Microbiome digest, October 8, 2014

Posted on October 8, 2014 by eliesbik

Blogging from our yearly retreat in Santa Cruz, California: Rethinking Enterotypes, Wolbachia phylogenomics, hydrothermal vents, and the influence of salamanders on soil microbiome.

Human Microbiome General

Genes & cells: Body microbes make useful molecules: Human microbiome produces thousands of drug candidates – Tina Hesman Saey – Science News

Human Gut Microbiome

Rethinking “Enterotypes” – Dan Knights – Cell Host and Microbe

“However, as discussed here, several different methods of collapsing enterotype variation into a few discrete clusters suggest that enterotype distribution is continuous and can vary widely within an individual.”

Fecal Bacterial Community Changes Associated with Isoflavone Metabolites in Postmenopausal Women after Soy Bar Consumption – Cindy H. Nakatsu – PLOS ONE

“Using DGGE profiles of PCR amplified 16S rRNA genes (V3 region) to compare microbial communities in fecal samples collected one week before and one week during soy supplementation revealed significant differences (ANOSIM p<0.03) before and after soy supplementation in all subjects. “

Insect microbiome

Phylogenomic analyses uncover origin and spread of the Wolbachia pandemic – Michael Gerth – Nature Communications

“Here we present the first comprehensive phylogenomic analysis of Wolbachia supergroup relationships based on new whole-genome-shotgun data.”

Coral microbiome

Comparing Bacterial Community Composition of Healthy and Dark Spot-Affected Siderastrea siderea in Florida and the Caribbean – Christina A. Kellogg – PLOS ONE

“Microbial-community DNA was extracted from coral samples (mucus, tissue, and skeleton), amplified using bacterial-specific primers, and applied to PhyloChip G3 microarrays to examine the bacterial diversity associated with this coral. “

Soil Microbiome

Summer temperature increase has distinct effects on the ectomycorrhizal fungal communities of moist tussock and dry tundra in Arctic Alaska – Luis N. Morgado – Global Change Biology

“We used Ion Torrent sequencing of the rDNA internal transcribed spacer 2 (ITS2) region to compare ECM fungal communities in plots with and without long-term experimental warming in both dry and moist tussock tundra.”

A metagenomics-based approach to the top-down effect on the detritivore food web: a salamanders influence on fungal communities within a deciduous forest – Donald M. Walker – Ecology and Evolution

“From each sample, DNA was extracted, fungal-specific amplification performed, and 454 pyrosequencing was used to sequence the nuclear ribosomal internal transcribed spacer (ITS2) region and partial ribosomal large subunit (LSU).”

Water microbiome

Evolutionary Strategies of Viruses, Bacteria and Archaea in Hydrothermal Vent Ecosystems Revealed through Metagenomics – Rika E Anderson – PLOS ONE

“Here, we explore the evolutionary strategies of both microorganisms and viruses in hydrothermal systems through comparative analysis of a cellular and viral metagenome, “

Metabolomics

Discovery and Characterization of Gut Microbiota Decarboxylases that Can Produce the Neurotransmitter Tryptamine – Brianna B. Williams – -Cell Host and Microbe

“Using a combination of genetics, biochemistry, and crystallography, we identify and characterize two phylogenetically distinct enzymes found in the human microbiome that decarboxylate tryptophan to form the β-arylamine neurotransmitter

Techniques

Selective Microbial Genomic DNA Isolation Using Restriction Endonucleases – Helen E. Barnes – PLOS ONE

“Using synthetic genome mixtures, we demonstrate 80% recovery of Escherichia coli genomic DNA even when only femtogram quantities are spiked into 10 µg of human DNA background.”

More Microbiology

Pseudomonas aeruginosa eradicates Staphylococcus aureus by manipulating the host immunity – Erwan Pernet – Nature Communications

“Our results indicate that a bacterium can eradicate another bacterium by manipulating the host immunity.”

Preparation and evaluation of low-calorie functional ice cream containing inulin, lactulose and Bifidobacterium lactis – Majid Hashemi- International Journal of Dairy Technology

“This study was aimed to investigate the effects of replacing 5% fat and sugar by inulin and lactulose, respectively, on the survival of Bifidobacterium lactis and physicochemical and sensorial characteristics of the ice cream. “

Microbes in the News

Second Genome, Mayo Clinic team up to explore the microbiome – Stephanie M. Lee – SF Gate

“Second Genome will identify up to eight conditions in which the microbiome potentially plays a role, and the Mayo Clinic will provide human clinical samples for patients with those diseases.”

Oral health affects overall health – PhillyTrib

“The evidence shows that an infection from periodontitis, or gum disease, can put you at risk for other serious conditions like heart disease, stroke and more.”

Safety Bees: Bacteria From Bees Used To Fight Infections – The Ledger

“A group of 13 lactic-acid bacteria found in fresh honey from the honey stomach of bees could be the key to bringing an old folk remedy into modern science”

Bik’s Picks

How dinosaurs divided their meals at the Jurassic dinner table – Science Daily

“How the largest animals to have ever walked on Earth fed, and how this allowed them to live alongside one another in prehistoric ecosystems, is the subject of new research.”

Imitation, Genetic Lineages, and Time Influenced the Morphological Evolution of the Violin – Daniel H. Chitwood – PLOS ONE

“Here, I provide an analysis of morphological evolution in the violin family, sampling the body shapes of over 9,000 instruments over 400 years of history.”

Cat Watch 2014: What’s it like being a cat? – BBC

“Cats are at a crucial point in their evolutionary journey as they transform from solitary hunters to domestic pets, a study by the BBC and the Royal Veterinary College has revealed.”
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General microbiology and science, July 15

Posted on July 15, 2014 by eliesbik

Dengue virus replication, poliovirus transmission, marine viral communities, primer choice, and CRISPRs systems and antibiotic resistance.

Dengue virus

Letter: Are viral small RNA regulating Dengue virus replication beyond serotype 2? – Esteban Finol – PNAS

Letter: Reply to Finol: Viral small RNA from Dengue virus and its egulatory role in different serotypes – Mazhar Hussain and Sassan Asgari – PNAS

Poliovirus

The role of older children and adults in wild poliovirus transmission – Isobel M. Blake – PNAS

“We fit a mathematical model of poliovirus transmission to time series data from two large outbreaks that affected adults (Tajikistan 2010, Republic of Congo 2010) using maximum-likelihood estimation based on iterated particle-filtering methods. “

Phages and viruses

Modeling ecological drivers in marine viral communities using comparative metagenomics and network analyses – Bonnie L. Hurwitz – PNAS

“Here we combine advances in bioinformatics (shared k-mer analyses) and social networking (regression modeling) to develop an annotation- and assembly-free visualization and analytical strategy for comparative metagenomics that uses all the data in a unified statistical framework. “

Contrasted coevolutionary dynamics between a bacterial pathogen and its bacteriophages – Alex Betts – PNAS

“We used experimental evolution between Pseudomonas aeruginosa and a panel of its lytic phages and found the full known range of coevolutionary dynamics.”

CRISPRs and antibiotic resistance

A CRISPR-Cas system enhances envelope integrity mediating antibiotic resistance and inflammasome evasion – Timothy R. Sampson – PNAS

“We demonstrate that components of a clustered, regularly interspaced, short palindromic repeats–CRISPR associated (CRISPR-Cas) system, a prokaryotic defense against viruses and foreign nucleic acid, act to regulate the permeability of the bacterial envelope, ultimately providing these cells with the capability to resist membrane damage caused by antibiotics. “

Extraction and amplification techniques

The Influence of DNA Extraction Procedure and Primer Set on the Bacterial Community Analysis by Pyrosequencing of Barcoded 16S rRNA Gene Amplicons – Ingo C. Starke – Molecular Biology International

“In this study, the effect of different DNA extraction procedures and primer sets on pyrosequencing results regarding the composition of bacterial communities in the ileum of piglets was investigated. “

Metagenomics general

Interpreting 16S metagenomic data without clustering to achieve sub-OTU resolution – Mikhail Tikhonov – ISME Journal

“We present a clustering-free approach to multi-sample Illumina data sets that can identify independent bacterial subpopulations regardless of the similarity of their 16S tag sequences. “

General Microbiology

Recovery of a Medieval Brucella melitensis Genome Using Shotgun Metagenomics – Gemma L. Kay – mBio

“We sequenced the metagenome of a calcified nodule from the skeleton of a 14th-century middle-aged male excavated from the medieval Sardinian settlement of Geridu. We obtained 6.5-fold coverage of a Brucella melitensis genome”

Review: The Ins and Outs of Bacterial Iron Metabolism – Elaine R. Frawley and Ferric C. Fang – Molecular Microbiology

“The recent discovery of putative iron efflux transporters in Salmonella enterica serovar Typhimurium is discussed in the context of cellular iron homeostasis.”

Genetic information transfer promotes cooperation in bacteria – Tatiana Dimitriu – PNAS

“Our experiments and models converge to show that when both cheating and cooperative genes are transferred, cooperators win against cheaters because transfer increases assortment among alleles, favoring cooperation.”

Challenges and Opportunities of Integrative Taxonomy for Research and Society – Taxonomic Research in the Era of OMICS Technologies (PDF) (Herausforderungen und Chancen der integrativen Taxonomie für Forschung und Gesellschaft) – Deutsche Akademie der Naturforscher Leopoldina e.V.

Microbiomes and metagenomes in need of professional classification – Rudolf Amann
The intestinal microbiome and human health: a new challenge for taxonomy of metagenomic data – Bärbel Stecher
Characterizing species boundaries and species histories in closely related fungi using comparative population genomic approaches – Eva H. Stukenbrock

The coming of age of microbial ecology – Ana E. Escalante and Silvia Pajares – Chapter in Open Access book: Frontiers in Ecology, Evolution and Complexity

“Despite major challenges, new technological advances in genomic sciences have prompted microbial ecology into a revolution in data generation that has allowed us to move beyond studies of single isolates to the study of entire microbial communities without reliance on culture-dependent methods.”

Review: The Dynamic Interactions between Salmonella and the Microbiota, within the Challenging Niche of the Gastrointestinal Tract – C. M. Anjam Khan – International Scholarly Research Notices

“This gastrointestinal pathogen not only faces the hostile defenses of the host’s immune system, but also faces fierce competition from the large and diverse community of microbiota for space and nutrients.”

Science and publishing

Is Social Media Saving Science? – Michael White – Pacific Standard

“Why do editors and expert reviewers, whose primary job is to vet manuscripts, miss major flaws that are so obvious to readers after the papers are published?”

Dr. Bik’s Picks

Effect of sleep deprivation on the human metabolome – Sarah K. Davies – PNAS

“Clear daily rhythms were observed in most metabolites, with 24 h wakefulness mainly reducing the amplitude of these rhythms.”

Comparison of five different RNA sources to examine the lactating bovine mammary gland transcriptome using RNA-Sequencing – Angela Cánovas – Nature Scientific Reports

“Our results provide a comparison between different sampling methods (invasive and non-invasive) to define the transcriptome of mammary gland tissue and milk cells.’

Superior time perception for lower musical pitch explains why bass-ranged instruments lay down musical rhythms – Michael J. Hove – PNAS

“Here, we show that, when two streams of tones are presented simultaneously, the brain better detects timing deviations in the lower-pitched than in the higher-pitched stream and that tapping synchronization to the tones is more influenced by the lower-pitched stream. “

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Non-human microbiome

Posted on July 8, 2014 by eliesbik

Microbiomes of frogs, kakapo birds, and very hot water springs. And a special on Ed DeLong.

Cow microbiome

Rumen Cellulosomics: Divergent Fiber-Degrading Strategies Revealed by Comparative Genome-Wide Analysis of Six Ruminococcal Strains – Bareket Dassa – PLOS ONE

“Here, we have used a bioinformatics-based approach to explore the cellulosome-related components of six genomes from two of the primary fiber-degrading bacteria in the rumen”

Reptile microbiome

Occurrence, Diversity, and Host Association of Intestinal Campylobacter, Arcobacter, and Helicobacter in Reptiles – Maarten J. Gilbert – PLOS ONE

“Based on PCR, Campylobacter, Arcobacter, and Helicobacter were detected in 69.3% of the reptiles; 82.5% of the chelonians, 63.8% of the lizards, and 58.0% of the snakes were positive for one or more of these genera.”

Amphibian microbiome

Tagging Frogs with Passive Integrated Transponders Causes Disruption of the Cutaneous Bacterial Community and Proliferation of Opportunistic Fungi – Rachael E. Antwis – Applied and Environmental Microbiology

“We find that PIT tagging causes a major disruption to the bacterial community associated with the skin of frogs (∼12-fold increase in abundance), as well as a concurrent proliferation in resident fungi (up to ∼200-fold increase).”

Bird microbiome

Influence of Hand Rearing and Bird Age on the Fecal Microbiota of the Critically Endangered Kakapo – David W. Waite – Applied and Environmental Microbiology

“Amplicon pyrosequencing revealed a juvenile fecal microbiota enriched with particular lactic acid bacteria compared to the microbiota of adults, although the overall community structure did not differ significantly among kakapos of different ages. “

Multilocus Sequence Typing Confirms Wild Birds as the Source of a Campylobacter Outbreak Associated with the Consumption of Raw Peas – Patrick S. L. Kwan – Applied and Environmental Microbiology

“Novel STs clustered closely with isolates typically associated with wild birds and the environment but distinct from lineages commonly seen in human infections. “

Sponge microbiome

In Situ Natural Product Discovery via an Artificial Marine Sponge – James J. La Clair – PLOS ONE

“Retrieving this artificial sponge from a tropical ecosystem after deployment for 320 hours afforded three actin–targeting jasplakinolide depsipeptides that had been discovered two decades earlier using traditional sponge specimen collection and isolation procedures.”

Water microbiology

Profile of Edward DeLong – Paul Gabrielsen – PNAS

“DeLong has learned that studying a reservoir of life as large and diverse as the ocean can lead to unexpected discoveries. “We’re continually being surprised,” he says.”

Handling Temperature Bursts Reaching 464°C: Different Microbial Strategies in the Sisters Peak Hydrothermal Chimney – Mirjam Perner – Applied and Environmental Microbiology

“The SP metagenome reveals considerable differences in the taxonomic composition from those of other hydrothermal vent and subsurface samples; these could be better explained by temperature than by other available abiotic parameters. “

Methanotrophic bacteria in warm geothermal spring sediments identified using stable isotope probing – Christine E. Sharp – FEMS Microbiology Ecology

“Quantitative (q)PCR of pmoA genes identified the position of the heavy (13C-labelled) DNA fractions in density gradients, and 16S rRNA gene pyrotag sequencing of the heavy fractions was performed to identify the active methanotrophs.”

Bacterial and archaeal communities in long-term contaminated surface and subsurface soil evaluated through co-extracted RNA and DNA – Anu Mikkonen – FEMS Microbiology Ecology

“Soil RNA and DNA were co-extracted along a contamination gradient at a landfarming field with aged crude oil contamination to investigate pollution-dependent differences in 16S rRNA and rRNA gene pools”

rpoD Gene Pyrosequencing for the Assessment of Pseudomonas Diversity in a Water Sample from the Woluwe River – David Sánchez – Applied and Environmental Microbiology

“Culture-independent methods consisted of cloning and pyrosequencing of a Pseudomonas rpoD amplicon from total DNA extracted from the same sample and amplified with selective rpoD gene primers. “

Influence of DNA Extraction Method, 16S rRNA Targeted Hypervariable Regions, and Sample Origin on Microbial Diversity Detected by 454 Pyrosequencing in Marine Chemosynthetic Ecosystems – Perrine Cruaud – Applied and Environmental Microbiology

“Thanks to statistical and diversity analyses as well as inference of operational taxonomic unit (OTU) networks, we show that (i) while DNA extraction methods do not seem to affect the results for some samples, they can lead to dramatic changes for others; and (ii) the choice of amplification and sequencing primers also considerably affects the microbial community detected in the samples.”

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Human microbiome digest, July 3

Posted on July 3, 2014 by eliesbik

Short chain fatty acids and gut microbiota, microbial eukaryotes in the human gut, Pseudomonas in stool, and a smelly Anaerococcus isolated from arm pits.

Gut microbiome

Adiposity, gut microbiota and faecal short chain fatty acids are linked in adult humans – J Fernandes – Nutrition & Diabetes

“Our objectives were to compare dietary intakes, faecal SCFA concentrations and gut microbial profiles in healthy lean (LN, BMIless than or equal to25) and overweight or obese (OWOB, BMI>25) participants.”

Ellagic Acid Metabolism by Human Gut Microbiota: Consistent Observation of Three Urolithin Phenotypes in Intervention Trials, Independent of Food Source, Age, and Health Status – Francisco A. Tomás-Barberán – Journal of Agricultural and Food Chemistry

“Interestingly, a higher percentage of phenotype B was observed in those volunteers with chronic illness (metabolic syndrome or colorectal cancer) associated with gut microbial imbalance (dysbiosis).”

Communities of microbial eukaryotes in the mammalian gut within the context of environmental eukaryotic diversity – Laura Wegener Parfrey – Frontiers in Microbiology

“We curated the SILVA ribosomal database to reflect current knowledge of eukaryotic taxonomy and employ it as a phylogenetic framework to compare eukaryotic diversity across environment. We show that adults from the non-western population harbor a diverse community of protists, and diversity in the human gut is comparable to that in other mammals.”

Faecal carriage of Pseudomonas aeruginosa in healthy humans: antimicrobial susceptibility and global genetic lineages – Vanesa Estepa – FEMS Microbiology Ecology

“The aim of this study was to analyse the Pseudomonas aeruginosa faecal carriage rate in 98 healthy humans and to perform the phenotypic and genotypic characterization of recovered isolates. The genetic relatedness among the isolates was analysed by pulsed-field gel electrophoresis and multilocus sequence typing that was compared with worldwide epidemic clones. “

Helminth Infections, Type-2 Immune Response, and Metabolic Syndrome – Aprilianto E. Wiria – PLOS Pathogens

“Are Helminth Infections Associated with Metabolic Syndrome?”

Skin microbiome

A newly discovered Anaerococcus strain responsible for axillary odor and a new axillary odor inhibitor, pentagalloyl glucose – Takayoshi Fujii – FEMS Microbiology Ecology

“We aimed to investigate anaerobic bacteria that had not been previously studied for axillary odor formation. A new anaerobic Anaerococcus sp. A20, that releases 3-hydroxy-3-metyl-hexanoic acid (HMHA, main component of axillary odor) from its glutamyl conjugate, was discovered from axillary isolates. “

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