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Moran Nunberg, Nir Werbner, Hadar Neuman, Marina Bersudsky, Alex Braiman, Moshe Ben-Shoshan, Meirav Ben Izhak, Yoram Louzoun, Ron N Apte, Elena Voronov, Omry Koren
Inflammatory bowel diseases (IBD) are a group of chronic inflammatory disorders of the intestine, with as-yet-unclear etiologies, affecting over a million people in the United States alone. With the emergence of microbiome research, numerous studies have shown a connection between shifts in the gut microbiota composition (dysbiosis) and patterns of IBD development. In a previous study, we showed that interleukin 1α (IL-1α) deficiency in IL-1α knockout (KO) mice results in moderate dextran sodium sulfate (DSS)-induced colitis compared to that of wild-type (WT) mice, characterized by reduced inflammation and complete healing, as shown by parameters of weight loss, disease activity index (DAI) score, histology, and cytokine expression...
May 2018: MSystems
Gabriel A Al-Ghalith, Benjamin Hillmann, Kaiwei Ang, Robin Shields-Cutler, Dan Knights
Next-generation sequencing technology is of great importance for many biological disciplines; however, due to technical and biological limitations, the short DNA sequences produced by modern sequencers require numerous quality control (QC) measures to reduce errors, remove technical contaminants, or merge paired-end reads together into longer or higher-quality contigs. Many tools for each step exist, but choosing the appropriate methods and usage parameters can be challenging because the parameterization of each step depends on the particularities of the sequencing technology used, the type of samples being analyzed, and the stochasticity of the instrumentation and sample preparation...
May 2018: MSystems
Owen Cronin, Wiley Barton, Peter Skuse, Nicholas C Penney, Isabel Garcia-Perez, Eileen F Murphy, Trevor Woods, Helena Nugent, Aine Fanning, Silvia Melgar, Eanna C Falvey, Elaine Holmes, Paul D Cotter, Orla O'Sullivan, Michael G Molloy, Fergus Shanahan
Many components of modern living exert influence on the resident intestinal microbiota of humans with resultant impact on host health. For example, exercise-associated changes in the diversity, composition, and functional profiles of microbial populations in the gut have been described in cross-sectional studies of habitual athletes. However, this relationship is also affected by changes in diet, such as changes in dietary and supplementary protein consumption, that coincide with exercise. To determine whether increasing physical activity and/or increased protein intake modulates gut microbial composition and function, we prospectively challenged healthy but sedentary adults with a short-term exercise regime, with and without concurrent daily whey protein consumption...
May 2018: MSystems
Lauren E Brooks, Sabah Ul-Hasan, Benjamin K Chan, Mark J Sistrom
Increasing rates of antibiotic-resistant bacterial infection are one of the most pressing contemporary global health concerns. The ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) have been identified as the leading global cause of multidrug-resistant bacterial infections, and overexpression of multidrug efflux (MEX) transport systems has been identified as one of the most critical mechanisms facilitating the evolution of multidrug resistance in ESKAPE pathogens...
May 2018: MSystems
Stefan Janssen, Daniel McDonald, Antonio Gonzalez, Jose A Navas-Molina, Lingjing Jiang, Zhenjiang Zech Xu, Kevin Winker, Deborah M Kado, Eric Orwoll, Mark Manary, Siavash Mirarab, Rob Knight
Recent algorithmic advances in amplicon-based microbiome studies enable the inference of exact amplicon sequence fragments. These new methods enable the investigation of sub-operational taxonomic units (sOTU) by removing erroneous sequences. However, short (e.g., 150-nucleotide [nt]) DNA sequence fragments do not contain sufficient phylogenetic signal to reproduce a reasonable tree, introducing a barrier in the utilization of critical phylogenetically aware metrics such as Faith's PD or UniFrac. Although fragment insertion methods do exist, those methods have not been tested for sOTUs from high-throughput amplicon studies in insertions against a broad reference phylogeny...
May 2018: MSystems
Weipeng Zhang, Ren-Mao Tian, Jin Sun, Salim Bougouffa, Wei Ding, Lin Cai, Yi Lan, Haoya Tong, Yongxin Li, Alan J Jamieson, Vladimir B Bajic, Jeffrey C Drazen, Douglas Bartlett, Pei-Yuan Qian
Amphipods are the dominant scavenging metazoan species in the Mariana Trench, the deepest known point in Earth's oceans. Here the gut microbiota of the amphipod Hirondellea gigas collected from the Challenger and Sirena Deeps of the Mariana Trench were investigated. The 11 amphipod individuals included for analyses were dominated by Psychromonas , of which a nearly complete genome was successfully recovered (designated CDP1). Compared with previously reported free-living Psychromonas strains, CDP1 has a highly reduced genome...
May 2018: MSystems
Luis M Rodriguez-R, Santosh Gunturu, James M Tiedje, James R Cole, Konstantinos T Konstantinidis
Estimations of microbial community diversity based on metagenomic data sets are affected, often to an unknown degree, by biases derived from insufficient coverage and reference database-dependent estimations of diversity. For instance, the completeness of reference databases cannot be generally estimated since it depends on the extant diversity sampled to date, which, with the exception of a few habitats such as the human gut, remains severely undersampled. Further, estimation of the degree of coverage of a microbial community by a metagenomic data set is prohibitively time-consuming for large data sets, and coverage values may not be directly comparable between data sets obtained with different sequencing technologies...
May 2018: MSystems
Jack A Gilbert, Janet K Jansson, Rob Knight
No abstract text is available yet for this article.
May 2018: MSystems
Vincent Baby, Jean-Christophe Lachance, Jules Gagnon, Jean-François Lucier, Dominick Matteau, Tom Knight, Sébastien Rodrigue
The creation and comparison of minimal genomes will help better define the most fundamental mechanisms supporting life. Mesoplasma florum is a near-minimal, fast-growing, nonpathogenic bacterium potentially amenable to genome reduction efforts. In a comparative genomic study of 13 M. florum strains, including 11 newly sequenced genomes, we have identified the core genome and open pangenome of this species. Our results show that all of the strains have approximately 80% of their gene content in common. Of the remaining 20%, 17% of the genes were found in multiple strains and 3% were unique to any given strain...
May 2018: MSystems
Yi-Chun Yeh, David M Needham, Ella T Sieradzki, Jed A Fuhrman
Mock communities have been used in microbiome method development to help estimate biases introduced in PCR amplification and sequencing and to optimize pipeline outputs. Nevertheless, the strong value of routine mock community analysis beyond initial method development is rarely, if ever, considered. Here we report that our routine use of mock communities as internal standards allowed us to discover highly aberrant and strong biases in the relative proportions of multiple taxa in a single Illumina HiSeqPE250 run...
May 2018: MSystems
Carolyn A Brotherton, Marnix H Medema, E Peter Greenberg
Microbes are a major source of antibiotics, pharmaceuticals, and other bioactive compounds. The production of many specialized microbial metabolites is encoded in biosynthetic gene clusters (BGCs). A challenge associated with natural product discovery is that many BGCs are not expressed under laboratory growth conditions. Here we report a genome-mining approach to discover BGCs with luxR -type quorum sensing (QS) genes, which code for regulatory proteins that control gene expression. Our results show that BGCs linked to genes coding for LuxR-like proteins are widespread in Proteobacteria ...
May 2018: MSystems
Eugen Bauer, Ines Thiele
An important hallmark of the human gut microbiota is its species diversity and complexity. Various diseases have been associated with a decreased diversity leading to reduced metabolic functionalities. Common approaches to investigate the human microbiota include high-throughput sequencing with subsequent correlative analyses. However, to understand the ecology of the human gut microbiota and consequently design novel treatments for diseases, it is important to represent the different interactions between microbes with their associated metabolites...
May 2018: MSystems
Kathy N Lam, Eric C Martens, Trevor C Charles
Functional metagenomics is a powerful method that allows the isolation of genes whose role may not have been predicted from DNA sequence. In this approach, first, environmental DNA is cloned to generate metagenomic libraries that are maintained in Escherichia coli, and second, the cloned DNA is screened for activities of interest. Typically, functional screens are carried out using E. coli as a surrogate host, although there likely exist barriers to gene expression, such as lack of recognition of native promoters...
May 2018: MSystems
Brett L Mellbye, Andrew T Giguere, Ganti S Murthy, Peter J Bottomley, Luis A Sayavedra-Soto, Frank W R Chaplen
Nitrification, the aerobic oxidation of ammonia to nitrate via nitrite, emits nitrogen (N) oxide gases (NO, NO2 , and N2 O), which are potentially hazardous compounds that contribute to global warming. To better understand the dynamics of nitrification-derived N oxide production, we conducted culturing experiments and used an integrative genome-scale, constraint-based approach to model N oxide gas sources and sinks during complete nitrification in an aerobic coculture of two model nitrifying bacteria, the ammonia-oxidizing bacterium Nitrosomonas europaea and the nitrite-oxidizing bacterium Nitrobacter winogradskyi ...
May 2018: MSystems
Ursula M McCormack, Tânia Curião, Toby Wilkinson, Barbara U Metzler-Zebeli, Henry Reyer, Tomas Ryan, Julia A Calderon-Diaz, Fiona Crispie, Paul D Cotter, Christopher J Creevey, Gillian E Gardiner, Peadar G Lawlor
Previous studies suggest a link between intestinal microbiota and porcine feed efficiency (FE). Therefore, we investigated whether fecal microbiota transplantation (FMT) in sows and/or neonatal offspring, using inocula derived from highly feed-efficient pigs, could improve offspring FE. Pregnant sows were assigned to control or FMT treatments and the subsequent offspring to control treatment, FMT once (at birth), or FMT four times (between birth and weaning). FMT altered sow fecal and colostrum microbiota compositions and resulted in lighter offspring body weight at 70 and 155 days of age when administered to sows and/or offspring...
May 2018: MSystems
Jeremiah J Minich, Qiyun Zhu, Stefan Janssen, Ryan Hendrickson, Amnon Amir, Russ Vetter, John Hyde, Megan M Doty, Kristina Stillwell, James Benardini, Jae H Kim, Eric E Allen, Kasthuri Venkateswaran, Rob Knight
Microbiome analyses of low-biomass samples are challenging because of contamination and inefficiencies, leading many investigators to employ low-throughput methods with minimal controls. We developed a new automated protocol, KatharoSeq (from the Greek katharos [clean]), that outperforms single-tube extractions while processing at least five times as fast. KatharoSeq incorporates positive and negative controls to reveal the whole bacterial community from inputs of as few as 50 cells and correctly identifies 90...
May 2018: MSystems
A Prieto, M Bernabeu, S Aznar, S Ruiz-Cruz, A Bravo, M H Queiroz, A Juárez
Bacterial genomes sometimes contain genes that code for homologues of global regulators, the function of which is unclear. In members of the family Enterobacteriaceae , cells express the global regulator H-NS and its paralogue StpA. In Escherichia coli , out of providing a molecular backup for H-NS, the role of StpA is poorly characterized. The enteroaggregative E. coli strain 042 carries, in addition to the hns and stpA genes, a third gene encoding an hns paralogue ( hns2 ). We present in this paper information about its biological function...
May 2018: MSystems
Tonya L Ward, Maria Gloria Dominguez-Bello, Tim Heisel, Gabriel Al-Ghalith, Dan Knights, Cheryl A Gale
With the advent of next-generation sequencing and microbial community characterization, we are beginning to understand the key factors that shape early-life microbial colonization and associated health outcomes. Studies characterizing infant microbial colonization have focused mostly on bacteria in the microbiome and have largely neglected fungi (the mycobiome), despite their relevance to mucosal infections in healthy infants. In this pilot study, we characterized the skin, oral, and anal mycobiomes of infants over the first month of life ( n = 17) and the anal and vaginal mycobiomes of mothers ( n = 16) by internal transcribed spacer 2 (ITS2) amplicon sequencing...
May 2018: MSystems
James C Stegen
To improve predictions of ecosystem function in future environments, we need to integrate the ecological and environmental histories experienced by microbial communities with hydrobiogeochemistry across scales. A key issue is whether we can derive generalizable scaling relationships that describe this multiscale integration. There is a strong foundation for addressing these challenges. We have the ability to infer ecological history with null models and reveal impacts of environmental history through laboratory and field experimentation...
March 2018: MSystems
Cauã Antunes Westmann, María-Eugenia Guazzaroni, Rafael Silva-Rocha
Engineering microbial systems allows the generation of new technologies having significant impact in the biotechnological industry and on human health. In the past few years, several synthetic biology approaches have been implemented in bacteria to allow precise engineering of novel regulatory circuits for several applications. The advent of high-throughput technologies and clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9-based DNA editing techniques have been pivotal in this process. Yet, despite the tremendous advances experienced recently, there are still a number of bottlenecks that need to be overcome in order to generate high-performance redesigned living machines, and the use of novel computer-aided approaches would be essential for this task...
March 2018: MSystems
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