The air spora close to a compost facility in Northeast Oklahoma: Part I—spore trap sampling

A compost facility in northeast Oklahoma is located relatively close to a residential area and is the focus of complaints about smell and concerns about health effects. Several species of Aspergillus have been known to cause health problems, and at least one of these species is dominant in compost. The atmosphere surrounding the compost facility was monitored for 1 year using Burkard spore traps to determine if there was a significant difference in Penicillium/Aspergillus type spores concentration between a test and control site. Samplers were situated 710 m downwind for the test site and 6,085 m upwind at the control site. There was no significant difference in mean concentration of Penicillium/Aspergillus type spores between the two sites (t = 0.576 P > 0.05). The mean concentration of total spores was significantly higher at the upwind control site (t = −7.64, P < 0.01). Wind direction was examined to determine if the compost facility was a possible source for any spikes in concentration. No clear relationship was found between wind direction and mean Penicillium/Aspergillus concentration at the test site, but peak concentrations of Penicillium/Aspergillus seen at the test site were on days when it was downwind from the composting facility. However, these concentrations were no higher than those seen at the control site on other days. If the compost was releasing large amounts of Penicillium/Aspergillus type spores into the atmosphere they were generally diluted to background levels by the time they reached the test site.     

Airborne fungi associated with ornamental plant propagation in greenhouses

The objective was to determine potential exposure to airborne fungi in greenhouses and to characterize the temporal patterns of airborne fungi in relation to environmental conditions. We analyzed air samples collected in two greenhouses. Results showed that the top 5 fungi in greenhouse 1 were Trichoderma, hyphal fragments, Aspergillus/Penicillium-like, Cladosporium, and Botrytis in a descending order. Those in greenhouse 2 were Aspergillus/Penicillium-like, Cladosporium, Botrytis, yeast-like, and hyphal fragments. Maximum concentrations of Trichoderma and total spores in greenhouse 1 were 36,426 and 49,729 spores/m³, respectively. Maximum concentrations of Aspergillus/Penicillium and total spores in greenhouse 2 were 46,961 and 71,037 spores/m³, respectively. Airborne fungal populations fluctuated dramatically within 2 h during work hours, tenfold for Aspergillus/Penicillium, 66-fold for Trichoderma, and sevenfold for total spores. QPCR detected Trichoderma harzianum ranging from 7 to 3,500 conidia E/m³. Aspergillus/Penicillium and Botrytis showed diurnal patterns, but not Trichoderma. Aspergillus/Penicillium and Cladosporium were positively correlated with temperature, relative humidity, dew point, heat index, and light and negatively with air movement and air pressure. Botrytis and Trichoderma were not correlated with the environmental factors. Greenhouse workers were potentially exposed up to 71,037 spores/m³ of airborne fungi.     

Preliminary studies on the effect of the Burkard alternate orifice on airborne fungal spore concentrations

The Burkard 7-day spore trap with standard orifice is commonly used by researchers in sampling outdoor air. The alternate orifice is reported to have higher efficiency in collecting small airborne fungal spores; however, no previous studies compared Burkard samplers with different orifices. This study was conducted to study the effect of the alternate orifice on the concentration of airborne fungal spores. Air samples were collected from July to October 2005 with two Burkard spore traps, one had the standard orifice and the second had the alternate orifice. The two spore traps were located on the roof of a building (12 m height) at the University of Tulsa, Oklahoma. Burkard daily slides were analyzed for airborne spores by light microscopy. The data from the two samplers were statistically analyzed using t-tests. The results indicated that the alternate orifice had significantly higher concentrations of Penicillium/Aspergillus-type spores and basidiospores than the standard orifice. By contrast, the standard orifice had significantly higher concentrations of Alternaria, ascospores, and other spores than the alternate orifice. The alternate orifice can be used to increase the efficiency of trapping small spores, which can be underestimated by using the standard orifice. However, additional comparison in other months of the year is recommended.     

Main airborne Ascomycota spores: characterization by culture, spore morphology, ribosomal DNA sequences and enzymatic analysis

The aim of this work was to identify the main allergy-related Ascomycetes fungal spores present in the atmosphere of Porto, using different and complementary techniques. The atmospheric sampling, performed in the atmosphere of Porto (Portugal) from August 2006 to July 2008, indicated Cladosporium, Penicillium, Aspergillus and Alternaria as the main fungal spore taxa. Alternaria and Cladosporium peaks were registered during summer. Aspergillus and Penicillium highest values were registered from late winter to early spring. Additionally, the Andersen sampler allowed the culture and isolation of the collected viable spores subsequently used for different identification approaches. The internal-transcribed spacer region of the nuclear ribosomal repeat unit sequences of airborne Ascomycetes fungi isolates revealed 11 taxonomically related fungal species. Among the identified taxa, Penicillum and Aspergillus presented the highest diversity, while only one species of Cladosporium and Alternaria, respectively, were identified. All selected fungal spore taxa possessed phosphatase, esterase, leucine arylamidase and β-glucosidase enzymatic activity, while none had lipase, cystine arylamidase, trypsin or β-glucuronidase activity. The association between the spore cell wall morphology, DNA-based techniques and enzymatic activity approaches allowed a more reliable identification procedure of the airborne Ascomycota fungal spores.     

Variation in airborne urediniospore concentration ofMelampsoridium betulinum

Yearly, seasonal and circadian variations in airborne urediniospore concentration of birch rust,Melampsoridium betulinum (Fries) Kleb., were studied in Turku, Oulu and Kevo during 1983–1988, using the Burkard spore trap. Variation among areas and the effects of weather parameters on spore concentration were also examined. The total number of spores was much higher in Oulu than at the other locations. The yearly variation was high at all locations. The urediniospore season usually started in August and peaked in September. Urediniospores showed clear circadian variation; a peak was observed in the afternoon. High wind speed significantly increased airborne urediniospore concentration; likewise temperature affected the concentration positively.     

Indoor and outdoor atmospheric fungal spores in the São Paulo metropolitan area (Brazil): species and numeric concentrations

The aim of this study was to estimate the indoor and outdoor concentrations of fungal spores in the Metropolitan Area of Sao Paulo (MASP), collected at different sites in winter/spring and summer seasons. The techniques adopted included cultivation (samples collected with impactors) and microscopic enumeration (samples collected with impingers). The overall results showed total concentrations of fungal spores as high as 36,000 per cubic meter, with a large proportion of non culturable spores (around 91% of the total). Penicillium sp. and Aspergillus sp. were the dominant species both indoors and outdoors, in all seasons tested, occurring in more than 30% of homes at very high concentrations of culturable airborne fungi [colony forming units(CFU) m⁻³]. There was no significant difference between indoor and outdoor concentrations. The total fungal spore concentration found in winter was 19% higher than that in summer. Heat and humidity were the main factors affecting fungal growth; however, a non-linear response to these factors was found. Thus, temperatures below 16°C and above 25°C caused a reduction in the concentration (CFU m⁻³) of airborne fungi, which fits with MASP climatalogy. The same pattern was observed for humidity, although not as clearly as with temperature given the usual high relative humidity (above 70%) in the study area. These results are relevant for public health interventions that aim to reduce respiratory morbidity among susceptible populations.     

Airborne Ascomycotina on the island of Crete: Seasonal patternsbased on an 8-year volumetric survey

An 8-year study was conducted on the island of Crete in order to identify airborne ascospores and to determine their seasonal pattern. A Burkard 7-day, volumetric spore-trap was continuously operated in the city of Irakleion – located in the center of the island – from 1994 through 2001. Relatively „high” ascospore counts (20 – 48 spores/m ³) were obtained from mid-spring through summer, while the rest of the year exhibited lower activity (8–16 spores/m³). The predominant ascospores identified were those of Leptosphaeria and Chaetomium; their concentrations varied from 1 or 2 spores up to a few dozens of spores/m³. Other spores encountered sporadically were: Ascobolus, Endophragmiella, Didymella, Diatrypaceae, Leptosphaerulina, Massaria, Pleospora, Sporormiella, Xylaria. The mean daily concentration of all identified ascospores was 30/m³ for the entire study period, corresponding to 13.9% of the total fungal load. Ascospores have been recognized as important inhalant allergens and have been implicated as contributing to symptoms of both rhinitis and asthma.     

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.     

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.     

Effects of meteorological factors on airborne bracken (<Emphasis Type="Italic">Pteridium aquilinum</Emphasis> (L.) Kuhn.) spores in Salamanca (middle-west Spain)

Temporal variation of airborne bracken (Pteridium aquilinum) spores concentration in Salamanca during 10 years from January 1998 to December 2007 were studied by using a Burkard spore trap, and correlations with some meteorological parameters were analyzed. The number of spores that were counted was very low, due probably to the distance between the spore trap and the main bracken populations which were located 70 km away from the city. Long-range transport caused by winds coming from the Second Quadrant (IIQ) is supposed to be responsible for the appearance of bracken spores in Salamanca. The season period from August to late October shows the most intense spore dispersal process, with an early morning distribution along the day. Years 2002 and 2007 with a low quantity of airborne spores were also characterized by low mean temperatures, always under 18°C from May to June. Daily spore concentration shows positive correlation with temperature and sun hours but negative with IVQ winds and with relative humidity. No correlation between daily spore concentration and rainfall was found. Also, a positive correlation between number of spores and IIQ winds was observed during the main spore season (MSS) and prepeak period (PRE).     

Temporal dynamics of airborne fungi in Havana (Cuba) during dry and rainy seasons: influence of meteorological parameters

The aim of this paper was to determine for first time the influence of the main meteorological parameters on the atmospheric fungal spore concentration in Havana (Cuba). This city is characterized by a subtropical climate with two different marked annual rainfall seasons during the year: a “dry season” and a “rainy season”. A nonviable volumetric methodology (Lanzoni VPPS-2000 sampler) was used to sample airborne spores. The total number of spores counted during the 2 years of study was 293,594, belonging to 30 different genera and five spore types. Relative humidity was the meteorological parameter most influencing the atmospheric concentration of the spores, mainly during the rainy season of the year. Winds coming from the SW direction also increased the spore concentration in the air. In terms of spore intradiurnal variation we found three different patterns: morning maximum values for Cladosporium, night peaks for Coprinus and Leptosphaeria, and uniform behavior throughout the whole day for Aspergillus/Penicillium."     

Chymostatin can combine with pepstatin to eliminate extracellular protease activity in cultures of <Emphasis Type="Italic">Aspergillus niger</Emphasis> NRRL-3

Aspergillus strains are being considered as potential hosts for recombinant heterologous protein production because of their excellent extracellular enzyme production characteristics. However, Aspergillus proteases are problematic in that they modify and degrade the heterologous proteins in the extracellular medium. In previous studies we observed that media adjustments and maintenance of a filamentous morphology greatly reduced protease activity and that a low concentration of the aspartic protease inhibitor pepstatin inhibited the latter protease activity to the extent of approximately 90%. In this paper we report that when the serine protease inhibitor chymostatin is used in combination with pepstatin 99–100% of total protease activity in Aspergillus cultures is inhibited. In protease assays a concentration of 30 μM chymostatin combined with 0.075 μM pepstatin was required for maximum inhibition. Inhibitor concentrations of chymostatin and pepstatin of 120 and 0.3 μM, respectively, when added to Aspergillus cultures, has no significant effect on biomass production, glucose utilization or culture pH pattern. The potential of using these protease inhibitors in cultures of recombinant Aspergillus strains producing heterologous proteins will now be investigated to determine if the previously observed recombinant protein denaturing effects of Aspergillus proteases can be negated.     

Indoor air quality in schools: exposure to fungal allergens

This study examined indoor air quality within schools in Kansas City, Spokane, Santa Fe, and Orlando. Air sampling was undertaken with both Andersen Single Stage Samplers and Burkard Personal Air Samplers. The data show a wide range of indoor exposures ranging from less than 100 colony forming units (CFU/m³) for viable fungi and 100 spores/m³ for total spores in Spokane and Santa Fe to concentrations over 6000 CFU/m³ for viable fungi and 15 000 spores/m³ for total fungi in Orlando and Kansas City, respectively. In the majority of sites the indoor airspora reflected the outdoor taxa withCladosporium the most abundant genus identified; however, several indoor locations had elevated levels ofPenicillium andAspergillus indicating possible sources of indoor contamination. Airborne basidiospores and smut spores were also fairly abundant in the schools and were among the top five taxa identified. The data also indicated that the airborne concentrations vary significantly during the day and between classrooms within each school. Continued studies in schools are needed to fully assess both the exposure levels and the clinical significance to atopic children allergic to these spores.     

Relationship between indoor and outdoor airborne fungal spores, pollen, and (1→3)-β-D-glucan in homes without visible mold growth

In this exploratory study, indoor and outdoor airborne fungal spores, pollen, and (1→3)-β-D-glucan levels were determined through long-term sampling (24-h) using a Button Personal Inhalable Aerosol Sampler. The air samples were collected in five Cincinnati area homes that had no visible mold growth. The total count of fungal spores and pollen in the collected samples was conducted under the microscope and Limulus Amebocyte Lysate (LAL) chromogenic assay method was utilized for the determination of the (1→3)-β-D-glucan concentration. For the combined number concentration of fungal spores and pollen, the indoor and outdoor geometric mean values were 573 and 6,435 m⁻³, respectively, with a geometric mean of the Indoor/Outdoor (I/O) ratio of .09. The geometric means of indoor and outdoor (1→3)-β-D-glucan concentrations were .92 and 6.44 ng m⁻³, respectively, with a geometric mean of the I/O ratio equal to .14. The I/O ratio of (1→3)-β-D-glucan concentration was found to be marginally greater than that calculated based on the combined number concentration of fungal spores and pollen. This suggests that (1→3)-β-D-glucan data are affected not only by intact spores and pollen grains but also by the airborne fragments of fungi, pollen, and plant material, which are ignored by traditional enumeration methodologies. Since the (1→3)-β-D-glucan level may elucidate the total exposure to fungal spores, pollen, and fungal fragments, its I/O ratio may be used as a risk marker for mold and pollen exposure in indoor environments.     

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”.     

黄曲霉毒素生物防控菌的筛选及鉴定

筛选黄曲霉毒素生物防控菌,为黄曲霉毒素的生物防控提供支持。以花生原产地土壤为材料,采用牛津杯法筛选所需菌株。对筛选出的拮抗菌株进行抑制产毒曲霉菌株的生长、产孢、降解黄曲霉毒素实验。筛选出2株黄曲霉毒素生防细菌,编号21-1-2、17-3,经鉴定,拮抗菌21-1-2为枯草芽胞杆菌,拮抗菌17-3为地衣芽胞杆菌。分别对拮抗菌对曲霉孢子萌发的抑制、抑制黄曲霉的生长和菌丝延长以及减少黄曲霉毒素的产生、对黄曲霉毒素的分解作用等几个方面进行研究,结果表明,拮抗菌可以明显抑制产毒曲霉孢子的萌发、生长、菌丝的延长,减少黄曲霉毒素的产生以及分解黄曲霉毒素。     

Quantification of airborne Aspergillus fumigatus spores in rabbit houses by real-time polymerase chain reaction

To accurately quantify airborne Aspergillus fumigatus (A. fumigatus) spores in rabbit houses, the real-time polymerase chain reaction (real-time PCR) and culture-based counting method (CCM) were employed to determine the airborne A. fumigatus spore concentrations. The results showed that, of the three rabbit houses (A, B, and C), the average concentrations of airborne A. fumigatus spores determined by real-time PCR were 3.0 × 10³, 3.3 × 10³, and 1.5 × 10³ spores/m³ air, respectively, while those determined by CCM were 2.5 × 10², 2.8 × 10², and 1.1 × 10² colony-forming unit/m³ air (CFU/m³ air), respectively, i.e., the former concentration was 12–14 times higher than the latter one. Therefore, the conventional CCM underestimated the concentrations of airborne fungal spores, and it is insufficient to determine the microbial aerosol concentration and evaluate the health risk only using CCM.     

Effects of endotoxin (lipopolysaccharides) on experimental aspergillosis in leukemic mice

In an attempt to evaluate effects of bacterial endotoxin on systemic fungal infection, experimental systemic Aspergillus infection was induced in leukemic mice (AKR strain) with (Group B) or without (Group A) preceding intraperitoneal administration of Pseudomonas aeruginosa derived lipopolysaccharides. All mice in group A died within 4 days after intravenous inoculation of Aspergillus fumigatus spores and developed extensive and disseminated fungal lesions without inflammatory reactions. In contrast, 5 of 10 mice in group B were alive at day 4 and 1 mouse in group B was alive when the experiment was terminated on the 14th day. These mice showed less extensive fungal lesions with definite, albeit minimal, inflammatory reactions which were composed of macrophages and neutrophils. In addition, serum iron levels and iron saturation rates were significantly lower in mice in group B than in group A. These results indicate that P. aeruginosa endotoxin has a deterring effect on systemic Aspergillus infection in leukemic mice.     

MonitoringAspergillus fumigatus aerosols from a composting facility

The large, outdoor Islip Yard Waste Composting Facility on Long Island, New York was investigated as a source of airborne fungus spores. The Burkard-Hirst volumetric spore trap was used for the first extensive sampling of small mold spores for this application. Samplers were operated continuously from 21 August to 30 November 1992 in the facility and in a suburban community about 540 m from the facility. A control site approximately 10 000 m from the facility was also sampled to establish background levels of fungus spores. The facility site had higher average readings ofAspergillus fumigatus spores than did the community and both were higher than the control.A. fumigatus was the only fungus among 30 categories tracked that differed significantly between the facility and control sites. It was also isolated repeatedly from the compost. Higher average levels ofA. fumigatus were measured in the community when winds blew from the facility, and also during times when the compost was moved or mixed at the facility. No correlation was found between wind direction or work times andA. fumigatus conidia at the control site. The study shows that this compost facility can produce a measurable increase in the number of airborneA. fumigatus conidia both at the edge of the facility and at 540 m downwind. It also demonstrates that the Burkard spore trap can be used for monitoring small, airborne mold spores, but it is a difficult and labor intensive task.     

Multi-year study of Ganoderma aerobiology

Ganoderma basidiospores are dominant members ofthe airspora in many regions of the world and areconsidered important airborne allergens. Theaerobiology of Ganoderma spores in the Tulsa,Oklahoma area was examined using Burkard VolumetricSpore Traps from 1987–1996. Ganodermaspores were present in the atmosphere on more than95% of the days from June through October with peakconcentrations generally occurring from late August tomid-October. The data showed marked interannualvariation, with seasonal totals in 1994 and 1995significantly higher than other years. Stepwisebackward multiple regression showed that cumulativeseason total was significantly related to Junetemperature and May through August precipitation(R² = 0.97, p < 0.01).