共查询到20条相似文献,搜索用时 15 毫秒
1.
Thailand border market is where the local Thais, Cambodians, Laotians, and Burmeses exchange their goods and culture at the
border checkpoints. It is considered to be the source of aerial disease transmission especially for foreigners because it
is always very crowded with people from all walks of life. Unhealthy air quality makes this area high risk of spread of airborne
diseases. This study assessed airborne concentrations of bacteria and fungi in a border market to improve exposure estimates
and develop efficient control strategies to reduce health risk. The density and distribution of airborne bacteria and fungi
were investigated in the Chong Chom border market in Surin Province, Thailand. Eighteen air sampling sites were taken from
outdoors and various work environments including indoor footpaths, wooden handicraft shops, electronic shops, the secondhand
clothing shops, and fruit market areas. Exposed Petri plate method and liquid impinger sampler were used for sampling at the
breathing zone, 1.5 m above the floor level, during weekend and holiday. Meteorological factors such as relative humidity,
temperature, and light intensity were collected by portable data logger. The relative humidity was 67–73%, and temperature
29–33°C, and light varied between 18 and 270 Lux m−2. Gram-positive and Gram-negative bacteria were found at a mean value of 104 CFU m−3, and airborne fungi of 103 CFU m−3 were recorded. The highest concentration of culturable airborne microorganisms was found along the indoor footpath (9.62 × 104 CFU m−3 and 750.00 CFU/plate/h for impingement and sedimentation methods, respectively), the fruit market area (7.86 × 104 CFU m−3 and 592.42 CFU/plate/h for impingement and sedimentation methods, respectively), and the secondhand clothing shop (4.59 × 103 CFU m−3 and 335.42 CFU/plate/h for impingement and sedimentation methods, respectively) for Gram-positive bacteria, Gram-negative
bacteria, and fungi, respectively. The lowest concentration of Gram-positive bacteria, Gram-negative bacteria, and fungi was
found only at the outdoor area at 1.53 × 104 CFU m−3, 0.93 × 104 CFU m−3 and 0.80 × 103 CFU m−3 by means of impingement method and 136.67 CFU/plate/h, 69.25 CFU/plate/h, and 62.00 CFU/plate/h by means of sedimentation
methods for Gram-positive bacteria, Gram-negative bacteria, and fungi, respectively. The most frequently present airborne
bacteria were identified as Bacillus, Corynebacteria, Diplococcus, Micrococcus, Acinetobacter, Alcaligenes, Enterobacter, and spore former rods. Acremonium, Aspergillus, Cladosporium, Penicillium, and Sporotrichum were the most frequently found aerosol fungi genera. The distribution of airborne microorganisms correlated with relative
humidity and light factors based on principal component analysis. In conclusion, the border market is a potential source of
aerial disease transmission and a various hazards of bioaerosols for workers, consumers, sellers, and tourists. The bioaerosol
concentration exceeded the standard of occupational exposure limit. Many major indicators of allergenic and toxigenic airborne
bacteria and fungi, Acinetobacter, Enterobacter, Pseudomonas, Cladosporium, Alternaria, Aspergillus, and Penicillium, were found in the various market environments. 相似文献
2.
In this study an attempt was made to evaluate the qualitative and quantitative fungal burden (load) in five different working
environments of South Assam (India) and the possible risks of indoor fungi to employees and stored products. Fungal concentrations
in different working environments were studied using a Burkard personal petriplate sampler. The survey was done in five different
working environments for one year. A total of 76 fungal types were recorded in the indoor air of South Assam during the survey
period. The maximum fungal concentration (5,437.6 ± 145.3 CFU m−3 air) was recorded in the indoor air of medical wards, followed by the paper-processing industry (3,871.7 ± 93.4 CFU m−3 air). However the lowest concentration was observed in the indoor air of a bakery (1,796.8 ± 54.4 CFU m−3 air). The most dominant fungal genera were Aspergillus (34.2%) followed by Penicillium (17.8%), Geotrichum (7.0%) and the most dominant fungal species were Aspergillus fumigatus (2,650.4 CFU m−3 air) followed by Aspergillus flavus (1,388.2 CFU m−3 air), Geotrichum candidum (1,280.3 CFU m−3 air), Aspergillus niger (783.3 CFU m−3 air), and Penicillium aurantiovirens (774.0 CFU m−3 air). The fungal species viz., Aspergillus
fumigatus, Penicillium
aurantiovirens, Aspergillus
flavus, Aspergillus
niger, Geotrichum
candidum, and Penicillium
thomii, which were recorded well above threshold levels, may lead to adverse health hazards to indoor workers. Setting occupational
exposure limits for indoor fungal spores as reference values is obligatory for prevention and control of adverse effects of
indoor fungal exposure. 相似文献
3.
Robert S. Dungan April B. Leytem Sheryl A. Verwey David L. Bjorneberg 《Aerobiologia》2010,26(3):171-184
Increased bioaerosol loadings in downwind plumes from concentrated animal feeding operations (CAFOs) may increase the risk
for allergy and infection in humans. In this study, we monitored airborne concentrations of culturable bacteria and fungi
at upwind (background) and downwind sites at a 10,000 milking cow dairy over the course of a year. The average bacterial concentrations
at the upwind site were 8.4 × 103 colony forming units (CFU) m−3 and increased to 9.9 × 105 CFU m−3 at the downwind edge of the cattle lots, decreasing to 6.3 × 104 CFU m−3 200 m farther downwind. At the same sites, the average fungal concentrations were 515, 945, and 1,010 CFU m−3, respectively. Significant correlations between the ambient weather conditions and airborne fungal and bacterial concentrations
were identified. Sequence analysis of PCR-amplified DNA from bacterial clones and fungal isolates revealed genus and species
level differences between upwind and downwind sites. Although we could not cultivate gram-negative bacteria, bacterial clones
at downwind sites identified as being gram-negative matched with the following genera: Acinetobacter, Bradyrhizobium, Escherichia, Idiomarina, Methylobacterium, Ralstonia, and Novosphingobium. Fungal isolates from downwind matched with the following genera: Acremonium, Alternaria, Ascomycte, Aspergillus, Basidiomycete, Cladosporium, Davidiella, Doratomyces, Emericella, Lewia, Onygenales, Penicillium, Rhizopus, and Ulocladium. None of the bacterial and fungal sequence matches were affiliated with genera and species known to be pathogenic to humans.
Overall, the data suggest that exposure to bioaerosols in the downwind environment decreases with increasing distance from
the open-lot dairy. 相似文献
4.
Dale W. Griffin Cristina Gonzalez Nuria Teigell Terry Petrosky Diana E. Northup Mark Lyles 《Aerobiologia》2011,27(1):25-35
The influence of sample-collection-time on the recovery of culturable airborne microorganisms using a low-flow-rate membrane-filtration
unit and a high-flow-rate liquid impinger were investigated. Differences in recoveries were investigated in four different
atmospheric environments, one mid-oceanic at an altitude of ~10.0 m, one on a mountain top at an altitude of ~3,000.0 m, one
at ~1.0 m altitude in Tallahassee, Florida, and one at ~1.0 m above ground in a subterranean-cave. Regarding use of membrane
filtration, a common trend was observed: the shorter the collection period, the higher the recovery of culturable bacteria
and fungi. These data also demonstrated that lower culturable counts were common in the more remote mid-oceanic and mountain-top
atmospheric environments with bacteria, fungi, and total numbers averaging (by sample time or method categories) <3.0 colony-forming
units (CFU) m−3. At the Florida and subterranean sites, the lowest average count noted was 3.5 bacteria CFU m−3, and the highest averaged 140.4 total CFU m−3. When atmospheric temperature allowed use, the high-volume liquid impinger utilized in this study resulted in much higher
recoveries, as much as 10× greater in a number of the categories (bacterial, fungal, and total CFU). Together, these data
illustrated that (1) the high-volume liquid impinger is clearly superior to membrane filtration for aeromicrobiology studies
if start-up costs are not an issue and temperature permits use; (2) although membrane filtration is more cost friendly and
has a ‘typically’ wider operational range, its limits include loss of cell viability with increased sample time and issues
with effectively extracting nucleic acids for community-based analyses; (3) the ability to recover culturable microorganisms
is limited in ‘extreme’ atmospheric environments and thus the use of a ‘limited’ methodology in these environments must be
taken into account; and (4) the atmosphere culls, i.e., everything is not everywhere. 相似文献
5.
Abdel Hameed A. Awad 《Aerobiologia》2007,23(1):59-69
A study was carried out on suspended dust, bacterial and fungal aerosols in a four-storey flourmill building located in Giza,
Egypt. Airborne microorganisms were quantitatively isolated using liquid impinger and gravimetric samplers during the period
from March 2004 to February 2005. Suspended dust varied from 1.96 to 16.3 mg m−3 and 0.69 to 1.8 mg m−3 in the indoor and outdoor environments, respectively. Suspended dust was significantly greater (P < 0.05) at bran package, double roller, purifiers and flour storage units in comparison to the outdoor reference site. The
dust levels exceed the occupational exposure limit (OEL) of 0.5 mg m−3 for flour dust. Airborne microbial counts were found at median values, between sampling locations, ranged from 0 to >104 CFU m−3. Gram-negative bacteria were found in small numbers (0–102 CFU m−3). The highest concentration of actinomycetes (>103 CFU m−3) was detected in the storage unit. Airborne fungal counts were found at the median values, between sampling locations, varied
from 103 to 104 CFU m−3. The counts of airborne bacteria and fungi were significantly greater (P < 0.05) at the purifiers and double roller mill units in comparison to the outdoor reference site using the liquid impinger
sampler. Microbial levels associated with bulk deposited dust averaged between 105 and 106 CFU g−1. Alcaligenes (5.4%) Pseudomonas (3.87%) and Enterobacter (3.1%) were the predominant Gram-negative species while Bacillus (29.4%) and Micrococci (13.9%) were the major components of Gram-positive bacteria. Aspergillus and Penicillium were the predominant fungal types indoor whereas Cladosporium (35.2%) and Aspergillus species (22.2%) were the predominant fungal types outdoor. A number of allergenic and toxigenic bioaerosols were found in
the flourmill workplace. 相似文献
6.
Filipa Antunes Mariana Hinzmann Manuel Lopes-Lima Jorge Machado Paulo Martins da Costa 《Microbial ecology》2010,60(2):304-309
Bivalves filter and accumulate large numbers of microorganisms present in the harvesting water. A complete understanding of
the balance between Anodonta cygnea and the microbiota present in their surrounding environment remains incomplete. Therefore, the aim of this study was to quantify
and identify the indigenous bacteria in the biological fluids of A. cygnea collected from Mira Lagoon in northern Portugal. The results showed Vibrio metschnikovii and Aeromonas sobria as the dominant groups. The median for total bacteria from mucus was 3.1 × 103 CFU g−1, whereas the range in means from fluids was 1.5 × 102 to 6.5 × 102 CFU ml−1. During the experimental work, Escherichia coli and enterococci were not detected in healthy A. cygnea. However, the periodic detection of E. coli and enterococci in Mira lagoon revealed its presence in the water. Our observations suggest that A. cygnea has the ability to filter and eliminate E. coli, present in the surrounding environment, through an active phagocytic process conducted by hemolymph circulating cells, the
hemocytes. 相似文献
7.
An experimental investigation was carried out to determine the agreement between two methods of viable bacteria aerosol detection.
Various amounts of Bacillus globigii (BG) spores were aerosolized in 1-s bursts into a HEPA-filtered air stream and sampled simultaneously with a fluorescence
aerosol particle sensor (FLAPS) and a slit to agar biological air sampler. The slit sampler incorporated 150-mm malt extract
culture plates, which were incubated at 37°C for at least 12 h before culturable BG particles were counted in terms of colony-forming
units (CFU). A relationship between CFU and optically detected viable bacteria particles was determined as culturable particle
concentrations decreased. Through further analytical procedures, the FLAPS showed a limit of detection (LOD) of 4.2 bacterial
particle/2.5 l of sampled air or 1.7 × 103 m−3. This real-time bacteria aerosol monitor could be used to detect burst contamination events during a surgical procedure.
The technology may be used for developing a dose–response relationship between bacterial particle exposure and infection,
a tool potentially helpful in determining patient risk. 相似文献
8.
Measurement of culturable airborne staphylococci downwind from a naturally ventilated broiler house 总被引:1,自引:0,他引:1
The objective of this study was to estimate the possible travel distance of airborne bacteria emitted from a naturally ventilated
broiler house by using staphylococci as indicator organisms. Air samples were taken during the second half of three fattening
periods with Impinger (AGI-30) in the barn and simultaneously upwind and downwind from the building. Staphylococci concentrations
varied between 1 × 106 and 1 × 107 cfu m−3 in the barn. No Staphylococci were detected in air samples at the upwind side. A strong exponential decrease of these bacteria
was observed at three sampling heights (1.5, 4.0 and 9.5 m) in the main wind direction downwind of the barn. Staphylococci
concentrations up to 5.9 × 103 cfu m−3 were detected at the farthest sampling point (333 m) downwind. Identification to the species level by means of a 16S–23S
ITS PCR confirmed that Staphylococcus spp. from downwind samples originated from the barn. Staphylococci served as an useful indicator to demonstrate the travel
distance of bacterial emissions originating from a naturally ventilated broiler house. These findings indicate that airborne
transmission of viable bacteria from this type of housing system to adjacent residential dwellings or animal houses several
hundred metres away is possible. 相似文献
9.
Abdel Hameed A. Awad Tarek H. Elmorsy Patrick M. Tarwater Christopher F. Green Shawn G. Gibbs 《Aerobiologia》2010,26(3):223-232
Inhalation of airborne microorganisms and organic dust is an occupational concern among workers in agricultural industries.
Airborne microorganisms and particulate matter samples were collected from poultry house, flourmill, textile, and food industry
sites by use of liquid impinger and gravimetric samplers. Particulate matter concentrations were recorded at median concentrations
of 1.56, 1.92, 4.39, and 0.7 mg/m3 in the occupied poultry house, textile, flourmill, and food indoor working environments, respectively. The highest median
particulate matter concentration (27.9 mg/m3) was detected at the flourmill’s stack site. The highest median indoor concentration of culturable airborne bacteria (6.23 × 105 CFU/m3) was found at the occupied poultry-house site and the lowest concentration (4.6 × 103 CFU/m3) was found at the food industry site. The highest median indoor concentration of culturable airborne fungi (3.15 × 104 CFU/m3) was found at the flourmill site whereas the lowest (1.24 × 103 CFU/m3) was found at the textile industry site. Bacillus and Staphylococcus were the predominant Gram-positive bacteria whereas Acinetobacter and Klebsiella were the predominant Gram-negative bacteria. Escherichia coli and Salmonella were only detected in the indoor air at the poultry house site. Aspergillus
flavus, Aspergillus niger, Penicillium, and yeast were the predominant fungal types at flourmill, textile, food industry, and poultry house, respectively. Workers
were continuously exposed to airborne microorganisms at a median value of 104 CFU/m3 in all the industries studied. 相似文献
10.
Wastewater that enters wastewater treatment plants contains lots of pathogenic and nonpathogenic microorganisms which can become bioaerosols during treatment processes and pose health hazard to workers and nearby residents. The emission of the bioaerosols from an urban wastewater treatment plant in spring and summer in different locations and downwind of the plant adopting an extended mechanical aeration system was investigated. Samples of bacteria and fungi were collected within 6 months at 10 selected points by an Anderson one-stage impactor. The highest concentration of bacteria (mean 1373 CFU/m3, 741–2817 CFU/m3) and fungi (mean 1384 CFU/m3, 212–1610 CFU/m3) was found in downwind of the aeration basins. Statistical analysis showed a significant relationship between concentration of bacterial bioaerosols at downwind side of the aeration basins and wind speed (p value <0.05) and temperature (p value <0.05). Also, in the spring and summer, between the number of bacteria and fungi inside the plant and outside the plant (downwind) a significant correlation was observed (p value ≤0.05). The concentrations of bacteria at a distance of 500 m downwind were much higher than those at the background (upwind) point in spring and summer. The processes of wastewater treatment especially using mechanical equipment to create turbulence can be considered as a major source of spreading airborne microorganisms to ambient air of wastewater treatment plants, and the bioaerosols can be dispersed to downwind distances affecting the nearby neighboring. Therefore, in order to decrease the bioaerosols emission, doing some course of actions such as covering the surface of aeration basins, changing the aeration methods and aeration equipment (e. g using diffuser aerator) may be effective. 相似文献
11.
Ma?gorzata Sowiak Karolina Bródka Alina Buczyńska Marcin Cyprowski Anna Kozajda Wojciech Sobala Irena Szadkowska-Stańczyk 《Aerobiologia》2012,28(2):121-133
The project was aimed at evaluating the potential occupational exposure of swine farm workers to dust and microorganisms present
in piggery bioaerosols (especially in its respirable fraction) under various breeding conditions. Sampling was carried out
in 14 buildings located at 13 pig breeding and production farms in Poland. Concentrations of inhalable and respirable dusts
in the air of the piggeries were low (means, respectively, 1.76 and 0.23 mg/m3). The concentration of microorganisms was generally high (mean = 3.53 × 105 cfu/m3). More than 96% of determined microorganisms were bacteria (mean = 3.42 × 105 cfu/m3). The fungal concentration was distinctly lower (mean = 2.71 × 103 cfu/m3). The concentration of bacteria in the respirable fraction of bioaerosol (mean = 1.51 × 105 cfu/m3) made up for 48.2% of their total concentration, while the level of fungi in that fraction (mean = 1.50 × 103 cfu/m3) formed 68.8% of the total fungal concentration. The concentration of inhalable dust was significantly modified by the type
of breeding system. The factors that significantly affected the total concentrations of microbes and bacteria, as well as
their levels in the bioaerosols’ respirable fraction were as follows: herd size, breeding system, feeding method and the type
of ventilation system. In the case of fungi, these were the livestock breeding system and the feeding method. Moreover, there
was a high positive correlation of inhalable dust concentrations with the fungal concentration, CO2 and relative humidity. A negative correlation was found between concentrations of each microbe group and the airflow velocity.
Swine farm workers are exposed to relatively low dust concentrations and high concentrations of microorganisms, bacteria in
particular. Fungi, to a much larger extent than bacteria, are correlated with the respirable particles of a piggery bioaerosol,
which may harm the respiratory system of exposed workers. 相似文献
12.
M. A. Martínez M. C. Martínez P. Bielza J. Tello A. Lacasa 《Journal of industrial microbiology & biotechnology》2011,38(1):3-11
In the region of Murcia (southeast Spain), sweet pepper has been grown as a monoculture in greenhouses for many years. Until
2005, when it was banned, soils were disinfested with methyl bromide (MB) to control pathogens and to prevent soil fatigue
effects. The genus Fusarium plays an important role in the microbiological component associated with yield decline in pepper monocultures. In the present
study, soils were treated with manure amendments, alone (biofumigation, B) or in combination with solarization (biosolarization,
BS), with or without the addition of pepper plant residues. The B and BS treatments were compared with a treatment using MB.
The extent of disinfestation was measured from the density of Fusarium spp. isolated from the soil before and after the respective treatments. Three different species were systematically isolated:
Fusarium oxysporum, Fusarium solani and Fusarium equiseti. The repeated use of manure amendments with pepper crop residues, without solarization, was unable to decrease the Fusarium spp. density (which increased from 2,047.17 CFU g−1 to 3,157.24 CFU g−1 before and after soil disinfestation, respectively), unlike MB-treated soil (in which the fungi decreased from 481.39 CFU g−1 to 23.98 CFU g−1). However, the effectiveness of the repeated application of BS in diminishing doses (with or without adding plant residues)
on Fusarium populations (reductions greater than 72%) was similar to or even greater than the effect of MB. 相似文献
13.
Many working environments are predisposed for larger than average amounts of fungi and other microorganisms often due to organic
material being handled. From 2003 to 2007, the area used for strawberry production in Denmark increased by 62%. The purpose
of this study was to determine the levels of exposure to microorganisms, endotoxin, (1→3)-β-d-glucan (β-glucan), and pollen in a field of strawberries. The study was carried out in eastern Denmark from the middle of
June to the beginning of August 2008. The strawberries were grown organically, and microbiological pest control agents (MPCAs)
were applied during this and former growth seasons. In order to measure exposure to inhalable bioaerosol components, we used
stationary filter samplers. Bioaerosol sampling was performed during 4 working days, and a total of 57 samplings were performed.
The filters were analysed for contents of fungi, MPCAs, endotoxin, β-glucan, and pollen. The mean exposure was 6,154 CFU Cladosporium sp. m−3, 1.0 × 105 fungal spores m−3, 4.1 × 104 hyphal fragments m−3, 5.8 × 103 pollen m−3, 57.3 ng β-glucan m−3, and 8.9 endotoxin units (EU) m−3. A significant and positive correlation was found between β-glucan and fungal spores and between CFU of Cladosporium sp. and CFU of fungi. We selected specifically for Metarhizium anisopliae, Beauveria bassiana, and the applied MPCAs Trichoderma harzianum, T. polysporum, and Bacillus thuringiensis but found none of these species. In conclusion, our study shows that berry pickers in this organic strawberry field were
potentially subjected to higher levels of fungal spores, Cladosporium sp., hyphal fragments, pollen, and thus also β-glucan than is usually seen in outdoor air. Exposure to MPCAs was not seen.
The exposure to endotoxin was only slightly higher than e.g. in a town. 相似文献
14.
This study investigates the exposure of workers to biological particles in a poultry litter burning plant in operation. The
microorganism concentrations were examined at different workplaces during procedures leading to increased emissions. The concentrations
of culturable airborne mesophilic, xerophilic and thermophilic microorganisms in the ambient air were tested inside and outside
of the burning plant using two different methods of measuring. The focus of this study was on the quantitative evaluation
of culturable bacteria as well as the quantitative and qualitative evaluation of gram-negative bacteria, fungi and thermophilic
actinomycetes. The maximum airborne concentrations were found in the delivery hall. Mesophilic bacteria concentrations reached
up to 1.7 × 106 CFU/m3; gram-negative bacteria up to 9.1 × 102 CFU/m3. Fungal propagule concentrations for xerophilic fungi were between 1.2 × 103 and 2.9 × 104 CFU/m3 and for mesophilic fungi between 4.4 × 102 and 2.9 × 104 CFU/m3. Among fungi, Aspergillus niger, Eurotium herbariorum and Scopulariopsis brevicaulis species were dominant. Thermophilic actinomycetes reached airborne concentrations of 8.7 × 104 CFU/m3, with increased concentrations of the pathogens causing extrinsic allergic alveolitis. The high concentrations of airborne
microorganisms in poultry litter burning plants and the potential hazard of the intake of microorganisms including potential
pathogens require the introduction of consistent measures in both technical areas and personnel management. 相似文献
15.
The present study tested the ability of Bacillus amyloliquefaciens and Microbacterium oleovorans to reduce Fusarium verticillioides populations and fumonisin accumulation in the maize agroecosystem. The impact of releasing these biocontrol agents on rhizospheric bacterial and fungal groups was also evaluated through isolation and identification of culturable microorganisms. When applied as seed coatings at a concentration of 107 CFU ml−1 both agents were effective in reducing F. verticillioides counts and fumonisin B1 and B2 content from maize grains. Rhizospheric counts of the pathogen were also decreased by use of B. amyloliquefaciens at 107 CFU ml−1. Richness and diversity indexes calculated for bacteria and fungi inhabiting the rhizosphere of maize remained unchanged following the addition of both biocontrol agents to seeds. Our research is being continued to further characterize the bacterial and fungal isolates with additional field assays. 相似文献
16.
Militello M Settanni L Aleo A Mammina C Moschetti G Giammanco GM Blàzquez MA Carrubba A 《Current microbiology》2011,62(4):1274-1281
This study was undertaken to characterize the essential oil (EO) of Artemisia arborescens growing wild in Sicily. EO, extracted by steam distillation, was examined for its chemical composition and for its capability
to inhibit some food-borne pathogen bacteria. A total of 43 compounds (13 monoterpene hydrocarbons, 14 oxygenated monoterpenes,
10 sesquiterpene hydrocarbons, three oxygenated sesquiterpenes and less amount of other three compounds), which account 93.73%
of the total oil, were identified by gas chromatography and gas chromatography–mass spectrometry. Oxygenated monoterpenes
(57.32%) constituted the main fraction, with β-thujone as the main compound (45.04%), followed by the sesquiterpene hydrocarbon
chamazulene (22.71%). Undiluted EO showed a large inhibition spectrum against strains of Listeria monocytogenes (34 out of 44), whilst it was ineffective against enterobacteria and salmonellas. The minimum inhibition concentration (MIC)
was evaluated for the two most sensitive strains (L. monocytogenes 186 and 7BO) at two cellular concentrations (106 and 107 CFU ml−1). The lowest MIC (0.625 μl ml−1, dilution of oil with acetone) was found for strain L. monocytogenes 186 at 106 CFU ml−1. 相似文献
17.
Published studies on household wastecollectors' exposure to airborne biologicalagents (bioaerosols) do not indicate highexposures to these agents. However, thesestudies did not consider several factors. Theobjective of this study was to characterize theexposure of waste collectors to bioaerosols andto propose solutions to control exposures tothese agents.Personal exposures of waste collectors tobioaerosols (total bacteria, endotoxins andmolds) were measured for seven types ofcollection during the summer, which representsthe worst conditions. The effect of truckcleaning was also evaluated. Meanconcentrations of bacteria were all in theorder of 103–104 CFU/m3 of air. Theintervention threshold was exceeded forendotoxins during the collection of compostonce every two weeks in the country. Meanconcentrations varied from 8.5 to 100 endotoxinunits per cubic meter of air (EU/m3). Measuredmean concentrations of molds were between 8,300and 98,170 CFU/m3 of air. Also, the cleaningof an empty garbage truck does not improve thequality of the air. On the other hand, a dirtytruck is not a major source of bioaerosols.The sources of these bioaerosols are leachate,particularly if the waste in the truck is oforganic origin, as well as the garbage pailsthat contain this waste. Unnecessary exposuresto these sources should therefore be avoided. For bioaerosols, stringent personal hygienemeasures remain one of the best means ofprevention. 相似文献
18.
Michel Almaguer-Chávez Teresa Rojas-Flores Vladimir Dobal-Amador Amado Batista-Mainegra Narovis Rives-Rodríguez María Jesús-Aira Ana N. Hernández-Lauzardo Annia Hernández-Rodríguez 《Aerobiologia》2012,28(2):177-183
The aerobiology can play a key role in protecting the rice crop since many fungi can cause serious damage to agricultural
areas. In this way, the ideal time to implement different security measures can be identified. To determine the presence of
potentially pathogenic fungi in the air of the rice agroecosystem, a weekly monitoring of viable fungi was carried out using
a volumetric sampler. Collected fungi were quantified, isolated, and identified based on their morphological characteristics.
The results obtained demonstrated that the annual average concentration of filamentous fungi in the atmosphere of rice agroecosystem
studied was 1,225 cfu m−3 levels ranging between 115 cfu m−3 (April) and 2,865 cfu m−3 (August). Pyricularia grisea was detected in the air for 5 months, since the second week of June until the first week of October, and highest average
concentration (25 cfu m−3) was observed in August. Of the meteorological factors evaluated, temperature and relative air humidity influence the concentration
of propagules of P. grisea in the air. Besides, other fungi were detected such as Curvularia, Bipolaris, Alternaria, and Cercospora, all with relevance to rice cultivation. This is the first characterization of aeromycological biodiversity in the studied
region. 相似文献
19.
A plant growth-promoting rhizobacterium (PGPR) was isolated and identified as Gordonia sp. S2RP-17, which showed ACC deaminase and siderophore synthesizing activities. Its maximum specific growth rate was 0.54 ± 0.12 d−1 at 5,000 mg L−1 of total petroleum hydrocarbon (TPH), and its maximum diesel degradation rate was 2,434.0 ± 124.4 mg L−1 d−1 at 20,000 mg L−1 of TPH. The growth of Zea mays was significantly promoted by the inoculation of Gordonia sp. S2RP-17 in the diesel-contaminated soil. Measured TPH removal efficiencies by various means were 13% by natural attenuation,
84.5% by planting Zea mays, and 95.8% by the combination of Zea mays and Gordonia sp. S2RP-17. The S2RP-17 cell counts were maintained at 1 × 106 CFU g-soil−1 during the remediation period, although they slightly decreased from their initial numbers (2.94 × 107 CFU g-soil−1). These results indicate that rhizoremediation using both Zea mays and Gordonia sp. S2RP-17 is a promising strategy for enhancing remediation efficiency of diesel-contaminated soils. 相似文献
20.
In 12 selected flats in Sosnowiec, Upper Silesia, the concentrations of particulate aerosol, bioaerosol and bacterial endotoxin
were examined. Concentrations of particulate aerosol, bacteria, fungi and endotoxin were in the order of 101–102
μg/m3, 101–103 cfu/m3, 100–102 cfu/m3 and 10−2–10−1 ng/m3, respectively. The most numerous group of microorganisms in indoor air during the winter season were Gram positive mesophilic
bacteria. They were more common in flats polluted with tobacco smoke. The concentrations of airborne endotoxins were higher
in flats polluted with tobacco smoke in all size ranges. The highest level of endotoxins was found in the fraction of fine
particles below 5μm. 相似文献