The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Ozlem Oyardi - One of the best experts on this subject based on the ideXlab platform.
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immunization against poly n acetylglucosamine reduces neutrophil activation and gvhd while sparing Microbial Diversity
Proceedings of the National Academy of Sciences of the United States of America, 2019Co-Authors: Jan Hulsdunker, Oliver S Thomas, Eileen Haring, Susanne Unger, Nicolas Gonzalo Nunez, Sonia Tugues, Sandra Duquesne, Colette Cywesbentley, Ozlem OyardiAbstract:Microbial invasion into the intestinal mucosa after allogeneic hematopoietic cell transplantation (allo-HCT) triggers neutrophil activation and requires antibiotic interventions to prevent sepsis. However, antibiotics lead to a loss of microbiota Diversity, which is connected to a higher incidence of acute graft-versus-host disease (aGVHD). AntiMicrobial therapies that eliminate invading bacteria and reduce neutrophil-mediated damage without reducing the Diversity of the microbiota are therefore highly desirable. A potential solution would be the use of antiMicrobial antibodies that target invading pathogens, ultimately leading to their elimination by innate immune cells. In a mouse model of aGVHD, we investigated the potency of active and passive immunization against the conserved Microbial surface polysaccharide poly-N-acetylglucosamine (PNAG) that is expressed on numerous pathogens. Treatment with monoclonal or polyclonal antibodies to PNAG (anti-PNAG) or vaccination against PNAG reduced aGVHD-related mortality. Anti-PNAG treatment did not change the intestinal Microbial Diversity as determined by 16S ribosomal DNA sequencing. Anti-PNAG treatment reduced myeloperoxidase activation and proliferation of neutrophil granulocytes (neutrophils) in the ileum of mice developing GVHD. In vitro, anti-PNAG treatment showed high antiMicrobial activity. The functional role of neutrophils was confirmed by using neutrophil-deficient LysMcreMcl1fl/fl mice that had no survival advantage under anti-PNAG treatment. In summary, the control of invading bacteria by anti-PNAG treatment could be a novel approach to reduce the uncontrolled neutrophil activation that promotes early GVHD and opens a new avenue to interfere with aGVHD without affecting commensal intestinal Microbial Diversity.
Liping Qiu - One of the best experts on this subject based on the ideXlab platform.
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erosion reduces soil Microbial Diversity network complexity and multifunctionality
The ISME Journal, 2021Co-Authors: Peter B. Reich, Liping Qiu, Qian Zhang, Hansong Zhu, Samiran BanerjeeAbstract:While soil erosion drives land degradation, the impact of erosion on soil Microbial communities and multiple soil functions remains unclear. This hinders our ability to assess the true impact of erosion on soil ecosystem services and our ability to restore eroded environments. Here we examined the effect of erosion on Microbial communities at two sites with contrasting soil texture and climates. Eroded plots had lower Microbial network complexity, fewer Microbial taxa, and fewer associations among Microbial taxa, relative to non-eroded plots. Soil erosion also shifted Microbial community composition, with decreased relative abundances of dominant phyla such as Proteobacteria, Bacteroidetes, and Gemmatimonadetes. In contrast, erosion led to an increase in the relative abundances of some bacterial families involved in N cycling, such as Acetobacteraceae and Beijerinckiaceae. Changes in microbiota characteristics were strongly related with erosion-induced changes in soil multifunctionality. Together, these results demonstrate that soil erosion has a significant negative impact on soil Microbial Diversity and functionality.
Peter D Steinberg - One of the best experts on this subject based on the ideXlab platform.
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host specificity in marine sponge associated bacteria and potential implications for marine Microbial Diversity
Environmental Microbiology, 2004Co-Authors: Michael W Taylor, Peter J Schupp, Ingela Dahllof, Staffan Kjelleberg, Peter D SteinbergAbstract:Summary BioDiversity is fundamental to both eukaryote and prokaryote ecology, yet investigations of Diversity often differ markedly between the two disciplines. Host specificity – the association of organisms with only a few (specialism) or many (generalism) host species – is recognized within eukaryote ecology as a key determinant of Diversity. In contrast, its implications for Microbial Diversity have received relatively little attention. Here we explore the relationship between Microbial Diversity and host specificity using marine sponge–bacteria associations. We used a replicated, hierarchical sampling design and both 16S rDNA- and rpoB-based denaturing gradient gel electrophoresis (DGGE) to examine whether three co-occurring sponges from temperate Australia –Cymbastela concentrica, Callyspongia sp. and Stylinos sp. – contained unique, specialized communities of microbes. Microbial communities varied little within each species of sponge, but variability among species was substantial. Over five seasons, the Microbial community in C. concentrica differed significantly from other sponges, which were more similar to seawater. Overall, three types of sponge-associated bacteria were identified via 16S rDNA sequencing of excised DGGE bands: ‘specialists’– found on only one host species, ‘sponge associates’– found on multiple hosts but not in seawater, and ‘generalists’ from multiple hosts and seawater. Analogous to other high Diversity systems, the degree of specificity of prokaryotes to host eukaryotes could have a potentially significant effect on estimates of marine Microbial Diversity.
Edith Bai - One of the best experts on this subject based on the ideXlab platform.
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decreasing soil Microbial Diversity is associated with decreasing Microbial biomass under nitrogen addition
Soil Biology & Biochemistry, 2018Co-Authors: Chao Wang, Dongwei Liu, Edith BaiAbstract:Abstract While aboveground bioDiversity has been widely studied, how Microbial bioDiversity responds to increasing nitrogen (N) deposition is still unclear. Here we conducted a meta-analysis to investigate the responses of soil Microbial Diversity and composition to N addition. Overall, we found N addition decreased both soil Microbial Diversity and the relative abundance of Actinobacteria and Nitrospirae, although the effect may vary among different ecosystems. The effect size on Microbial Shannon index was positively correlated with the changes in soil Microbial biomass under N addition. The initial soil conditions, the duration of treatment, the N addition rate and changes in soil organic carbon under N addition all affected the effect sizes of N addition on Microbial Shannon index, while changes in soil pH played a minor role. Overall, our results suggest that the losses of Microbial Diversity with increasing N deposition rate would alter ecosystem functions and may have profound feedbacks to global climate change.
Rob Knight - One of the best experts on this subject based on the ideXlab platform.
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stress response gut Microbial Diversity and sexual signals correlate with social interactions
Biology Letters, 2016Co-Authors: Iris I Levin, Rob Knight, David M Zonana, Bailey K Fosdick, Se Jin Song, Rebecca J SafranAbstract:Theory predicts that social interactions are dynamically linked to phenotype. Yet because social interactions are difficult to quantify, little is known about the precise details on how interactivity is linked to phenotype. Here, we deployed proximity loggers on North American barn swallows ( Hirundo rustica erythrogaster ) to examine intercorrelations among social interactions, morphology and features of the phenotype that are sensitive to the social context: stress-induced corticosterone (CORT) and gut Microbial Diversity. We analysed relationships at two spatial scales of interaction: (i) body contact and (ii) social interactions occurring between 0.1 and 5 m. Network analysis revealed that relationships between social interactions, morphology, CORT and gut Microbial Diversity varied depending on the sexes of the individuals interacting and the spatial scale of interaction proximity. We found evidence that body contact interactions were related to Diversity of socially transmitted microbes and that looser social interactions were related to signalling traits and CORT.
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individuals diet Diversity influences gut Microbial Diversity in two freshwater fish threespine stickleback and eurasian perch
Ecology Letters, 2014Co-Authors: Daniel I Bolnick, Rob Knight, Lisa K Snowberg, Philipp E Hirsch, Christian L Lauber, Gregory J Caporaso, Richard SvanbackAbstract:Vertebrates' diets profoundly influence the composition of symbiotic gut Microbial communities. Studies documenting diet-microbiota associations typically focus on univariate or categorical diet variables. However, in nature individuals often consume diverse combinations of foods. If diet components act independently, each providing distinct Microbial colonists or nutrients, we expect a positive relationship between diet Diversity and Microbial Diversity. We tested this prediction within each of two fish species (stickleback and perch), in which individuals vary in their propensity to eat littoral or pelagic invertebrates or mixtures of both prey. Unexpectedly, in most cases individuals with more generalised diets had less diverse microbiota than dietary specialists, in both natural and laboratory populations. This negative association between diet Diversity and Microbial Diversity was small but significant, and most apparent after accounting for complex interactions between sex, size and diet. Our results suggest that multiple diet components can interact non-additively to influence gut Microbial Diversity.
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reconstructing the Microbial Diversity and function of pre agricultural tallgrass prairie soils in the united states
Science, 2013Co-Authors: Joshua Ladau, Jonathan W Leff, S M Owens, Katherine S Pollard, Noah Fierer, Jose C Clemente, Rob KnightAbstract:Native tallgrass prairie once dominated much of the midwestern United States, but this biome and the soil Microbial Diversity that once sustained this highly productive system have been almost completely eradicated by decades of agricultural practices. We reconstructed the soil Microbial Diversity that once existed in this biome by analyzing relict prairie soils and found that the biogeographical patterns were largely driven by changes in the relative abundance of Verrucomicrobia, a poorly studied bacterial phylum that appears to dominate many prairie soils. Shotgun metagenomic data suggested that these spatial patterns were associated with strong shifts in carbon dynamics. We show that metagenomic approaches can be used to reconstruct below-ground biogeochemical and Diversity gradients in endangered ecosystems; such information could be used to improve restoration efforts, given that even small changes in below-ground Microbial Diversity can have important impacts on ecosystem processes.
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species divergence and the measurement of Microbial Diversity
Fems Microbiology Reviews, 2008Co-Authors: Catherine A Lozupone, Rob KnightAbstract:Diversity measurement is important for understanding community structure and dynamics, but has been particularly challenging for microorganisms. Microbial community characterization using small subunit rRNA (SSU rRNA) gene sequences has revealed an extensive, previously unsuspected Diversity that we are only now beginning to understand, especially now that advanced sequencing technologies are producing datasets containing hundreds of thousands of sequences from hundreds of samples. Efforts to quantify Microbial Diversity often use taxon-based methods that ignore the fact that not all species are equally related, which can therefore obscure important patterns in the data. For example, α-Diversity (Diversity within communities) is often estimated as the number of species in a community (species richness), and β-Diversity (partitioning of Diversity among communities) is often based on the number of shared species. Methods for measuring α- and β-Diversity that account for different levels of divergence between individuals have recently been more widely applied. These methods are more powerful than taxon-based methods because microorganisms in a community differ dramatically in sequence similarity, which also often correlates with phenotypic similarity in key features such as metabolic capabilities. Consequently, divergence-based methods are providing new insights into Microbial community structure and function.
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species divergence and the measurement of Microbial Diversity
Fems Microbiology Reviews, 2008Co-Authors: Catherine A Lozupone, Rob KnightAbstract:Diversity measurement is important for understanding community structure and dynamics, but has been particularly challenging for microorganisms. Microbial community characterization using small subunit rRNA (SSU rRNA) gene sequences has revealed an extensive, previously unsuspected Diversity that we are only now beginning to understand, especially now that advanced sequencing technologies are producing datasets containing hundreds of thousands of sequences from hundreds of samples. Efforts to quantify Microbial Diversity often use taxon-based methods that ignore the fact that not all species are equally related, which can therefore obscure important patterns in the data. For example, α-Diversity (Diversity within communities) is often estimated as the number of species in a community (species richness), and β-Diversity (partitioning of Diversity among communities) is often based on the number of shared species. Methods for measuring α- and β-Diversity that account for different levels of divergence between individuals have recently been more widely applied. These methods are more powerful than taxon-based methods because microorganisms in a community differ dramatically in sequence similarity, which also often correlates with phenotypic similarity in key features such as metabolic capabilities. Consequently, divergence-based methods are providing new insights into Microbial community structure and function.