentrations favour increased sunshine, higher near-surface soil temperature and dry conditions (pattern B). The behaviour of some fungal spores during the warm season has proven unclear (pattern C). This study demonstrates the need for investigations throughout the year and the evaluation with complementary statistical methods, regarding the correct interpretation of airborne mycoflora relationships with meteorological parameters.     

The air spora of an orchid greenhouse

The orchid collection of the ELTE Botanical Garden, Budapest, Hungary was monitored for airborne fungi using viable and non-viable air-sampling methods (Hirst-type and a 3-stage Andersen sampler) with three different culture media. A new culture method was also applied to identify fungal spores from Hirst-type samples. The aim of this study was to determine the diversity, human- and phytopathological potential of the air spora. To find out sources of airborne fungi, samples were collected from the air in an adjacent greenhouse and outdoors, and from necrotic plants. A total of 58 genera were found in the air samples. Cladosporium and Penicillium spp. were common members of the airborne biota. A high proportion (27.5%) of identified genera may be presented as a member of microbial consortium associated with the orchids. Airborne fungi potentially pathogenic to humans were also detected. One species, Zygosporium masonii, was new to Hungary. Statistical analysis indicated that conditions of sampling had significant effects. The principal component analysis elucidated the three principal components representing 75.34% of the total variance; the clusters of variables were related to the three types of culture media. Relative abundance of small-sized spores was high, presumably because of the fungal species composition and accelerated sedimentation of large spores in still air. Apparently, in the studied orchid greenhouse, a specific mycobiota developed due to the climate and hosts (Orchideaceae) grown there.     

Airborne fungal spores in the coastal plain of Israel: A preliminary survey

Airborne spores were monitored during the years 1993–1995 in three cities along the coastal plain of Israel: Ramat Gan, Tel Aviv (Ramat Aviv) and Haifa. Seasonal fluctuations in the concentration of airborne spores were recorded. The following genera of fungi were identified:Alternaria, Cladosporium, Coprinus, Curvularia, Drechslera. Diplococcum, Epicoccum, Fusarium, Leptosphaeria, Pithomyces, Puccinia, Sphacelotheca, Stemphylium andUstilago. Unidentified spores were very rare and in negligible numbers. The dominant airborne fungal spores wereCladosporium andAlternaria. The monthly variations in airborne spores, observed among the three cities, seem to be rather minor. The recorded levels of airborne spores were below the concentrations that are accepted as threshold levels for provocation of clinical responses.