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Author (up) Ege, M.J.; Mayer, M.; Normand, A.-C.; Genuneit, J.; Cookson, W.O.C.M.; Braun-Fahrlander, C.; Heederik, D.; Piarroux, R.; von Mutius, E. file  url
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  Title Exposure to environmental microorganisms and childhood asthma Type Journal Article
  Year 2011 Publication The New England Journal of Medicine Abbreviated Journal N Engl J Med  
  Volume 364 Issue 8 Pages 701-709  
  Keywords Adolescent; *Agriculture; Asthma/*epidemiology/immunology; Bacteria/*isolation & purification; Biodiversity; Child; Cross-Sectional Studies; Dust/analysis; Environmental Exposure/*analysis; Female; Fungi/*isolation & purification; Humans; Hypersensitivity/*epidemiology/immunology; Immunoglobulin E/blood; Logistic Models; Male; Microbiome; Polymorphism, Single-Stranded Conformational; Prevalence; Risk Factors; Surveys and Questionnaires  
  Abstract BACKGROUND: Children who grow up in environments that afford them a wide range of microbial exposures, such as traditional farms, are protected from childhood asthma and atopy. In previous studies, markers of microbial exposure have been inversely related to these conditions. METHODS: In two cross-sectional studies, we compared children living on farms with those in a reference group with respect to the prevalence of asthma and atopy and to the diversity of microbial exposure. In one study--PARSIFAL (Prevention of Allergy-Risk Factors for Sensitization in Children Related to Farming and Anthroposophic Lifestyle)--samples of mattress dust were screened for bacterial DNA with the use of single-strand conformation polymorphism (SSCP) analyses to detect environmental bacteria that cannot be measured by means of culture techniques. In the other study--GABRIELA (Multidisciplinary Study to Identify the Genetic and Environmental Causes of Asthma in the European Community [GABRIEL] Advanced Study)--samples of settled dust from children's rooms were evaluated for bacterial and fungal taxa with the use of culture techniques. RESULTS: In both studies, children who lived on farms had lower prevalences of asthma and atopy and were exposed to a greater variety of environmental microorganisms than the children in the reference group. In turn, diversity of microbial exposure was inversely related to the risk of asthma (odds ratio for PARSIFAL, 0.62; 95% confidence interval [CI], 0.44 to 0.89; odds ratio for GABRIELA, 0.86; 95% CI, 0.75 to 0.99). In addition, the presence of certain more circumscribed exposures was also inversely related to the risk of asthma; this included exposure to species in the fungal taxon eurotium (adjusted odds ratio, 0.37; 95% CI, 0.18 to 0.76) and to a variety of bacterial species, including Listeria monocytogenes, bacillus species, corynebacterium species, and others (adjusted odds ratio, 0.57; 95% CI, 0.38 to 0.86). CONCLUSIONS: Children living on farms were exposed to a wider range of microbes than were children in the reference group, and this exposure explains a substantial fraction of the inverse relation between asthma and growing up on a farm. (Funded by the Deutsche Forschungsgemeinschaft and the European Commission.).  
  Call Number Serial 1983  
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Author (up) Tian, C.; Wang, C.; Tian, Y.; Wu, X.; Xiao, B. file  url
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  Title Vertical distribution of Fe and Fe(III)-reducing bacteria in the sediments of Lake Donghu, China Type Journal Article
  Year 2015 Publication Canadian Journal of Microbiology Abbreviated Journal Can J Microbiol  
  Volume 61 Issue 8 Pages 575-583  
  Keywords Bacteria/*isolation & purification/metabolism; China; Ferric Compounds/*metabolism; Geobacter/metabolism; Geologic Sediments/*microbiology; Iron/*analysis; Lakes/*microbiology; Fe faiblement cristallin; Fe reduction; Fe(III)-reducing bacteria; Lake Donghu; bacteries reductrices de Fe(III); distribution verticale; lac Donghu; poorly crystalline Fe; reduction de Fe; vertical distribution  
  Abstract In lake sediments, iron (Fe) is the most versatile element, and the redox cycling of Fe has a wide influence on the biogeochemical cycling of organic and inorganic substances. The aim of the present study was to analyze the vertical distribution of Fe and Fe(III)-reducing bacteria (FeRB) in the surface sediment (30 cm) of Lake Donghu, China. At the 3 sites we surveyed, FeRB and Fe(II)-oxidizing bacteria (FeOB) coexisted in anoxic sediments. Geobacter-related FeRB accounted for 5%-31% of the total Bacteria, while Gallionella-related FeOB accounted for only 0.1%-1.3%. A significant correlation between the relative abundance of poorly crystalline Fe and Geobacter spp. suggested that poorly crystalline Fe favored microbial Fe(III) reduction. Poorly crystalline Fe and Geobacter spp. were significantly associated with solid-phase Fe(II) and total inorganic phosphorus levels. Pore water Fe(II) concentrations negatively correlated with NO3(-) at all sites. We concluded that Geobacter spp. were abundant in the sediments of Lake Donghu, and the redox of Fe might participate in the cycling of nitrogen and phosphorus in sediments. These observations provided insight into the roles of microbial Fe cycling in lake sediments.  
  Call Number Serial 1205  
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