DOCSLIB.ORG

Mars Sample Return Backward Contamination – Strategic Advice and Requirements Report from the ESF-ESSC Study Group on MSR Planetary Protection Requirements

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Mars Sample Return Backward Contamination – Strategic Advice and Requirements Report from the ESF-ESSC Study Group on MSR Planetary Protection Requirements Mars Sample Return backward contamination – Strategic advice and requirements Report from the ESF-ESSC Study Group on MSR Planetary Protection Requirements. European Science Foundation (ESF) European Space Sciences Committee (ESSC) The European Science Foundation (ESF) is an The European Space Sciences Committee (ESSC), independent, non-governmental organisation, the established in 1975, grew from the need to give members of which are 72 national funding agencies, European space scientists a voice in the space arena research performing agencies and academies from 30 at a time when successive US space science missions countries. and NASA’s Apollo missions dominated space The strength of ESF lies in its influential membership research. More than 35 years later, the ESSC actively and in its ability to bring together the different domains collaborates with the European Space Agency (ESA), of European science in order to meet the challenges of the European Commission, national space agencies the future. and the ESF Member Organisations. This has made Since its establishment in 1974, ESF, which has its ESSC a reference name in space sciences within headquarters in Strasbourg with offices in Brussels Europe. and Ostend, has assembled a host of organisations The mission of the ESSC today is to provide an that span all disciplines of science, to create a independent forum for scientists to debate space common platform for cross-border cooperation in sciences issues. The ESSC is represented ex officio Europe. in all ESA’s scientific advisory bodies, in ESA’s High- ESF is dedicated to promoting collaboration in level Science Policy Advisory Committee advising scientific research and in funding of research and its Director General, it has members in the EC’s FP7 science policy across Europe. Through its activities space advisory group, and it has observer status in and instruments, ESF has made major contributions to ESA’s Ministerial Council. At the international level, science in a global context. ESF covers the following ESSC maintains strong relationships with the National scientific domains: Humanities, Life, Earth and Research Council’s (NRC) Space Studies Board in the Environmental Sciences, Medical Sciences, Physical US. and Engineering Sciences, Social Sciences, Marine The ESSC is the European Science Foundation’s (ESF) Sciences, Materials Science and Engineering, Nuclear Expert Committee on space sciences and the ESF’s Physics, Polar Sciences, Radio Astronomy, Space interface with the European space community. Sciences. www.esf.org/essc www.esf.org The European Science Foundation hosts six Expert Authors Boards and Committees: Walter Ammann, John Barros, Allan Bennett, • The European Space Sciences Committee (ESSC) Jim Bridges, Joseph Fragola, Armel Kerrest, • The Nuclear Physics European Collaboration Karina Marshall-Bowman, Hervé Raoul, Petra Rettberg, Committee (NuPECC) John Rummel, Mika Salminen, Erko Stackebrandt, • The Marine Board-ESF (MB-ESF) Nicolas Walter • The European Polar Board (EPB) • The Committee on Radio Astronomy Frequencies (CRAF) ESF Support Staff • The Materials Science and Engineering Expert Committee (MatSEEC) Nicolas Walter, Senior Science Officer Karina Marshall-Bowman, Junior Science Officer In the statutory review of the Expert Boards Johanne Martinez-Schmitt, Administrator and Committees conducted in 2011, the Review Panel concluded unanimously that all Boards and Committees provide multidisciplinary scientific Contact services in the European and in some cases global framework that are indispensable for Europe’s Nicolas Walter scientific landscape, and therefore confirmed the need Senior Science Officer for their continuation. Physical, Engineering and Space Sciences Unit The largely autonomous Expert Boards and Tel: +33 (0)3 88 76 71 66 Committees are vitally important to provide in-depth Email: [email protected] and focused scientific expertise, targeted scientific and policy advice, and to initiate strategic developments in areas of research, infrastructure, environment and society in Europe. Cover picture: ISBN: 978-2-918428-67-1 European Space Agency Printing: Ireg – Strasbourg July 2012 Contents Foreword: Mission Statement 3 1. Mars Sample Return Mission and planetary protection – background 5 1.1 Planetary protection regulatory framework 5 1.2 Mars Sample Return Mission concept 6 1.3 Sterilisation: concept, methods and limitations 7 1.4 Summary of advice from past committees 9 2. From remote exploration to returning samples 10 2.1 New missions for new knowledge 10 2.2 The importance of not compromising the sample and the Mars surface 11 2.3 The challenge raised by a returned sample 11 2.4 Considering backward contamination through particle size 12 3. Life as we know it and size limits 14 3.1 Life as we know it 14 3.2 Approaching the issue of minimum size limit for life 14 3.3 Characteristics of the smallest cells 15 3.4 Viruses 17 3.5 Gene transfer agents (GTAs) 18 3.6 From new knowledge to new requirements 19 3.7 Perspectives for the future 21 4. Defining the adequate level of assurance for a non-release 22 4.1 From risk to level of assurance 22 4.2 Approaching the unknown and considering consequences 22 4.3 The Precautionary Principle in the context of MSR 25 4.4 Emission optimisation strategies 25 4.5 Quantitative risk levels used by regulators 27 4.6 Updating the appropriate level of assurance 31 4.7 Potential verification methods 32 5. From release to risk: a framework to approach the consequences 33 5.1 The sequence of events leading to environmental consequences 33 5.2 Estimate of the overall risk 35 5.3 Direct consequences for human health 35 5.4 Being prepared 38 6. Perceived risk: differences between the general public and experts 39 7. Regulatory and legal aspects of a Mars Sample Return Mission 42 7.1 Obligation to prevent pollution/contamination of Outer Space and the Earth 42 7.2 Responsibility and liability of States 43 7.3 The necessity/utility to give some legal value to measures preventing damage 44 8. Study Group findings and recommendations 45 8.1 Mars exploration and sample return 45 8.2 Uncertainties, Precautionary Principle and optimisation 45 8.3 On particle size 46 8.4 Public perception 47 8.5 On the required level of assurance 47 8.6 Implication for design 48 8.7 Accompanying measures 48 References 50 Annex 1: ESF-ESSC Study Group composition 57 Annex 2: Risk perception workshop – participation, consensus statements and recommendations 58 Foreword: Mission Statement l l l As planetary protection regulations have a signifi- The mandate of the Study Group was to: 3 cant impact on mission design, engineering and “Recommend the level of assurance for the exclu- overall cost, it is critical that the guidelines are sion of an unintended release of a potential Mars implemented with proper justification and are re- life form into the Earth’s biosphere for a Mars evaluated on a regular basis. Sample Return mission”. In June 2011, the European Space Agency The starting point of this activity was the asked the European Science Foundation (ESF) in requirement used since the late 1990s specifying coordination with its European Space Sciences that: ‘the probability that a single unsterilised particle Committee (ESSC) to perform a study regarding of 0.2 micron diameter or greater is released into the planetary protection regulations for a Mars Sample Earth environment shall be less than 106’. Return (MSR) mission. Specifically, ESF was asked The value for the maximum particle size was to perform a study on the level of assurance of derived from the NRC-SSB 1999 report ‘Size Limits preventing an unintended release of Martial par- of Very Small Microorganisms: Proceedings of a ticles into the Earth’s biosphere in the frame of an Workshop’, which declared that 0.25 ± 0,05 µm MSR mission. ESF commissioned a study group of was the lower size limit for life as we know it (NRC, 12 high-level, international and multidisciplinary 1999). However, the past decade has shown enor- experts (see Annex 1 for Study Group composi- mous advances in microbiology, and microbes in tion) to evaluate the current requirements, and to the 0.10–0,15 µm range have been discovered in provide new insights and recommendations where various environments. Therefore, the value for the applicable. The Study Group was formed following maximum particle size that could be released into a call for nominations addressed to several research the Earth’s biosphere is revisited and re-evaluated organisations in Europe and beyond as well as to in this report. Also, the current level of assurance the ESF standing committees on Life, Earth and of preventing the release of a Mars particle is recon- Environmental Sciences (LESC), Medical Research sidered. (EMRC), Physical and Engineering Sciences (PESC) To complete its mandate, the Study Group met as well as Social Sciences (SCSS) and Humanities on three occasions between June and November (SCH). 2011 and commissioned the organisation of a work- Mars Sample Return backward contamination – Strategic advice and requirements shop dedicated to risk perception held in January 2012. The outcome and recommendations from the risk perception workshop (see Annex 2 for details) were used as direct inputs in the formulation of the advice contained in this report. 1. Mars Sample Return Mission and planetary protection – background l l l 5 1.1 Planetary protection regulatory policy, while also providing guidelines to spacefar- framework ing nations. Planetary protection considers two types
Load more

Recommended publications
  • Cross-References ASTEROID IMPACT Definition and Introduction History of Impact Cratering Studies
    18 ASTEROID IMPACT Tedesco, E. F., Noah, P. V., Noah, M., and Price, S. D., 2002. The identification and confirmation of impact structures on supplemental IRAS minor planet survey. The Astronomical Earth were developed: (a) crater morphology, (b) geo- 123 – Journal, , 1056 1085. physical anomalies, (c) evidence for shock metamor- Tholen, D. J., and Barucci, M. A., 1989. Asteroid taxonomy. In Binzel, R. P., Gehrels, T., and Matthews, M. S. (eds.), phism, and (d) the presence of meteorites or geochemical Asteroids II. Tucson: University of Arizona Press, pp. 298–315. evidence for traces of the meteoritic projectile – of which Yeomans, D., and Baalke, R., 2009. Near Earth Object Program. only (c) and (d) can provide confirming evidence. Remote Available from World Wide Web: http://neo.jpl.nasa.gov/ sensing, including morphological observations, as well programs. as geophysical studies, cannot provide confirming evi- dence – which requires the study of actual rock samples. Cross-references Impacts influenced the geological and biological evolu- tion of our own planet; the best known example is the link Albedo between the 200-km-diameter Chicxulub impact structure Asteroid Impact Asteroid Impact Mitigation in Mexico and the Cretaceous-Tertiary boundary. Under- Asteroid Impact Prediction standing impact structures, their formation processes, Torino Scale and their consequences should be of interest not only to Earth and planetary scientists, but also to society in general. ASTEROID IMPACT History of impact cratering studies In the geological sciences, it has only recently been recog- Christian Koeberl nized how important the process of impact cratering is on Natural History Museum, Vienna, Austria a planetary scale.
    [Show full text]
  • Questioning the Surface of Mars As the 21St Century's Ultimate Pioneering Destination in Space
    Questioning The Surface Of Mars As The 21st Century's Ultimate Pioneering Destination In Space Small Bodies Assessment Group Meeting #13 Washington D.C. 1 July 2015 Questioning Mars As The Ultimate Pioneering Destination In Space Background And Context • Foreseeable human-initiated activity in space can be divided into two categories - Exploring (e.g. Lewis & Clark ca. 1805): survey foreign territory + A major component of NASA's charter + Can be conducted by humans directly or by robots under human control + Virtual human presence is possible via tele-robotics stationed < 100,000 km away + Mars never approaches Earth closer than 56 million km - Pioneering (e.g. Pilgrims ca.1620): put down multi-generation roots in foreign territory + NOT in NASA's charter + MUST be conducted by humans in situ and ultimately return sustained profits + Any examples to date are dubious and Earth-centered (e.g. communication satellites) • Mars is widely accepted as the ultimate 21st century pioneering destination in space - Why would 202,586* adults volunteer in 2013 for a one-way trip to the surface of Mars? - What are potential obstacles to pioneering the surface of Mars? - Might there be more accessible and hospitable pioneering destinations than Mars? * The number of applications actually completed and submitted to Mars One was reported in 2015 to be 4227. Daniel R. Adamo ([email protected]) 1 1 July 2015 Questioning Mars As The Ultimate Pioneering Destination In Space History† Indicates Humans Pioneer For Compelling Reasons • Escape from war, starvation,
    [Show full text]
  • Planetary Defence Activities Beyond NASA and ESA
    Planetary Defence Activities Beyond NASA and ESA Brent W. Barbee 1. Introduction The collision of a significant asteroid or comet with Earth represents a singular natural disaster for a myriad of reasons, including: its extraterrestrial origin; the fact that it is perhaps the only natural disaster that is preventable in many cases, given sufficient preparation and warning; its scope, which ranges from damaging a city to an extinction-level event; and the duality of asteroids and comets themselves---they are grave potential threats, but are also tantalising scientific clues to our ancient past and resources with which we may one day build a prosperous spacefaring future. Accordingly, the problems of developing the means to interact with asteroids and comets for purposes of defence, scientific study, exploration, and resource utilisation have grown in importance over the past several decades. Since the 1980s, more and more asteroids and comets (especially the former) have been discovered, radically changing our picture of the solar system. At the beginning of the year 1980, approximately 9,000 asteroids were known to exist. By the beginning of 2001, that number had risen to approximately 125,000 thanks to the Earth-based telescopic survey efforts of the era, particularly the emergence of modern automated telescopic search systems, pioneered by the Massachusetts Institute of Technology’s (MIT’s) LINEAR system in the mid-to-late 1990s.1 Today, in late 2019, about 840,000 asteroids have been discovered,2 with more and more being found every week, month, and year. Of those, approximately 21,400 are categorised as near-Earth asteroids (NEAs), 2,000 of which are categorised as Potentially Hazardous Asteroids (PHAs)3 and 2,749 of which are categorised as potentially accessible.4 The hazards posed to us by asteroids affect people everywhere around the world.
    [Show full text]
  • Section 4. Guidance Document on Horizontal Gene Transfer Between Bacteria
    306 - PART 2. DOCUMENTS ON MICRO-ORGANISMS Section 4. Guidance document on horizontal gene transfer between bacteria 1. Introduction Horizontal gene transfer (HGT) 1 refers to the stable transfer of genetic material from one organism to another without reproduction. The significance of horizontal gene transfer was first recognised when evidence was found for ‘infectious heredity’ of multiple antibiotic resistance to pathogens (Watanabe, 1963). The assumed importance of HGT has changed several times (Doolittle et al., 2003) but there is general agreement now that HGT is a major, if not the dominant, force in bacterial evolution. Massive gene exchanges in completely sequenced genomes were discovered by deviant composition, anomalous phylogenetic distribution, great similarity of genes from distantly related species, and incongruent phylogenetic trees (Ochman et al., 2000; Koonin et al., 2001; Jain et al., 2002; Doolittle et al., 2003; Kurland et al., 2003; Philippe and Douady, 2003). There is also much evidence now for HGT by mobile genetic elements (MGEs) being an ongoing process that plays a primary role in the ecological adaptation of prokaryotes. Well documented is the example of the dissemination of antibiotic resistance genes by HGT that allowed bacterial populations to rapidly adapt to a strong selective pressure by agronomically and medically used antibiotics (Tschäpe, 1994; Witte, 1998; Mazel and Davies, 1999). MGEs shape bacterial genomes, promote intra-species variability and distribute genes between distantly related bacterial genera. Horizontal gene transfer (HGT) between bacteria is driven by three major processes: transformation (the uptake of free DNA), transduction (gene transfer mediated by bacteriophages) and conjugation (gene transfer by means of plasmids or conjugative and integrated elements).
    [Show full text]
  • General Assembly Distr.: General 7 January 2005
    United Nations A/AC.105/839 General Assembly Distr.: General 7 January 2005 Original: English Committee on the Peaceful Uses of Outer Space Scientific and Technical Subcommittee Forty-second session Vienna, 21 February-4 March 2004 Item 10 of the provisional agenda∗ Near-Earth objects Information on research in the field of near-Earth objects carried out by international organizations and other entities Note by the Secretariat Contents Page I. Introduction ................................................................... 2 II. Replies received from international organizations and other entities ..................... 2 European Space Agency ......................................................... 2 The Spaceguard Foundation ...................................................... 17 __________________ ∗ A/AC.105/C.1/L.277. V.05-80067 (E) 010205 020205 *0580067* A/AC.105/839 I. Introduction In accordance with the agreement reached at the forty-first session of the Scientific and Technical Subcommittee (A/AC.105/823, annex II, para. 18) and endorsed by the Committee on the Peaceful Uses of Outer Space at its forty-seventh session (A/59/20, para. 140), the Secretariat invited international organizations, regional bodies and other entities active in the field of near-Earth object (NEO) research to submit reports on their activities relating to near-Earth object research for consideration by the Subcommittee. The present document contains reports received by 17 December 2004. II. Replies received from international organizations and other entities European Space Agency Overview of activities of the European Space Agency in the field of near-Earth object research: hazard mitigation Summary 1. Near-Earth objects (NEOs) pose a global threat. There exists overwhelming evidence showing that impacts of large objects with dimensions in the order of kilometres (km) have had catastrophic consequences in the past.
    [Show full text]
  • NASA's Near-Earth Object Program
    NASA’s Near-Earth Object Program (Spaceguard) Don Yeomans Manager, NASA Near-Earth Object Program Office Meteor Crater Arizona History of Known NEO Population The Inner Solar System in 2006 201118001900195019901999 Known • 500,000 Earth minor planets Crossing •7750 NEOs Outside • 1200 PHAs Earth’s Orbit Scott Manley Armagh Observatory NASA’s NEO Search Program (Current Systems) Minor Planet Center (MPC) • IAU sanctioned NEO-WISE • Int’l observation database • Initial orbit determination www.cfa.harvard.edu/iau/mpc. html NEO Program Office @ JPL • Program coordination JPL • Precision orbit determination Sun-synch LEO • Automated SENTRY www.neo.jpl.nasa.gov Catalina Sky Pan-STARRS LINEAR Survey MIT/LL UofAZ Arizona & Australia Uof HI Soccoro, NM Haleakula, Maui3 The Importance of Near-Earth Objects •Science •Future Space Resources •Planetary Defense •Exploration NASA’s NEO Program Office at JPL Coordination and Metrics Automatic orbit updates as new data arrive SENTRY system Relational database for NEO orbits & characteristics Conduct research on: Discovery efficiency Improving observational data Modeling dynamics Optimal mitigation processes Impact warnings & outreach http://www.jpl.nasa.gov/asteroidwatch / NEO Program Office: http://neo.jpl.nasa.gov/ Near-Earth Asteroid Discoveries Start of NASA NEO Program Discovery Completion Within Size Intervals 40% 8% <1% 87% JPL’s SENTY NEO Risk Page http://neo.jpl.nasa.gov/risk/ Object Year Potential Impact Velocity H Estimated Palermo Torino Designation Range Impacts Prob. (km/s) (mag.) Diameter
    [Show full text]
  • The Asteroid Impact Hazard: Historical Perspective
    The Asteroid Impact Hazard: Historical Perspective David Morrison NASA SSERVI (NASA Ames Research Center) Asteroid Grand Challenge Virtual Seminar" NASA GRAND CHALLENGE : Find all objects capable of threatening human populations and determine how to deal with them. Historical Quotes" • Should a comet in its course strike the Earth, it might instantly beat it to pieces. But our comfort is, the same great Power that made the Universe, governs it by his providence. And such terrible catastrophes will not happen till 'tis best they should … Benjamin Franklin (1757) • Men should be free from this fear ... for the probability of [a comet] striking the Earth within the span of a human lifetime is slim, even though the probability of such an impact occurring in the course of centuries is very great … Laplace (c. 1790) • Who knows whether, when a comet shall approach this globe to destroy it, as it often has been and will be destroyed, men will not tear rocks from their foundations by means of steam, and hurl mountains, as the giants are said to have done, against the flaming mass? - and then we shall have traditions of Titans again, and of wars with Heaven... Lord Byron (1822) • Civilization could be entirely destroyed by the unexpected impact of an asteroid or comet. Thousands of years of history could be erased in a single day, and with it the hopes for future generations … Clark Chapman & David Morrison (1989) • If some day in the future we discover well in advance that an asteroid that is big enough to cause a mass extinction is going to hit the Earth, and then we alter the course of that asteroid so that it does not hit us, it will be one of the most important accomplishments in all of history… U.S.
    [Show full text]
  • Defending Planet Earth: Near-Earth Object Surveys and Hazard Mitigation Strategies Final Report
    PREPUBLICATION COPY—SUBJECT TO FURTHER EDITORIAL CORRECTION Defending Planet Earth: Near-Earth Object Surveys and Hazard Mitigation Strategies Final Report Committee to Review Near-Earth Object Surveys and Hazard Mitigation Strategies Space Studies Board Aeronautics and Space Engineering Board Division on Engineering and Physical Sciences THE NATIONAL ACADEMIES PRESS Washington, D.C. www.nap.edu PREPUBLICATION COPY—SUBJECT TO FURTHER EDITORIAL CORRECTION THE NATIONAL ACADEMIES PRESS 500 Fifth Street, N.W. Washington, DC 20001 NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance. This study is based on work supported by the Contract NNH06CE15B between the National Academy of Sciences and the National Aeronautics and Space Administration. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the agency that provided support for the project. International Standard Book Number-13: 978-0-309-XXXXX-X International Standard Book Number-10: 0-309-XXXXX-X Copies of this report are available free of charge from: Space Studies Board National Research Council 500 Fifth Street, N.W. Washington, DC 20001 Additional copies of this report are available from the National Academies Press, 500 Fifth Street, N.W., Lockbox 285, Washington, DC 20055; (800) 624-6242 or (202) 334-3313 (in the Washington metropolitan area); Internet, http://www.nap.edu.
    [Show full text]
  • Neossat: a Collaborative Microsatellite Project for Space
    SSC08-III-5 NEOSSat : A Collaborative Microsatellite Project for Space Based Object Detection William Harvey Canadian Space Agency 6767, Route de l'Aéroport, St-Hubert, QC, Canada, J3Y 8Y9; (450) 926-4477 [email protected] Tony Morris Defence Research and Development Canada 3701 Carling Avenue, Ottawa, Ontario, K1A 0Z4; 613 990-4326 [email protected] ABSTRACT Recognizing the importance of space-based Near Earth Object (NEO) detection and Surveillance of Space (SoS), the Canadian Space Agency and Defence Research and Development Canada are proceeding with the development and construction of NEOSSat. NEOSSat's two missions are to make observations to discover asteroids and comets near Earth's orbit (Near Earth Space Surveillance or NESS) and to demonstrate surveillance of satellites and space debris (High Earth Orbit Space Surveillance or HEOSS). This micro-satellite project will deploy a 15 cm telescope into a 630 km low earth orbit in 2010. This will be the first space-based system of its kind. NEOSSat represents a win-win opportunity for CSA and DRDC who recognized there were significant common interests with this microsatellite project. The project will yield data that can be used by the NEOSSat team and leveraged by external stakeholders to address important issues with NEOs, satellite metric data and debris cataloguing. In the contexts of risks and rewards as well as confidence building, NEOSSat is providing CSA and DRDC with valuable insights about collaboration on a microsatellite program and this paper presents our views and lessons learned. INTRODUCTION The NEOSSat microsatellite project satisfies several The Near Earth Object Surveillance Satellite objectives: 1) discover and determine the orbits of (NEOSSat) is the first jointly sponsored microsatellite Near-Earth Objects (NEO's) that cannot be efficiently project between the Canadian Space Agency CSA and detected from the ground, 2) demonstrate the ability of Defence Research and Development Canada (DRDC).
    [Show full text]
  • Phage As Agents of Lateral Gene Transfer Carlos Canchaya, Ghislain Fournous, Sandra Chibani-Chennoufi, Marie-Lise Dillmann and Harald Bru¨ Ssowã
    417 Phage as agents of lateral gene transfer Carlos Canchaya, Ghislain Fournous, Sandra Chibani-Chennoufi, Marie-Lise Dillmann and Harald Bru¨ ssowà When establishing lysogeny, temperate phages integrate their Lateral gene transfer genome as a prophage into the bacterial chromosome. With about 100 sequenced genomes of bacteria in the Prophages thus constitute in many bacteria a substantial part public database and many more to come, genomics has of laterally acquired DNA. Some prophages contribute changed our understanding of microbiology. In fact, the lysogenic conversion genes that are of selective advantage to genomes of bacteria are remarkably fluid. A substantial the bacterial host. Occasionally, phages are also involved part of the bacterial DNA is not transferred from the in the lateral transfer of other mobile DNA elements or parental cell to its descendent (‘vertical’ transfer), but is bacterial DNA. Recent advances in the field of genomics acquired horizontally by transformation, conjugation or have revealed a major impact by phages on bacterial transduction (‘lateral’ transfer) [1]. The replacement of chromosome evolution. a tree-like by a web-like representation of the phyloge- netic relationship between bacteria is a visual expression Addresses of this change in perception of microbial evolution. An Nestle´ Research Centre, CH-1000 Lausanne 26, Vers-chez-les-Blanc, important element of mobile DNA is bacteriophages. Switzerland à Infection of a bacterial cell with a temperate phage e-mail: [email protected] (Figure 1a,b) can have two outcomes: multiplication of the phage with concomitant lysis of the bacterial host Current Opinion in Microbiology 2003, 6:417–424 (Figure 1c) or lysogenization, (i.e.
    [Show full text]
  • Gene Transfer Agents in Plant Pathogenic Bacteria: Comparative Mobilomics, Genomic Survey and Recombinogenic Impacts
    Gene Transfer Agents in Plant Pathogenic Bacteria: Comparative Mobilomics, Genomic Survey and Recombinogenic Impacts Mustafa O Jibrin University of Florida Gerald V. Minsavage University of Florida Erica M. Goss University of Florida Pamela D. Roberts University of Florida Jeffrey B Jones ( [email protected] ) University of Florida https://orcid.org/0000-0003-0061-470X Research article Keywords: Prokaryotic mobile genetic elements Posted Date: August 29th, 2019 DOI: https://doi.org/10.21203/rs.2.10679/v1 License: This work is licensed under a Creative Commons Attribution 4.0 International License. Read Full License Page 1/18 Abstract Background Gene transfer agents (GTAs) are phage-like mediators of gene transfer in bacterial species. Typically, strains of a bacteria species which have GTA shows more recombination than strains without GTAs. GTA-mediated gene transfer activity has been shown for few bacteria, with Rhodobacter capsulatus being the prototypical GTA. GTA have not been previously studied in plant pathogenic bacteria. A recent study inferring recombination in strains of the bacterial spot xanthomonads identied a Nigerian lineage which showed unusual recombination background. We initially set out to understand genomic drivers of recombination in this genome by focusing on mobile genetic elements. Results We identied a unique cluster which was present in the Nigerian strain but absent in other sequenced strains of bacterial spot xanthomonads. The protein sequence of a gene within this cluster contained the GTA_TIM domain that is present in bacteria with GTA. We identied GTA clusters in other Xanthomonas species as well as species of Agrobacterium and Pantoea. Recombination analyses showed that generally, strains of Xanthomonas with GTA have more inferred recombination events than strains without GTA, which could lead to genome divergence.
    [Show full text]
  • Dissemination of Antimicrobial Resistance in Microbial Ecosystems Through Horizontal Gene Transfer
    REVIEW published: 19 February 2016 doi: 10.3389/fmicb.2016.00173 Dissemination of Antimicrobial Resistance in Microbial Ecosystems through Horizontal Gene Transfer Christian J. H. von Wintersdorff 1, John Penders 1, 2, Julius M. van Niekerk 2, Nathan D. Mills 1, Snehali Majumder 2, Lieke B. van Alphen 2, Paul H. M. Savelkoul 1, 2, 3 and Petra F. G. Wolffs 1, 2* 1 Department of Medical Microbiology, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center+, Maastricht, Netherlands, 2 Department of Medical Microbiology, Caphri School for Public Health and Primary Care, Maastricht University Medical Center+, Maastricht, Netherlands, 3 Department of Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, Netherlands The emergence and spread of antibiotic resistance among pathogenic bacteria has been a rising problem for public health in recent decades. It is becoming increasingly recognized that not only antibiotic resistance genes (ARGs) encountered in clinical pathogens are of relevance, but rather, all pathogenic, commensal as well as Edited by: Gilberto Igrejas, environmental bacteria—and also mobile genetic elements and bacteriophages—form University of Trás-os-Montes and Alto a reservoir of ARGs (the resistome) from which pathogenic bacteria can acquire Douro, Portugal resistance via horizontal gene transfer (HGT). HGT has caused antibiotic resistance to Reviewed by: spread from commensal and environmental species to pathogenic ones, as has been Jose Luis Balcazar, Catalan Institute for Water Research, shown for some clinically important ARGs. Of the three canonical mechanisms of HGT, Spain conjugation is thought to have the greatest influence on the dissemination of ARGs.
    [Show full text]