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Bibliography on: Metagenomics

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ESP: PubMed Auto Bibliography 09 Apr 2020 at 01:31 Created: 

Metagenomics

While genomics is the study of DNA extracted from individuals — individual cells, tissues, or organisms — metagenomics is a more recent refinement that analyzes samples of pooled DNA taken from the environment, not from an individual. Like genomics, metagenomic methods have great potential in many areas of biology, but none so much as in providing access to the hitherto invisible world of unculturable microbes, often estimated to comprise 90% or more of bacterial species and, in some ecosystems, the bulk of the biomass. A recent describes how this new science of metagenomics is beginning to reveal the secrets of our microbial world: The opportunity that stands before microbiologists today is akin to a reinvention of the microscope in the expanse of research questions it opens to investigation. Metagenomics provides a new way of examining the microbial world that not only will transform modern microbiology but has the potential to revolutionize understanding of the entire living world. In metagenomics, the power of genomic analysis is applied to entire communities of microbes, bypassing the need to isolate and culture individual bacterial community members.

Created with PubMed® Query: metagenomic OR metagenomics OR metagenome NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)

RevDate: 2020-04-08

Kaur K, Khatri I, Akhtar A, et al (2020)

Metagenomics analysis reveals features unique to Indian distal gut microbiota.

PloS one, 15(4):e0231197 pii:PONE-D-19-16291.

Various factors including diet, age, geography, culture and socio-economic status have a role in determining the composition of the human gut microbiota. The human gut microbial composition is known to be altered in disease conditions. Considering the important role of the gut microbiome in maintaining homeostasis and overall health, it is important to understand the microbial diversity and the functional metagenome of the healthy gut. Here, we characterized the microbiota of 31 fecal samples from healthy individuals of Indian ethnic tribes from Ladakh, Jaisalmer and Khargone by shotgun metagenomic sequencing. Sequence analysis revealed that Bifidobacterium and Prevotella were the key microbes contributing to the differences among Jaisalmer, Khargone and Ladakh samples at the genus level. Our correlation network study identified carbohydrate-active enzymes and carbohydrate binding proteins that are associated with specific genera in the different Indian geographical regions studied. Network analysis of carbohydrate-active enzymes and genus abundance revealed that the presence of different carbohydrate-active enzymes is driven by differential abundance of genera. The correlation networks were different in the different geographical regions, and these interactions suggest the role of less abundant genera in shaping the gut environment. We compared our data with samples from different countries and found significant differences in taxonomic composition and abundance of carbohydrate-active enzymes in the gut microbiota as compared to the other countries.

RevDate: 2020-04-08

Damian D, Maghembe R, Damas M, et al (2020)

Application of Viral Metagenomics for Study of Emerging and Reemerging Tick-Borne Viruses.

Vector borne and zoonotic diseases (Larchmont, N.Y.) [Epub ahead of print].

Ticks are important vectors for different tick-borne viruses, some of which cause diseases and death in humans, livestock, and wild animals. Tick-borne encephalitis virus, Crimean-Congo hemorrhagic fever virus, Kyasanur forest disease virus, severe fever with thrombocytopenia syndrome virus, Heartland virus, African swine fever virus, Nairobi sheep disease virus, and Louping ill virus are just a few examples of important tick-borne viruses. The majority of tick-borne viruses have RNA genomes that routinely undergo rapid genetic modifications such as point mutations during their replication. These genomic changes can influence the spread of viruses to new habitats and hosts and lead to the emergence of novel viruses that can pose a threat to public health. Therefore, investigation of the viruses circulating in ticks is important to understand their diversity, host and vector range, and evolutionary history, as well as to predict new emerging pathogens. The choice of detection method is important, as most methods detect only those viruses that have been previously well described. On the other hand, viral metagenomics is a useful tool to simultaneously identify all the viruses present in a sample, including novel variants of already known viruses or completely new viruses. This review describes tick-borne viruses, their historical background of emergence, and their reemergence in nature, and the use of viral metagenomics for viral discovery and studies of viral evolution.

RevDate: 2020-04-08

Macedo TZ, de Souza Dornelles H, do Valle Marques AL, et al (2020)

The influence of upflow velocity and hydraulic retention time changes on taxonomic and functional characterization in Fluidized Bed Reactor treating commercial laundry wastewater in co-digestion with domestic sewage.

Biodegradation pii:10.1007/s10532-020-09895-x [Epub ahead of print].

A large-scale (19.8L) Fluidized Bed Reactor (FBR) operated for 592 days was used to assess the removal performance of linear alkylbenzene sulfonate (LAS). Adjustments in hydraulic retention time (HRT) (18 and 30 h), ethanol (50, 100, 200 mg L-1) and linear alkylbenzene sulfonate (LAS) concentration (6.3-24.7 mg L-1) with taxonomic and functional characterization of biomass using Whole Genome Shotgun Metagenomic (WGSM) represented a major step forward for optimizing biological treatments of LAS. In addition, the variation of the upflow velocity (0.5, 0.7 and 0.9 cm s-1) was investigated, which is a parameter that had not yet been correlated with the possibilities of LAS removal in FBR. Lower Vup (0.5 cm s-1) allied to higher ethanol concentration (200 mg L-1) resulted in lower LAS removal (29%) with predominance of methanogenic archaea and genes related to methanogenesis, while higher Vup (0.9 cm s-1) led to aerobic organisms and oxidative phosphorylation genes. An intermediate Vup (0.7 cm s-1) and higher HRT (30 h) favored sulfate reducing bacteria and genes related to sulfur metabolism, which resulted in the highest LAS (83%) and COD (77%) removal efficiency.

RevDate: 2020-04-08

Arredondo-Hernández R, Schmulson M, Orduña P, et al (2020)

Mucosal Microbiome Profiles Polygenic Irritable Bowel Syndrome in Mestizo Individuals.

Frontiers in cellular and infection microbiology, 10:72.

Irritable bowel syndrome (IBS) is the most frequent functional gastrointestinal disorder, worldwide, with a high prevalence among Mestizo Latin Americans. Because several inflammatory disorders appear to affect this population, a further understanding of host genomic background variants, in conjunction with colonic mucosa dysbiosis, is necessary to determine IBS physiopathology and the effects of environmental pressures. Using a simple polygenic model, host single nucleotide polymorphisms (SNPs) and the taxonomic compositions of microbiota were compared between IBS patients and healthy subjects. As proof of concept, five IBS-Rome III patients and five healthy controls (HCs) were systematically studied. The human and bacterial intestinal metagenome of each subject was taxonomically annotated and screened for previously annotated IBS, ulcerative colitis, and Crohn's disease-associated SNPs or taxon abundance. Dietary data and fecal markers were collected and associated with the intestinal microbiome. However, more than 1,000 variants were found, and at least 76 SNPs differentiated IBS patients from HCs, as did associations with 4 phyla and 10 bacterial genera. In this study, we found elements supporting a polygenic background, with frequent variants, among the Mestizo population, and the colonic mucosal enrichment of Bacteroides, Alteromonas, Neisseria, Streptococcus, and Microbacterium, may serve as a hallmark for IBS.

RevDate: 2020-04-08

Pan X, Zhang D, Nguyen DN, et al (2020)

Postnatal Gut Immunity and Microbiota Development Is Minimally Affected by Prenatal Inflammation in Preterm Pigs.

Frontiers in immunology, 11:420.

Chorioamnionitis (CA), resulting from intra-amniotic inflammation, is a frequent cause of preterm birth and exposes the immature intestine to bacterial toxins and/or inflammatory mediators before birth via fetal swallowing. This may affect intestinal immune development, interacting with the effects of enteral feeding and gut microbiota colonization just after birth. Using preterm pigs as model for preterm infants, we hypothesized that prenatal exposure to gram-negative endotoxin influences postnatal bacterial colonization and gut immune development. Pig fetuses were given intra-amniotic lipopolysaccharide (LPS) 3 days before preterm delivery by cesarean section and were compared with littermate controls (CON) at birth and after 5 days of formula feeding and spontaneous bacterial colonization. Amniotic fluid was collected for analysis of leukocyte counts and cytokines, and the distal small intestine was analyzed for endotoxin level, morphology, and immune cell counts. Intestinal gene expression and microbiota were analyzed by transcriptomics and metagenomics, respectively. At birth, LPS-exposed pigs showed higher intestinal endotoxin, neutrophil/macrophage density, and shorter villi. About 1.0% of intestinal genes were affected at birth, and DMBT1, a regulator of mucosal immune defense, was identified as the hub gene in the co-expression network. Genes related to innate immune response (TLR2, LBP, CD14, C3, SFTPD), neutrophil chemotaxis (C5AR1, CSF3R, CCL5), and antigen processing (MHC II genes and CD4) were also affected, and expression levels correlated with intestinal neutrophil/macrophage density and amniotic fluid cytokine levels. On day 5, LPS and CON pigs showed similar sensitivity to necrotizing enterocolitis, endotoxin levels, morphology, immune cell counts, gene expressions, and microbiota composition (except for difference in some low-abundant species). Our results show that CA markedly affects intestinal genes at preterm birth, including genes related to immune cell infiltration. However, a few days later, following the physiological adaptations to preterm birth, CA had limited effects on intestinal structure, function, gene expression, bacterial colonization, and necrotizing enterocolitis sensitivity. We conclude that short-term, prenatal intra-amniotic inflammation is unlikely to exert marked effects on intestinal immune development in preterm neonates beyond the immediate neonatal period.

RevDate: 2020-04-08

Sun F, Yang H, Wang G, et al (2020)

Combination Analysis of Metatranscriptome and Metagenome Reveal the Composition and Functional Response of Coral Symbionts to Bleaching During an El Niño Event.

Frontiers in microbiology, 11:448.

With the abnormal rise in ocean temperatures globally in recent years, coral bleaching is becoming common and serious. However, the response mechanisms and processes of coral symbionts to bleaching are not well understood. In this study, metagenomics and metatranscriptomics were used to explore the composition of coral symbionts and their functions in response to coral bleaching. All four bleaching coral species displayed a significant reduction of the abundance and function of Dinophyceae-like eukaryotes at the DNA and RNA levels. However, different species of bleaching coral have their own characteristic symbiotic components. Bleaching Acropora tenuis and Goniastrea minuta corals exhibited a very high abundance of prokaryotes and associated gene functions, especially for opportunistic bacteria. In contrast, algae and fungi were identified as the main microbial associate components and had relatively high RNA abundance in bleaching Pocillopora verrucosa and Pocillopora meandrina. Different coral species, whether unbleached or bleaching, have the same symbiotic taxa that perform the same biological functions in vivo. Different stages of bleaching, or transitional states, were identified by different genome content and functional gene abundance among bleaching corals. These stages should be considered in future coral bleaching studies to accurately determine symbiont structure and function. An implicit hypothesis is that there is a causal relationship between the stability of eukaryotic communities and coral bleaching.

RevDate: 2020-04-08

Colagiero M, Rosso LC, Catalano D, et al (2020)

Response of Tomato Rhizosphere Bacteria to Root-Knot Nematodes, Fenamiphos and Sampling Time Shows Differential Effects on Low Level Taxa.

Frontiers in microbiology, 11:390.

A factorial taxonomic metabarcoding study was carried out to determine the effect of root-knot nematodes (Meloidogyne incognita, RKN) and the nematocide fenamiphos on the rhizosphere microbiome of tomato. Plants inoculated (or not) with RKN second-stage juveniles (J2), and treated (or not) with the nematocide, were tested in a 6 months greenhouse assay using a RKN-free soil proceeding from an organic crop. Rhizosphere soil was sampled at J2 inoculation, 3 months later (before the second nematocidal treatment), and again after 3 months. At each sampling, the RNAs were extracted and the 16S rRNA V4 regions sequenced with a Next Generation Sequencing (NGS) protocol. Changes in bacteria metagenomic profiles showed an effect of the treatments applied, with different representations of taxa in samples receiving nematodes and fenamiphos, at the two sampling times. In general, a tendence was observed toward an increase number of OTUs at 6 months, in all treatments. β-Proteobacteria were the most abundant class, for all treatments and times. When compared to soil before transplanting, the presence of tomato roots increased frequency of Actinobacteria and Thermoleophilia, reducing abundance of Solibacteres. At lowest taxonomic levels the samples clustered in groups congruent with the treatments applied, with OTUs differentially represented in relation to RKN and/or fenamiphos applications. Bacillus, Corynebacterium, Streptococcus, and Staphylococcus were more represented at 6 months in samples inoculated with RKN. The nematodes with the nematocide application increased the emergence of rare OTUs or reduced/enhanced the abundance of other taxa, from different lineages.

RevDate: 2020-04-08

McHugh AJ, Feehily C, Fenelon MA, et al (2020)

Tracking the Dairy Microbiota from Farm Bulk Tank to Skimmed Milk Powder.

mSystems, 5(2): pii:5/2/e00226-20.

Microorganisms from the environment can enter the dairy supply chain at multiple stages, including production, milk collection, and processing, with potential implications for quality and safety. The ability to track these microorganisms can be greatly enhanced by the use of high-throughput DNA sequencing (HTS). Here HTS, both 16S rRNA gene amplicon and shotgun metagenomic sequencing were applied to investigate the microbiomes of fresh mid- and late-lactation milk collected from farm bulk tanks, collection tankers, milk silos, skimmed milk silos, a cream silo, and powder samples to investigate the microbial changes throughout a skim milk powder manufacturing process. 16S rRNA gene analysis established that the microbiota of raw milks from farm bulk tanks and in collection tankers were very diverse but that psychrotrophic genera associated with spoilage, Pseudomonas and Acinetobacter, were present in all samples. Upon storage within the whole-milk silo at the processing facility, the species Pseudomonas fluorescens and Acinetobacter baumannii became dominant. The skimmed milk powder generated during the mid-lactation period had a microbial composition that was very different from that of raw milk; specifically, two thermophilic genera, Thermus and Geobacillus, were enriched. In contrast, the microbiota of skimmed milk powder generated from late-lactation milk more closely resembled that of the raw milk and was dominated by spoilage-associated psychrotrophic bacteria. This study demonstrates that the dairy microbiota can differ significantly across different sampling days. More specifically, HTS can be used to trace microbial species from raw milks through processing to final powdered products.IMPORTANCE Microorganisms can enter and persist in dairy at several stages of the processing chain. Detection of microorganisms within dairy food processing is currently a time-consuming and often inaccurate process. This study provides evidence that high-throughput sequencing can be used as an effective tool to accurately identify microorganisms along the processing chain. In addition, it demonstrates that the populations of microbes change from raw milk to the end product. Routine implementation of high-throughput sequencing would elucidate the factors that influence population dynamics. This will enable a manufacturer to adopt control measures specific to each stage of processing and respond in an effective manner, which would ultimately lead to increased food safety and quality.

RevDate: 2020-04-08

Loeffler C, Karlsberg A, Martin LS, et al (2020)

Improving the usability and comprehensiveness of microbial databases.

BMC biology, 18(1):37 pii:10.1186/s12915-020-0756-z.

Metagenomics studies leverage genomic reference databases to generate discoveries in basic science and translational research. However, current microbial studies use disparate reference databases that lack consistent standards of specimen inclusion, data preparation, taxon labelling and accessibility, hindering their quality and comprehensiveness, and calling for the establishment of recommendations for reference genome database assembly. Here, we analyze existing fungal and bacterial databases and discuss guidelines for the development of a master reference database that promises to improve the quality and quantity of omics research.

RevDate: 2020-04-08
CmpDate: 2020-04-06

Tang L (2020)

Learning the diversity of giant viruses.

Nature methods, 17(3):253.

RevDate: 2020-04-08
CmpDate: 2020-04-06

Bentley S (2020)

The fix is in.

Nature microbiology, 5(3):393-394.

RevDate: 2020-04-08
CmpDate: 2020-04-06

Pendergrass SA, Buyske S, Jeff JM, et al (2019)

A phenome-wide association study (PheWAS) in the Population Architecture using Genomics and Epidemiology (PAGE) study reveals potential pleiotropy in African Americans.

PloS one, 14(12):e0226771.

We performed a hypothesis-generating phenome-wide association study (PheWAS) to identify and characterize cross-phenotype associations, where one SNP is associated with two or more phenotypes, between thousands of genetic variants assayed on the Metabochip and hundreds of phenotypes in 5,897 African Americans as part of the Population Architecture using Genomics and Epidemiology (PAGE) I study. The PAGE I study was a National Human Genome Research Institute-funded collaboration of four study sites accessing diverse epidemiologic studies genotyped on the Metabochip, a custom genotyping chip that has dense coverage of regions in the genome previously associated with cardio-metabolic traits and outcomes in mostly European-descent populations. Here we focus on identifying novel phenome-genome relationships, where SNPs are associated with more than one phenotype. To do this, we performed a PheWAS, testing each SNP on the Metabochip for an association with up to 273 phenotypes in the participating PAGE I study sites. We identified 133 putative pleiotropic variants, defined as SNPs associated at an empirically derived p-value threshold of p<0.01 in two or more PAGE study sites for two or more phenotype classes. We further annotated these PheWAS-identified variants using publicly available functional data and local genetic ancestry. Amongst our novel findings is SPARC rs4958487, associated with increased glucose levels and hypertension. SPARC has been implicated in the pathogenesis of diabetes and is also known to have a potential role in fibrosis, a common consequence of multiple conditions including hypertension. The SPARC example and others highlight the potential that PheWAS approaches have in improving our understanding of complex disease architecture by identifying novel relationships between genetic variants and an array of common human phenotypes.

RevDate: 2020-04-08
CmpDate: 2020-04-08

Liang YX, Wen P, Wang Y, et al (2019)

The Constipation-Relieving Property of d-Tagatose by Modulating the Composition of Gut Microbiota.

International journal of molecular sciences, 20(22):.

d-tagatose, a monosaccharide as well as a dietary supplement, has been reported as having a wide range of applicability in the food industry, however, the prebiotic activity, anticonstipation effects, and related mechanisms are still unclear. In this study, using the loperamide-induced constipation Kunming mice as the animal model, the effects of d-tagatose for the prevention of constipation were evaluated by gastrointestinal transit experiment and defecation experiment. Furthermore, the underlying mechanism was clarified by evaluating the change of the biochemical indicators and analyzing 16S rRNA amplicon of gut microbiota among the different mice groups. The results showed that the gastrointestinal transit rate, fecal number, and weight in six hours were significantly enhanced after the administration of d-tagatose. In addition, d-tagatose significantly increased the serum levels of acetylcholine (Ach) and substance P (SP), whereas the serum levels of nitric oxide (NO) were significantly decreased. Moreover, the 16S rRNA sequencing analysis revealed that the changes in the gut microbiota caused by constipation were restored by d-tagatose treatment. In conclusion, this study indicated that the administration of d-tagatose as a dietary supplement can effectively prevent and relieve constipation in Kunming mice, and it is a promising prebiotic candidate with constipation-relieving properties.

RevDate: 2020-04-08
CmpDate: 2020-04-08

Wang Y, Miller M, Astrakhan Y, et al (2019)

Identifying Crohn's disease signal from variome analysis.

Genome medicine, 11(1):59.

BACKGROUND: After years of concentrated research efforts, the exact cause of Crohn's disease (CD) remains unknown. Its accurate diagnosis, however, helps in management and preventing the onset of disease. Genome-wide association studies have identified 241 CD loci, but these carry small log odds ratios and are thus diagnostically uninformative.

METHODS: Here, we describe a machine learning method-AVA,Dx (Analysis of Variation for Association with Disease)-that uses exonic variants from whole exome or genome sequencing data to extract CD signal and predict CD status. Using the person-specific coding variation in genes from a panel of only 111 individuals, we built disease-prediction models informative of previously undiscovered disease genes. By additionally accounting for batch effects, we were able to accurately predict CD status for thousands of previously unseen individuals from other panels.

RESULTS: AVA,Dx highlighted known CD genes including NOD2 and new potential CD genes. AVA,Dx identified 16% (at strict cutoff) of CD patients at 99% precision and 58% of the patients (at default cutoff) with 82% precision in over 3000 individuals from separately sequenced panels.

CONCLUSIONS: Larger training panels and additional features, including other types of genetic variants and environmental factors, e.g., human-associated microbiota, may improve model performance. However, the results presented here already position AVA,Dx as both an effective method for revealing pathogenesis pathways and as a CD risk analysis tool, which can improve clinical diagnostic time and accuracy. Links to the AVA,Dx Docker image and the BitBucket source code are at https://bromberglab.org/project/avadx/ .

RevDate: 2020-04-08
CmpDate: 2020-04-08

Tiffany CR, AJ Bäumler (2019)

Dysbiosis: from fiction to function.

American journal of physiology. Gastrointestinal and liver physiology, 317(5):G602-G608.

Advances in data collection technologies reveal that an imbalance (dysbiosis) in the composition of host-associated microbial communities (microbiota) is linked to many human illnesses. This association makes dysbiosis a central concept for understanding how the human microbiota contributes to health and disease. However, it remains problematic to define the term dysbiosis by cataloguing microbial species names. Here, we discuss how incorporating the germ-organ concept, ecological assumptions, and immunological principles into a theoretical framework for microbiota research provides a functional definition for dysbiosis. The generation of such a framework suggests that the next logical step in microbiota research will be to illuminate the mechanistic underpinnings of dysbiosis, which often involves a weakening of immune mechanisms that balance our microbial communities.

RevDate: 2020-04-08
CmpDate: 2020-04-08

Zhou F, Paz HA, Sadri M, et al (2019)

Dietary bovine milk exosomes elicit changes in bacterial communities in C57BL/6 mice.

American journal of physiology. Gastrointestinal and liver physiology, 317(5):G618-G624.

Exosomes and exosome-like vesicles participate in cell-to-cell communication in animals, plant, and bacteria. Dietary exosomes in bovine milk are bioavailable in nonbovine species, but a fraction of milk exosomes reaches the large intestine. We hypothesized that milk exosomes alter the composition of the gut microbiome in mice. C57BL/6 mice were fed AIN-93G diets, defined by their content of bovine milk exosomes and RNA cargos: exosome/RNA-depleted (ERD) versus exosome/RNA-sufficient (ERS) diets. Feeding was initiated at age 3 wk, and cecum content was collected at ages 7, 15, and 47 wk. Microbial communities were identified by 16S rRNA gene sequencing. Milk exosomes altered bacterial communities in the murine cecum. The abundance of three phyla, seven families, and 52 operational taxonomic units (OTUs) was different in the ceca from mice fed ERD and ERS (P < 0.05). For example, at the phylum level, Tenericutes had more than threefold abundance in ERS mice at ages 15 and 47 wk compared with ERD mice (P < 0.05). At the family level, Verrucomicrobiaceae were much less abundant in ERS mice compared with ERD mice age 47 wk (P < 0.05). At the OTU level, four OTUs from the family of Lachnospiraceae were more than two times more abundant in ERS mice compared with ERD at age 7 and 47 wk (P < 0.05). We conclude that exosomes in bovine milk alter microbial communities in nonbovine species, suggesting that exosomes and their cargos participate in the crosstalk between bacterial and animal kingdoms.NEW & NOTEWORTHY This is the first report that exosomes from bovine milk alter microbial communities in mice. This report suggests that the gut microbiome facilitates cell-to-cell communication by milk exosomes across species boundaries, and milk exosomes facilitate communication across animal and bacteria kingdoms.

RevDate: 2020-04-08
CmpDate: 2020-04-07

Harvey E, Rose K, Eden JS, et al (2019)

Identification of diverse arthropod associated viruses in native Australian fleas.

Virology, 535:189-199.

Fleas are important vectors of zoonotic disease. However, little is known about the natural diversity and abundance of flea viruses, particularly in the absence of disease associations, nor the evolutionary relationships among those viruses found in different parasitic vector species. Herein, we present the first virome scale study of fleas, based on the meta-transcriptomic analysis of 52 fleas collected along the eastern coast of Australia. Our analysis revealed 18 novel RNA viruses belonging to nine viral families with diverse genome organizations, although the majority (72%) possessed single-stranded positive-sense genomes. Notably, a number of the viruses identified belonged to the same phylogenetic groups as those observed in ticks sampled at the same locations, although none were likely associated with mammalian infection. Overall, we identified high levels of genomic diversity and abundance of viruses in the flea species studied, and established that fleas harbor viruses similar to those seen to other vectors.

RevDate: 2020-04-07

An X, Chen Y, Chen G, et al (2020)

Integrated metagenomic and metaproteomic analyses reveal potential degradation mechanism of azo dye-Direct Black G by thermophilic microflora.

Ecotoxicology and environmental safety, 196:110557 pii:S0147-6513(20)30396-1 [Epub ahead of print].

Direct Black G (DBG) is a typical toxic azo dye with extensive applications but it poses a serious threat to the aquatic ecosystem and humans. It is necessary to efficiently and safely remove DBG from environments by the application of various treatment technologies. A thermophilic microflora previously isolated from the soil can effectively metabolize DBG. However, the molecular basis of DBG degradation by this thermophilic microflora remains unknown. In this study, metagenomic sequencing technology and qRT-PCR have been used to elucidate the functional potential of genes and their modes of action on DBG. A quantitative metaproteomic method was further utilized to identify the relative functional proteins involved. Subsequently, the possible co-metabolic molecular mechanisms of DBG degradation by candidate genes and functional proteins of the thermophilic microflora were illustrated. The combination of metagenomics and metaproteomics to investigate the degradation of DBG by a microflora was reported for the first time in recent literature; this can further provide a deep insight into the molecular degradation mechanism of dye pollutants by natural microflora.

RevDate: 2020-04-07

Libisch B, Keresztény T, Kerényi Z, et al (2020)

Metagenomic Analysis of Acquired Antibiotic Resistance Determinants in the Gut Microbiota of Wild Boars (Sus Scrofa) - Preliminary Results.

Journal of veterinary research, 64(1):111-118 pii:jvetres-2020-0015.

Introduction: Land application of manure that contains antibiotics and resistant bacteria may facilitate the establishment of an environmental reservoir of antibiotic-resistant microbes, promoting their dissemination into agricultural and natural habitats. The main objective of this study was to search for acquired antibiotic resistance determinants in the gut microbiota of wild boar populations living in natural habitats.

Material and Methods: Gastrointestinal samples of free-living wild boars were collected in the Zemplén Mountains in Hungary and were characterised by culture-based, metagenomic, and molecular microbiological methods. Bioinformatic analysis of the faecal microbiome of a hunted wild boar from Japan was used for comparative studies. Also, shotgun metagenomic sequencing data of two untreated sewage wastewater samples from North Pest (Hungary) from 2016 were analysed by bioinformatic methods. Minimum spanning tree diagrams for seven-gene MLST profiles of 104 E. coli strains isolated in Europe from wild boars and domestic pigs were generated in Enterobase.

Results: In the ileum of a diarrhoeic boar, a dominant E. coli O112ab:H2 strain with intermediate resistance to gentamicin, tobramycin, and amikacin was identified, displaying sequence type ST388 and harbouring the EAST1 toxin astA gene. Metagenomic analyses of the colon and rectum digesta revealed the presence of the tetQ, tetW, tetO, and mefA antibiotic resistance genes that were also detected in the gut microbiome of four other wild boars from the mountains. Furthermore, the tetQ and cfxA genes were identified in the faecal microbiome of a hunted wild boar from Japan.

Conclusion: The gastrointestinal microbiota of the free-living wild boars examined in this study carried acquired antibiotic resistance determinants that are highly prevalent among domestic livestock populations.

RevDate: 2020-04-07

Rani A, Ranjan R, Metwally AA, et al (2020)

Abundance of Multidrug Resistance Efflux Pumps in the Urinary Metagenome of Kidney Transplant Patients.

BioMed research international, 2020:5421269.

Antibiotic resistance including the emergence of multidrug resistant microbes has become a public health crisis. In this study, we analyzed the antibiotic resistance genes (ARGs) in the urinary metagenome of the kidney transplant and healthy subjects using metagenomic shotgun sequencing. Our data suggest an increased abundance of antibiotic resistance genes in the kidney transplant subjects. In addition, the antibiotic resistance genes identified in the transplant subjects were predominantly composed of multidrug efflux pumps (MDEPs) which are evolutionarily ancient, commonly encoded on chromosomes rather than plasmids, and have a low rate of mutation. Since the MDEPs had a low abundance in the healthy subjects, we speculate that the MDEPs may enhance the fitness of bacteria to survive in the high stress environment of transplantation that includes multiple stressors including surgery, antibiotics, and immunosuppressive agents.

RevDate: 2020-04-07

Suzuki S, T Yamada (2020)

Probabilistic model based on circular statistics for quantifying coverage depth dynamics originating from DNA replication.

PeerJ, 8:e8722 pii:8722.

Background: With the development of DNA sequencing technology, static omics profiling in microbial communities, such as taxonomic and functional gene composition determination, has become possible. Additionally, the recently proposed in situ growth rate estimation method allows the applicable range of current comparative metagenomics to be extended to dynamic profiling. However, with this method, the applicable target range is presently limited. Furthermore, the characteristics of coverage depth during replication have not been sufficiently investigated.

Results: We developed a probabilistic model that mimics coverage depth dynamics. This statistical model explains the bias that occurs in the coverage depth due to DNA replication and errors that arise from coverage depth observation. Although our method requires a complete genome sequence, it involves a stable to low coverage depth (>0.01×). We also evaluated the estimation using real whole-genome sequence datasets and reproduced the growth dynamics observed in previous studies. By utilizing a circular distribution in the model, our method facilitates the quantification of unmeasured coverage depth features, including peakedness, skewness, and degree of density, around the replication origin. When we applied the model to time-series culture samples, the skewness parameter, which indicates the asymmetry, was stable over time; however, the peakedness and degree of density parameters, which indicate the concentration level at the replication origin, changed dynamically. Furthermore, we demonstrated the activity measurement of multiple replication origins in a single chromosome.

Conclusions: We devised a novel framework for quantifying coverage depth dynamics. Our study is expected to serve as a basis for replication activity estimation from a broader perspective using the statistical model.

RevDate: 2020-04-07

Okamura Y, Morimoto N, Ikeda D, et al (2020)

Interleukin-17A/F1 Deficiency Reduces Antimicrobial Gene Expression and Contributes to Microbiome Alterations in Intestines of Japanese medaka (Oryzias latipes).

Frontiers in immunology, 11:425.

In mammals, interleukin (IL)-17A and F are hallmark inflammatory cytokines that play key roles in protection against infection and intestinal mucosal immunity. In the gastrointestinal tract (GI), the induction of antimicrobial peptide (AMP) production via Paneth cells is a fundamental role of IL-17A and F in maintaining homeostasis of the GI microbiome and health. Although mammalian IL-17A and F homologs (referred to as IL-17A/F1-3) have been identified in several fish species, their function in the intestine is poorly understood. Additionally, the fish intestine lacks Paneth cells, and its GI structure is very different from that of mammals. Therefore, the GI microbiome modulatory mechanism via IL-17A/F genes has not been fully elucidated. In this study, Japanese medaka (Oryzias latipes) were used as a teleost model, and IL-17A/F1-knockout (IL-17A/F1-KO) medaka were established using the CRISPR/Cas9 genome editing technique. Furthermore, two IL-17A/F1-deficient medaka strains were generated, including one strain containing a 7-bp deletion (-7) and another with an 11-bp addition (+11). After establishing F2 homozygous KO medaka, transcriptome analysis (RNA-seq) was conducted to elucidate IL-17A/F1-dependent gene induction in the intestine. Results of RNA-seq and real-time PCR (qPCR) demonstrated down-regulation of immune-related genes, including interleukin-1β (IL-1β), complement 1q subunit C (C1qc), transferrin a (Tfa), and G-type lysozyme (LyzG), in IL-17A/F1-KO medaka. Interestingly, protein and lipid digestive enzyme genes, including phospholipase A2, group IB (pla2g1b), and elastase-1-like (CELA1), were also downregulated in the intestines of IL-17A/F1-KO medaka. Furthermore, to reveal the influence of these downregulated genes on the gut microbiome in IL-17A/F1-KO, 16S rRNA-based metagenomic sequencing analysis was conducted to analyze the microbiome constitution. Under a non-exposed state, the intestinal microbiome of IL-17A/F1-KO medaka differed at the phylum level from wild-type, with significantly higher levels of Verrucomicrobia and Planctomycetes. Additionally, at the operational taxonomic unit (OTU) level of the human and fish pathogens, the Enterobacteriaceae Plesiomonas shigelloides was the dominant species in IL-17A/F1-KO medaka. These findings suggest that IL-17A/F1 is involved in the maintenance of a healthy gut microbiome.

RevDate: 2020-04-07

McDonald RC, Watts JEM, HJ Schreier (2020)

Corrigendum: Effect of Diet on the Enteric Microbiome of the Wood-Eating Catfish Panaque nigrolineatus.

Frontiers in microbiology, 11:331.

[This corrects the article DOI: 10.3389/fmicb.2019.02687.].

RevDate: 2020-04-07

Ekanayake A, Madegedara D, Chandrasekharan V, et al (2020)

Respiratory Bacterial Microbiota and Individual Bacterial Variability in Lung Cancer and Bronchiectasis Patients.

Indian journal of microbiology, 60(2):196-205.

Respiratory bacterial microbiota plays a key role in human health. Lung cancer microbiome is a significant yet an understudied area while bronchiectasis microbiome is often studied. We assessed the bacterial microbiota in the upper and lower respiratory tract of the patients with lung cancer and bronchiectasis against a healthy group and their variations in individuality. 16S rRNA gene based metagenomic sequencing was used to detect entire bacterial community along with conventional aerobic bacterial culturing. In comparison to healthy, increased bacterial diversity was observed in diseased population. Abundance of more than 1% was considered and bacteria were identified in 97% similarity. Only lung cancer patients exhibited bacteria specific to the disease: Corynebacterium tuberculostearicum and Keratinibaculum paraultunense. However, Enterococcus faecalis and Delftia tsuruhatensis were also observed limited to lung cancer and bronchiectasis respectively, in less than 1% but supported with bacterial culturing. In conclusion the disease condition and intra-group variability should be considered in future with larger cohorts to understand individual patient variability highlighting the social habits and gender of the individual.

RevDate: 2020-04-07

McGovern BH, Ford CB, Henn MR, et al (2020)

SER-109, an Investigational Microbiome Drug to Reduce Recurrence after Clostridioides difficile infection: Lessons Learned from a Phase 2 Trial.

Clinical infectious diseases : an official publication of the Infectious Diseases Society of America pii:5817059 [Epub ahead of print].

BACKGROUND: Recurrent C. difficile infection (rCDI) is associated with loss of microbial diversity and microbe-derived secondary bile acids, which inhibit C. difficile germination and growth. SER-109, an investigational microbiome drug of donor-derived, purified spores, reduced recurrence in a dose-ranging, open-label Phase (Ph)1 study in subjects with multiply rCDI.

METHODS: In a Ph2 double-blind trial, subjects with clinical resolution on standard-of-care antibiotics were stratified by age (< or ≥65 years) and randomized 2:1 to single-dose SER-109 or placebo. Subjects were diagnosed at study entry by PCR or toxin testing. Safety, C. difficile-positive diarrhea through week 8, SER-109 engraftment and bile acid changes were assessed.

RESULTS: 89 subjects were enrolled; 67% were female; 80.9% diagnosed by PCR. rCDI rates were lower in the SER-109 arm than placebo (44.1% versus 53.3%, respectively) but did not meet statistical significance. In a pre-planned analysis, rates were reduced among subjects ≥65 years (45.2% versus 80%, respectively; RR:1.77, 95% CI:1.11-2.81) while the <65 group showed no benefit. Early engraftment of SER-109 was associated with non-recurrence (p <0.05) and increased secondary bile acid concentrations (p<0.0001). Whole metagenomic sequencing from this study and our prior Ph1 study revealed previously unappreciated dose-dependent engraftment kinetics and confirmed an association between early engraftment and nonrecurrence. Engraftment kinetics suggest that Ph2 dosing was suboptimal. Adverse events were generally mild-to-moderate in severity.

CONCLUSIONS: Early SER-109 engraftment was associated with reduced CDI recurrence and favorable safety was observed. A higher dose of SER-109 and requirements for toxin testing were implemented in the current Ph3 trial.

RevDate: 2020-04-07

Boros Á, László Z, Pankovics P, et al (2020)

High prevalence, genetic diversity and a potentially novel genotype of Sapelovirus A (Picornaviridae) in enteric and respiratory samples in Hungarian swine farms.

The Journal of general virology [Epub ahead of print].

All of the known porcine sapeloviruses (PSVs) currently belong to a single genotype in the genus Sapelovirus (family Picornaviridae). Here, the complete genome of a second, possibly recombinant, genotype of PSV strain SZ1M-F/PSV/HUN2013 (MN807752) from a faecal sample of a paraplegic pig in Hungary was characterized using viral metagenomics and RT-PCR. This sapelovirus strain showed only 64 % nucleotide identity in the VP1 region to its closest PSV-1 relative. Complete VP1 sequence-based epidemiological investigations of PSVs circulating in Hungary showed the presence of diverse strains found in high prevalence in enteric and respiratory samples collected from both asymptomatic and paraplegic pigs from 12 swine farms. Virus isolation attempts using PK-15 cell cultures were successful in 3/8 cases for the classic but not the novel PSV genotype. Sequence comparisons of faeces and isolate strains derived VP1 showed that cultured PSV strains not always represent the dominant PSVs found in vivo.

RevDate: 2020-04-07

Tian R, Ning D, He Z, et al (2020)

Small and mighty: adaptation of superphylum Patescibacteria to groundwater environment drives their genome simplicity.

Microbiome, 8(1):51 pii:10.1186/s40168-020-00825-w.

BACKGROUND: The newly defined superphylum Patescibacteria such as Parcubacteria (OD1) and Microgenomates (OP11) has been found to be prevalent in groundwater, sediment, lake, and other aquifer environments. Recently increasing attention has been paid to this diverse superphylum including > 20 candidate phyla (a large part of the candidate phylum radiation, CPR) because it refreshed our view of the tree of life. However, adaptive traits contributing to its prevalence are still not well known.

RESULTS: Here, we investigated the genomic features and metabolic pathways of Patescibacteria in groundwater through genome-resolved metagenomics analysis of > 600 Gbp sequence data. We observed that, while the members of Patescibacteria have reduced genomes (~ 1 Mbp) exclusively, functions essential to growth and reproduction such as genetic information processing were retained. Surprisingly, they have sharply reduced redundant and nonessential functions, including specific metabolic activities and stress response systems. The Patescibacteria have ultra-small cells and simplified membrane structures, including flagellar assembly, transporters, and two-component systems. Despite the lack of CRISPR viral defense, the bacteria may evade predation through deletion of common membrane phage receptors and other alternative strategies, which may explain the low representation of prophage proteins in their genomes and lack of CRISPR. By establishing the linkages between bacterial features and the groundwater environmental conditions, our results provide important insights into the functions and evolution of this CPR group.

CONCLUSIONS: We found that Patescibacteria has streamlined many functions while acquiring advantages such as avoiding phage invasion, to adapt to the groundwater environment. The unique features of small genome size, ultra-small cell size, and lacking CRISPR of this large lineage are bringing new understandings on life of Bacteria. Our results provide important insights into the mechanisms for adaptation of the superphylum in the groundwater environments, and demonstrate a case where less is more, and small is mighty.

RevDate: 2020-04-07

Zhou Y, Coventry DR, Gupta VVSR, et al (2020)

The preceding root system drives the composition and function of the rhizosphere microbiome.

Genome biology, 21(1):89 pii:10.1186/s13059-020-01999-0.

BACKGROUND: The soil environment is responsible for sustaining most terrestrial plant life, yet we know surprisingly little about the important functions carried out by diverse microbial communities in soil. Soil microbes that inhabit the channels of decaying root systems, the detritusphere, are likely to be essential for plant growth and health, as these channels are the preferred locations of new root growth. Understanding the microbial metagenome of the detritusphere, and how it responds to agricultural management such as crop rotations and soil tillage, is vital for improving global food production.

RESULTS: This study establishes an in-depth soil microbial gene catalogue based on the living-decaying rhizosphere niches in a cropping soil. The detritusphere microbiome regulates the composition and function of the rhizosphere microbiome to a greater extent than plant type: rhizosphere microbiomes of wheat and chickpea were homogenous (65-87% similarity) in the presence of decaying root (DR) systems but were heterogeneous (3-24% similarity) where DR was disrupted by tillage. When the microbiomes of the rhizosphere and the detritusphere interact in the presence of DR, there is significant degradation of plant root exudates by the rhizosphere microbiome, and genes associated with membrane transporters, carbohydrate and amino acid metabolism are enriched.

CONCLUSIONS: The study describes the diversity and functional capacity of a high-quality soil microbial metagenome. The results demonstrate the contribution of the detritusphere microbiome in determining the metagenome of developing root systems. Modifications in root microbial function through soil management can ultimately govern plant health, productivity and food security.

RevDate: 2020-04-07

Montalvo-Rodríguez R, JA Maupin-Furlow (2020)

Insights through Genetics of Halophilic Microorganisms and Their Viruses.

Genes, 11(4): pii:genes11040388.

Halophilic microorganisms are found in all domains of life and thrive in hypersaline (high salt content) environments. These unusual microbes have been a subject of study for many years due to their interesting properties and physiology. Study of the genetics of halophilic microorganisms (from gene expression and regulation to genomics) has provided understanding into mechanisms of how life can occur at high salinity levels. Here we highlight recent studies that advance knowledge of biological function through study of the genetics of halophilic microorganisms and their viruses.

RevDate: 2020-04-07

Prodinger F, Endo H, Gotoh Y, et al (2020)

An Optimized Metabarcoding Method for Mimiviridae.

Microorganisms, 8(4): pii:microorganisms8040506.

Mimiviridae is a group of viruses with large genomes and virions. Ecological relevance of Mimiviridae in marine environments has been increasingly recognized through the discoveries of novel isolates and metagenomic studies. To facilitate ecological profiling of Mimiviridae, we previously proposed a meta-barcoding approach based on 82 degenerate primer pairs (i.e., MEGAPRIMER) targeting the DNA polymerase gene of Mimiviridae. The method detected a larger number of operational taxonomic units (OTUs) in environmental samples than previous methods. However, it required large quantities of DNA and was laborious due to the use of individual primer pairs. Here, we examined coastal seawater samples using varying PCR conditions and purification protocols to streamline the MEGAPRIMER method. Mixing primer pairs in "cocktails" reduced the required amount of environmental DNA by 90%, while reproducing the results obtained by the original protocol. We compared the results obtained by the meta-barcoding approach with quantifications using qPCR for selected OTUs. This revealed possible amplification biases among different OTUs, but the frequency profiles for individual OTUs across multiple samples were similar to those obtained by qPCR. We anticipate that the newly developed MEGAPRIMER protocols will be useful for ecological investigation of Mimiviridae in a larger set of environmental samples.

RevDate: 2020-04-06

He P, Wu Y, Huang W, et al (2020)

Characteristics of and variation in airborne ARGs among urban hospitals and adjacent urban and suburban communities: A metagenomic approach.

Environment international, 139:105625 pii:S0160-4120(19)33328-8 [Epub ahead of print].

Environmental antibiotic resistance genes (ARGs) have received much attention, while the characteristics of ARGs carried by particulate matter (PM) as a function of urban functional region are almost unknown. In this study, ARGs carried by PM2.5 and PM10 in an urban hospital, a nearby urban community and the nearest suburban community were detected using metagenomics. In total, 643 ARG subtypes belonging to 22 different ARG types were identified. The chloramphenicol exporter gene, sul1, bacA, and lnuA were the most abundant ARG subtypes in all air samples. The hospital exhibited higher ARG abundance and richness than the nearby communities. ARG profiles depended on functional region: hospital and suburban samples clustered separately, and samples from the nearby urban community interspersed among them. The representation of multidrug and quinolone resistance genes decayed with distance from the hospital to the urban community to the suburban community, indicating that hospital PM may be a hotspot for ARGs encoding proteins conferring multidrug and quinolone resistance. Airborne ARGs carried by PM in the hospital environment were more closely associated with clinically important pathogens than were those in nearby communities. In particular, carbapenemase genes, including blaNDM,blaKPC,blaIMP,blaVIM,and blaOXA-48, were discovered in hospital PM. In the suburban community, crAssphage, a human host-specific bacteriophage, was applied to predict ARG abundance and found to be enriched due to anthropogenic pollution but showed no clear evidence for ARG selection. In the hospital and the nearby urban community, the drivers of ARGs were complex. Our results highlighted that PM ARGs were closely related to human activities and revealed a potential hotspot, which could provide new evidence for further research and consequently mitigate the formation of airborne ARGs and transfer risks.

RevDate: 2020-04-06

Lagoa-Costa B, Kennes C, MC Veiga (2020)

Cheese whey fermentation into volatile fatty acids in an anaerobic sequencing batch reactor.

Bioresource technology, 308:123226 pii:S0960-8524(20)30497-1 [Epub ahead of print].

The present research explored the optimization of volatile fatty acids (VFA) production from cheese whey in an anaerobic sequencing batch reactor (AnSBR). For that purpose, changes of solid and hydraulic retention times (SRT and HRT) were applied. Moreover, the experiments were coupled to metagenomic analyses by 16S rRNA sequencing. The results showed an enhancement of the process effectiveness at longer SRT and shorter HRT. The degree of acidification (DA) improved from 0.73 to 0.83 when increasing the SRT from 5 to 15 days. It also increased from 0.79 to 0.83 when lowering the HRT from 3 to 1 day. The acidification yield (YVFA/S) improved from 0.78 to 0.87 and from 0.86 to 0.90 g COD-VFA g COD-Lactose-1 when increasing the SRT from 5 to 15 days and decreasing the HRT from 3 to 1 day, respectively. Hydrolytic bacteria dominated the microbial community at the shortest SRT, although they were replaced by acidogenic bacteria at longer SRT.

RevDate: 2020-04-06

Wang CX, Huang Z, Fang X, et al (2020)

Comparison of Broad-range Polymerase Chain Reaction and Metagenomic Next-generation Sequencing for the Diagnosis of Prosthetic Joint Infection.

International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases pii:S1201-9712(20)30188-0 [Epub ahead of print].

PURPOSE: The aims of our study were to (1) evaluate the concordance of both methods for detecting prosthetic joint infection (PJI) pathogens in joint fluid and to (2) clarify whether broad-range polymerase chain reaction (BR-PCR) can be used as a verification method for metagenomic next-generation sequencing (mNGS) for PJI diagnosis.

METHODS: In total, 63 patients underwent total joint arthroplasty, with 45 PJI and 18 aseptic failure patients included. Joint fluids were sampled after antibiotics were withheld for more than 2 weeks, and then, culture, BR-PCR and mNGS were performed for all samples.

RESULTS: The joint fluid BR-PCR sensitivity was 82.2%, which was not significantly different from that of mNGS (95.6%) or culture (77.8%). The specificities of the 3 methods were all 94.4%. BR-PCR failed to identify the pathogens in 1 polymicrobial infection patient and 4 fungal infection patients.

CONCLUSION: mNGS was more sensitive than BR-PCR for detecting PJI pathogens in joint fluid. BR-PCR is insufficient for use as an mNGS verification method.

RevDate: 2020-04-06

Pickert G, Wirtz S, Matzner J, et al (2020)

Wheat Consumption Aggravates Colitis in Mice via Amylase Trypsin Inhibitor-mediated Dysbiosis.

Gastroenterology pii:S0016-5085(20)30447-9 [Epub ahead of print].

BACKGROUND & AIMS: Wheat has become the world´s major staple and its consumption correlates with prevalence of non-communicable disorders such as inflammatory bowel diseases. Amylase trypsin inhibitors (ATIs), a component of wheat, activate the intestine's innate immune response via toll-like receptor 4 (TLR4). We investigated the effects of wheat and ATIs on severity of colitis and fecal microbiota in mice.

METHODS: C57BL/6 wildtype and Tlr4-/- mice were fed wheat- or ATI-containing diets or a wheat-free (control) diet and then given dextran sodium sulfate to induce colitis; we also studied Il10-/- mice, which develop spontaneous colitis. Changes in fecal bacteria were assessed by taxa-specific quantitative PCR and 16S ribosomal RNA metagenomic sequencing. Feces were collected from mice on wheat-containing, ATI-containing, control diets and transplanted to intestines of mice with and without colitis on control or on ATI-containing diets. Intestinal tissues were collected and analyzed by histology, immunohistochemistry and flow cytometry. Bacteria with reported immunomodulatory effects were incubated with ATIs and analyzed in radial diffusion assays.

RESULTS: The wheat- or ATI-containing diets equally increased inflammation in intestinal tissues of C57BL/6 mice with colitis, compared with mice on control diets. The ATI-containing diet promoted expansion of taxa associated with development of colitis comparable to the wheat-containing diet. ATIs inhibited proliferation of specific human commensal bacteria in radial diffusion assays. Transplantation of microbiota from feces of mice fed the wheat- or ATI-containing diets to intestines of mice on control diets increased the severity of colitis in these mice. The ATI-containing diet did not increase the severity of colitis in Tlr4-/- mice.

CONCLUSIONS: Consumption of wheat or wheat-ATIs increases intestinal inflammation in mice with colitis, via TLR4, and alters their fecal microbiota. Wheat-based, ATI-containing diets therefore activate TLR4 signaling and promote intestinal dysbiosis.

RevDate: 2020-04-06

Kappel BA, De Angelis L, Heiser M, et al (2020)

Cross-omics analysis revealed gut microbiome-related metabolic pathways underlying atherosclerosis development after antibiotics treatment.

Molecular metabolism pii:S2212-8778(20)30049-1 [Epub ahead of print].

OBJECTIVE: The metabolic influence of gut microbiota plays a pivotal role in the pathogenesis of cardiometabolic diseases. Antibiotics affect intestinal bacterial diversity, and long-term usage has been identified as an independent risk factor for atherosclerosis-driven events. The aim of this study was to explore the interaction between gut dysbiosis by antibiotics and metabolic pathways with the impact on atherosclerosis development.

METHODS: We combined oral antibiotics with different diets in an Apolipoprotein E-knockout mouse model linking gut microbiota to atherosclerotic lesion development via an integrative cross-omics approach including serum metabolomics and cecal 16S rRNA targeted metagenomic sequencing. We further investigated patients with carotid atherosclerosis compared to control subjects with comparable cardiovascular risk.

RESULTS: Here, we show that increased atherosclerosis by antibiotics was connected to a loss of intestinal diversity and alterations of microbial metabolic functional capacity with a major impact on the host serum metabolome. Pathways were modulated by antibiotics and connected to atherosclerosis, which included diminished tryptophan and disturbed lipid metabolism. These pathways were related to the reduction of certain members of Bacteroidetes and Clostridia by antibiotics in the gut. Patients with atherosclerosis presented a similar metabolic signature as those induced by antibiotics in our mouse model.

CONCLUSION: Taken together, this work provides insights into the complex interaction between intestinal microbiota and host metabolism. Our data highlight that detrimental effects of antibiotics on the gut flora are connected to a pro-atherogenic metabolic phenotype beyond classical risk factors.

RevDate: 2020-04-06

Byrd DA, Sinha R, Hoffman KL, et al (2020)

Comparison of Methods To Collect Fecal Samples for Microbiome Studies Using Whole-Genome Shotgun Metagenomic Sequencing.

mSphere, 5(1): pii:5/1/e00827-19.

Few previous studies have assessed stability and "gold-standard" concordance of fecal sample collection methods for whole-genome shotgun metagenomic sequencing (WGSS), an increasingly popular method for studying the gut microbiome. We used WGSS data to investigate ambient temperature stability and putative gold-standard concordance of microbial profiles in fecal samples collected and stored using fecal occult blood test (FOBT) cards, fecal immunochemical test (FIT) tubes, 95% ethanol, or RNAlater. Among 15 Mayo Clinic employees, for each collection method, we calculated intraclass correlation coefficients (ICCs) to estimate stability of fecal microbial profiles after storage for 4 days at ambient temperature and concordance with immediately frozen, no-solution samples (i.e., the putative gold standard). ICCs were estimated for multiple metrics, including relative abundances of select phyla, species, KEGG k-genes (representing any coding sequence that had >70% identity and >70% query coverage with respect to a known KEGG ortholog), KEGG modules, and KEGG pathways; species and k-gene alpha diversity; and Bray-Curtis and Jaccard species beta diversity. ICCs for microbial profile stability were excellent (≥90%) for fecal samples collected via most of the collection methods, except those preserved in 95% ethanol. Concordance with the immediately frozen, no-solution samples varied for all collection methods, but the number of observed species and the beta diversity metrics tended to have higher concordance than other metrics. Our findings, taken together with previous studies and feasibility considerations, indicated that FOBT cards, FIT tubes, and RNAlater are acceptable choices for fecal sample collection methods in future WGSS studies.IMPORTANCE A major direction for future microbiome research is implementation of fecal sample collections in large-scale, prospective epidemiologic studies. Studying microbiome-disease associations likely requires microbial data to be pooled from multiple studies. Our findings suggest collection methods that are most optimal to be used standardly across future WGSS microbiome studies.

RevDate: 2020-04-06

Moniruzzaman M, Martinez-Gutierrez CA, Weinheimer AR, et al (2020)

Dynamic genome evolution and complex virocell metabolism of globally-distributed giant viruses.

Nature communications, 11(1):1710 pii:10.1038/s41467-020-15507-2.

The discovery of eukaryotic giant viruses has transformed our understanding of the limits of viral complexity, but the extent of their encoded metabolic diversity remains unclear. Here we generate 501 metagenome-assembled genomes of Nucleo-Cytoplasmic Large DNA Viruses (NCLDV) from environments around the globe, and analyze their encoded functional capacity. We report a remarkable diversity of metabolic genes in widespread giant viruses, including many involved in nutrient uptake, light harvesting, and nitrogen metabolism. Surprisingly, numerous NCLDV encode the components of glycolysis and the TCA cycle, suggesting that they can re-program fundamental aspects of their host's central carbon metabolism. Our phylogenetic analysis of NCLDV metabolic genes and their cellular homologs reveals distinct clustering of viral sequences into divergent clades, indicating that these genes are virus-specific and were acquired in the distant past. Overall our findings reveal that giant viruses encode complex metabolic capabilities with evolutionary histories largely independent of cellular life, strongly implicating them as important drivers of global biogeochemical cycles.

RevDate: 2020-04-06

Sabuda MC, Brazelton WJ, Putman LI, et al (2020)

A dynamic microbial sulfur cycle in a serpentinizing continental ophiolite.

Environmental microbiology [Epub ahead of print].

Serpentinization is the hydration and oxidation of ultramafic rock, which occurs as oceanic lithosphere is emplaced onto continental margins (ophiolites), and along the seafloor as faulting exposes this mantle-derived material to circulating hydrothermal fluids. This process leads to distinctive fluid chemistries as molecular hydrogen (H2) and hydroxyl ions (OH-) are produced and reduced carbon compounds are mobilized. Serpentinizing ophiolites also serve as a vector to transport sulfur compounds from the seafloor onto the continents. We investigated hyperalkaline, sulfur-rich, brackish groundwater in a serpentinizing continental ophiolite to elucidate the role of sulfur compounds in fueling in situ microbial activities. Here we illustrate that key sulfur-cycling taxa, including Dethiobacter, Desulfitispora, and 'Desulforudis', persist throughout this extreme environment. Biologically catalyzed redox reactions involving sulfate, sulfide, and intermediate sulfur compounds are thermodynamically favorable in the groundwater, which indicates they may be vital to sustaining life in these characteristically oxidant- and energy- limited systems. Further, metagenomic and metatranscriptomic analyses reveal a complex network involving sulfate reduction, sulfide oxidation, and thiosulfate reactions. Our findings highlight the importance of the complete inorganic sulfur cycle in serpentinizing fluids and suggest sulfur biogeochemistry provides a key link between terrestrial serpentinizing ecosystems and their submarine heritage. This article is protected by copyright. All rights reserved.

RevDate: 2020-04-06

Joshi N, Sharma M, SP Singh (2020)

Characterization of a novel xylanase from an extreme temperature hot spring metagenome for xylooligosaccharide production.

Applied microbiology and biotechnology pii:10.1007/s00253-020-10562-7 [Epub ahead of print].

In this study, the metagenomic resource generated from an aquatic habitat of extreme temperature was screened for the identification of a novel xylanase, XynM1. Gene sequence analysis designated it as a member of glycoside hydrolase (GH) family 10. The metagenomic DNA fragment was cloned, expressed in Escherichia coli, and the purified protein was biochemically characterized. The optimum temperature and pH for the XynM1 xylanase were found to be at 80 °C and 7, respectively. It exhibited worthwhile pH stability by retaining about 70% activity in the range of pH 6 to 9 after the exposure for 12 h at 25 °C. Thermostability analysis established considerable heat tolerance in XynM1 protein at elevated temperatures, displaying about 50% residual activity after the exposure of 40 °C, 50 °C, 60 °C, and 70 °C for 20 h, 12 h, 6 h, and 1.5 h, respectively. The effects of additives such as metals, surfactants, and organic solvents were evaluated on the activity of XynM1. It was able to retain about 50% of its initial activity in the presence of NaCl concentration of 1 to 5 M. The novel xylanase was capable of hydrolyzing the hemicellulosic polymer, derived from diverse biomass sources, e.g., beechwood xylan, wheat arabinoxylan, corncob xylan, and sweet sorghum xylan. The XynM1-treated beechwood xylan manifested catalytic release of xylooligosaccharides (XOS) of 2-6 DP. The novel GH10 xylanase is a promising biocatalyst that could be ascribed for biomass conversion and production of prebiotic XOS biomolecules.

RevDate: 2020-04-05

Yue Y, Shao T, Long X, et al (2020)

Microbiome structure and function in rhizosphere of Jerusalem artichoke grown in saline land.

The Science of the total environment, 724:138259 pii:S0048-9697(20)31772-1 [Epub ahead of print].

The improvement and development of saline-alkali soils is currently a hot economic and scientific issue, and exploring the correlation between rhizosphere microorganisms of plants growing on saline-alkali soils and their salt tolerance has become the key point of related research. In our study, the community structure of microorganism and various properties of saline soils were characterized in which Jerusalem artichoke grown along a soil salinity gradient. A variety of basic soil properties were measured and the amplicon was performed as well as metagenomic sequencing on coastal saline soils using various techniques (such as RDA analysis and the assembly of genomes) to evaluate microbial functions. In addition, WGCNA (Weighted gene coexpression network analysis) method was used to identify the species related to salt stress and the sequence binning to assemble two enriched putative bacterial genomes. The research showed the cultivation of Jerusalem artichoke on saline soil changed soil physico-chemical and enzymatic properties; most of the rapidly changing as well as the long-term stable properties differed significantly between the rhizosphere and bulk soils. The amplicon and metagenomic sequencing revealed the function and structure of microorganisms varied between the rhizosphere and bulk soils, with greater microbial diversity in the rhizosphere. Catalase activity and the moisture content were the factors with the greatest impact on microorganisms. The putative genomes of two species of microorganisms (belong to Nitrospira and Gemmatimonas) were assembled, identified microbial species that were highly responsive to salt stress and that may play a key role in saline soil, stressed the important role of archaea in microbial communities in response to salt stress. The study provides a comprehensive understanding of the microbial community structure in the rhizosphere of Jerusalem artichoke to enable the improvement and economic development of saline land.

RevDate: 2020-04-05

Almeida OGG, Pinto UM, Matos CB, et al (2020)

Does Quorum Sensing play a role in microbial shifts along spontaneous fermentation of cocoa beans? An in silico perspective.

Food research international (Ottawa, Ont.), 131:109034.

Cocoa fermentation is a spontaneous process shaped by a variable microbial ecosystem which is assembled due to cross-feeding relationship among yeasts and bacteria, resulting in a synchronized microbial succession started by yeasts, followed by lactic acid bacteria (LAB) and finalized by acetic acid bacteria (AAB). Several studies have indicated the effect of microbial interactions in food ecosystems highlighting the importance of quorum sensing (QS) in bacterial adaptation in harsh environments modulating several phenotypes such as biofilm formation, tolerance to acid stress, bacteriocin production, competence, morphological modifications, motility, among others. However, antagonic interactions also occur, and can be marked by Quorum Quenching (QQ) activity, negatively impacting QS regulated phenotypes. Our current knowledge regarding microbial cocoa composition and functioning is based on culture-based analysis and culture-independent PCR-based methods. Therefore, we set out to investigate the application of metagenomics analysis on a classical spontaneous cocoa fermentation in order to describe: (I) the microbial taxonomic composition; (II) the functional potential of the cocoa microbiome; (III) the microbiome putative QS potential; and (IV) the microbiome QQ potential. Both aims III and IV are related to the expression of effectors that may confer advantageous traits along fermentation which can explain their dominance in specific time zones during the entire process. We have observed a bacterial succession shaped by yeasts and filamentous fungi and then Enterobacteriaceales, LAB and AAB, as well as a diverse genetic metabolic potential related to proteins and carbohydrates metabolism associated to the yeast Saccharomyces cerevisiae and members of the Enterobacteriaceales order and LAB and AAB groups. In addition, in silico evidences of interspecific QS arsenal were found in members of the genera Enterobacter, Lactobacillus, Bacillus and Pantoea, while inferences of intraspecific QS potential were found in the members of the genera Bacillus, Enterobacter, Komagataeibacter, Lactobacillus and Pantoea. In addition, a QQ potential was detected in Lactobacillus and in AAB members. These findings indicate that QS and QQ may modulate bacterial dominance in different time points during fermentation, along with cross-feeding, being responsible for their maintenance in a large time range.

RevDate: 2020-04-05

Zhao CC, JB Eun (2020)

Shotgun metagenomics approach reveals the bacterial community and metabolic pathways in commercial hongeo product, a traditional Korean fermented skate product.

Food research international (Ottawa, Ont.), 131:109030.

The aim of this study was to investigate the microbial diversity and microbial metabolic pathways using a metagenomic approach in commercial hongeo samples collected from five different fish processing plants. Community comparison analysis indicated that hongeo samples from different fish processing plants have a similar microbial structure at genus level, but the relative abundance of these genera showed a significant difference among different hongeo samples. Four bacterial genera including Psychrobacter, Pseudomonas, Clostridium, and Oblitimonas were detected in all hongeo samples with a high relative abundance, which associated with the nitrogen compound accumulation and ammonia flavor formation in hongeo samples. In addition, some alkaliphilic marine lactic acid bacteria (LAB) belonging to the genera Marinilactibacillus and Jeotgalibaca were detected in hongeo samples, indicating that this product might be a useful source for finding novel bacteria and possibly marine LAB. Through functional profiling analysis, it was found that hongeo samples had higher bacterial gene content related to amino acid metabolism, followed by carbohydrate metabolism and inorganic ion metabolism. The results of this study provide an important information for understanding the mechanism of quality characteristics and ammonia flavor formation in hongeo products.

RevDate: 2020-04-05

Keshavarzian A, Engen P, Bonvegna S, et al (2020)

The gut microbiome in Parkinson's disease: A culprit or a bystander?.

Progress in brain research, 252:357-450.

In recent years, large-scale metagenomics projects such as the Human Microbiome Project placed the gut microbiota under the spotlight of research on its role in health and in the pathogenesis several diseases, as it can be a target for novel therapeutical approaches. The emerging concept of a microbiota modulation of the gut-brain axis in the pathogenesis of neurodegenerative disorders has been explored in several studies in animal models, as well as in human subjects. Particularly, research on changes in the composition of gut microbiota as a potential trigger for alpha-synuclein (α-syn) pathology in Parkinson's disease (PD) has gained increasing interest. In the present review, we first provide the basis to the understanding of the role of gut microbiota in healthy subjects and the molecular basis of the gut-brain interaction, focusing on metabolic and neuroinflammatory factors that could trigger the alpha-synuclein conformational changes and aggregation. Then, we critically explored preclinical and clinical studies reporting on the changes in gut microbiota in PD, as compared to healthy subjects. Furthermore, we examined the relationship between the gut microbiota and PD clinical features, discussing data consistently reported across studies, as well as the potential sources of inconsistencies. As a further step toward understanding the effects of gut microbiota on PD, we discussed the relationship between dysbiosis and response to dopamine replacement therapy, focusing on Levodopa metabolism. We conclude that further studies are needed to determine whether the gut microbiota changes observed so far in PD patients is the cause or, instead, it is merely a consequence of lifestyle changes associated with the disease. Regardless, studies so far strongly suggest that changes in microbiota appears to be impactful in pathogenesis of neuroinflammation. Thus, dysbiotic microbiota in PD could influence the disease course and response to medication, especially Levodopa. Future research will assess the impact of microbiota-directed therapeutic intervention in PD patients.

RevDate: 2020-04-04

Pan X, Lin L, Zhang W, et al (2020)

Metagenome sequencing to unveil the resistome in a deep subtropical lake on the Yunnan-Guizhou Plateau, China.

Environmental pollution (Barking, Essex : 1987), 263(Pt B):114470 pii:S0269-7491(19)36995-7 [Epub ahead of print].

Erhai Lake in the Yunnan-Guizhou Plateau, a typical subtropical deep lake, experienced long-time input of nutrients and pollutants, which provides beneficial conditions for evolution and spread of resistance genes. In this study, the profile of bacterial community, antibiotic and metal resistance genes in sediments of Erhai Lake were analyzed via high-thought sequencing of 16S rRNA and metagenomic DNA. Proteobacteria, Firmicutes, Nitrospirae, and Bacteroidetes were found to be the main composition of the bacterial community. Multidrug-, bacitracin-, macrolide-lincosamide-streptogramin (MLS)- and tetracycline resistance genes were the primary antibiotic resistance gene (ARG) types with high relative abundance, whereas Multi-metal-, and arsenic- resistance genes were the primary metal resistance gene (MRG) types. The effects of nitrogen and phosphorus on the abundance of ARGs and MRGs depended on the different types. Some specific ARG (fosmidomycin resistance genes) and MRG types (multi-metal resistance genes) also showed significant geographic distribution. Bacterial community was the main driver shaping the resistome. Nutrients also played an essential role in structuring the bacterial community and resistome in the sediments of Erhai Lake. This study sheds light on the distribution and fate of resistome under a high load of nitrogen and phosphorus in a deep lake.

RevDate: 2020-04-04

Fergusson CH, Coloma JMF, Valentine MC, et al (2020)

Development of a Custom MALDI-TOF Mass Spectrometric Database for Identification of Environmental Burkholderia and Related Genera.

Applied and environmental microbiology pii:AEM.00354-20 [Epub ahead of print].

Success of microbial natural products discovery programs is dependent on quick and concise discrimination between isolates from diverse environments. However, laboratory isolation and identification of priority genera using current 16S rRNA PCR-based methods is both challenging and time-consuming. An emerging strategy for rapid isolate discrimination is protein fingerprinting via MALDI mass spectrometry. Using our in-house environmental isolate repository, we have created a main spectral (MSP) library for the Bruker Biotyper MALDI mass spectrometer that contains 95 entries including Burkholderia, Caballeronia, Paraburkholderia, and other environmentally related genera. The library creation required the acquisition of over 2,250 mass spectra, which were manually reviewed for quality control and consolidated into a single reference library using the commercial software platform. We tested the effectiveness of the reference library by analyzing 49 environmental isolate strains using two different sample preparation methods. Overall this approach correctly identified all strains to the genus level, provided that suitable reference spectra were present in the MSP library. In this study, we present a fast, accurate method for taxonomic assignment of environmentally-derived bacteria from the order Burkholderiales, providing a valuable alternative to tradißtional PCR-based methods. The MSP library described in this manuscript is available in the supporting information.IMPORTANCE The Gram-negative proteobacterial order Burkholderiales has emerged as a promising source of novel natural products in recent years. This order includes the genus Burkholderia and the newly defined genera Caballeronia and Paraburkholderia However, development of this resource has been hampered by difficulties with rapid and selective isolation of Burkholderiales strains from the environment. Environmental metagenome sequencing has revealed that natural products potential is not evenly distributed throughout the microbial world; thus, large but targeted microbial isolate libraries are needed to effectively explore natural products chemical space. To study these organisms efficiently, methods to quickly identify isolates to the genus level are required. MALDI-TOF MS is already used in clinical settings to reliably identify unknown bacterial pathogens. We have adapted similar methodology using the MALDI Biotyper instrument to rapidly identify Burkholderia, Caballeronia, and Paraburkholderia environmental isolates for downstream natural products discovery.

RevDate: 2020-04-04

Levy Karin E, Mirdita M, J Söding (2020)

MetaEuk-sensitive, high-throughput gene discovery, and annotation for large-scale eukaryotic metagenomics.

Microbiome, 8(1):48 pii:10.1186/s40168-020-00808-x.

BACKGROUND: Metagenomics is revolutionizing the study of microorganisms and their involvement in biological, biomedical, and geochemical processes, allowing us to investigate by direct sequencing a tremendous diversity of organisms without the need for prior cultivation. Unicellular eukaryotes play essential roles in most microbial communities as chief predators, decomposers, phototrophs, bacterial hosts, symbionts, and parasites to plants and animals. Investigating their roles is therefore of great interest to ecology, biotechnology, human health, and evolution. However, the generally lower sequencing coverage, their more complex gene and genome architectures, and a lack of eukaryote-specific experimental and computational procedures have kept them on the sidelines of metagenomics.

RESULTS: MetaEuk is a toolkit for high-throughput, reference-based discovery, and annotation of protein-coding genes in eukaryotic metagenomic contigs. It performs fast searches with 6-frame-translated fragments covering all possible exons and optimally combines matches into multi-exon proteins. We used a benchmark of seven diverse, annotated genomes to show that MetaEuk is highly sensitive even under conditions of low sequence similarity to the reference database. To demonstrate MetaEuk's power to discover novel eukaryotic proteins in large-scale metagenomic data, we assembled contigs from 912 samples of the Tara Oceans project. MetaEuk predicted >12,000,000 protein-coding genes in 8 days on ten 16-core servers. Most of the discovered proteins are highly diverged from known proteins and originate from very sparsely sampled eukaryotic supergroups.

CONCLUSION: The open-source (GPLv3) MetaEuk software (https://github.com/soedinglab/metaeuk) enables large-scale eukaryotic metagenomics through reference-based, sensitive taxonomic and functional annotation. Video abstract.

RevDate: 2020-04-04

Chandrarathna HPSU, Liyanage TD, Edirisinghe SL, et al (2020)

Marine Microalgae, Spirulina maxima-Derived Modified Pectin and Modified Pectin Nanoparticles Modulate the Gut Microbiota and Trigger Immune Responses in Mice.

Marine drugs, 18(3): pii:md18030175.

This study evaluated the modulation of gut microbiota, immune responses, and gut morphometry in C57BL/6 mice, upon oral administration of S. maxima-derived modified pectin (SmP, 7.5 mg/mL) and pectin nanoparticles (SmPNPs; 7.5 mg/mL). Metagenomics analysis was conducted using fecal samples, and mice duodenum and jejunum were used for analyzing the immune response and gut morphometry, respectively. The results of metagenomics analysis revealed that the abundance of Bacteroidetes in the gut increased in response to both modified SmP and SmPNPs (75%) as compared with that in the control group (66%), while that of Firmicutes decreased in (20%) as compared with that in the control group (30%). The mRNA levels of mucin, antimicrobial peptide, and antiviral and gut permeability-related genes in the duodenum were significantly (p < 0.05) upregulated (> 2-fold) upon modified SmP and SmPNPs feeding. Protein level of intestinal alkaline phosphatase was increased (1.9-fold) in the duodenum of modified SmPNPs feeding, evidenced by significantly increased goblet cell density (0.5 ± 0.03 cells/1000 µm2) and villi height (352 ± 10 µm). Our results suggest that both modified SmP and SmPNPs have the potential to modulate gut microbial community, enhance the expression of immune related genes, and improve gut morphology.

RevDate: 2020-04-03

Stebner A, Ensser A, Geißdörfer W, et al (2020)

Molecular diagnosis of polymicrobial brain abscesses with 16S rDNA-based next generation sequencing.

Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases pii:S1198-743X(20)30173-7 [Epub ahead of print].

OBJECTIVES: Brain abscesses lead to high mortality despite antibiotic and surgical treatment. Identification of causative bacteria is important to guide antibiotic therapy, but culture-based methods and molecular diagnostics by Sanger sequencing of 16S PCR products are hampered by antibiotic treatment and the often polymicrobial nature of brain abscesses. We have applied 16S rRNA-based next generation sequencing (NGS) for metagenomic analysis of intracranial (brain and epidural) abscess and meningitis samples.

METHODS: 79 samples from 54 patients with intracranial abscesses or meningitis were included. DNA was subjected to 16S PCR. Amplicons were analyzed with the Illumina MiSeq system, sequence reads were blasted versus the NCBI 16S bacterial database and analyzed using MEGAN software. Results were compared to Gram-staining, culture and Sanger-sequencing.

RESULTS: The NGS workflow was successful for 51 intracranial (46 brain and 5 epidural) abscess and 9 meningitis samples. Inclusion of (mono)-bacterial meningitis samples allowed to establish a cut-off criterion for exclusion of contaminating sequences. A total of 86 bacterial taxa were identified in brain abscesses by NGS, with Streptococcus intermedius and Fusobacterium nucleatum as most prevalent species, whereas Propionibacterium and Staphylococcus spp. were associated with epidural abscesses. NGS identified two or more bacterial taxa in 31/51 intracranial abscesses, revealing the polymicrobial nature of these infections and allowing to discriminate up to 16 bacterial taxa per sample.

CONCLUSION: These results extend earlier studies showing that NGS methods expand the spectrum of bacteria detected in brain abscesses and demonstrate that the MiSeq platform is suitable for metagenomic diagnostics of this severe infection.

RevDate: 2020-04-03

Hess MK, Rowe SJ, Van Stijn TC, et al (2020)

A restriction enzyme reduced representation sequencing approach for low-cost, high-throughput metagenome profiling.

PloS one, 15(4):e0219882 pii:PONE-D-19-18566.

Microbial community profiles have been associated with a variety of traits, including methane emissions in livestock. These profiles can be difficult and expensive to obtain for thousands of samples (e.g. for accurate association of microbial profiles with traits), therefore the objective of this work was to develop a low-cost, high-throughput approach to capture the diversity of the rumen microbiome. Restriction enzyme reduced representation sequencing (RE-RRS) using ApeKI or PstI, and two bioinformatic pipelines (reference-based and reference-free) were compared to bacterial 16S rRNA gene sequencing using repeated samples collected two weeks apart from 118 sheep that were phenotypically extreme (60 high and 58 low) for methane emitted per kg dry matter intake (n = 236). DNA was extracted from freeze-dried rumen samples using a phenol chloroform and bead-beating protocol prior to RE-RRS. The resulting sequences were used to investigate the repeatability of the rumen microbial community profiles, the effect of laboratory and analytical method, and the relationship with methane production. The results suggested that the best method was PstI RE-RRS analyzed with the reference-free approach, which accounted for 53.3±5.9% of reads, and had repeatabilities of 0.49±0.07 and 0.50±0.07 for the first two principal components (PC1 and PC2), phenotypic correlations with methane yield of 0.43±0.06 and 0.46±0.06 for PC1 and PC2, and explained 41±8% of the variation in methane yield. These results were significantly better than for bacterial 16S rRNA gene sequencing of the same samples (p<0.05) except for the correlation between PC2 and methane yield. A Sensitivity study suggested approximately 2000 samples could be sequenced in a single lane on an Illumina HiSeq 2500, meaning the current work using 118 samples/lane and future proposed 384 samples/lane are well within that threshold. With minor adaptations, our approach could be used to obtain microbial profiles from other metagenomic samples.

RevDate: 2020-04-03

Eckert EM, Di Cesare A, Fontaneto D, et al (2020)

Every fifth published metagenome is not available to science.

PLoS biology, 18(4):e3000698 pii:PBIOLOGY-D-19-03403 [Epub ahead of print].

Have you ever sought to use metagenomic DNA sequences reported in scientific publications? Were you successful? Here, we reveal that metagenomes from no fewer than 20% of the papers found in our literature search, published between 2016 and 2019, were not deposited in a repository or were simply inaccessible. The proportion of inaccessible data within the literature has been increasing year-on-year. Noncompliance with Open Data is best predicted by the scientific discipline of the journal. The number of citations, journal type (e.g., Open Access or subscription journals), and publisher are not good predictors of data accessibility. However, many publications in high-impact factor journals do display a higher likelihood of accessible metagenomic data sets. Twenty-first century science demands compliance with the ethical standard of data sharing of metagenomes and DNA sequence data more broadly. Data accessibility must become one of the routine and mandatory components of manuscript submissions-a requirement that should be applicable across the increasing number of disciplines using metagenomics. Compliance must be ensured and reinforced by funders, publishers, editors, reviewers, and, ultimately, the authors.

RevDate: 2020-04-03

Pellow D, Mizrahi I, R Shamir (2020)

PlasClass improves plasmid sequence classification.

PLoS computational biology, 16(4):e1007781 pii:PCOMPBIOL-D-19-02219 [Epub ahead of print].

Many bacteria contain plasmids, but separating between contigs that originate on the plasmid and those that are part of the bacterial genome can be difficult. This is especially true in metagenomic assembly, which yields many contigs of unknown origin. Existing tools for classifying sequences of plasmid origin give less reliable results for shorter sequences, are trained using a fraction of the known plasmids, and can be difficult to use in practice. We present PlasClass, a new plasmid classifier. It uses a set of standard classifiers trained on the most current set of known plasmid sequences for different sequence lengths. We tested PlasClass sequence classification on held-out data and simulations, as well as publicly available bacterial isolates and plasmidome samples and plasmids assembled from metagenomic samples. PlasClass outperforms the state-of-the-art plasmid classification tool on shorter sequences, which constitute the majority of assembly contigs, allowing it to achieve higher F1 scores in classifying sequences from a wide range of datasets. PlasClass also uses significantly less time and memory. PlasClass can be used to easily classify plasmid and bacterial genome sequences in metagenomic or isolate assemblies. It is available under the MIT license from: https://github.com/Shamir-Lab/PlasClass.

RevDate: 2020-04-03

Allio R, Schomaker-Bastos A, Romiguier J, et al (2020)

MitoFinder: efficient automated large-scale extraction of mitogenomic data in target enrichment phylogenomics.

Molecular ecology resources [Epub ahead of print].

Thanks to the development of high-throughput sequencing technologies, target enrichment sequencing of nuclear ultraconserved DNA elements (UCEs) now allows routinely inferring phylogenetic relationships from thousands of genomic markers. Recently, it has been shown that mitochondrial DNA (mtDNA) is frequently sequenced alongside the targeted loci in such capture experiments. Despite its broad evolutionary interest, mtDNA is rarely assembled and used in conjunction with nuclear markers in capture-based studies. Here, we developed MitoFinder, a user-friendly bioinformatic pipeline, to efficiently assemble and annotate mitogenomic data from hundreds of UCE libraries. As a case study, we used ants (Formicidae) for which 501 UCE libraries have been sequenced whereas only 29 mitogenomes are available. We compared the efficiency of four different assemblers (IDBA-UD, MEGAHIT, MetaSPAdes, and Trinity) for assembling both UCE and mtDNA loci. Using MitoFinder, we show that metagenomic assemblers, in particular MetaSPAdes, are well suited to assemble both UCEs and mtDNA. Mitogenomic signal was successfully extracted from all 501 UCE libraries allowing confirming species identification using CO1 barcoding. Moreover, our automated procedure retrieved 296 cases in which the mitochondrial genome was assembled in a single contig, thus increasing the number of available ant mitogenomes by an order of magnitude. By leveraging the power of metagenomic assemblers, MitoFinder provides an efficient tool to extract complementary mitogenomic data from UCE libraries, allowing testing for potential mito-nuclear discordance. Our approach is potentially applicable to other sequence capture methods, transcriptomic data, and whole genome shotgun sequencing in diverse taxa.

RevDate: 2020-04-03

Barnard E, Shi B, Kang D, et al (2020)

Author Correction: The balance of metagenomic elements shapes the skin microbiome in acne and health.

Scientific reports, 10(1):6037 pii:10.1038/s41598-020-62764-8.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

RevDate: 2020-04-03

Osakunor DNM, Munk P, Mduluza T, et al (2020)

The gut microbiome but not the resistome is associated with urogenital schistosomiasis in preschool-aged children.

Communications biology, 3(1):155 pii:10.1038/s42003-020-0859-7.

Helminth parasites have been shown to have systemic effects in the host. Using shotgun metagenomic sequencing, we characterise the gut microbiome and resistome of 113 Zimbabwean preschool-aged children (1-5 years). We test the hypothesis that infection with the human helminth parasite, Schistosoma haematobium, is associated with changes in gut microbial and antimicrobial resistance gene abundance/diversity. Here, we show that bacteria phyla Bacteroidetes, Firmicutes, Proteobacteria, and fungi phyla Ascomycota, Microsporidia, Zoopagomycota dominate the microbiome. The abundance of Proteobacteria, Ascomycota, and Basidiomycota differ between schistosome-infected versus uninfected children. Specifically, infection is associated with increases in Pseudomonas, Stenotrophomonas, Derxia, Thalassospira, Aspergillus, Tricholoma, and Periglandula, with a decrease in Azospirillum. We find 262 AMR genes, from 12 functional drug classes, but no association with individual-specific data. To our knowledge, we describe a novel metagenomic dataset of Zimbabwean preschool-aged children, indicating an association between urogenital schistosome infection and changes in the gut microbiome.

RevDate: 2020-04-03

Stamps BW, JR Spear (2020)

Identification of Metagenome-Assembled Genomes Containing Antimicrobial Resistance Genes, Isolated from an Advanced Water Treatment Facility.

Microbiology resource announcements, 9(14): pii:9/14/e00003-20.

Here, we present 95 metagenome-assembled genomes (MAGs) that harbor antimicrobial resistance genes, isolated from samples obtained in a large advanced wastewater reclamation facility prior to microfiltration. The MAGs were not in abundance after filtration at the facility and represent a useful resource to the water treatment community at large.

RevDate: 2020-04-03

Sun S, Jones RB, AA Fodor (2020)

Inference-based accuracy of metagenome prediction tools varies across sample types and functional categories.

Microbiome, 8(1):46 pii:10.1186/s40168-020-00815-y.

BACKGROUND: Despite recent decreases in the cost of sequencing, shotgun metagenome sequencing remains more expensive compared with 16S rRNA amplicon sequencing. Methods have been developed to predict the functional profiles of microbial communities based on their taxonomic composition. In this study, we evaluated the performance of three commonly used metagenome prediction tools (PICRUSt, PICRUSt2, and Tax4Fun) by comparing the significance of the differential abundance of predicted functional gene profiles to those from shotgun metagenome sequencing across different environments.

RESULTS: We selected 7 datasets of human, non-human animal, and environmental (soil) samples that have publicly available 16S rRNA and shotgun metagenome sequences. As we would expect based on previous literature, strong Spearman correlations were observed between predicted gene compositions and gene relative abundance measured with shotgun metagenome sequencing. However, these strong correlations were preserved even when the abundance of genes were permuted across samples. This suggests that simple correlation coefficient is a highly unreliable measure for the performance of metagenome prediction tools. As an alternative, we compared the performance of genes predicted with PICRUSt, PICRUSt2, and Tax4Fun to sequenced metagenome genes in inference models associated with metadata within each dataset. With this approach, we found reasonable performance for human datasets, with the metagenome prediction tools performing better for inference on genes related to "housekeeping" functions. However, their performance degraded sharply outside of human datasets when used for inference.

CONCLUSION: We conclude that the utility of PICRUSt, PICRUSt2, and Tax4Fun for inference with the default database is likely limited outside of human samples and that development of tools for gene prediction specific to different non-human and environmental samples is warranted. Video abstract.

RevDate: 2020-04-03

Zhang W, Cao S, Ding W, et al (2020)

Structure and function of the Arctic and Antarctic marine microbiota as revealed by metagenomics.

Microbiome, 8(1):47 pii:10.1186/s40168-020-00826-9.

BACKGROUND: The Arctic and Antarctic are the two most geographically distant bioregions on earth. Recent sampling efforts and following metagenomics have shed light on the global ocean microbial diversity and function, yet the microbiota of polar regions has not been included in such global analyses.

RESULTS: Here a metagenomic study of seawater samples (n = 60) collected from different depths at 28 locations in the Arctic and Antarctic zones was performed, together with metagenomes from the Tara Oceans. More than 7500 (19%) polar seawater-derived operational taxonomic units could not be identified in the Tara Oceans datasets, and more than 3,900,000 protein-coding gene orthologs had no hits in the Ocean Microbial Reference Gene Catalog. Analysis of 214 metagenome assembled genomes (MAGs) recovered from the polar seawater microbiomes, revealed strains that are prevalent in the polar regions while nearly undetectable in temperate seawater. Metabolic pathway reconstruction for these microbes suggested versatility for saccharide and lipids biosynthesis, nitrate and sulfate reduction, and CO2 fixation. Comparison between the Arctic and Antarctic microbiomes revealed that antibiotic resistance genes were enriched in the Arctic while functions like DNA recombination were enriched in the Antarctic.

CONCLUSIONS: Our data highlight the occurrence of dominant and locally enriched microbes in the Arctic and Antarctic seawater with unique functional traits for environmental adaption, and provide a foundation for analyzing the global ocean microbiome in a more complete perspective. Video abstract.

RevDate: 2020-04-03
CmpDate: 2020-04-03

Liang YN, Yu JG, Zhang DB, et al (2019)

Indigo Naturalis Ameliorates Dextran Sulfate Sodium-Induced Colitis in Mice by Modulating the Intestinal Microbiota Community.

Molecules (Basel, Switzerland), 24(22):.

Indigo naturalis (IN) is a traditional Chinese medicine, named Qing-Dai, which is extracted from indigo plants and has been used to treat patients with inflammatory bowel disease (IBD) in China and Japan. Though there are notable effects of IN on colitis, the mechanisms remain elusive. Regarding the significance of alterations of intestinal flora related to IBD and the poor water solubility of the blue IN powder, we predicted that the protective action of IN on colitis may occur through modifying gut microbiota. To investigate the relationships of IN, colitis, and gut microbiomes, a dextran sulfate sodium (DSS)-induced mice colitis model was tested to explore the protective effects of IN on macroscopic colitis symptoms, the histopathological structure, inflammation cytokines, and gut microbiota, and their potential functions. Sulfasalazine (SASP) was used as the positive control. Firstly, because it was a mixture, the main chemical compositions of indigo and indirubin in IN were detected by ultra-performance liquid chromatography (UPLC). The clinical activity score (CAS), hematoxylin and eosin (H&E) staining results, and enzyme-linked immunosorbent assay (ELISA) results in this study showed that IN greatly improved the health conditions of the tested colitis mice, ameliorated the histopathological structure of the colon tissue, down-regulated pro-inflammatory cytokines, and up-regulated anti-inflammatory cytokines. The results of 16S rDNA sequences analysis with the Illumina MiSeq platform showed that IN could modulate the balance of gut microbiota, especially by down-regulating the relative quantity of Turicibacter and up-regulating the relative quantity of Peptococcus. The therapeutic effect of IN may be closely related to the anaerobic gram-positive bacteria of Turicibacter and Peptococcus. The inferred metagenomes from 16S data using PICRUSt demonstrated that decreased metabolic genes, such as through biosynthesis of siderophore group nonribosomal peptides, non-homologous end-joining, and glycosphingolipid biosynthesis of lacto and neolacto series, may maintain microbiota homeostasis during inflammation from IN treatment in DSS-induced colitis.

RevDate: 2020-04-02

Kim SI, Kim E, Aghasa A, et al (2020)

Shift in bacterial diversity in acidogenesis of gelatin and gluten seeded with various anaerobic digester inocula.

Bioresource technology, 306:123158 pii:S0960-8524(20)30429-6 [Epub ahead of print].

The aim of this study was to investigate divergence of bacteria degrading model proteins of food-processing wastewater. Gelatin and gluten were used as substrate to represent animal and plant proteins from food wastes, respectively. The inocula were obtained from eight full-scale anaerobic digestion reactors. Food-to-microorganism ratio was 3 g chemical oxygen demand equivalent of substrate per 1 g volatile suspended solids of inoculum. A first-order reaction model revealed reaction constants ranged 1.34 ≤ k ≤ 2.30 d-1 for gelatin and 0.63 ≤ k ≤ 1.69 d-1 for gluten. Metagenomic analysis of 16s rRNA sequences showed that dominant bacteria after gelatin degradation batch were different for each inocula. Klebsiella aerogenes, Hathewaya, Peptoclostridium, or Clostridium collagenovorans were most abundant. Klebsiella aerogenes was the most abundant species after gluten degradation for all inocula.

RevDate: 2020-04-02

Maoloni A, Blaiotta G, Ferrocino I, et al (2020)

Microbiological characterization of Gioddu, an Italian fermented milk.

International journal of food microbiology, 323:108610 pii:S0168-1605(20)30104-5 [Epub ahead of print].

Gioddu, also known as "Miciuratu", "Mezzoraddu" or "Latte ischidu" (literally meaning acidulous milk), is the sole variety of traditional Italian fermented milk. The aim of the present study was to elucidate the microbiota and the mycobiota occurring in artisan Gioddu sampled from three Sardinian producers by combining the results of viable counting on selective culture media and high-throughput sequencing. Physico-chemical parameters were also measured. The overall low pH values (3.80-4.22) recorded in the analyzed Gioddu samples attested the strong acidifying activity carried out by lactic acid bacteria during fermentation. Viable counts revealed the presence of presumptive lactococci, presumptive lactobacilli and non-Saccharomyces yeasts. A complex (kefir-like) microbiota of bacteria and yeasts was unveiled through sequencing. In more detail, Lactobacillus delbrueckii was found to dominate in Gioddu together with Streptococcus thermophilus, thus suggesting the establishment of a yogurt-like protocooperation. Unexpectedly, in all the three analyzed batches from two out of the three producers Lactobacillus kefiri was also detected, thus representing an absolute novelty, which suggests the presence of bioactive compounds (e.g. exopolysaccharides) similar to those characterizing milk kefir beverage. Mycobiota population, studied for the very first time in Gioddu, revealed a more complex composition, with Kluyveromyces marxianus, Galactomyces candidum and Geotrichum galactomyces constituting the core species. Further research is needed to disclose the eventual occurence in Gioddu of probiotic cultures and bioactive compounds (e.g. exopolysaccharides, angiotensin-converting enzyme inhibitory peptides and antimicrobial compounds) with potential health-benefits for the consumers.

RevDate: 2020-04-02

Yan Y, Drew DA, Markowitz A, et al (2020)

Structure of the Mucosal and Stool Microbiome in Lynch Syndrome.

Cell host & microbe pii:S1931-3128(20)30169-4 [Epub ahead of print].

The gut microbiota has been associated with colorectal cancer (CRC), but causal alterations preceding CRC have not been elucidated. To prospectively assess microbiome changes prior to colorectal neoplasia, we investigated samples from 100 Lynch syndrome patients using 16S rRNA gene sequencing of colon biopsies, coupled with metagenomic and metatranscriptomic sequencing of feces. Colectomy and CRC history represented the largest effects on microbiome profiles. A subset of Clostridiaceae were depleted in stool corresponding with baseline adenomas, while Desulfovibrio was enriched both in stool and in mucosal biopsies. A classifier leveraging stool metatranscriptomes resulted in modest power to predict interval development of preneoplastic colonic adenoma. Predictive transcripts corresponded with a shift in flagellin contributors and oxidative metabolic microenvironment, potentially factors in local CRC pathogenesis. This suggests that the effectiveness of prospective microbiome monitoring for adenomas may be limited but supports the potential causality of these consistent, early microbial changes in colonic neoplasia.

RevDate: 2020-04-02

Wang YG, Gao Y, Feng J, et al (2020)

Effect of Modified Xijiao Dihuang Decoction () on Intestinal Flora and Th17/Treg in Rats with Radiation Enteritis.

Chinese journal of integrative medicine pii:10.1007/s11655-020-3261-x [Epub ahead of print].

OBJECTIVE: To observe the effect of Modified Xijiao Dihuang Decoction (, MXDD) on rats with radiation enteritis, and explore its action mechanism.

METHODS: Thirty female Sprague Dawley rats were divided into the control, model, dexamethasone (DXM), golden bifid (GB) and MXDD groups using random number table, 6 rats in each group. Except the control group, the other rats were developed into radiation enteritis model by exposing to a single 60Co-γ ray at a dose of 11 Gy. The rats in the DXM, GB and MXDD groups were treated with DXM (1.425 mg/kg), GB (0.8 g/kg) and MXDD (36.0 g/kg) for 3 days, respectively. Body weight and diarrhea condition of rats were evaluated daily. On day 3, the feces of rats were collected for intestinal flora detection and the small intestinal tissues were also collected. Bacterial species annotation, alpha and beta diversities as well as composition of intestinal flora were detected and compared. The protein and mRNA expressions of interleukin 17 (IL-17), retinoid-related orphan nuclear receptor gamma t (ROR-γt) and forkhead/ winged helix transcription factor p3 (FoxP3) were determined by Western blot and polymerase chain reaction, respectively. The abundance and diversity of intestinal flora as well as the proportion at the phylum and genus levels were assayed by 16S rRNA metagenome sequencing. Correlation between intestinal flora and Th17/Treg was analyzed by heatmap method.

RESULTS: On day 1 to 3 after radiation, compared with the control group, the body weight in model group was decreased (P<0.05 or P<0.01). Compared with the model group, MXDD could alleviate weight loss and diarrhea caused by irradiation. At the phylum level, MXDD cause a significant increase in Firmicutes, and a decrease in Proteobacteria (P<0.05 or P<0.01). At the genus level, MXDD reduced the proportion of Escherichia Shigella (P<0.01). In addition, IL-17 and FoxP3 mRNA and protein expression levels were down-regulated and ROR-γt was up-regulated by MXDD treatment (P<0.05). Besides, Firmicutes and Lactobacillus were positively correlated with FoxP3 (r=0.73, 0.79, respectively; P<0.01), negatively correlated with IL-17 (r=0.66, 0.64, respectively; P<0.01 or P<0.05) and ROR-γt (r0.73, 0.81, respectively; P<0.01). Proteobacteria and Escherichia Shigella both had positive correlation with IL-17 (r 0.77, 0.57, respectively; P<0.01 or P<0.05) and ROR-γt (r=0.94, 0.79, respectively; P<0.01) and negative correlation with FoxP3 (r0.74, 0.65; P<0.01).

CONCLUSION: MXDD could improve the survival status of irradiated rats by regulating the richness, diversity and composition of intestinal flora, and restoring the balance of Th17/Treg.

RevDate: 2020-04-02

Li W, Tapiainen T, Brinkac L, et al (2020)

Vertical transmission of gut microbiome and antimicrobial resistance genes in infants exposed to antibiotics at birth.

The Journal of infectious diseases pii:5814973 [Epub ahead of print].

Vertical transmission of maternal microbes is a major route for establishing the gut microbiome in newborns. The impact of perinatal antibiotics on vertical transmission of microbes and antimicrobial resistance is not well understood. Using a metagenomic approach, we analyzed the fecal samples from mothers and vaginally delivered infants from a control group (10 pairs) and a treatment group (10 pairs) receiving perinatal antibiotics. Antibiotic-usage had a significant impact on the main source of inoculum in the gut microbiome of newborns. The control group had significantly more species transmitted from mothers to infants (p=0.03) than the antibiotic-treated group. Approximately 72% of the gut microbial population of infants at 3-7 days after birth in the control group was transmitted from their mothers, versus only 25% in the antibiotic-treated group. In conclusion, perinatal antibiotics markedly disturbed vertical transmission and changed the source of gut colonization towards horizontal transfer from the environment to the infants.

RevDate: 2020-04-02

Greene LK, Williams CV, Junge RE, et al (2020)

A role for gut microbiota in host niche differentiation.

The ISME journal pii:10.1038/s41396-020-0640-4 [Epub ahead of print].

If gut microbes influence host behavioral ecology in the short term, over evolutionary time, they could drive host niche differentiation. We explored this possibility by comparing the gut microbiota of Madagascar's folivorous lemurs from Indriidae and Lepilemuridae. Occurring sympatrically in the eastern rainforest, our four, target species have different dietary specializations, including frugo-folivory (sifakas), young-leaf folivory (indri and woolly lemurs), and mature-leaf folivory (sportive lemurs). We collected fecal samples, from 2013 to 2017, and used amplicon sequencing, metagenomic sequencing, and nuclear magnetic resonance spectroscopy, respectively, to integrate analyses of gut microbiome structure and function with analysis of the colonic metabolome. The lemurs harbored species-specific microbiomes, metagenomes, and metabolomes that were tuned to their dietary specializations: Frugo-folivores had greater microbial and metagenomic diversity, and harbored generalist taxa. Mature-leaf folivores had greater individual microbiome variation, and taxa and metabolites putatively involved in cellulolysis. The consortia even differed between related, young-leaf specialists, with indri prioritizing metabolism of fiber and plant secondary compounds, and woolly lemurs prioritizing amino-acid cycling. Specialized gut microbiota and associated gastrointestinal morphologies enable folivores to variably tolerate resource fluctuation and support nutrient extraction from challenging resources (e.g., by metabolizing plant secondary compounds or recalcitrant fibers), perhaps ultimately facilitating host species' diversity and specialized feeding ecologies.

RevDate: 2020-04-02

Zhao R, Summers ZM, Christman GD, et al (2020)

Metagenomic views of microbial dynamics influenced by hydrocarbon seepage in sediments of the Gulf of Mexico.

Scientific reports, 10(1):5772 pii:10.1038/s41598-020-62840-z.

Microbial cells in the seabed are thought to persist by slow population turnover rates and extremely low energy requirements. External stimulations such as seafloor hydrocarbon seeps have been demonstrated to significantly boost microbial growth; however, the microbial community response has not been fully understood. Here we report a comparative metagenomic study of microbial response to natural hydrocarbon seeps in the Gulf of Mexico. Subsurface sediments (10-15 cm below seafloor) were collected from five natural seep sites and two reference sites. The resulting metagenome sequencing datasets were analyzed with both gene-based and genome-based approaches. 16S rRNA gene-based analyses suggest that the seep samples are distinct from the references by both 16S rRNA fractional content and phylogeny, with the former dominated by ANME-1 archaea (~50% of total) and Desulfobacterales, and the latter dominated by the Deltaproteobacteria, Planctomycetes, and Chloroflexi phyla. Sulfate-reducing bacteria (SRB) are present in both types of samples, with higher relative abundances in seep samples than the references. Genes for nitrogen fixation were predominantly found in the seep sites, whereas the reference sites showed a dominant signal for anaerobic ammonium oxidation (anammox). We recovered 49 metagenome-assembled genomes and assessed the microbial functional potentials in both types of samples. By this genome-based analysis, the seep samples were dominated by ANME-1 archaea and SRB, with the capacity for methane oxidation coupled to sulfate reduction, which is consistent with the 16S rRNA-gene based characterization. Although ANME-1 archaea and SRB are present in low relative abundances, genome bins from the reference sites are dominated by uncultured members of NC10 and anammox Scalindua, suggesting a prevalence of nitrogen transformations for energy in non-seep pelagic sediments. This study suggests that hydrocarbon seeps can greatly change the microbial community structure by stimulating nitrogen fixation, inherently shifting the nitrogen metabolism compared to those of the reference sediments.

RevDate: 2020-04-02

Bengtsson RJ, Wee BA, Yebra G, et al (2020)

Metagenomic sequencing of clinical samples reveals a single widespread clone of Lawsonia intracellularis responsible for porcine proliferative enteropathy.

Microbial genomics [Epub ahead of print].

Lawsonia intracellularis is a Gram-negative obligate intracellular bacterium that is the aetiological agent of proliferative enteropathy (PE), a common intestinal disease of major economic importance in pigs and other animal species. To date, progress in understanding the biology of L. intracellularis for improved disease control has been hampered by the inability to culture the organism in vitro. In particular, our understanding of the genomic diversity and population structure of clinical L. intercellularis is very limited. Here, we utilized a metagenomic shotgun approach to directly sequence and assemble 21 L. intracellularis genomes from faecal and ileum samples of infected pigs and horses across three continents. Phylogenetic analysis revealed a genetically monomorphic clonal lineage responsible for infections in pigs, with distinct subtypes associated with infections in horses. The genome was highly conserved, with 94 % of genes shared by all isolates and a very small accessory genome made up of only 84 genes across all sequenced strains. In part, the accessory genome was represented by regions with a high density of SNPs, indicative of recombination events importing novel gene alleles. In summary, our analysis provides the first view of the population structure for L. intracellularis, revealing a single major lineage associated with disease of pigs. The limited diversity and broad geographical distribution suggest the recent emergence and clonal expansion of an important livestock pathogen.

RevDate: 2020-04-02

Liu SJ, Wang Q, Li TT, et al (2020)

Characterization of the First Genome of Porcine mastadenovirus B (HNU1 Strain) and Implications on Its Lymphoid and Special Origin.

Virologica Sinica pii:10.1007/s12250-020-00210-9 [Epub ahead of print].

Porcine adenoviruses (PAdVs) are classified into three species, PAdV-A, PAdV-B, and PAdV-C. The genomes of PAdV-A and PAdV-C have been well characterized. However, the genome of PAdV-B has never been completely sequenced, and the epidemiology of PAdV-B remains unclear. In our study, we have identified a novel strain of PAdV-B, named PAdV-B-HNU1, in porcine samples collected in China by viral metagenomic assay and general PCR. The genome of PAdV-B-HNU1 is 31,743 bp in length and highly similar to that of California sea lion adenovirus 1 (C. sea lion AdV-1), which contains typical mastadenoviral structures and some unique regions at the carboxy-terminal end. Especially, PAdV-B-HNU1 harbors a dUTPase coding region not clustering with other mastadenoviruses except for C. sea lion AdV-1 and a fiber coding region homologous with galectin 4 and 9 of animals. However, the variance of GC contents between PAdV-B-HNU1 (55%) and C. sea lion AdV-1 (36%) indicates their differential evolutionary paths. Further epidemiologic study revealed a high positive rate (51.7%) of PAdV-B-HNU1 in porcine lymph samples, but low positive rates of 10.2% and 16.1% in oral swabs and rectal swabs, respectively. In conclusion, this study characterized a novel representative genome of a lymphotropic PAdV-B with unique evolutionary origin, which contributes to the taxonomical and pathogenic studies of PAdVs.

RevDate: 2020-04-02

Basolo A, Hohenadel M, Ang QY, et al (2020)

Effects of underfeeding and oral vancomycin on gut microbiome and nutrient absorption in humans.

Nature medicine pii:10.1038/s41591-020-0801-z [Epub ahead of print].

Direct evidence in humans for the impact of the microbiome on nutrient absorption is lacking. We conducted an extended inpatient study using two interventions that we hypothesized would alter the gut microbiome and nutrient absorption. In each, stool calorie loss, a direct proxy of nutrient absorption, was measured. The first phase was a randomized cross-over dietary intervention in which all participants underwent in random order 3 d of over- and underfeeding. The second was a randomized, double-blind, placebo-controlled pharmacologic intervention using oral vancomycin or matching placebo (NCT02037295). Twenty-seven volunteers (17 men and 10 women, age 35.1 ± 7.3, BMI 32.3 ± 8.0), who were healthy other than having impaired glucose tolerance and obesity, were enrolled and 25 completed the entire trial. The primary endpoints were the effects of dietary and pharmacological intervention on stool calorie loss. We hypothesized that stool calories expressed as percentage of caloric intake would increase with underfeeding compared with overfeeding and increase during oral vancomycin treatment. Both primary endpoints were met. Greater stool calorie loss was observed during underfeeding relative to overfeeding and during vancomycin treatment compared with placebo. Key secondary endpoints were to evaluate the changes in gut microbial community structure as evidenced by amplicon sequencing and metagenomics. We observed only a modest perturbation of gut microbial community structure with under- versus overfeeding but a more widespread change in community structure with reduced diversity with oral vancomycin. Increase in Akkermansia muciniphila was common to both interventions that resulted in greater stool calorie loss. These results indicate that nutrient absorption is sensitive to environmental perturbations and support the translational relevance of preclinical models demonstrating a possible causal role for the gut microbiome in dietary energy harvest.

RevDate: 2020-04-02

Zhu F, Ju Y, Wang W, et al (2020)

Metagenome-wide association of gut microbiome features for schizophrenia.

Nature communications, 11(1):1612 pii:10.1038/s41467-020-15457-9.

Evidence is mounting that the gut-brain axis plays an important role in mental diseases fueling mechanistic investigations to provide a basis for future targeted interventions. However, shotgun metagenomic data from treatment-naïve patients are scarce hampering comprehensive analyses of the complex interaction between the gut microbiota and the brain. Here we explore the fecal microbiome based on 90 medication-free schizophrenia patients and 81 controls and identify a microbial species classifier distinguishing patients from controls with an area under the receiver operating characteristic curve (AUC) of 0.896, and replicate the microbiome-based disease classifier in 45 patients and 45 controls (AUC = 0.765). Functional potentials associated with schizophrenia include differences in short-chain fatty acids synthesis, tryptophan metabolism, and synthesis/degradation of neurotransmitters. Transplantation of a schizophrenia-enriched bacterium, Streptococcus vestibularis, appear to induces deficits in social behaviors, and alters neurotransmitter levels in peripheral tissues in recipient mice. Our findings provide new leads for further investigations in cohort studies and animal models.

RevDate: 2020-04-02

Lal Gupta C, Kumar Tiwari R, E Cytryn (2020)

Platforms for elucidating antibiotic resistance in single genomes and complex metagenomes.

Environment international, 138:105667 pii:S0160-4120(19)34242-4 [Epub ahead of print].

Antibiotic or antimicrobial resistance (AR) facilitated by the vertical and/or horizontal transfer of antibiotic resistance genes (ARGs), is a serious global health challenge. While traditionally associated with pathogens in clinical environments, it is becoming increasingly clear that non-clinical environments may also be reservoirs of ARGs. The recent improvements in rapid and affordable next generation sequencing technologies along with sophisticated bioinformatics platforms has the potential to revolutionize diagnostic microbiology and microbial surveillance. Through the study and characterization of ARGs in bacterial genomes and complex metagenomes, we are now able to reveal the genetic scope of AR in single bacteria and complex communities, and obtain important insights into AR dynamics at species, population and community levels, providing novel epidemiological and ecological perspectives. A suite of bioinformatics pipelines and ARG databases are currently available for genomic and metagenomic data analyses. However, different platforms may significantly vary and therefore, it is crucial to choose the tools that are most suitable for the specific analysis being conducted. This review provides a detailed account of available bioinformatics platforms for identification and characterization of ARGs and associated genetic elements within single bacterial isolates and complex environmental samples. It focuses primarily on currently available ARG databases, employing a comprehensive benchmarking pipeline to identify ARGs in four bacterial genomes (Aeromonas salmonicida, Bacillus cereus, Burkholderia sp. and Escherichia coli) and three shotgun metagenomes (human gut, poultry litter and soil) providing insight into which databases should be used for different analytical scenarios.

RevDate: 2020-04-02

Chee-Sanford JC, Connor L, Krichels A, et al (2020)

Hierarchical detection of diverse Clade II (atypical) nosZ genes using new primer sets for classical- and multiplex PCR array applications.

Journal of microbiological methods pii:S0167-7012(20)30233-5 [Epub ahead of print].

The reduction of nitrous oxide (N2O) to N2 represents the key terminal step in canonical denitrification. Nitrous oxide reductase (NosZ), the enzyme associated with this biological step, however, is not always affiliated with denitrifying microorganisms. Such organisms were shown recently to possess a Clade II (atypical) nosZ gene, in contrast to Clade I (typical) nosZ harbored in more commonly studied denitrifiers. Subsequent phylogenetic analyses have shown that Clade II NosZ are affiliated with a much broader diversity of microorganisms than those with Clade I NosZ, the former including both non-denitrifiers and denitrifiers. Most studies attempting to characterize the nosZ gene diversity using DNA-based PCR approaches have only focused on Clade I nosZ, despite recent metagenomic sequencing studies that have demonstrated the dominance of Clade II nosZ genes in many ecosystems, particularly soil. As a result, these studies have greatly underestimated the genetic potential for N2O reduction present in ecosystems. Because the high diversity of Clade II NosZ makes it impossible to design a universal primer set that would effectively amplify all nosZ genes in this clade, we developed a suite of primer sets to specifically target seven of ten designated subclades of Clade II nosZ genes. The new primer sets yield suitable product sizes for paired end amplicon sequencing and qPCR, demonstrated here in their use for both conventional single-reaction and multiplex array platforms. In addition, we show the utility of these primers for detecting nosZ gene transcripts from mRNA extracted from soil.

RevDate: 2020-04-02

Pan J, Zhou Z, Béjà O, et al (2020)

Genomic and transcriptomic evidence of light-sensing, porphyrin biosynthesis, Calvin-Benson-Bassham cycle, and urea production in Bathyarchaeota.

Microbiome, 8(1):43 pii:10.1186/s40168-020-00820-1.

BACKGROUND: Bathyarchaeota, a newly proposed archaeal phylum, is considered as an important driver of the global carbon cycle. However, due to the great diversity of them, there is limited genomic information that accurately encompasses the metabolic potential of the entire archaeal phylum.

RESULTS: In the current study, nine metagenome-assembled genomes of Bathyarchaeota from four subgroups were constructed from mangrove sediments, and metatranscriptomes were obtained for evaluating their in situ transcriptional activities. Comparative analyses with reference genomes and the transcripts of functional genes posit an expanded role for Bathyarchaeota in phototrophy, autotrophy, and nitrogen and sulfur cycles, respectively. Notably, the presence of genes for rhodopsins, cobalamin biosynthesis, and the oxygen-dependent metabolic pathways in some Bathyarchaeota subgroup 6 genomes suggest a light-sensing and microoxic lifestyle within this subgroup.

CONCLUSIONS: The results of this study expand our knowledge of metabolic abilities and diverse lifestyles of Bathyarchaeota, highlighting the crucial role of Bathyarchaeota in geochemical cycle. Video abstract.

RevDate: 2020-04-02

Ling Y, Wang J, Yin J, et al (2020)

Genomic organization of a Gamma-6 papillomavirus metagenomic discovered from vaginal swab samples of Chinese pregnant women.

Virology journal, 17(1):44 pii:10.1186/s12985-020-01319-9.

A complete genome sequence of human papillomaviruses (HPV) named as HPV-ujs-21015 was determined by viral metagenomic and PCR methods. The complete genome is 7354 bp in length with GC content of 41.7%, of which the genome was predicted to contain six ORFs (Open Reading Frame, ORF) coding for four early proteins (E7, E1, E4, and E2) and two late proteins (L1 and L2). Phylogenetic analysis based on the complete genome and the L1 protein showed that HPV-ujs-21015 belongs to a type 214 member within genus Gamma-6 papillomavirus. It is the first complete genome of Gamma-6 papillomavirus discovered from pregnant women in China.

RevDate: 2020-04-02

Christo-Foroux E, Alempic JM, Lartigue A, et al (2020)

Characterization of Mollivirus kamchatka, the First Modern Representative of the Proposed Molliviridae Family of Giant Viruses.

Journal of virology, 94(8): pii:JVI.01997-19.

Microbes trapped in permanently frozen paleosoils (permafrost) are the focus of increasing research in the context of global warming. Our previous investigations led to the discovery and reactivation of two Acanthamoeba-infecting giant viruses, Mollivirus sibericum and Pithovirus sibericum, from a 30,000-year old permafrost layer. While several modern pithovirus strains have since been isolated, no contemporary mollivirus relative was found. We now describe Mollivirus kamchatka, a close relative to M. sibericum, isolated from surface soil sampled on the bank of the Kronotsky River in Kamchatka, Russian Federation. This discovery confirms that molliviruses have not gone extinct and are at least present in a distant subarctic continental location. This modern isolate exhibits a nucleocytoplasmic replication cycle identical to that of M. sibericum Its spherical particle (0.6 μm in diameter) encloses a 648-kb GC-rich double-stranded DNA genome coding for 480 proteins, of which 61% are unique to these two molliviruses. The 461 homologous proteins are highly conserved (92% identical residues, on average), despite the presumed stasis of M. sibericum for the last 30,000 years. Selection pressure analyses show that most of these proteins contribute to virus fitness. The comparison of these first two molliviruses clarify their evolutionary relationship with the pandoraviruses, supporting their provisional classification in a distinct family, the Molliviridae, pending the eventual discovery of intermediary missing links better demonstrating their common ancestry.IMPORTANCE Virology has long been viewed through the prism of human, cattle, or plant diseases, leading to a largely incomplete picture of the viral world. The serendipitous discovery of the first giant virus visible under a light microscope (i.e., >0.3 μm in diameter), mimivirus, opened a new era of environmental virology, now incorporating protozoan-infecting viruses. Planet-wide isolation studies and metagenome analyses have shown the presence of giant viruses in most terrestrial and aquatic environments, including upper Pleistocene frozen soils. Those systematic surveys have led authors to propose several new distinct families, including the Mimiviridae, Marseilleviridae, Faustoviridae, Pandoraviridae, and Pithoviridae We now propose to introduce one additional family, the Molliviridae, following the description of M. kamchatka, the first modern relative of M. sibericum, previously isolated from 30,000-year-old arctic permafrost.

RevDate: 2020-04-02
CmpDate: 2020-04-02

Cheong HC, Yap PSX, Chong CW, et al (2019)

Diversity of endocervical microbiota associated with genital Chlamydia trachomatis infection and infertility among women visiting obstetrics and gynecology clinics in Malaysia.

PloS one, 14(11):e0224658.

The cervical microbiota constitutes an important protective barrier against the invasion of pathogenic microorganisms. A disruption of microbiota within the cervical milieu has been suggested to be a driving factor of sexually transmitted infections. These include Chlamydia trachomatis which frequently causes serious reproductive sequelae such as infertility in women. In this study, we profiled the cervical microbial composition of a population of 70 reproductive-age Malaysian women; among which 40 (57.1%) were diagnosed with genital C. trachomatis infection, and 30 (42.8%) without C. trachomatis infection. Our findings showed a distinct compositional difference between the cervical microbiota of C. trachomatis-infected subjects and subjects without C. trachomatis infection. Specifically, significant elevations of mostly strict and facultative anaerobes such as Streptococcus, Megasphaera, Prevotella, and Veillonella in the cervical microbiota of C. trachomatis-positive women were detected. The results from the current study highlights an interaction of C. trachomatis with the environmental microbiome in the endocervical region.

RevDate: 2020-04-02
CmpDate: 2020-04-02

Uribe RV, van der Helm E, Misiakou MA, et al (2019)

Discovery and Characterization of Cas9 Inhibitors Disseminated across Seven Bacterial Phyla.

Cell host & microbe, 26(5):702.

RevDate: 2020-04-02
CmpDate: 2020-04-02

Madhusoodanan J (2019)

News Feature: Do hosts and their microbes evolve as a unit?.

Proceedings of the National Academy of Sciences of the United States of America, 116(29):14391-14394.

RevDate: 2020-04-01

Barbut F, J Couturier (2019)

[Interactions between intestinal microbiota and Clostridioides difficile].

La Revue du praticien, 69(7):784-791.

Interactions between intestinal microbiota and clostridioides difficile. Clostridioides difficile is a spore-forming anaerobic Gram-positive bacillus that is responsible for diarrhea and post-antibiotic colitis. Approximately 20,000 inpatients are infected by C. difficile in France per year. This bacterium is recognized as an emerging pathogen responsible for community-acquired diarrhea. Antibiotic therapy is the main risk factor for C. difficile infection (CDI) because it leads to intestinal dysbiosis and loss of "colonization resistance". C. difficile from endogenous or exogenous origin can then establish, multiply and produce its two toxins causing enterocyte lesions and a significant inflammatory reaction. The loss of colonization resistance has been associated with the loss of microbial diversity, particularly of some taxa that play a protective role. These variations of bacterial communities lead to changes in functions that can be explored by metabolomic or metagenomic approaches. Data from these experiments led to mechanistic assumptions about resistance or susceptibility to CDI. Microbiota studies have also pushed physicians to develop therapeutic approaches based on biotherapies. These therapies aim at repopulating the colon by a healthy microbiota either by fecal microbiota transplantation or by the administration of strains and cocktails of strains to restore the colonization resistance effect.

RevDate: 2020-04-01

Mai BHA, Drancourt M, G Aboudharam (2020)

Ancient dental pulp: Masterpiece tissue for paleomicrobiology.

Molecular genetics & genomic medicine [Epub ahead of print].

INTRODUCTION: Dental pulp with special structure has become a good reference sample in paleomicrobiology-related blood-borne diseases, many pathogens were detected by different methods based on the diagnosis of nucleic acids and proteins.

OBJECTIVES: This review aims to propose the preparation process from ancient teeth collection to organic molecule extraction of dental pulp and summary, analyze the methods that have been applied to detect septicemic pathogens through ancient dental pulps during the past 20 years following the first detection of an ancient microbe.

METHODS: The papers used in this review with two main objectives were obtained from PubMed and Google scholar with combining keywords: "ancient," "dental pulp," "teeth," "anatomy," "structure," "collection," "preservation," "selection," "photography," "radiography," "contamination," "decontamination," "DNA," "protein," "extraction," "bone," "paleomicrobiology," "bacteria," "virus," "pathogen," "molecular biology," "proteomics," "PCR," "MALDI-TOF," "LC/MS," "ELISA," "immunology," "immunochromatography," "genome," "microbiome," "metagenomics."

RESULTS: The analysis of ancient dental pulp should have a careful preparation process with many different steps to give highly accurate results, each step complies with the rules in archaeology and paleomicrobiology. After the collection of organic molecules from dental pulp, they were investigated for pathogen identification based on the analysis of DNA and protein. Actually, DNA approach takes a principal role in diagnosis while the protein approach is more and more used. A total of seven techniques was used and ten bacteria (Yersinia pestis, Bartonella quintana, Salmonella enterica serovar Typhi, Salmonella enterica serovar Paratyphi C, Mycobacterium leprae, Mycobacterium tuberculosis, Rickettsia prowazeki, Staphylococcus aureus, Borrelia recurrentis, Bartonella henselae) and one virus (Anelloviridae) were identified. Y. pestis had the most published in quantity and all methods were investigated for this pathogen, S. aureus and B. recurrentis were identified by three different methods and others only by one. The combining methods interestingly increase the positive rate with ELISA, PCR and iPCR in Yersinia pestis diagnosis. Twenty-seven ancient genomes of Y. pestis and one ancient genome of B. recurrentis were reconstructed. Comparing to the ancient bone, ancient teeth showed more advantage in septicemic diagnosis. Beside pathogen identification, ancient pulp help to distinguish species.

CONCLUSIONS: Dental pulp with specific tissue is a suitable sample for detection of the blood infection in the past through DNA and protein identification with the correct preparation process, furthermore, it helps to more understand the pathogens of historic diseases and epidemics.

RevDate: 2020-04-01

McGhee JJ, Rawson N, Bailey BA, et al (2020)

Meta-SourceTracker: application of Bayesian source tracking to shotgun metagenomics.

PeerJ, 8:e8783 pii:8783.

Background: Microbial source tracking methods are used to determine the origin of contaminating bacteria and other microorganisms, particularly in contaminated water systems. The Bayesian SourceTracker approach uses deep-sequencing marker gene libraries (16S ribosomal RNA) to determine the proportional contributions of bacteria from many potential source environments to a given sink environment simultaneously. Since its development, SourceTracker has been applied to an extensive diversity of studies, from beach contamination to human behavior.

Methods: Here, we demonstrate a novel application of SourceTracker to work with metagenomic datasets and tested this approach using sink samples from a study of coastal marine environments. Source environment metagenomes were obtained from metagenomics studies of gut, freshwater, marine, sand and soil environments. As part of this effort, we implemented features for determining the stability of source proportion estimates, including precision visualizations for performance optimization, and performed domain-specific source-tracking analyses (i.e., Bacteria, Archaea, Eukaryota and viruses). We also applied SourceTracker to metagenomic libraries generated from samples collected from the International Space Station (ISS).

Results: SourceTracker proved highly effective at predicting the composition of known sources using shotgun metagenomic libraries. In addition, we showed that different taxonomic domains sometimes presented highly divergent pictures of environmental source origins for both the coastal marine and ISS samples. These findings indicated that applying SourceTracker to separate domains may provide a deeper understanding of the microbial origins of complex, mixed-source environments, and further suggested that certain domains may be preferable for tracking specific sources of contamination.

RevDate: 2020-04-01

Carter KM, Lu M, Jiang H, et al (2020)

An Information-Based Approach for Mediation Analysis on High-Dimensional Metagenomic Data.

Frontiers in genetics, 11:148.

The human microbiome plays a critical role in the development of gut-related illnesses such as inflammatory bowel disease and clinical pouchitis. A mediation model can be used to describe the interaction between host gene expression, the gut microbiome, and clinical/health situation (e.g., diseased or not, inflammation level) and may provide insights into underlying disease mechanisms. Current mediation regression methodology cannot adequately model high-dimensional exposures and mediators or mixed data types. Additionally, regression based mediation models require some assumptions for the model parameters, and the relationships are usually assumed to be linear and additive. With the microbiome being the mediators, these assumptions are violated. We propose two novel nonparametric procedures utilizing information theory to detect significant mediation effects with high-dimensional exposures and mediators and varying data types while avoiding standard regression assumptions. Compared with available methods through comprehensive simulation studies, the proposed method shows higher power and lower error. The innovative method is applied to clinical pouchitis data as well and interesting results are obtained.

RevDate: 2020-04-01

Wu M, Yang S, Wang S, et al (2020)

Effect of Berberine on Atherosclerosis and Gut Microbiota Modulation and Their Correlation in High-Fat Diet-Fed ApoE-/- Mice.

Frontiers in pharmacology, 11:223.

Atherosclerosis and its associated cardiovascular diseases (CVDs) are serious threats to human health and have been reported to be associated with the gut microbiota. Recently, the role of berberine (BBR) in atherosclerosis and gut microbiota has begun to be appreciated. The purposes of this study were to observe the effects of high or low doses of BBR on atherosclerosis and gut microbiota modulation, and to explore their correlation in ApoE-/- mice fed a high-fat diet. A significant decrease in atherosclerotic lesions was observed after treatment with BBR, with the effect of the high dose being more obvious. Both BBR treatments significantly reduced total cholesterol, APOB100, and very low-density lipoprotein cholesterol levels but levels of high/low-density lipoprotein cholesterol and lipoprotein (a) were only reduced by high-dose BBR. Decreased pro-inflammatory cytokines tumor necrosis factor-alpha, interleukin (IL)-1β, IL-6 and increased anti-inflammatory IL-10 and adiponectin levels were observed in the high-dose BBR group, but no decrease in IL-6 or increase in IL-10 was evident using the low-dose of BBR. 16S rRNA sequencing showed that BBR significantly altered the community compositional structure of gut microbiota. Specifically, BBR enriched the abundance of Roseburia, Blautia, Allobaculum, Alistipes, and Turicibacter, and changed the abundance of Bilophila. These microbiota displayed good anti-inflammatory effects related to the production of short-chain fatty acids (SCFAs) and were related to glucolipid metabolism. Alistipes and Roseburia were significantly enriched in high-dose BBR group while Blautia and Allobaculum were more enriched in low-dose, and Turicibacter was enriched in both BBR doses. Metagenomic analysis further showed an elevated potential for lipid and glycan metabolism and synthesis of SCFAs, as well as reduced potential of TMAO production after BBR treatment. The findings demonstrate that both high and low-dose BBR can improve serum lipid and systemic inflammation levels, and alleviate atherosclerosis induced by high-fat diet in ApoE-/- mice. The effects are more pronounced for the high dose. This anti-atherosclerotic effect of BBR may be partly attributed to changes in composition and functions of gut microbiota which may be associated with anti-inflammatory and metabolism of glucose and lipid. Notably, gut microbiota alterations showed different sensitivity to BBR dose.

RevDate: 2020-04-01

Chaudhari DS, Dhotre DP, Agarwal DM, et al (2020)

Gut, oral and skin microbiome of Indian patrilineal families reveal perceptible association with age.

Scientific reports, 10(1):5685 pii:10.1038/s41598-020-62195-5.

The human microbiome plays a key role in maintaining host homeostasis and is influenced by age, geography, diet, and other factors. Traditionally, India has an established convention of extended family arrangements wherein three or more generations, bound by genetic relatedness, stay in the same household. In the present study, we have utilized this unique family arrangement to understand the association of age with the microbiome. We characterized stool, oral and skin microbiome of 54 healthy individuals from six joint families by 16S rRNA gene-based metagenomics. In total, 69 (1.03%), 293 (2.68%) and 190 (8.66%) differentially abundant OTUs were detected across three generations in the gut, skin and oral microbiome, respectively. Age-associated changes in the gut and oral microbiome of patrilineal families showed positive correlations in the abundance of phyla Proteobacteria and Fusobacteria, respectively. Genera Treponema and Fusobacterium showed a positive correlation with age while Granulicatella and Streptococcus showed a negative correlation with age in the oral microbiome. Members of genus Prevotella illustrated high abundance and prevalence as a core OTUs in the gut and oral microbiome. In conclusion, this study highlights that precise and perceptible association of age with microbiome can be drawn when other causal factors are kept constant.

RevDate: 2020-04-01

Vemuri R, Shankar EM, Chieppa M, et al (2020)

Beyond Just Bacteria: Functional Biomes in the Gut Ecosystem Including Virome, Mycobiome, Archaeome and Helminths.

Microorganisms, 8(4): pii:microorganisms8040483.

Gut microbiota refers to a complex network of microbes, which exerts a marked influence on the host's health. It is composed of bacteria, fungi, viruses, and helminths. Bacteria, or collectively, the bacteriome, comprises a significant proportion of the well-characterized microbiome. However, the other communities referred to as 'dark matter' of microbiomes such as viruses (virome), fungi (mycobiome), archaea (archaeome), and helminths have not been completely elucidated. Development of new and improved metagenomics methods has allowed the identification of complete genomes from the genetic material in the human gut, opening new perspectives on the understanding of the gut microbiome composition, their importance, and potential clinical applications. Here, we review the recent evidence on the viruses, fungi, archaea, and helminths found in the mammalian gut, detailing their interactions with the resident bacterial microbiota and the host, to explore the potential impact of the microbiome on host's health. The role of fecal virome transplantations, pre-, pro-, and syn-biotic interventions in modulating the microbiome and their related concerns are also discussed.

RevDate: 2020-04-01

Leitão AL, Costa MC, Gabriel AF, et al (2020)

Interspecies Communication in Holobionts by Non-Coding RNA Exchange.

International journal of molecular sciences, 21(7): pii:ijms21072333.

Complex organisms are associations of different cells that coexist and collaborate creating a living consortium, the holobiont. The relationships between the holobiont members are essential for proper homeostasis of the organisms, and they are founded on the establishment of complex inter-connections between all the cells. Non-coding RNAs are regulatory molecules that can also act as communication signals between cells, being involved in either homeostasis or dysbiosis of the holobionts. Eukaryotic and prokaryotic cells can transmit signals via non-coding RNAs while using specific extracellular conveyors that travel to the target cell and can be translated into a regulatory response by dedicated molecular machinery. Within holobionts, non-coding RNA regulatory signaling is involved in symbiotic and pathogenic relationships among the cells. This review analyzes current knowledge regarding the role of non-coding RNAs in cell-to-cell communication, with a special focus on the signaling between cells in multi-organism consortia.

RevDate: 2020-04-01

Czaplicki LM, Redfern LK, Cooper EM, et al (2020)

Investigating the mycobiome of the Holcomb Creosote Superfund Site.

Chemosphere, 252:126208 pii:S0045-6535(20)30401-X [Epub ahead of print].

Even though many fungi are known to degrade a range of organic chemicals and may be advantageous for targeting hydrophobic chemicals with low bioavailability due to their ability to secrete extracellular enzymes, fungi are not commonly leveraged in the context of bioremediation. Here we sought to examine the fungal microbiome (mycobiome) at a model creosote polluted site to determine if fungi were prevalent under high PAH contamination conditions as well as to identify potential mycostimulation targets. Several significant positive associations were detected between OTUs and mid-to high-molecular weight PAHs. Several OTUs were closely related to taxa that have previously been identified in culture-based studies as PAH degraders. In particular, members belonging to the Ascomycota phylum were the most diverse at higher PAH concentrations suggesting this phylum may be promising biostimulation targets. There were nearly three times more positive correlations as compared to negative correlations, suggesting that creosote-tolerance is more common than creosote-sensitivity in the fungal community. Future work including shotgun metagenomic analysis would help confirm the presence of specific degradation genes. Overall this study suggests that mycobiome and bacterial microbiome analyses should be performed in parallel to devise the most optimal in situ biostimulation treatment strategies.

RevDate: 2020-04-01

Srivastava GN, Malwe AS, Sharma AK, et al (2020)

A machine learning based classification tool for the prediction of biofilm inhibitory molecules.

Genomics pii:S0888-7543(19)30549-X [Epub ahead of print].

Identification of biofilm inhibitory small molecules appears promising for therapeutic intervention against biofilm-forming bacteria. However, the experimental identification of such molecules is a time-consuming task, and thus, the computational approaches emerge as promising alternatives. We developed the 'Molib' tool to predict the biofilm inhibitory activity of small molecules. We curated a training dataset of biofilm inhibitory molecules, and the structural and chemical features were used for feature selection, followed by algorithms optimization and building of machine learning-based classification models. On five-fold cross validation, Random Forest-based descriptor, fingerprint and hybrid classification models showed accuracies of 0.93, 0.88 and 0.90, respectively. The performances of all models were evaluated on two different validation datasets including biofilm inhibitory and non-inhibitory molecules, attesting to its accuracy (≥ 0.90). The Molib web server would serve as a highly useful and reliable tool for the prediction of biofilm inhibitory activity of small molecules.

RevDate: 2020-04-01

Wang C, Huang Z, Li W, et al (2020)

Can metagenomic next-generation sequencing identify the pathogens responsible for culture-negative prosthetic joint infection?.

BMC infectious diseases, 20(1):253 pii:10.1186/s12879-020-04955-2.

BACKGROUND: The aims of this study were to (1) evaluate the efficacy and safety of targeted antibiotics for the treatment of culture-negative prosthetic joint infection based on metagenomic next-generation sequencing results and (2) verify the accuracy and reliability of metagenomic next-generation sequencing for identifying pathogens related to culture-negative prosthetic joint infection.

METHODS: Ninety-seven consecutive PJI patients, including 27 patients with culture-negative prosthetic joint infection, were treated surgically at our center. Thirteen of the 27 culture-negative prosthetic joint infection patients, who were admitted before June 2017 and treated with empirical antibiotics, comprised the empirical antibiotic group (EA group), and the other 14 patients, who were admitted after June 2017 and treated with targeted antibiotics according to their metagenomic next-generation sequencing results, were classified as the targeted antibiotic group (TA group). The short-term infection control rate, incidence of antibiotic-related complications and costs were compared between the two groups.

RESULTS: Two of the patients in the EA group experienced debridement and prolonged antimicrobial therapy due to wound infection after the initial revision surgery. No recurrent infections were observed in the TA group; however, no significant difference in the infection control rate was found between the two groups (83.33% vs 100%, P = 0.217). More cases of antibiotic-related complications were recorded in the EA group (6 cases) than in the TA group (1 case), but the difference was not statistically significant (P = 0.0697). The cost of antibiotics obtained for the EA group was 20,168.37 Yuan (3236.38-45,297.16), which was higher than that found for the TA group (10,164.16 Yuan, 2959.54-16,661.04, P = 0.04).

CONCLUSIONS: Targeted antibiotic treatment for culture-negative prosthetic joint infection based on metagenomic next-generation sequencing results is associated with a favorable outcome, and metagenomic next-generation sequencing is a reliable tool for identifying pathogens related to culture-negative prosthetic joint infection.

RevDate: 2020-04-01

Xu L, Surathu A, Raplee I, et al (2020)

The effect of antibiotics on the gut microbiome: a metagenomics analysis of microbial shift and gut antibiotic resistance in antibiotic treated mice.

BMC genomics, 21(1):263 pii:10.1186/s12864-020-6665-2.

BACKGROUND: Emergence of antibiotic resistance is a global public health concern. The relationships between antibiotic use, the gut community composition, normal physiology and metabolism, and individual and public health are still being defined. Shifts in composition of bacteria, antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) after antibiotic treatment are not well-understood.

METHODS: This project used next-generation sequencing, custom-built metagenomics pipeline and differential abundance analysis to study the effect of antibiotic monotherapy on resistome and taxonomic composition in the gut of Balb/c mice infected with E. coli via transurethral catheterization to investigate the evolution and emergence of antibiotic resistance.

RESULTS: There is a longitudinal decrease of gut microbiota diversity after antibiotic treatment. Various ARGs are enriched within the gut microbiota despite an overall reduction of the diversity and total amount of bacteria after antibiotic treatment. Sometimes treatment with a specific class of antibiotics selected for ARGs that resist antibiotics of a completely different class (e.g. treatment of ciprofloxacin or fosfomycin selected for cepA that resists ampicillin). Relative abundance of some MGEs increased substantially after antibiotic treatment (e.g. transposases in the ciprofloxacin group).

CONCLUSIONS: Antibiotic treatment caused a remarkable reduction in diversity of gut bacterial microbiota but enrichment of certain types of ARGs and MGEs. These results demonstrate an emergence of cross-resistance as well as a profound change in the gut resistome following oral treatment of antibiotics.

RevDate: 2020-04-01
CmpDate: 2020-04-01

Gusareva ES, Acerbi E, Lau KJX, et al (2019)

Microbial communities in the tropical air ecosystem follow a precise diel cycle.

Proceedings of the National Academy of Sciences of the United States of America, 116(46):23299-23308.

The atmosphere is vastly underexplored as a habitable ecosystem for microbial organisms. In this study, we investigated 795 time-resolved metagenomes from tropical air, generating 2.27 terabases of data. Despite only 9 to 17% of the generated sequence data currently being assignable to taxa, the air harbored a microbial diversity that rivals the complexity of other planetary ecosystems. The airborne microbial organisms followed a clear diel cycle, possibly driven by environmental factors. Interday taxonomic diversity exceeded day-to-day and month-to-month variation. Environmental time series revealed the existence of a large core of microbial taxa that remained invariable over 13 mo, thereby underlining the long-term robustness of the airborne community structure. Unlike terrestrial or aquatic environments, where prokaryotes are prevalent, the tropical airborne biomass was dominated by DNA from eukaryotic phyla. Specific fungal and bacterial species were strongly correlated with temperature, humidity, and CO2 concentration, making them suitable biomarkers for studying the bioaerosol dynamics of the atmosphere.

RevDate: 2020-03-31

Hiramatsu Y, Suzuki K, Motooka D, et al (2020)

Expression of small RNAs of Bordetella pertussis colonizing murine tracheas.

Microbiology and immunology [Epub ahead of print].

We performed RNA sequencing on Bordetella pertussis, the causative agent of whooping cough, and identified 9 novel small RNAs (sRNAs) that were transcribed during the bacterial colonization of murine tracheas. Among them, four sRNAs were more strongly expressed in vivo than in vitro. Moreover, the expression of 8 sRNAs was not regulated by the BvgAS two-component system, which is the master regulator for the expression of genes contributing to the bacterial infection. The present results suggest a BvgAS-independent gene regulatory system involving the sRNAs that is active during B. pertussis infection. This article is protected by copyright. All rights reserved.

RevDate: 2020-03-31

Chen M, Guo WL, Li QY, et al (2020)

The protective mechanism of Lactobacillus plantarum FZU3013 against non-alcoholic fatty liver associated with hyperlipidemia in mice fed a high-fat diet.

Food & function [Epub ahead of print].

Lactobacillus plantarum FZU3013, a probiotic previously isolated from the traditional brewing process of Hongqu rice wine, may have the beneficial effect of improving the disorders of lipid metabolism. This study aimed to investigate the role of L. plantarum FZU3013 in improving non-alcoholic fatty liver (NAFL) associated with hyperlipidemia in mice fed a high-fat diet. The results indicated that L. plantarum FZU3013 intervention significantly reduced the HFD-induced body weight gain and the abnormal levels of serum total triglycerides (TG), total cholesterol (TC) and low-density lipoprotein (LDL-C), and inhibited the excessive accumulation of liver lipids. In addition, L. plantarum FZU3013 also promoted the excretion of bile acids through feces. Metagenomic and multivariate statistical analysis revealed that L. plantarum FZU3013 made significant structural changes in the intestinal microbiome of the mice fed with HFD, in particular by modulating the relative abundance of some function related microbial phylotypes. Furthermore, ultra-performance liquid chromatography with quadruple-time of flight mass spectrometry (UPLC-QTOF/MS)-based liver metabolomics demonstrated that L. plantarum FZU3013 had a significant regulatory effect on the composition of liver metabolites in hyperlipidemic mice, especially on the levels of some important biomarkers involved in the pathways of glycerophospholipid metabolism, fatty acid degradation, fatty acid elongation, glycerolipid metabolism, primary bile acid biosynthesis, arachidonic acid metabolism, etc. Moreover, L. plantarum FZU3013 regulated the mRNA expression levels of the genes responsible for liver lipid and cholesterol metabolism. L. plantarum FZU3013 intervention increased the hepatic mRNA levels of cholesterol 7α-hydroxylase (CYP7A1) and the bile salt export pump (BSEP), suggesting enhanced bile acid synthesis and excretion from the liver. These findings present new evidence supporting that L. plantarum FZU3013 has the potential to improve lipid metabolism disorders through modulating specific intestinal microbial phylotypes and regulating hepatic lipid metabolism related genes, therefore it could be used as a potential functional food for the prevention of NAFL and hyperlipidemia.

RevDate: 2020-03-31

Chen ML, Becraft ED, Pachiadaki M, et al (2020)

Hiding in Plain Sight: The Globally Distributed Bacterial Candidate Phylum PAUC34f.

Frontiers in microbiology, 11:376.

Bacterial candidate phylum PAUC34f was originally discovered in marine sponges and is widely considered to be composed of sponge symbionts. Here, we report 21 single amplified genomes (SAGs) of PAUC34f from a variety of environments, including the dark ocean, lake sediments, and a terrestrial aquifer. The diverse origins of the SAGs and the results of metagenome fragment recruitment suggest that some PAUC34f lineages represent relatively abundant, free-living cells in environments other than sponge microbiomes, including the deep ocean. Both phylogenetic and biogeographic patterns, as well as genome content analyses suggest that PAUC34f associations with hosts evolved independently multiple times, while free-living lineages of PAUC34f are distinct and relatively abundant in a wide range of environments.

RevDate: 2020-03-31

Ko G, Kim PG, Cho Y, et al (2020)

Bioinformatics services for analyzing massive genomic datasets.

Genomics & informatics, 18(1):e8.

The explosive growth of next-generation sequencing data has resulted in ultra-large-scale datasets and ensuing computational problems. In Korea, the amount of genomic data has been increasing rapidly in the recent years. Leveraging these big data requires researchers to use large-scale computational resources and analysis pipelines. A promising solution for addressing this computational challenge is cloud computing, where CPUs, memory, storage, and programs are accessible in the form of virtual machines. Here, we present a cloud computing-based system, Bio-Express, that provides user-friendly, cost-effective analysis of massive genomic datasets. Bio-Express is loaded with predefined multi-omics data analysis pipelines, which are divided into genome, transcriptome, epigenome, and metagenome pipelines. Users can employ predefined pipelines or create a new pipeline for analyzing their own omics data. We also developed several web-based services for facilitating downstream analysis of genome data. Bio-Express web service is freely available at https://www.bioexpress.re.kr/.

RevDate: 2020-03-31

Kotay SM, Parikh HI, Barry K, et al (2020)

Nutrients influence the dynamics of Klebsiella pneumoniae carbapenemase producing enterobacterales in transplanted hospital sinks.

Water research, 176:115707 pii:S0043-1354(20)30243-8 [Epub ahead of print].

Antimicrobial resistance has been recognized as a threat to human health. The role of hospital sinks acting as a reservoir for some of the most concerning antibiotic resistant organisms, carbapenemase producing Enterobacterales (CPE) is evident but not well understood. Strategies to prevent establishment, interventions to eliminate these reservoirs and factors which drive persistence of CPE are not well established. We use a uniquely designed sink lab to transplant CPE colonized hospital sink plumbing with an aim to understand CPE dynamics in a controlled setting, notably exploiting both molecular and culture techniques. After ex situ installation the CPE population in the sink plumbing drop from previously detectable to undetectable levels. The addition of nutrients is followed by a quick rebound in CPE detection in the sinks after as many as 37 days. We did not however detect a significant shift in microbial community structure or the overall resistance gene carriage in longitudinal samples from a subset of these transplanted sinks using whole shotgun metagenomic sequencing. Comparing nutrient types in a benchtop culture study model, protein rich nutrients appear to be the most supportive for CPE growth and biofilm formation ability. The role of nutrients exposure is determining factor for maintaining a high bioburden of CPE in the sink drains and P-traps. Therefore, limiting nutrient disposal into sinks has reasonable potential with regard to decreasing the CPE wastewater burden, especially in hospitals seeking to control an environmental reservoir.

RevDate: 2020-03-30

Jia S, Bian K, Shi P, et al (2020)

Metagenomic profiling of antibiotic resistance genes and their associations with bacterial community during multiple disinfection regimes in a full-scale drinking water treatment plant.

Water research, 176:115721 pii:S0043-1354(20)30258-X [Epub ahead of print].

For comprehensive insights into the effects of multiple disinfection regimes on antibiotic resistome in drinking water, this study utilized metagenomic approaches to reveal the changing patterns of antibiotic resistance genes (ARGs) and bacterial community as well as their associations. A total of 297 ARGs within 17 types were detected in the drinking water, and their total relative abundance ranged from 195.49 ± 24.85 to 626.31 ± 38.61 copies of ARGs per cell. The total ARG abundance was significantly increased after the antimicrobial resin and ultraviolet (AR/UV) disinfection while significantly decreased after the ozone and chlorine (O3/Cl2) disinfection and remained stable after AR/Cl2 disinfection. Overall, 18 ARGs including bacA, mexT, and blaOXA-12, mainly affiliated to bacitracin, multidrug, and beta-lactam, were persistent and discriminative during all the disinfection strategies in drinking water, and they were considered as key ARGs that represent the antibiotic resistome during drinking water disinfection. Additionally, possible hosts of 50% key ARGs were revealed based on co-occurrence network. During multiple disinfection processes, the change of Fusobacteriales and Aeromonadaceae in abundance mainly contributed to the abundance shift of bacA, and Pseudomonas mainly increased the abundance of mexT. These findings indicated that bacterial community shift may be the key factor driving the change of antibiotic resistome during disinfection. The strong association between antibiotic resistome alteration and bacterial community shift proposed in this study may enhance our understanding of the underlying mechanism of the disinfection effects on antibiotic resistance and benefit effective measures to improve safety of drinking water.

RevDate: 2020-03-30

Aalto SL, Suurnäkki S, von Ahnen M, et al (2020)

Nitrate removal microbiology in woodchip bioreactors: A case-study with full-scale bioreactors treating aquaculture effluents.

The Science of the total environment, 723:138093 pii:S0048-9697(20)31606-5 [Epub ahead of print].

Woodchip bioreactors are viable low-cost nitrate (NO3-) removal applications for treating agricultural and aquaculture discharges. The active microbial biofilms growing on woodchips are conducting nitrogen (N) removal, reducing NO3- while oxidizing the carbon (C) from woodchips. However, bioreactor age, and changes in the operating conditions or in the microbial community might affect the NO3- removal as well as potentially promote nitrous oxide (N2O) production through either incomplete denitrification or dissimilatory NO3- reduction to ammonium (DNRA). Here, we combined stable isotope approach, amplicon sequencing, and captured metagenomics for studying the potential NO3- removal rates, and the abundance and community composition of microbes involved in N transformation processes in the three different full-scale woodchip bioreactors treating recirculating aquaculture system (RAS) effluents. We confirmed denitrification producing di‑nitrogen gas (N2) to be the primary NO3- removal pathway, but found that 6% of NO3- could be released as N2O under high NO3- concentrations and low amounts of bioavailable C, whereas DNRA rates tend to increase with the C amount. The abundance of denitrifiers was equally high between the studied bioreactors, yet the potential NO3- removal rates were linked to the denitrifying community diversity. The same core proteobacterial groups were driving the denitrification, while Bacteroidetes dominated the DNRA carrying microbes in all the three bioreactors studied. Altogether, our results suggest that woodchip bioreactors have a high genetic potential for NO3- removal through a highly abundant and diverse denitrifying community, but that the rates and dynamics between the NO3- removal pathways depend on the other factors (e.g., bioreactor design, operating conditions, and the amount of bioavailable C in relation to the incoming NO3- concentrations).

RevDate: 2020-03-30

Desbrousses C, Archer F, Colin A, et al (2020)

High-Throughput Sequencing (HTS) of newly synthetized RNAs enables one shot detection and identification of live mycoplasmas and differentiation from inert nucleic acids.

Biologicals : journal of the International Association of Biological Standardization pii:S1045-1056(20)30040-3 [Epub ahead of print].

Mycoplasma contamination threatens both the safety of biologics produced in cell substrates as well as the quality of scientific results based on cell-culture observations. Methods currently used to detect contamination of cells include culture, enzymatic activity, immunofluorescence and PCR but suffer from some limitations. High throughput sequencing (HTS) can be used to identify microbes like mycoplasmas in biologics since it enables an unbiased approach to detection without the need to design specific primers to pre-amplify target sequences but it does not enable the confirmation of microbial infection since this could reflect carryover of inert sequences. In order to unambiguously differentiate the presence of live or dead mycoplasmas in biological products, the present method was developed based on metabolic RNA labelling of newly synthetized mycoplasmal RNAs. HTS of labelled RNA detected A549 cell infection with Acholeplasma laidlawii in a manner similar to both PCR and culture and demonstrated that this technique can unambiguously identify bacterial species and differentiates infected cells from cells exposed to a high inoculum of heat-inactivated mycoplasmas. This method therefore combines the advantage of culture (that detects only live microorganisms) with those of molecular tests (rapidity) together with a very broad range of bacterial detection and identification.

RevDate: 2020-03-30
CmpDate: 2020-03-30

Khilyas IV, Sorokina AV, Elistratova AA, et al (2019)

Microbial diversity and mineral composition of weathered serpentine rock of the Khalilovsky massif.

PloS one, 14(12):e0225929.

Endolithic microbial communities survive nutrient and energy deficient conditions while contributing to the weathering of their mineral substrate. This study examined the mineral composition and microbial communities of fully serpentinized weathered rock from 0.1 to 6.5 m depth at a site within the Khalilovsky massif, Orenburg Region, Southern Ural Mountains, Russia. The mineral composition includes a major content of serpentinite family (mostly consisting of lizardite and chrysotile), magnesium hydrocarbonates (hydromagnesite with lesser amounts of hydrotalcite and pyroaurite) concentrated in the upper layers, and clay minerals. We found that the deep-seated weathered serpentinites are chrysotile-type minerals, while the middle and surface serpentinites mostly consist of lizardite and chrysotile types. Microbial community analysis, based on 16S rRNA gene sequencing, showed a similar diversity of phyla throughout the depth profile. The dominant bacterial phyla were the Actinobacteria (of which unclassified genera in the orders Acidimicrobiales and Actinomycetales were most numerous), Chloroflexi (dominated by an uncultured P2-11E order) and the Proteobacteria (predominantly class Betaproteobacteria). Densities of several groups of bacteria were negatively correlated with depth. Occurrence of the orders Actinomycetales, Gaiellales, Solirubrobacterales, Rhizobiales and Burkholderiales were positively correlated with depth. Our findings show that endolithic microbial communities of the Khalilovsky massif have similar diversity to those of serpentine soils and rocks, but are substantially different from those of the aqueous environments of actively serpentinizing systems.

RevDate: 2020-03-30
CmpDate: 2020-03-30

Choi S, Lee JG, Lee AR, et al (2019)

Helicobacter pylori antibody and pepsinogen testing for predicting gastric microbiome abundance.

PloS one, 14(12):e0225961.

BACKGROUND: Although the high-throughput sequencing technique is useful for evaluating gastric microbiome, it is difficult to use clinically. We aimed to develop a predictive model for gastric microbiome based on serologic testing.

METHODS: This study was designed to analyze sequencing data obtained from the Hanyang University Gastric Microbiome Cohort, which was established initially to investigate gastric microbial composition according to the intragastric environment. We evaluated the relationship between the relative abundance of potential gastric cancer-associated bacteria (nitrosating/nitrate-reducing bacteria or type IV secretion system [T4SS] protein gene-contributing bacteria) and serologic markers (IgG anti-Helicobacter pylori [HP] antibody or pepsinogen [PG] levels).

RESULTS: We included 57 and 26 participants without and with HP infection, respectively. The relative abundance of nitrosating/nitrate-reducing bacteria was 4.9% and 3.6% in the HP-negative and HP-positive groups, respectively, while that of T4SS protein gene-contributing bacteria was 20.5% and 6.5% in the HP-negative and HP-positive groups, respectively. The relative abundance of both nitrosating/nitrate-reducing bacteria and T4SS protein gene-contributing bacteria increased exponentially as PG levels decreased. Advanced age (only for nitrosating/nitrate-reducing bacteria), a negative result of IgG anti-HP antibody, low PG levels, and high Charlson comorbidity index were associated with a high relative abundance of nitrosating/nitrate-reducing bacteria and T4SS protein gene-contributing bacteria. The adjusted coefficient of determination (R2) was 53.7% and 70.0% in the model for nitrosating/nitrate-reducing bacteria and T4SS protein gene-contributing bacteria, respectively.

CONCLUSION: Not only the negative results of IgG anti-HP antibody but also low PG levels were associated with a high abundance of nitrosating/nitrate-reducing bacteria and T4SS protein gene-contributing bacteria.

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ESP Quick Facts

ESP Origins

In the early 1990's, Robert Robbins was a faculty member at Johns Hopkins, where he directed the informatics core of GDB — the human gene-mapping database of the international human genome project. To share papers with colleagues around the world, he set up a small paper-sharing section on his personal web page. This small project evolved into The Electronic Scholarly Publishing Project.

ESP Support

In 1995, Robbins became the VP/IT of the Fred Hutchinson Cancer Research Center in Seattle, WA. Soon after arriving in Seattle, Robbins secured funding, through the ELSI component of the US Human Genome Project, to create the original ESP.ORG web site, with the formal goal of providing free, world-wide access to the literature of classical genetics.

ESP Rationale

Although the methods of molecular biology can seem almost magical to the uninitiated, the original techniques of classical genetics are readily appreciated by one and all: cross individuals that differ in some inherited trait, collect all of the progeny, score their attributes, and propose mechanisms to explain the patterns of inheritance observed.

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In reading the early works of classical genetics, one is drawn, almost inexorably, into ever more complex models, until molecular explanations begin to seem both necessary and natural. At that point, the tools for understanding genome research are at hand. Assisting readers reach this point was the original goal of The Electronic Scholarly Publishing Project.

ESP Usage

Usage of the site grew rapidly and has remained high. Faculty began to use the site for their assigned readings. Other on-line publishers, ranging from The New York Times to Nature referenced ESP materials in their own publications. Nobel laureates (e.g., Joshua Lederberg) regularly used the site and even wrote to suggest changes and improvements.

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When the site began, no journals were making their early content available in digital format. As a result, ESP was obliged to digitize classic literature before it could be made available. For many important papers — such as Mendel's original paper or the first genetic map — ESP had to produce entirely new typeset versions of the works, if they were to be available in a high-quality format.

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Early support from the DOE component of the Human Genome Project was critically important for getting the ESP project on a firm foundation. Since that funding ended (nearly 20 years ago), the project has been operated as a purely volunteer effort. Anyone wishing to assist in these efforts should send an email to Robbins.

ESP Plans

With the development of methods for adding typeset side notes to PDF files, the ESP project now plans to add annotated versions of some classical papers to its holdings. We also plan to add new reference and pedagogical material. We have already started providing regularly updated, comprehensive bibliographies to the ESP.ORG site.

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Papers in Classical Genetics

The ESP began as an effort to share a handful of key papers from the early days of classical genetics. Now the collection has grown to include hundreds of papers, in full-text format.

Digital Books

Along with papers on classical genetics, ESP offers a collection of full-text digital books, including many works by Darwin (and even a collection of poetry — Chicago Poems by Carl Sandburg).

Timelines

ESP now offers a much improved and expanded collection of timelines, designed to give the user choice over subject matter and dates.

Biographies

Biographical information about many key scientists.

Selected Bibliographies

Bibliographies on several topics of potential interest to the ESP community are now being automatically maintained and generated on the ESP site.

ESP Picks from Around the Web (updated 07 JUL 2018 )