23 research outputs found

    Ocean currents shape the microbiome of Arctic marine sediments

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    Prokaryote communities were investigated on the seasonally stratified Alaska Beaufort Shelf (ABS). Water and sediment directly underlying water with origin in the Arctic, Pacific or Atlantic oceans were analyzed by pyrosequencing and length heterogeneity-PCR in conjunction with physicochemical and geographic distance data to determine what features structure ABS microbiomes. Distinct bacterial communities were evident in all water masses. Alphaproteobacteria explained similarity in Arctic surface water and Pacific derived water. Deltaproteobacteria were abundant in Atlantic origin water and drove similarity among samples. Most archaeal sequences in water were related to unclassified marine Euryarchaeota. Sediment communities influenced by Pacific and Atlantic water were distinct from each other and pelagic communities. Firmicutes and Chloroflexi were abundant in sediment, although their distribution varied in Atlantic and Pacific influenced sites. Thermoprotei dominated archaea in Pacific influenced sediments and Methanomicrobia dominated in methane-containing Atlantic influenced sediments. Length heterogeneity-PCR data from this study were analyzed with data from methane-containing sediments in other regions. Pacific influenced ABS sediments clustered with Pacific sites from New Zealand and Chilean coastal margins. Atlantic influenced ABS sediments formed another distinct cluster. Density and salinity were significant structuring features on pelagic communities. Porosity co-varied with benthic community structure across sites and methane did not. This study indicates that the origin of water overlying sediments shapes benthic communities locally and globally and that hydrography exerts greater influence on microbial community structure than the availability of methane

    Microbial functional change is linked with clinical outcomes after capsular fecal transplant in cirrhosis

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    BACKGROUND. Hepatic encephalopathy (HE) is associated with poor outcomes. A prior randomized, pilot trial demonstrated safety after oral capsular fecal microbial transplant (FMT) in HE, with favorable changes in microbial composition and cognition. However, microbial functional changes are unclear. The aim of this study was to determine the effect of FMT on the gut-brain axis compared with placebo, using microbial function based on bile acids (BAs), inflammation (serum IL-6, LPS-binding protein [LBP]), and their association with EncephalApp. METHODS. Twenty cirrhotic patients were randomized 1:1 into groups that received 1-time FMT capsules from a donor enriched in Lachnospiraceae and Ruminococcaceae or placebo capsules, with 5-month follow-up for safety outcomes. Stool microbiota and BA; serum IL-6, BA, and LBP; and EncephalApp were analyzed at baseline and 4 weeks after FMT/placebo. Correlation networks among microbiota, BAs, EncephalApp, IL-6, and LBP were performed before/after FMT. RESULTS. FMT-assigned participants had 1 HE recurrence and 2 unrelated infections. Six placebo-assigned participants developed negative outcomes. FMT, but not placebo, was associated with reduced serum IL-6 and LBP and improved EncephalApp. FMT-assigned participants demonstrated higher deconjugation and secondary BA formation in feces and serum compared with baseline. No change was seen in placebo. Correlation networks showed greater complexity after FMT compared with baseline. Beneficial taxa, such as Ruminococcaceae, Verrucomicrobiaceae, and Lachnospiraceae, were correlated with cognitive improvement and decrease in inflammation after FMT. Fecal/serum secondary/primary ratios and PiCRUST secondary BA pathways did not increase in participants who developed poor outcomes. CONCLUSION. Gut microbial function in cirrhosis is beneficially affected by capsular FMT, with improved inflammation and cognition. Lower secondary BAs in FMT recipients could select for participants who develop negative outcomes. TRIAL REGISTRATION. Clinicaltrials.gov NCT03152188. FUNDING. National Center for Advancing Translational Sciences NIH grant R21TR002024, VA Merit Review grant 2I0CX001076, the United Kingdom National Institute for Health Research Biomedical Facility at Imperial College London, the British Heart Foundation, Wellcome Trust, and King’s College London

    Identification of a biomarker panel for colorectal cancer diagnosis

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    <p>Abstract</p> <p>Background</p> <p>Malignancies arising in the large bowel cause the second largest number of deaths from cancer in the Western World. Despite progresses made during the last decades, colorectal cancer remains one of the most frequent and deadly neoplasias in the western countries.</p> <p>Methods</p> <p>A genomic study of human colorectal cancer has been carried out on a total of 31 tumoral samples, corresponding to different stages of the disease, and 33 non-tumoral samples. The study was carried out by hybridisation of the tumour samples against a reference pool of non-tumoral samples using Agilent Human 1A 60-mer oligo microarrays. The results obtained were validated by qRT-PCR. In the subsequent bioinformatics analysis, gene networks by means of Bayesian classifiers, variable selection and bootstrap resampling were built. The consensus among all the induced models produced a hierarchy of dependences and, thus, of variables.</p> <p>Results</p> <p>After an exhaustive process of pre-processing to ensure data quality--lost values imputation, probes quality, data smoothing and intraclass variability filtering--the final dataset comprised a total of 8, 104 probes. Next, a supervised classification approach and data analysis was carried out to obtain the most relevant genes. Two of them are directly involved in cancer progression and in particular in colorectal cancer. Finally, a supervised classifier was induced to classify new unseen samples.</p> <p>Conclusions</p> <p>We have developed a tentative model for the diagnosis of colorectal cancer based on a biomarker panel. Our results indicate that the gene profile described herein can discriminate between non-cancerous and cancerous samples with 94.45% accuracy using different supervised classifiers (AUC values in the range of 0.997 and 0.955).</p

    Novel fluorescent protein from Hydnophora rigida possess cyano emission

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    10.1016/j.bbrc.2010.04.136Biochemical and Biophysical Research Communications3963631-636BBRC

    A Molecular Comparison of Plumage and Soil Bacteria across Biogeographic, Ecological, and Taxonomic Scales

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    We used molecular methods to determine the microbial community of soil and avian plumage across biogeographic, ecological, and taxonomic scales. A total of 17 soil and 116 feather samples were collected from five avian species across multiple habitat types within one Neotropical and one temperate locality. Hypotheses regarding patterns of microbial composition relative to acquisition and dispersal of plumage bacteria in the ecosystem were tested by comparing microbial communities within and between soil and plumage. Samples from the plumage of American Redstarts (Setophaga ruticilla) were collected across both habitat types and geographic scales for intraspecific comparisons. The microbial diversity in avian plumage was moderately diverse and was dominated by Pseudomonas species. Despite a highly significant individual bird effect on microbial composition of the plumage, we detected significant biogeographic and type of habitat effects. Pseudomonas species were more abundant on the temperate site when all avian species were included in the analysis, and Bacillus subtilis and Xanthomonas groups were more abundant on the Neotropical site for redstarts alone. However, 16S rDNA sequence libraries were not significantly different between Jamaican and Maryland redstarts. Biogeographic and habitat effects were significant and more pronounced for soil samples indicating lower dispersal of soil microbiota. We detected a significant difference between soil and plumage microbial communities suggesting that soil plays a small role in plumage bacterial acquisition. Our results suggest bacterial communities on the plumage of birds are dynamic and may change at different stages in a bird’s annual cycle

    Variation in Plumage Microbiota Depends on Season and Migration

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    Migratory birds can be efficient dispersers of pathogens, yet we know little about the effect of migration and season on the microbial community in avian plumage. This is the first study to describe and compare the microbial plumage community of adult and juvenile migratory birds during the annual cycle and compare the plumage community of migrants to that of resident birds at both neotropical and nearctic locations. We used length heterogeneity PCR (16S rRNA) to describe the microbial assemblage sampled from the plumage of 66 birds in two age classes and from 16 soil samples. Resident birds differed significantly in plumage microbial community composition from migrants (R ≥ 0.238, P \u3c 0.01). Nearctic resident birds had higher plumage microbial diversity than nearctic migrants (R = 0.402, P \u3c 0.01). Plumage microbial composition differed significantly between fall premigratory and either breeding (R ≥ 0.161, P \u3c 0.05) or nonbreeding stages (R = 0.267, P \u3c 0.01). Six bacterial operational taxonomic units contributed most to the dissimilarities found in this assay. Soil microbial community composition was significantly different from all samples of plumage microbial communities (R ≥ 0.700, P \u3c 0.01). The plumage microbial community varies in relation to migration strategy and stage of the annual cycle. We suggest that plumage microbial acquisition begins in the first year at natal breeding locations and reaches equilibrium at the neotropical wintering sites. These data lead us to conclude that migration and season play an important role in the dynamics of the microbial community in avian plumage and may reflect patterns of pathogen dispersal by birds
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