Academic literature on the topic 'Endotoxin glucans'

The exposure to biocontaminants in animal facilities represents a risk for developing infectious, allergic and toxic diseases. The aim of this study was to determine what factors could be associated with a high level of exposure to biological agents through the measure and characterization of airborne fungi, bacteria, endotoxin, (1,3)-β-d-glucan and animal allergens. Airborne microorganisms were collected with an air sampler and identified by microscopic and biochemical methods. Endotoxin, (1,3)-β-d-glucan, Mus m 1, Rat n 1, Can f 1, Fel d 1, Equ c 4 allergens were detected on inhalable dust samples by Kinetic LAL, Glucatell, and ELISA assays, respectively. Our data evidenced that changing cages is a determinant factor in increasing the concentration of the airborne biocontaminants; the preparation of bedding and distribution of feed, performed in the storage area, is another critical working task in terms of exposure to endotoxins (210.7 EU/m3) and (1,3)-β-d-glucans (4.3 ng/m3). The highest concentration of Mus m 1 allergen (61.5 ng/m3) was observed in the dirty washing area. The detection of expositive peaks at risk of sensitization (>2 μg/g) by Fel d 1 in animal rooms shows passive transport by operators themselves, highlighting their role as vehicle between occupational and living environments.

ABSTRACT In August and September 2005, Hurricanes Katrina and Rita caused breeches in the New Orleans, LA, levee system, resulting in catastrophic flooding. The city remained flooded for several weeks, leading to extraordinary mold growth in homes. To characterize the potential risks of mold exposures, we measured airborne molds and markers of molds and bacteria in New Orleans area homes. In October 2005, we collected air samples from 5 mildly water-damaged houses, 15 moderately to heavily water-damaged houses, and 11 outdoor locations. The air filters were analyzed for culturable fungi, spores, (1→3,1→6)-β-d-glucans, and endotoxins. Culturable fungi were significantly higher in the moderately/heavily water-damaged houses (geometric mean = 67,000 CFU/m3) than in the mildly water-damaged houses (geometric mean = 3,700 CFU/m3) (P = 0.02). The predominant molds found were Aspergillus niger, Penicillium spp., Trichoderma, and Paecilomyces. The indoor and outdoor geometric means for endotoxins were 22.3 endotoxin units (EU)/m3 and 10.5 EU/m3, respectively, and for (1→3,1→6)-β-d-glucans were 1.7 μg/m3 and 0.9 μg/m3, respectively. In the moderately/heavily water-damaged houses, the geometric means were 31.3 EU/m3 for endotoxins and 1.8 μg/m3 for (1→3,1→6)-β-d-glucans. Molds, endotoxins, and fungal glucans were detected in the environment after Hurricanes Katrina and Rita in New Orleans at concentrations that have been associated with health effects. The species and concentrations were different from those previously reported for non-water-damaged buildings in the southeastern United States.

Glucan phosphate has been shown to enhance antimicrobial immunity in a variety of experimental models. However, the mechanisms by which glucans enhance resistance to infection remain largely unknown. Interferon-γ (IFN-γ) is a key regulator of both innate and acquired immunity. Suppression of IFN-γ production is a prominent feature of the altered immune response that follows major trauma or sepsis. The present studies were designed to determine the effect of glucan phosphate on IFN-γ expression in normal mice and endotoxin [lipopolysaccharide (LPS)]-tolerant mice. The model of LPS tolerance was used because it results in patterns of cytokine expression similar to those commonly observed following severe trauma or sepsis. Glucan treatment potentiated LPS-induced IFN-γ expression in control mice. The induction of LPS tolerance resulted in marked suppression of LPS-induced IFN-γ production. However, co-administration of glucan with LPS, during the tolerance induction phase, attenuated the LPS-tolerant response. Interleukin-12 (IL-12) and IL-18 are important mediators of LPS-induced IFN-γ production. LPS-induced IL-12 p40 mRNA expression was increased in the spleens of glucan-treated mice compared with controls. Induction of LPS tolerance caused marked suppression of IL-12 production, a response that was attenuated by glucan treatment. IL-18 was constitutively expressed in both control and LPS-tolerant mice, and LPS-induced serum levels of IL-18 were increased in mice treated with glucan. T cells isolated from glucan-treated mice exhibited increased IFN-γ expression in response to IL-12 and IL-18, as well as increased expression of the IL-12 and IL-18 receptors. The ability of glucan to potentiate IFN-γ expression in control mice provides a potential mechanism by which glucan enhances antimicrobial immunity. The ability of glucan to attenuate suppressed IFN-γ expression in LPS-tolerant mice denotes its potential benefit for the treatment of trauma and sepsis-induced immunosuppression.

ABSTRACT In working environments, especially in confined spaces like greenhouses, elevated concentrations of airborne microorganisms may become a problem for workers' health. Additionally, the use of microbial pest control agents (MPCAs) may increase exposure to microorganisms. The aim of this study was to investigate tomato growers' exposure to naturally occurring bioaerosol components [dust, bacteria, fungi, actinomycetes, (1→3)-β-d-glucans, and endotoxin] and MPCAs applied by drip irrigation. Airborne dust was collected with filter samplers and analyzed for microorganisms by plate counts and total counts using a microscope. Analysis of (1→3)-β-d-glucan and endotoxin content was performed by kinetic, chromatic Limulus amoebocyte lysate tests. The fungal strain (Trichoderma harzianum) from the biocontrol product Supresivit was identified by PCR analysis. Measurements were performed on the day of drip irrigation and 1 week, 1 month, and 3 months after the irrigation. T. harzianum from Supresivit could be detected only on the day of treatment. Streptomyces griseoviridis, an applied MPCA, was not detected in the air during this investigation. We found that bioaerosol exposure increases during the growth season and that exposure to fungi, bacteria, and endotoxin can reach levels during the harvest period that may cause respiratory symptoms in growers. The collected data indicate that MPCAs applied by drip irrigation do not become airborne later in the season.

ABSTRACT As part of environmental management policies in Europe, separate collection of organic household waste and nonorganic household waste has become increasingly common. As waste is often stored indoors, this policy might increase microbial exposure in the home environment. In this study we evaluated the association between indoor storage of organic waste and levels of microbial agents in house dust. The levels of bacterial endotoxins, mold β(1→3)-glucans, and fungal extracullar polysaccharides (EPS) of Aspergillus andPenicillium species were determined in house dust extracts as markers of microbial exposure. House dust samples were collected in 99 homes in The Netherlands selected on the basis of whether separated organic waste was present in the house. In homes in which separated organic waste was stored indoors for 1 week or more the levels of endotoxin, EPS, and glucan were 3.2-, 7.6-, and 4.6-fold higher, respectively (all P < 0.05), on both living room and kitchen floors than the levels in homes in which only nonorganic residual waste was stored indoors. Increased levels of endotoxin and EPS were observed, 2.6- and 2.1-fold (P < 0.1), respectively, when separated organic waste was stored indoors for 1 week or less, whereas storage of nonseparated waste indoors had no effect on microbial agent levels (P > 0.2). The presence of textile floor covering was another major determinant of microbial levels (P < 0.05). Our results indicate that increased microbial contaminant levels in homes are associated with indoor storage of separated organic waste. These increased levels might increase the risk of bioaerosol-related respiratory symptoms in susceptible people.

Livestock dust contains immunologically potent substances including allergens, endotoxins, microbial compounds, bacteria, fungi, viruses, pathogenic infectious organisms, particulate matter (PM), various poisonous gases such as ammonia, hydrogen sulphide (H2S), methyl acetate, propanoic acid, heptane etc.It stimulates the immune system through inflammatory and allergenic microbial agents (molds, bacteria, virus and allergens) and microbial-associated molecular patterns (e.g., endotoxin, glucans and peptidoglycans), to result in inflammatory reactions. Farmers are at the risk of developing airway diseases resulting from repeatedly exposures on the livestock farms. There is a paucity of data on in vivo and in vitro cellular and molecular changes following multiple exposures to these livestock contaminants and their long-term impact on the environment as well as human health. The mechanisms of lung dysfunction are still largely unknown. So, there is strong need to look at the combined effect of all the components of livestock dust as stimulatory factors for respiratory hazards. The development of preventive strategies to reduce exposure will be required- in-depth and identification of factors that affect day-to-day variability in exposure.

ABSTRACT Occupational exposure to wood dust and biohazards associated with wood dust (endotoxins, (1->3)-b-D-glucans, Gram (-)ve bacteria and fungi), their correlation to respiratory function, and symptoms among woodworkers have been investigated in the present study. Wood dust, endotoxins, and allergenic fungi are the main hazards found in woodworking environments. Relatively very few studies have been done on wood dust exposure. The present study was designed to comprehensively investigate the health effects of wood dust exposure, and in particular provide new information regarding: Exposure to (1->3)-b-D-glucans in an occupational environment; Levels of exposure to wood dust and biohazards associated with wood dust in different woodworking environments; Correlations among personal exposures, especially correlations between (1->3)-b-D-glucans and fungi exposures, and endotoxins and Gram (-)ve bacteria exposures; Effects of personal exposure to biohazards on lung function; Effects of personal exposure to biohazards on work-related symptoms; and Determinants of inhalable exposures (provide which factors in the environment influence the personal inhalable exposures). Workers at four different woodworking processes; two logging sites, four sawmills, one major woodchipping operation and five joineries situated in the state of New South Wales in Australia were studied for personal exposure to inhalable dust (n=182) and respirable dust (n=81), fungi (n=120), Gram (-)ve bacteria (n=120), inhalable endotoxin (n=160), respirable endotoxin (n=79), inhalable (1->3)-b-D-glucan (n=105), and respirable (1->3)-b-D-glucan (n=62). The workers (n=168) were also tested for lung function. A questionnaire study (n=195) was carried out to determine the prevalence of work-related symptoms. The geometric mean inhalable exposure at logging sites was 0.56 mg/m3 (n=7), sawmills 1.59 mg/m3 (n=93), the woodchipping mill 1.86 mg/m3 (n=9) and joineries 3.68 mg/m3 (n=66). Overall, sixty two percent of the exposures exceeded the current standards. Among joineries, 95% of the hardwood exposures and 35% of the softwood exposures were above the relevant standards. Compared with green mills, the percentage of samples, which exceeded the hardwood standard was high for dry mills (70% in dry mills, 50% in green mills). The respirable dust exposures were high at the joineries compared with the other worksites. Exposure levels to fungi at logging sites and sawmills were in the range 103-104 cfu/m3, woodchipping 103-105 cfu/m3 and joineries 102-104 cfu/m3. The predominant fungi found at sawmills were Penicillium spp. High exposure levels of Aureobasidium pullulans were also found at two sawmills. At the woodchipping mill the predominant species were Aspergillus fumigatus, Penicillium spp., and Paecilomyces spp. The sawmills, which employed kiln drying processes, had lower exposure levels of fungi compared with the green mills. Those workplaces which had efficient dust control systems showed less exposure to fungi and bacteria. Although mean endotoxin levels were lower than the suggested threshold value of 20 ng/m3, some personal exposures at sawmills and joineries exceeded the threshold limit value. The mean inhalable (1->3)-b-D-glucan level at the woodchipping mill was 2.32 ng/m3, at sawmills 1.37 ng/m3, at logging sites 2.02 ng/m3, and at joineries 0.43 ng/m3. For the respirable size fraction, mean endotoxin and mean (1->3)-b-D-glucan concentrations were much lower, being similar to observed dust concentrations. Significant correlations were found between mean inhalable endotoxin and Gram (-)ve bacteria levels (p<0.0001), and mean airborne inhalable (1->3)-b-D-glucan and fungi levels (p=0.0003). The correlations between mean respirable endotoxin levels vs Gram (-)ve bacteria exposure levels (p=0.005), and respirable (1->3)-b-D-glucan exposure levels vs total fungi levels (p=0.005) were also significant. Significant correlations were found between lung function and personal exposures. Multivariate analyses showed that the effect of all the personal exposures on cross-shift decrements in lung function was more prominent among sawmill and chip mill workers compared with joinery workers. Woodworkers had markedly high prevalence of cough, phlegm, chronic bronchitis, frequent headaches, throat and eye irritations, and nasal symptoms compared with controls. Among the woodworkers, smokers had a high prevalence of chronic bronchitis (20%) compared with non-smokers (10%). Some workers also reported a variety of allergy problems due to exposure to various types of wood dust. Both joinery workers and sawmill and chip mill workers revealed significant correlations between work-related symptoms and personal exposures. Chronic bronchitis was significantly correlated with personal exposure to wood dust, endotoxin, (1->3)-b-D-glucan, fungi, and Gram (-)ve bacteria among joinery workers. Whereas among sawmill workers chronic bronchitis was significantly correlated with personal exposure to endotoxin, (1->3)-b-D-glucan, and fungi. Woodworkers showed significant positive correlations between percentage cross-shift change (decrease) in lung function and respiratory symptoms. Significant inverse correlations were also found among percentage predicted lung function and respiratory symptoms. The elevated inhalable dust exposures observed in this study can be explained by a combination of factors, including: lack of awareness of potential health effects of wood dust exposure among both management and workers, aging equipment, inadequate and ineffective dust extraction systems or usually none especially for hand held tools, poor maintenance of the ventilation system in some, non-segregation of dusty processes, dry sweeping, and the use of compressed air jets. The determinant-of-exposure analysis confirmed the field observations. The significant determinants of personal inhalable dust exposures (n=163) were found to be: local exhaust ventilation, job title, use of hand-held tools, cleaning method used, use of compressed air, and green or dry wood processed. Type of wood processed was not found to be statistically significant. A majority of workers (~90%) did not wear appropriate respirators approved for wood dust, while the workers who did wear them, used them on average less than 50% of the time. Workers should be protected by controlling dust at its source. When exposure to wood dust cannot be avoided, engineering controls should be supplemented with the use of appropriate personal protective equipment.

Background and aims: The immune, respiratory and central nervous system start developing during pregnancy and continue during the first years of life. Therefore, environmental exposures during these periods may play a role on the maturation of these systems. In particular, the exposure to indoor microbial agents, indoor factors such as pets or dampness, and to household cleaning products during infancy or childhood may have important implications in the development processes. This thesis aims to assess the long term effects of indoor exposure to microbial agents and chemical based cleaning products on respiratory and mental health among children from birth to the age of 13 years old. Methods: We used data from nine European birth cohorts that are part of three projects: the European HITEA project, the Spanish INMA project; and the German GINIplus and LISAplus birth cohort studies. Information on the exposure to indoor dampness, pet ownership, the use of cleaning products and allergy and respiratory health was periodically collected through questionnaires and health tests. Living room dust samples were collected when the children were 2-3 months and analysed for microbial agents concentrations (bacterial endotoxin, fungal extracellular polysaccharides (EPS) from Aspergillus spp. and Penicillium spp, and mould β(1,3)- glucans). Multivariable regression models were used to assess the associations between the exposures and the health outcomes. Results: 1) Concentrations of measured microbial agents varied differently across the cohorts. 2) Season of dust sampling, dog ownership, indoor report of dampness, and number of people living in the home is associated with the concentrations of microbial agents. 3) Early life exposure to endotoxin and dogs in the home is associated with lower levels of FeNO at school age. 4) Domestic use of cleaning sprays, air fresheners and solvents during pregnancy is associated with a higher prevalence of wheezing and LRTI during the first year of life. 5) At school age, bystander exposure to domestic cleaning sprays increases the levels of FeNO, and exposure to air freshening sprays and solvents decreases the lung function. 6) Persistent exposure to indoor dampness during early life has negative effects on the cognitive function and social competences at 4 years old. 7) Exposure to visible mould, dampness and pet ownership during the first 10 years of life increases the risk of borderline or abnormal scores in the SDQ at 10 years of age. Conclusion: Our results suggest that indoor exposure to microbial agents during early life and exposure to chemical based cleaning products during pregnancy, infancy and childhood play a role in the development of the respiratory, immune and central nervous systems.
Introducció i objectius: El desenvolupament dels sistemes immunitari, respiratori i nerviós central comença durant l’embaràs i continua al llarg la infància. Així, els primers anys de vida són moments crucials en que qualsevol exposició ambiental pot influir el desenvolupament d’aquests sistemes. Concretament, l’exposició durant la infància a agents microbiològics, humitat, animals de companyia i productes de neteja pot tenir implicacions importants en els processos de maduració d’aquests sistemes. L’objectiu principal d’aquesta tesi és el d’avaluar els efectes a llarg termini de la exposició a agents microbiològics i a productes de neteja de base química a la llar, sobre la salut respiratòria i mental des del naixement fins a l’edat de 13 anys. Mètodes: En aquesta tesi hem fet servir dades de nou cohorts de naixement europees que formen part de tres projectes: el projecte europeu HITEA, el projecte espanyol INMA, i els estudis alemanys GINIplus i LISAplus. La informació sobre la exposició a humitat, a animals de companyia, la utilització de productes de neteja, al·lèrgies i salut respiratòria es va recollir en tots els projectes mitjançant qüestionaris administrats als pares/mares i proves mèdiques o tests neuropsicològics. A més, es van recollir mostres de pols dels menjadors de les cases quan els nens/es tenien 2-3 mesos d’edat que es van analitzar per determinar les concentracions d’agents microbiològics (endotoxines bacterianes, polisacàrids extracel·lulars (EPS) d’Aspergillus spp. i Penicillium spp i β(1,3)-glucans fúngics). Per l’avaluació de les associacions entre exposicions i resultats de salut s’han desenvolupat models de regressió múltiple. Resultats: 1) Les concentracions d’agents microbiològics mesurats en pols de les llars varien per cohort. 2) L’estació de l’any en que es recull la mostra de pols, la presència de gossos a la casa, reportar humitat a la casa i el número de persones que hi viuen estan associats amb la concentració d’agents microbiològics a la pols. 3) L’exposició durant els primers mesos de vida a endotoxines i gossos a la llar s’associa amb nivells baixos de FeNO a edat escolar. 4) L’ús d’esprais i dissolvents per la neteja de la casa, i ambientadors durant l’embaràs està relacionat amb un increment en la prevalença de sibilants i infeccions respiratòries de vies baixes al llarg del primer any de vida. 5) En edat escolar, la exposició passiva a productes de neteja domèstics utilitzats en forma d’esprais incrementa els nivells de FeNO, i l’exposició a esprais ambientadors i dissolvents per la neteja de la llar disminueix la funció pulmonar. 6) L’exposició persistent a humitat a la llar durant els 2 primers anys de vida té un efecte negatiu sobre la funció cognitiva i les competències socials mesurades als 4 anys d’edat. 7) L’exposició a fongs procedents de la humitat, a humitat i a animals de companyia a casa al llarg dels primers 10 anys de vida incrementa el risc de puntuacions “borderline” o anormals al questionari SDQ administrat als 10 anys. Conclusió: els resultats presentats en aquesta tesi suggereixen que l’exposició a agents microbiològics durant els primers mesos de vida i l’exposició a productes de neteja durant l’embaràs i la infància juguen un paper important en el desenvolupament dels sistemes respiratori, immunològic i nerviós central.

Commercial composting is becoming more prevalent in the UK as biodegradable municipal waste is being diverted from landfill. Exposure to the organisms actively grown during the composting of waste are known to cause adverse effects on respiratory health when these organisms, or fragments of these organisms, become airborne forming a ‘bioaerosol’. The aim of this Thesis is to characterise compost workers’ exposure levels to bioaerosols by measuring their exposure to dust, endotoxin and β-(1-3) glucan and to use this exposure data to inform the development of evidence-based risk assessment and risk mitigation measures. In general, workers’ exposure to dust was low in the four sites studied but there was extensive variation in personal exposure levels. The inhalable fraction was found to be the predominant fraction of concern. Manual sorting and the screening of final product gave rise to high exposures to inhalable dust on occasion. Despite dust levels being generally low, workers’ exposures to endotoxin and to a lesser extent β-(1-3) glucan were elevated and workers were exposed to levels thought to be related to respiratory symptoms and disease. Any activities involving the movement of waste resulted in elevated levels of endotoxin and β-(1-3) glucan at all four sites investigated in this study. Vehicle operators’ exposure levels were high and a multi-faceted strategy is needed to reduce exposure levels to an acceptable level. Currently, no Workplace Exposure Limits or agreed dose-response estimates exist in the UK to manage workers’ exposure levels. Consequently the risk to worker’s health is difficult to characterise. The COSHH Regulations require employers to reduce compost workers’ exposure levels to bioaerosols ‘so far as is reasonably practical’. This study discusses the need for site-specific, task-specific risk assessments to be conducted and that robust risk mitigation measures are required to minimise the impact on compost workers health.

Asthma is the leading chronic illness in children in the United States. Since children in the U.S. spend a majority of their time indoors there is an increased need to understand key sources of daily asthma triggers in the home. Bacterial endotoxin, dust mite allergens and β-D-glucan have been shown to be potent inducers of asthma attacks, and high levels of these allergens in homes can trigger attacks in those with asthma. We aim to better understand the risks to those with asthma that might be associated with evaporative cooler (EC) use in low-income homes. ECs are often promoted because of their low energy consumption and decreased environmental impact compared to central air conditioning (AC). Because of their lower cost, ECs are more widely used in low-income homes. ECs use evaporation to cool the air, which leads to higher indoor relative humidity. This may create an ecological niche for house dust mites in semi-arid climates where they are normally absent. EC sump water also provides an ideal environment for bacteria and fungi to grow, possibly resulting in EC loading the air with more potential asthma triggers than central air conditioning. We sampled low-income homes around Utah county with central air and evaporative cooling and tested them for the presence of dust mite allergens, β-D-glucan and endotoxin. There were significantly higher levels of endotoxins and β-(1→3)-D-glucans in the EC homes compared to the AC homes, with increased odds of dust mite allergen prevalence but not at clinically significant levels. These findings suggest that in semi-arid environments, endotoxin and β-(1→3)-D-glucan levels in homes with evaporative coolers are more elevated than dust mite allergens.

博士
國立臺灣大學
公共衛生研究所
86
To evaluate dose-response relationships between work-related airway inflammation and systemic sysmptoms and dampness exposure, a cross-sectional study on risk factors was carried out among 1,237 employees in 19 air-conditioning office buildings in August and September 1995 in the subtropical Taipei area. Completed self-reported questionnaires included their sociodemographic, indoor environmental quality perceptions, workspace factors, dampness exposure, and occurrence of allergicdiseases, respiratory diseases and airway inflammation / systemic symptoms. Dampness exposures included in data analyses as indexes were combinations of stuffy odor, mold, water damage and a history of flooding.The most common airway inflammation and systemic symptoms were headache, lethargy/ fatigue and eye irritation, while the least symptom was shortness of breath. Alsoallergic rhinitis was the most prevalent respiratory complain among the respondents. After controlling for age,sex, job dissatisfaction, ventilationand atopy, the odds ratio (OR) for eyeirritation for employees was 1.34 when either stuffy odor or mold was presentin the buildings. The OR increased to 1.72 when both stuffy odor and mold were present, to 3.14 when sign of water damage was also present, and to 5.03 when all four dampness exposure characteristics were noticed in buildings. Indoor dampness is a very common condition in office buildings in the city, the presenceof dampness in the building has a dose-response effect for eye irritation, cough,and lethargy/fatigue among employees. In addition, indoor bioaerosols (bacteria, fungi, endotoxin, and beta-1,3-glucan) weredetermined in 8 daycare centers, 8 office buildings, and 8 domesticenvironmentsin the Taipei area. The associations between indoor dampness, bioaerosols, and airway inflammation / systemic symptoms were furtherly performed using a questionnairesurvey. It was demonstrated that the median contents of indoorbacteria and fungi were the highest for daycare centers, followed by those for homes and for office buildings. The similar patterns were observed for endotoxin and beta-1,3-glucan.Regarding the airway inflammation andsystemic symptoms, the prevalence rateswere higher for females in office building than those in daycare centers, and most symptoms were more prevalent for females than for males. Regarding bioaerosolexposure in relation to airway inflammation and systemic symptoms, there was a strongassociation between beta-1,3-glucan and lethargy/fatigue. In Taiwan, the predominant perennial allergens are house dust mite (HDM) and fungi. However, mite allergen levels in these subtropical homes were always found to be higher than the threshold for sensitization of HDM allergic responses, therefore, the amounts of mite allergen might not be the determining factor for allergy sensitization. Organic dusts and gaseous pollutants are regarded as potential risk factors for allergic diseases. Furthermore, we have shown that nonspecific innate immune responses induced by lipopolysaccharide(LPS) and beta-1,3-D-glucan may influence the type of antigen-specific immune effector function. In this study, it was observed that inhaled LPS and beta-1,3-D-glucan (Grifolan) can abrogate airway inhalation-induced IgE- specifictolerance and enhance airwayallergen-specific IgE responses. These results havepotential implications forunderstanding the development of aerosolized allergen-induced airway allergicresponses.