Download or read book The Lifestyles of Viruses in the Sunlit Ocean Revealed Through Isolation Genomics and Infection Dynamics written by Michael Curtis Grier Carlson and published by . This book was released on 2015 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the sunlit ocean, heterotrophic and photosynthetic microbes are prey for earth’s most abundant predators. Viruses are regulators of microbial communities, terminating phytoplankton blooms, altering biogeochemical cycles through cell lysis, and driving evolution through horizontal gene transfer. However, viral infection in the marine environment is unquantified. My research seeks understand infection in the ocean through a model marine host-virus system and through coupled studies of virus diversity and gene expression in the field. The model host were diatoms, which contribute to global biogeochemical cycles, form the base of coastal food webs, and account for approximately one fifth of global photosynthesis. The first chapter details the isolation and characterization of a novel virus that infects the toxigenic diatom Pseudo-nitzschia multiseries. The virus had the largest genome of any single stranded DNA (ssDNA) virus isolated, with a gene complement atypical for ssDNA viruses. The virus had a broad host range, infecting hosts from the distantly related centric and pennate diatom groups. The infection dynamics were host dependent, varying orders of magnitude in burst size from 220 to 9,300 viruses cell-1 and between 12-60 hours in latent period. The second chapter assesses the interactions of numerous Pseudo-nitzschia hosts and natural viral communities by isolating 41 new Pseudo-nitzschia and challenging them with 20 environmental virus samples. Pseudo-nitzschia cultures were infected in 8% of the crosses. Viral infectivity intensified during the summer when the most permissive hosts were isolated, and viral communities were most infective of co-occurring hosts. Genotyping of the Pseudo-nitzschia cultures revealed subgroups of genetically identical hosts that were differentially infected suggesting that diatom diversity is an impediment to viral termination of diatom blooms. In the third chapter, viral infection was measured by comparing viral metagenomes to host metatranscriptomes on a coastal to open ocean transect. A small fraction of the total viral population was actively infecting. Viral groups such as the archeoviruses, virophage, and ssDNA viruses had different distributions and were differentially enriched in particle-associated and free-living metatranscriptomes. Viral expression was not correlated with virus to host ratios suggesting that microbial populations were at different stages of infection. Finally, auxiliary metabolic genes in Synechococcus phage were differentially expressed between stations despite similar community composition suggesting that auxiliary genes help viruses succeed under certain conditions. By linking culture based and culture-independent explorations of viral ecology, this research highlights the diversity of viruses in the ocean and the lifestyles that have made them successful.
Download or read book Viruses Essential Agents of Life written by Günther Witzany and published by Springer Science & Business Media. This book was released on 2012-11-13 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: A renaissance of virus research is taking centre stage in biology. Empirical data from the last decade indicate the important roles of viruses, both in the evolution of all life and as symbionts of host organisms. There is increasing evidence that all cellular life is colonized by exogenous and/or endogenous viruses in a non-lytic but persistent lifestyle. Viruses and viral parts form the most numerous genetic matter on this planet.
Download or read book Origin and Evolution of Viruses written by Esteban Domingo and published by Elsevier. This book was released on 2008-06-23 with total page 573 pages. Available in PDF, EPUB and Kindle. Book excerpt: New viral diseases are emerging continuously. Viruses adapt to new environments at astounding rates. Genetic variability of viruses jeopardizes vaccine efficacy. For many viruses mutants resistant to antiviral agents or host immune responses arise readily, for example, with HIV and influenza. These variations are all of utmost importance for human and animal health as they have prevented us from controlling these epidemic pathogens. This book focuses on the mechanisms that viruses use to evolve, survive and cause disease in their hosts. Covering human, animal, plant and bacterial viruses, it provides both the basic foundations for the evolutionary dynamics of viruses and specific examples of emerging diseases. - NEW - methods to establish relationships among viruses and the mechanisms that affect virus evolution - UNIQUE - combines theoretical concepts in evolution with detailed analyses of the evolution of important virus groups - SPECIFIC - Bacterial, plant, animal and human viruses are compared regarding their interation with their hosts
Download or read book Viruses of Microorganisms written by Paul Hyman and published by Caister Academic Press Limited. This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Viruses of microorganisms (VoMs) are the world's most abundant viruses. There are viruses for every known microbe and VoMs are usually described in terms of their hosts as algal viruses, archaeal viruses, bacteriophages, virophages, fungal viruses and protozoan viruses. A key feature of infection by VoMs is that they often kill the host. This allows VoMs to play a key role in modifying microbial communities and in nutrient cycling in various environments. When the host is itself a pathogen then VoMs may be exploited to create novel antimicrobial strategies. In fact phage therapy for a variety of antibiotic-resistant bacterial pathogens is currently at the clinical trial stage. When they don't kill the host, VoMs can still play important roles in the ecology and evolution of their hosts via various forms of virus-mediated horizontal gene transfer. Important in nature, these processes have also been used in the laboratory in genetic engineering techniques. In this multi-authored volume, international experts review the genomics, ecology, comparative biology and biotechnological applications of these fascinating viruses. Chapters have extensive reference sections that should encourage readers to pursue each subject in greater detail. This unique reference volume is a must-read for everyone working with VoMs, from the PhD student to the experienced scientist, in academia, the pharmaceutical or biotechnology industries and working in clinical environments.
Download or read book The Social Biology of Microbial Communities written by Institute of Medicine and published by National Academies Press. This book was released on 2013-01-10 with total page 633 pages. Available in PDF, EPUB and Kindle. Book excerpt: Beginning with the germ theory of disease in the 19th century and extending through most of the 20th century, microbes were believed to live their lives as solitary, unicellular, disease-causing organisms . This perception stemmed from the focus of most investigators on organisms that could be grown in the laboratory as cellular monocultures, often dispersed in liquid, and under ambient conditions of temperature, lighting, and humidity. Most such inquiries were designed to identify microbial pathogens by satisfying Koch's postulates.3 This pathogen-centric approach to the study of microorganisms produced a metaphorical "war" against these microbial invaders waged with antibiotic therapies, while simultaneously obscuring the dynamic relationships that exist among and between host organisms and their associated microorganisms-only a tiny fraction of which act as pathogens. Despite their obvious importance, very little is actually known about the processes and factors that influence the assembly, function, and stability of microbial communities. Gaining this knowledge will require a seismic shift away from the study of individual microbes in isolation to inquiries into the nature of diverse and often complex microbial communities, the forces that shape them, and their relationships with other communities and organisms, including their multicellular hosts. On March 6 and 7, 2012, the Institute of Medicine's (IOM's) Forum on Microbial Threats hosted a public workshop to explore the emerging science of the "social biology" of microbial communities. Workshop presentations and discussions embraced a wide spectrum of topics, experimental systems, and theoretical perspectives representative of the current, multifaceted exploration of the microbial frontier. Participants discussed ecological, evolutionary, and genetic factors contributing to the assembly, function, and stability of microbial communities; how microbial communities adapt and respond to environmental stimuli; theoretical and experimental approaches to advance this nascent field; and potential applications of knowledge gained from the study of microbial communities for the improvement of human, animal, plant, and ecosystem health and toward a deeper understanding of microbial diversity and evolution. The Social Biology of Microbial Communities: Workshop Summary further explains the happenings of the workshop.
Download or read book Mycorrhiza Manual written by Ajit Varma and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 539 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mycorrhiza - symbiotic associations between plant roots and fungi - play a major role in many fundamental plant functions such as mineral nutrition or stress resistance. As the link between plants and the soil, mycorrhiza are now of great interest for developing new strategies in sustainable agriculture. Since they allow a decreased use of fertilizer and pesticides, negative impacts on the environment can be minimized. With contributions from renowned international scientists, this manual offers a great variety of practical protocols for analyzing mycorrhiza, including the latest molecular, biochemical, genetical, and physiological techniques.
Download or read book Studies in Viral Ecology Volume 1 written by Christon J. Hurst and published by John Wiley & Sons. This book was released on 2011-06-20 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explains the ecology of viruses by examining their interactive dynamics with their hosting species (in this volume, in microbes and plants), including the types of transmission cycles that viruses have evolved encompassing principal and alternate hosts, vehicles, and vectoring species. Examining virology from an organismal biology approach and focusing on the concept that viral infections represent areas of overlap in the ecologies of the involved species, Viral Ecology is essential for students and professionals who either may be non-virologists or virologists whose previous familiarity has been very specialized.
Download or read book Flexible Viruses written by Vladimir Uversky and published by John Wiley & Sons. This book was released on 2012-02-07 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides up-to-date information on experimental and computational characterization of the structural and functional properties of viral proteins, which are widely involved in regulatory and signaling processes. With chapters by leading research groups, it features current information on the structural and functional roles of intrinsic disorders in viral proteomes. It systematically addresses the measles, HIV, influenza, potato virus, forest virus, bovine virus, hepatitis, and rotavirus as well as viral genomics. After analyzing the unique features of each class of viral proteins, future directions for research and disease management are presented.
Download or read book Phage Therapy Past Present and Future written by Stephen T. Abedon and published by Frontiers Media SA. This book was released on 2017-09-05 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: Historically, the first observation of a transmissible lytic agent that is specifically active against a bacterium (Bacillus anthracis) was by a Russian microbiologist Nikolay Gamaleya in 1898. At that time, however, it was too early to make a connection to another discovery made by Dmitri Ivanovsky in 1892 and Martinus Beijerinck in 1898 on a non-bacterial pathogen infecting tobacco plants. Thus the viral world was discovered in two of the three domains of life, and our current understanding is that viruses represent the most abundant biological entities on the planet. The potential of bacteriophages for infection treatment have been recognized after the discoveries by Frederick Twort and Felix d’Hérelle in 1915 and 1917. Subsequent phage therapy developments, however, have been overshadowed by the remarkable success of antibiotics in infection control and treatment, and phage therapy research and development persisted mostly in the former Soviet Union countries, Russia and Georgia, as well as in France and Poland. The dramatic rise of antibiotic resistance and especially of multi-drug resistance among human and animal bacterial pathogens, however, challenged the position of antibiotics as a single most important pillar for infection control and treatment. Thus there is a renewed interest in phage therapy as a possible additive/alternative therapy, especially for the infections that resist routine antibiotic treatment. The basis for the revival of phage therapy is affected by a number of issues that need to be resolved before it can enter the arena, which is traditionally reserved for antibiotics. Probably the most important is the regulatory issue: How should phage therapy be regulated? Similarly to drugs? Then the co-evolving nature of phage-bacterial host relationship will be a major hurdle for the production of consistent phage formulae. Or should we resort to the phage products such as lysins and the corresponding engineered versions in order to have accurate and consistent delivery doses? We still have very limited knowledge about the pharmacodynamics of phage therapy. More data, obtained in animal models, are necessary to evaluate the phage therapy efficiency compared, for example, to antibiotics. Another aspect is the safety of phage therapy. How do phages interact with the immune system and to what costs, or benefits? What are the risks, in the course of phage therapy, of transduction of undesirable properties such as virulence or antibiotic resistance genes? How frequent is the development of bacterial host resistance during phage therapy? Understanding these and many other aspects of phage therapy, basic and applied, is the main subject of this Topic.
Download or read book Gene Drives on the Horizon written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2016-08-28 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research on gene drive systems is rapidly advancing. Many proposed applications of gene drive research aim to solve environmental and public health challenges, including the reduction of poverty and the burden of vector-borne diseases, such as malaria and dengue, which disproportionately impact low and middle income countries. However, due to their intrinsic qualities of rapid spread and irreversibility, gene drive systems raise many questions with respect to their safety relative to public and environmental health. Because gene drive systems are designed to alter the environments we share in ways that will be hard to anticipate and impossible to completely roll back, questions about the ethics surrounding use of this research are complex and will require very careful exploration. Gene Drives on the Horizon outlines the state of knowledge relative to the science, ethics, public engagement, and risk assessment as they pertain to research directions of gene drive systems and governance of the research process. This report offers principles for responsible practices of gene drive research and related applications for use by investigators, their institutions, the research funders, and regulators.
Download or read book Molecular Epidemiology written by Paul A. Schulte and published by Academic Press. This book was released on 2012-12-02 with total page 609 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book will serve as a primer for both laboratory and field scientists who are shaping the emerging field of molecular epidemiology. Molecular epidemiology utilizes the same paradigm as traditional epidemiology but uses biological markers to identify exposure, disease or susceptibility. Schulte and Perera present the epidemiologic methods pertinent to biological markers. The book is also designed to enumerate the considerations necessary for valid field research and provide a resource on the salient and subtle features of biological indicators.
Download or read book Global Trends 2040 written by National Intelligence Council and published by Cosimo Reports. This book was released on 2021-03 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The ongoing COVID-19 pandemic marks the most significant, singular global disruption since World War II, with health, economic, political, and security implications that will ripple for years to come." -Global Trends 2040 (2021) Global Trends 2040-A More Contested World (2021), released by the US National Intelligence Council, is the latest report in its series of reports starting in 1997 about megatrends and the world's future. This report, strongly influenced by the COVID-19 pandemic, paints a bleak picture of the future and describes a contested, fragmented and turbulent world. It specifically discusses the four main trends that will shape tomorrow's world: - Demographics-by 2040, 1.4 billion people will be added mostly in Africa and South Asia. - Economics-increased government debt and concentrated economic power will escalate problems for the poor and middleclass. - Climate-a hotter world will increase water, food, and health insecurity. - Technology-the emergence of new technologies could both solve and cause problems for human life. Students of trends, policymakers, entrepreneurs, academics, journalists and anyone eager for a glimpse into the next decades, will find this report, with colored graphs, essential reading.
Download or read book Archaeal Virus host Interactions written by Tessa Quax and published by . This book was released on 2013 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work presented in this thesis provides novel insights in several aspects of the molecular biology of Archaea, Bacteria and their viruses. The archaeal virus Sulfolobus islandicus rod-shaped virus 2 (SIRV2), has a remarkable infection cycle. Infection with SIRV2 results in the formation of large virus associated pyramids (VAPs) on the host cell surface. The pyramids open during the final step of the infection cycle, to allow the release of virions. This virus release mechanism is unique. The VAPs are formed by self-assembly of one virus-encoded protein, PVAP. VAPs exist as discrete particles, and are baseless pyramids with heptagonal perimeter. The assembly process of the VAPs is described, based on cryo-electron tomography experiments and mutational analysis of PVAP. VAPs consists of two layers of which the outer one continuous with the cell membrane. PVAP expression in bacterial and eukaryotic cells resulted in VAP formation on nearly all membranes, demonstrating that PVAP serves as a universal membrane remodeling system, which might be exploited for biotechnological purposes. Whole transcriptome sequencing allowed determination of a global map of virus and host gene expression during the infection cycle. Host genes involved in anti-viral defence are activated (i.e. CRISPR-Cas and toxin anti-toxin systems). The multi-subunit protein complexes crucial for CRISPR anti-viral defence have an uneven stoichiometry and are encoded on operons. It is shown that differential translation is a key determinant of modulated expression of genes clustered in operons and that codon bias generally is the best in silico indicator of unequal protein production.
Download or read book Genome Mapping and Genomics in Animal Associated Microbes written by Vishvanath Nene and published by Springer Science & Business Media. This book was released on 2008-11-24 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: Achievements and progress in genome mapping and the genomics of microbes supersede by far those for higher plants and animals, in part due to their enormous economic implication but also smaller genome size. In the post-genomic era, whole genome sequences of animal-associated microbes are providing clues to depicting the genetic basis of the complex host-pathogen relationships and the evolution of parasitism; and to improving methods of controlling pathogens. This volume focuses on a globally important group of intracellular prokaryotic pathogens which affect livestock animals. These include Brucella, Mycobacterium, Anaplasma and Ehrlichia, as well as the protozoan pathogens Cryptosporidium and Theileria, for which genome sequence data is available. Insights from comparative genomics of the microbes described provide clues to the adaptation involved in host-microbe interactions, as well as resources potentially useful for application in future research and product development.
Download or read book The Lichen Symbiosis written by Vernon Ahmadjian and published by John Wiley & Sons. This book was released on 1993-08-30 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Not only an invaluable reference to what is known about lichen bionts and their interactions but also a guide to future studies. Compares various aspects of lichen-forming bionts with those of other fungi, algae and cyanobacteria. Features in-depth descriptions of culture methods. Includes over 1000 references representing a selective sampling in such subjects as air pollution, photosynthesis and respiration.
Download or read book Encyclopedia of Infectious Diseases written by Michel Tibayrenc and published by John Wiley & Sons. This book was released on 2007-07-31 with total page 807 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discover how the application of novel multidisciplinary, integrative approaches and technologies are dramatically changing our understanding of the pathogenesis of infectious diseases and their treatments. Each article presents the state of the science, with a strong emphasis on new and emerging medical applications. The Encyclopedia of Infectious Diseases is organized into five parts. The first part examines current threats such as AIDS, malaria, SARS, and influenza. The second part addresses the evolution of pathogens and the relationship between human genetic diversity and the spread of infectious diseases. The next two parts highlight the most promising uses of molecular identification, vector control, satellite detection, surveillance, modeling, and high-throughput technologies. The final part explores specialized topics of current concern, including bioterrorism, world market and infectious diseases, and antibiotics for public health. Each article is written by one or more leading experts in the field of infectious diseases. These experts place all the latest findings from various disciplines in context, helping readers understand what is currently known, what the next generation of breakthroughs is likely to be, and where more research is needed. Several features facilitate research and deepen readers' understanding of infectious diseases: Illustrations help readers understand the pathogenesis and diagnosis of infectious diseases Lists of Web resources serve as a gateway to important research centers, government agencies, and other sources of information from around the world Information boxes highlight basic principles and specialized terminology International contributions offer perspectives on how infectious diseases are viewed by different cultures A special chapter discusses the representation of infectious diseases in art With its multidisciplinary approach, this encyclopedia helps point researchers in new promising directions and helps health professionals better understand the nature and treatment of infectious diseases.
Download or read book Molecular Biology and Pathogenicity of Mycoplasmas written by Shmuel Razin and published by Springer Science & Business Media. This book was released on 2007-05-08 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt: was the result of the efforts of Robert Cleverdon. The rapidly developing discipline of molecular biology and the rapidly expanding knowledge of the PPLO were brought together at this meeting. In addition to the PPLO specialists, the conference invited Julius Marmur to compare PPLO DNA to DNA of other organisms; David Garfinkel, who was one of the first to develop computer models of metabolism; Cyrus Levinthal to talk about coding; and Henry Quastler to discuss information theory constraints on very small cells. The conference was an announcement of the role of PPLO in the fundamental understanding of molecular biology. Looking back 40-some years to the Connecticut meeting, it was a rather bold enterprise. The meeting was international and inter-disciplinary and began a series of important collaborations with influences resonating down to the present. If I may be allowed a personal remark, it was where I first met Shmuel Razin, who has been a leading figure in the emerging mycoplasma research and a good friend. This present volume is in some ways the fulfillment of the promise of that early meeting. It is an example of the collaborative work of scientists in building an understanding of fundamental aspects of biology.
