DOCSLIB.ORG

Ecology and Evolution of Antimicrobial Resistance in Bacterial Communities

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Ecology and Evolution of Antimicrobial Resistance in Bacterial Communities This is a repository copy of Ecology and evolution of antimicrobial resistance in bacterial communities. White Rose Research Online URL for this paper: https://eprints.whiterose.ac.uk/168705/ Version: Published Version Article: Bottery, Michael J. orcid.org/0000-0001-5790-1756, Pitchford, Jonathan W. orcid.org/0000- 0002-8756-0902 and Friman, Ville Petri orcid.org/0000-0002-1592-157X (2020) Ecology and evolution of antimicrobial resistance in bacterial communities. ISME Journal. ISSN 1751-7362 https://doi.org/10.1038/s41396-020-00832-7 Reuse This article is distributed under the terms of the Creative Commons Attribution (CC BY) licence. This licence allows you to distribute, remix, tweak, and build upon the work, even commercially, as long as you credit the authors for the original work. More information and the full terms of the licence here: https://creativecommons.org/licenses/ Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ The ISME Journal https://doi.org/10.1038/s41396-020-00832-7 PERSPECTIVE Ecology and evolution of antimicrobial resistance in bacterial communities 1 1,2 1 Michael J. Bottery ● Jonathan W. Pitchford ● Ville-Petri Friman Received: 17 April 2020 / Revised: 29 October 2020 / Accepted: 3 November 2020 © The Author(s) 2020. This article is published with open access Abstract Accumulating evidence suggests that the response of bacteria to antibiotics is significantly affected by the presence of other interacting microbes. These interactions are not typically accounted for when determining pathogen sensitivity to antibiotics. In this perspective, we argue that resistance and evolutionary responses to antibiotic treatments should not be considered only a trait of an individual bacteria species but also an emergent property of the microbial community in which pathogens are embedded. We outline how interspecies interactions can affect the responses of individual species and communities to antibiotic treatment, and how these responses could affect the strength of selection, potentially changing the trajectory of resistance evolution. Finally, we identify key areas of future research which will allow for a more complete understanding of 1234567890();,: 1234567890();,: antibiotic resistance in bacterial communities. We emphasise that acknowledging the ecological context, i.e. the interactions that occur between pathogens and within communities, could help the development of more efficient and effective antibiotic treatments. Introduction result, clinical susceptibility to antibiotics might not translate well to the successful treatment of polymicrobial infections The global use and misuse of antibiotics has led to the where pathogens are typically embedded in complex mul- evolution and spread of bacterial resistance to all routinely tispecies microbial communities. Interspecies interactions used antibiotics. In order to effectively tackle the spread of are not typically accounted for when assessing antibiotic antimicrobial resistance (AMR) through antimicrobial sensitivity and resistance evolution in the context of anti- stewardship or development of novel antimicrobial com- biotic treatments. In this perspective, we focus on the role pounds, understanding how bacteria adapt and evolve to of interspecies bacterial interactions on the selection of pre- survive antibiotic treatments is crucial. Here we argue that to existing resistance, and on how interactions within bacterial fully understand the evolution of AMR we must study the communities could change the evolutionary trajectory of emergence of resistance within the context of microbial de novo resistance, i.e., the evolutionary dynamics and communities. While the composition, structure and interac- outcomes of antibiotic exposure, particularly within a clin- tions within microbial populations are known to affect the ical context. horizontal gene transfer (HGT) of antibiotic resistance [1–3], The ability of a bacterial strain to survive antibiotic it is becoming evident that intra- and interspecies interac- exposure is commonly assessed in monoculture measure- tions also influence how species respond and evolve under ments of growth, through broth microdilution or agar antibiotic exposure within microbial communities. As a dilution assays, to quantify a minimum inhibitory con- centration (MIC) [4]. These in vitro methods test the sus- ceptibility of individual bacterial strains determining MIC breakpoints and providing informed choices of anti- * Michael J. Bottery microbial interventions. However, our understanding and [email protected] interpretation of MIC measurements has improved in recent 1 Department of Biology, University of York, Wentworth Way, years. Higher initial population densities can result in lower York YO10 5DD, UK susceptibility to some antibiotics, a phenomenon called the fi 2 Department of Mathematics, University of York, Heslington, inoculum effect [5, 6]. In addition, bio lm growth can York YO10 5DD, UK dramatically increase the effective MIC of a population and M. J. Bottery et al. alter the rates of resistance evolution when compared to evolvable trait, as has been demonstrated in the evolution of planktonic cells [7, 8]. Finally, it is increasingly evident that tolerance through the optimisation of lag-times to match the sub-MIC antibiotic concentrations can positively select for intervals of antibiotic exposure [21]. Whereas resistance and resistance mutations, increase HGT of antimicrobial resis- tolerance are considered properties of a population, persis- tance genes (ARGs), and elevate mutation rates; all of tence describes the ability of a small sub-population of a which will increase the likelihood of resistance evolution clonal bacterial population to enter a state of dormancy, [9–12]. As such the minimal selective concentration (MSC) allowing it to survive high concentrations of antibiotic while and predicted no effect concentration have become impor- the rest of the population is rapidly killed [22, 23]. Both tant metrics for understanding and controlling the evolution tolerance and persistence allows surviving bacteria to and spread of resistance [13]. resume normal growth after the depletion of the antibiotic. The effect of ecological context, i.e., the type and dynamics of microbial interactions that occur between pathogens and the surrounding community, is often over- Interspecies interactions can alter responses looked when considering antibiotic efficacy and the evolu- to antibiotics tion of resistance. We currently predominantly consider antibiotic sensitivity as an independent trait of an individual Interspecies interactions can have a profound effect upon strain. However, it is clear that inter- and intra-species the outcome of antibiotic treatment. We define three main interactions within both clinical and environmental com- ways in which bacterial communities, or subpopulations of munities, as well as the physical properties of the associated communities, can survive exposure to antimicrobials due to microbial community, can alter the physiological state and interspecies interactions: (1) Collective resistance, interac- antibiotic susceptibility of bacteria [14]. Interspecies inter- tions within a community that elevate the ability of its actions are especially common in polymicrobial infections members to resist the action of an antibiotic and continue to where multiple species contribute to disease [15]. These grow in the presence of antibiotics thus increasing the MIC interactions not only affect the severity of infections but of the community. (2) Collective tolerance, interactions could also alter the exposure and physiological responses to within a community that alter cell state, such as slowing antibiotics. We thus argue that bacterial ability to withstand down metabolism, and thus slow down the rate of cell death antibiotic treatments, and the consequent evolution of during transient exposure to antibiotics without an increase resistance to those treatments, should be viewed as an in MIC. (3) Exposure protection, interactions within a emergent property of a microbial community rather than community that protect its sensitive members during anti- simply a trait of a particular species. biotic treatment by reducing the effective concentration of To discuss the effects of antimicrobial exposure on antibiotic [24, 25]. These definitions are not mutually microbial communities we must first distinguish the dif- exclusive; interactions could have multiple different effects, ferent ways in which bacteria survive in the presence of and multiple different mechanisms may act simultaneously antibiotics. Resistance is often defined as the inheritable within a community. ability of a cell to grow at high concentrations of an anti- Many of the known mechanisms that provide collective biotic, irrespective of the duration of exposure [16]. Its resistance, tolerance or exposure protection are density- mechanisms are many and varied [17]. Resistance can be dependent, providing protection to large, dense populations intrinsic, whereby the physiological properties of all mem- [25] through the inactivation of antibiotics, biofilm forma- bers of a species allow it to resist the action of certain tion and quorum sensing-activated responses [26–28]. antibiotics; or acquired, either through de novo mutation
Load more

Recommended publications
  • Bringing a Trait‐Based Approach to Plant‐Associated Fungi
    Biol. Rev. (2020), 95, pp. 409–433. 409 doi: 10.1111/brv.12570 Fungal functional ecology: bringing a trait-based approach to plant-associated fungi Amy E. Zanne1,∗ , Kessy Abarenkov2, Michelle E. Afkhami3, Carlos A. Aguilar-Trigueros4, Scott Bates5, Jennifer M. Bhatnagar6, Posy E. Busby7, Natalie Christian8,9, William K. Cornwell10, Thomas W. Crowther11, Habacuc Flores-Moreno12, Dimitrios Floudas13, Romina Gazis14, David Hibbett15, Peter Kennedy16, Daniel L. Lindner17, Daniel S. Maynard11, Amy M. Milo1, Rolf Henrik Nilsson18, Jeff Powell19, Mark Schildhauer20, Jonathan Schilling16 and Kathleen K. Treseder21 1Department of Biological Sciences, George Washington University, Washington, DC 20052, U.S.A. 2Natural History Museum, University of Tartu, Vanemuise 46, Tartu 51014, Estonia 3Department of Biology, University of Miami, Coral Gables, FL 33146, U.S.A. 4Freie Universit¨at-Berlin, Berlin-Brandenburg Institute of Advanced Biodiversity Research, 14195 Berlin, Germany 5Department of Biological Sciences, Purdue University Northwest, Westville, IN 46391, U.S.A. 6Department of Biology, Boston University, Boston, MA 02215, U.S.A. 7Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97330, U.S.A. 8Department of Plant Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, U.S.A. 9Department of Biology, University of Louisville, Louisville, KY 40208, U.S.A. 10Evolution & Ecology Research Centre, School of Biological Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia 11Department of Environmental Systems Science, Institute of Integrative Biology, ETH Z¨urich, 8092, Z¨urich, Switzerland 12Department of Ecology, Evolution, and Behavior, and Department of Forest Resources, University of Minnesota, St. Paul, MN 55108, U.S.A.
    [Show full text]
  • Resistance and Resilience: a Conceptual Framework for Silviculture
    For. Sci. 60(6):1205–1212 APPLIED RESEARCH http://dx.doi.org/10.5849/forsci.13-507 silviculture Resistance and Resilience: A Conceptual Framework for Silviculture Robert J. DeRose and James N. Long Increasingly, forest management goals include building or maintaining resistance and/or resilience to disturbances in the face of climate change. Although a multitude of descriptive definitions for resistance and resilience exist, to evaluate whether specific management activities (silviculture) are effective, prescriptive characterizations are necessary. We introduce a conceptual framework that explicitly differentiates resistance and resilience, denotes appropriate scales, and establishes the context for evaluation—structure and composition. Generally, resistance is characterized as the influence of structure and composition on disturbance, whereas resilience is characterized as the influence of disturbance on subsequent structure and composition. Silvicultural utility of the framework is demonstrated by describing disturbance-specific, time-bound structural and compositional objectives for building resistance and resilience to two fundamentally different disturbances: wildfires and spruce beetle outbreaks. The conceptual framework revealed the crucial insight that attempts to build stand or landscape resistance to spruce beetle outbreaks will ultimately be unsuccessful. This frees the silviculturist to focus on realistic goals associated with building resilience to likely inevitable outbreaks. Ultimately, because structure and composition, at appropriate scales, are presented as the standards for evaluation and manipulation, the framework is broadly applicable to many kinds of disturbance in various forest types. Keywords: adaptation, desired future conditions, forest management objectives, forest service, planning rule he terms resistance and resilience have been used in the explicitly differentiates resistance and resilience, delimits appropri- ecological literature for nearly 40 years (Holling 1973).
    [Show full text]
  • High Dimensionality of the Stability of a Marine Benthic Ecosystem
    bioRxiv preprint doi: https://doi.org/10.1101/2020.10.21.349035; this version posted December 2, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 1 High dimensionality of the stability of a marine benthic ecosystem 2 3 Nelson Valdivia1, 2, *, Moisés A. Aguilera3, 4, Bernardo R. Broitman5 4 5 1Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de 6 Chile, Campus Isla Teja, Valdivia, Chile 7 2Centro FONDAP de Investigación de Dinámicas de Ecosistemas Marinos de Altas Latitudes 8 (IDEAL) 9 3Departamento de Biología Marina, Facultad de Ciencias del Mar, Universidad Católica del 10 Norte, Larrondo 1281, Coquimbo, Chile 11 4Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Universidad Católica del Norte, 12 Ossandón 877, Coquimbo, Chile 13 5Departamento de Ciencias, Facultad de Artes Liberales & Bioengineering Innovation 14 Center, Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Av. Padre Hurtado 15 750, Viña del Mar, Chile 16 *Corresponding author Tel.: +56632221557, Fax: +56632221455, E-mail: 17 [email protected] 18 Nelson Valdivia ORCID ID: https://orcid.org/0000-0002-5394-2072 19 Bernardo R. Broitman ORCID ID: http://orcid.org/0000-0001-6582-3188 20 Moisés A. Aguilera ORCID ID: https://orcid.org/0000-0002-3517-6255 1 bioRxiv preprint doi: https://doi.org/10.1101/2020.10.21.349035; this version posted December 2, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission.
    [Show full text]
  • Purified Bioactive Compounds from Mentha Spp. Oils As a Source of Candidosis Treatment
    Incentivo governamental para Arranjos Produtivos Locais de Plantas Medicinais e Fitoterápicos no âmbito do SUS REVISÃO FARMACOLOGIA Purified bioactive compounds from Mentha spp. oils as a source of Candidosis treatment. A brief review Compostos bioativos purificados de óleos de Mentha spp. como fonte de tratamento de candidose. Uma breve revisão DOI 10.5935/2446-4775.20170009 1BONI, Giovana C.*; 1FEIRIA, Simone N. B. de; 1HÖFLING, José F. 1University of Campinas - UNICAMP, Piracicaba Dental School, Piracicaba, SP, Brazil. *Correspondência: [email protected] Abstract Medicinal plants have been the subject of many studies in an attempt to discovery alternative drugs, since they are sources of potentially bioactive compounds that may act in the maintenance of human health. The discovery of new antimicrobial substances or biocomponents derived from natural products has been important in the control of microorganisms, especially due to the increase of cases of resistance to conventional antimicrobials. In parallel, yeasts of the genus Candida are becoming a public health problem in the last decades due to the increase of infections denominated candidosis. Candida spp. has mechanisms of virulence, such as polymorphism and biofilm formation, that facilitate the development of the infection and difficult the treatment. In this sense, studies found in the literature with bioactive compounds from Mentha spp. essential oil, describe their antifungal action, especially from the isolated compounds as carvone, mentone, menthofuran and pulegone. In this sense, this review describes studies about antimicrobial activity of these compounds especially against yeasts of Candida species and some particularities of this genus such as virulence mechanisms once these themes are crucial for the development of new alternative drugs and/or antifungal agents that may act as adjuncts to conventional treatments against these microorganisms.
    [Show full text]
  • I've Gut a Feeling: Microbiota Impacting the Conceptual And
    International Journal of Molecular Sciences Review I’ve Gut A Feeling: Microbiota Impacting the Conceptual and Experimental Perspectives of Personalized Medicine Amedeo Amedei 1,2,* and Federico Boem 1 1 Department of Experimental and Clinical Medicine, University of Florence, Largo Brambilla, 03 50134, Firenze, Italy; [email protected] 2 Department of Biomedicine, Azienda Ospedaliera Universitaria Careggi (AOUC), Largo Brambilla, 03 50134, Firenze, Italy * Correspondence: amedeo.amedei@unifi.it Received: 21 September 2018; Accepted: 16 November 2018; Published: 27 November 2018 Abstract: In recent years, the human microbiota has gained increasing relevance both in research and clinical fields. Increasing studies seem to suggest the centrality of the microbiota and its composition both in the development and maintenance of what we call “health” and in generating and/or favoring (those cases in which the microbiota’s complex relational architecture is dysregulated) the onset of pathological conditions. The complex relationships between the microbiota and human beings, which invest core notions of biomedicine such as “health” and “individual,” do concern not only problems of an empirical nature but seem to require the need to adopt new concepts and new perspectives in order to be properly analysed and utilized, especially for their therapeutic implementation. In this contribution we report and discuss some of the theoretical proposals and innovations (from the ecological component to the notion of polygenomic organism) aimed at producing this change of perspective. In conclusion, we summarily analyze what impact and what new challenges these new approaches might have on personalized/person centred/precision medicine. Keywords: microbiome; health; precision medicine; genomics 1.
    [Show full text]
  • Resilience, Invariability, and Ecological Stability Across Levels of Organization
    bioRxiv preprint doi: https://doi.org/10.1101/085852; this version posted November 11, 2016. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Resilience, Invariability, and Ecological Stability across Levels of Organization Bart Haegeman1, Jean-Fran¸coisArnoldi1, Shaopeng Wang1;2;3, Claire de Mazancourt1, Jos´eM. Montoya1;4 & Michel Loreau1 1 Centre for Biodiversity Theory and Modelling, Theoretical and Experimental Ecology Station, CNRS and Paul Sabatier University, Moulis, France 2 German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leip- zig, Germany 3 Institute of Ecology, Friedrich Schiller University Jena, Jena, Germany 4 Ecological Networks and Global Change Group, Theoretical and Experimental Ecol- ogy Station, CNRS and Paul Sabatier University, Moulis, France Abstract Ecological stability is a bewildering broad concept. The most common stability measures are asymptotic resilience, widely used in theoretical studies, and measures based on tempo- ral variability, commonly used in empirical studies. We construct measures of invariability, defined as the inverse of variability, that can be directly compared with asymptotic re- silience. We show that asymptotic resilience behaves like the invariability of the most variable species, which is often a rare species close to its extinction boundary. Therefore, asymptotic resilience displays complete loss of stability with changes in community composi- tion. In contrast, mean population invariability and ecosystem invariability are insensitive to rare species and quantify stability consistently whether details of species composition are considered or not. Invariability provides a consistent framework to predict diversity- stability relationships that agree with empirical data at population and ecosystem levels.
    [Show full text]
  • Advances in Population Ecology and Species Interactions in Mammals
    Journal of Mammalogy, 100(3):965–1007, 2019 DOI:10.1093/jmammal/gyz017 Advances in population ecology and species interactions in mammals Downloaded from https://academic.oup.com/jmammal/article-abstract/100/3/965/5498024 by University of California, Davis user on 24 May 2019 Douglas A. Kelt,* Edward J. Heske, Xavier Lambin, Madan K. Oli, John L. Orrock, Arpat Ozgul, Jonathan N. Pauli, Laura R. Prugh, Rahel Sollmann, and Stefan Sommer Department of Wildlife, Fish, & Conservation Biology, University of California, Davis, CA 95616, USA (DAK, RS) Museum of Southwestern Biology, University of New Mexico, MSC03-2020, Albuquerque, NM 97131, USA (EJH) School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, United Kingdom (XL) Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611, USA (MKO) Department of Integrative Biology, University of Wisconsin, Madison, WI 73706, USA (JLO) Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, CH-8057, Switzerland (AO, SS) Department of Forest and Wildlife Ecology, University of Wisconsin, Madison, WI 53706, USA (JNP) School of Environmental and Forest Sciences, University of Washington, Seattle, WA 98195, USA (LRP) * Correspondent: [email protected] The study of mammals has promoted the development and testing of many ideas in contemporary ecology. Here we address recent developments in foraging and habitat selection, source–sink dynamics, competition (both within and between species), population cycles, predation (including apparent competition), mutualism, and biological invasions. Because mammals are appealing to the public, ecological insight gleaned from the study of mammals has disproportionate potential in educating the public about ecological principles and their application to wise management.
    [Show full text]
  • Navigating the Complexity of Ecological Stability
    Ecology Letters, (2016) 19: 1172–1185 doi: 10.1111/ele.12648 REVIEW AND SYNTHESIS Navigating the complexity of ecological stability Abstract Ian Donohue,1,2* Human actions challenge nature in many ways. Ecological responses are ineluctably complex, Helmut Hillebrand,3 Jose M. demanding measures that describe them succinctly. Collectively, these measures encapsulate the Montoya,4 Owen L. Petchey,5 Stuart overall ‘stability’ of the system. Many international bodies, including the Intergovernmental L. Pimm,6 Mike S. Fowler,7 Kevin Science-Policy Platform on Biodiversity and Ecosystem Services, broadly aspire to maintain or Healy,1,2 Andrew L. Jackson,1,2 enhance ecological stability. Such bodies frequently use terms pertaining to stability that lack clear Miguel Lurgi,8 Deirdre McClean,1,2 definition. Consequently, we cannot measure them and so they disconnect from a large body of 9 theoretical and empirical understanding. We assess the scientific and policy literature and show Nessa E. O’Connor, Eoin J. that this disconnect is one consequence of an inconsistent and one-dimensional approach that O’Gorman10 and Qiang Yang1,2 ecologists have taken to both disturbances and stability. This has led to confused communication of the nature of stability and the level of our insight into it. Disturbances and stability are multi- dimensional. Our understanding of them is not. We have a remarkably poor understanding of the impacts on stability of the characteristics that define many, perhaps all, of the most important ele- ments of global change. We provide recommendations for theoreticians, empiricists and policy- makers on how to better integrate the multidimensional nature of ecological stability into their research, policies and actions.
    [Show full text]
  • Science Citation Indexed Journal List
    SCIENCE CITATION INDEXED JOURNAL LIST Sr.No. Journal Title ISSN E-ISSN Publisher 1 2D MATERIALS 2053-1583 2053-1583 IOP PUBLISHING LTD 2 3 BIOTECH 2190-572X 2190-5738 SPRINGER HEIDELBERG 3 3D PRINTING AND ADDITIVE MANUFACTURING 2329-7662 2329-7670 MARY ANN LIEBERT, INC 4 4OR-A QUARTERLY JOURNAL OF OPERATIONS RESEARCH 1619-4500 1614-2411 SPRINGER HEIDELBERG 5 AAPG BULLETIN 0149-1423 1558-9153 AMER ASSOC PETROLEUM GEOLOGIST 6 AAPS JOURNAL 1550-7416 1550-7416 SPRINGER 7 AAPS PHARMSCITECH 1530-9932 1530-9932 SPRINGER 8 AATCC JOURNAL OF RESEARCH 2330-5517 2330-5517 AMER ASSOC TEXTILE CHEMISTS COLORISTS-AATCC 9 AATCC REVIEW 1532-8813 1532-8813 AMER ASSOC TEXTILE CHEMISTS COLORISTS-AATCC 10 ABDOMINAL RADIOLOGY 2366-004X 2366-0058 SPRINGER ABHANDLUNGEN AUS DEM MATHEMATISCHEN SEMINAR DER 11 0025-5858 1865-8784 SPRINGER HEIDELBERG UNIVERSITAT HAMBURG 12 ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY 0065-7727 AMER CHEMICAL SOC 13 ACADEMIC EMERGENCY MEDICINE 1069-6563 1553-2712 WILEY 14 ACADEMIC MEDICINE 1040-2446 1938-808X LIPPINCOTT WILLIAMS & WILKINS 15 ACADEMIC PEDIATRICS 1876-2859 1876-2867 ELSEVIER SCIENCE INC 16 ACADEMIC RADIOLOGY 1076-6332 1878-4046 ELSEVIER SCIENCE INC 17 ACAROLOGIA 0044-586X 2107-7207 ACAROLOGIA-UNIVERSITE PAUL VALERY 18 ACCOUNTABILITY IN RESEARCH-POLICIES AND QUALITY ASSURANCE 0898-9621 1545-5815 TAYLOR & FRANCIS INC 19 ACCOUNTS OF CHEMICAL RESEARCH 0001-4842 1520-4898 AMER CHEMICAL SOC 20 ACCREDITATION AND QUALITY ASSURANCE 0949-1775 1432-0517 SPRINGER 21 ACI MATERIALS JOURNAL 0889-325X 1944-737X AMER CONCRETE
    [Show full text]
  • Rapid Adaptation of Predation Resistance in Bacteria Isolated from a Seawater Microcosm
    Vol. 78: 81–92, 2016 AQUATIC MICROBIAL ECOLOGY Published online December 21 doi: 10.3354/ame01802 Aquat Microb Ecol OPENPEN ACCESSCCESS Rapid adaptation of predation resistance in bacteria isolated from a seawater microcosm P. Mathisen1, J. Thelaus2, S. Sjöstedt de Luna3, A. Andersson1,* 1Dept. of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden 2Division of CBRN Defence and Security, FOI Swedish Defence Research Agency, 901 82 Umeå, Sweden 3Dept. of Mathematics and Mathematical Statistics, Umeå University, 901 87 Umeå, Sweden ABSTRACT: Bacterial defense against protozoan grazing has been shown to occur in many different bacteria. Predation resistance traits may however be plastic, making bacterial com munities resilient or resistant to predation perturbations. We studied the adaptation of predation resistance traits in bacteria isolated from a microcosm experiment. In the initial microcosm ex periment the predation pressure on bacteria varied markedly, while changes in the bacterial community composition could not be verified. Seven bacteria were isolated from the microcosm (Micrococcus sp., Rhodobacter sp., Paracoccus sp., Shewanella sp., Rhizobium sp. and 2 un identified species) and these were re- peatedly exposed to high predation by the ciliate Tetrahymena pyriformis. High variations in edibil- ity and rate of adaptation of predation resistance traits were observed among the strains. The initial mortality rate of the different bacterial taxa and the change over time varied by a factor of 7 and 24, respectively. Rhodobacter sp. was already predation resistant at the start of the experiment and did not change much over time, while Micrococcus sp., Paracoccus sp. and Shewanella sp. initially were relatively edible and later developed predation resistance.
    [Show full text]
  • The Evolutionary Ecology of Resistance to Parasitoids by Drosophila
    Heredity 84 (2000) 1±8 Received 6 September 1999, accepted 29 November 1999 Short Review The evolutionary ecology of resistance to parasitoids by Drosophila M. D. E. FELLOWES * & H. C. J. GODFRAY à NERC Centre for Population Biology and àDepartment of Biology, Imperial College at Silwood Park, Ascot, Berkshire SL5 7PY, UK Parasitoids are the most important natural enemies of many now ®rm evidence that resistance is costly to Drosophila, and insect species. Larvae of many Drosophila species can defend the nature of this cost is discussed, and the possibility that it themselves against attack by parasitoids through a cellular may involve a reduction in metabolic rate considered. Com- immune response called encapsulation. The paper reviews parative data on encapsulation and metabolic rates across recent studies of the evolutionary biology and ecological seven Drosophila species provides support for this hypothesis. genetics of resistance in Drosophila, concentrating on Finally, the possible population and community ecological D. melanogaster. The physiological basis of encapsulation, consequences of evolution in the levels of host resistance are and the genes known to interfere with resistance are brie¯y examined. summarized. Evidence for within- and between-population genetic variation in resistance from isofemale line, arti®cial Keywords: Drosophila melanogaster, encapsulation, life- selection and classical genetic studies are reviewed. There is history trade-os, metabolic rate, parasitoid, resistance development (idiobiont parasitoids) or continues development Introduction (koinobiont parasitoids) after attack (Godfray, 1994). Among All organisms face attack by pathogens, parasites and pred- the most common parasitoids of European D. melanogaster ators. Understanding how adaptive changes in resistance and are koinobiont larval endoparasitoids of the genera Asobara virulence in¯uence the interactions between victim and natural (Braconidae: Alysiinae) and Leptopilina (Cynipoidea: Eucoil- enemy is a major challenge for population biologists.
    [Show full text]
  • Starr Thesis
    Disentangling the rhizosphere community through stable isotope informed genome-resolved metagenomics and assembled metatranscriptomes By Evan P. Starr A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Microbiology in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Jillian F. Banfield, Co-Chair Professor Mary K. Firestone, Co-Chair Professor Britt Koskella Summer 2019 Abstract Disentangling the holistic rhizosphere community through stable isotope informed genome- resolved metagenomics and assembled metatranscriptomes By Evan P Starr Doctor of Philosophy in Microbiology University of California, Berkeley Professor Jillian Banfield, Co-Chair Professor Mary Firestone, Co-Chair The functioning, health, and productivity of soil is intimately tied to the complex network of interactions in the rhizosphere. Because of this, the rhizosphere has been rigorously studied for over a century, but due to technical limitations many aspects of soil biology have been overlooked. In order to better understand rhizosphere functioning, my work has focused on the less explored organisms and interactions in microbial communities, this includes unculturable bacteria along with viruses and eukaryotes. Only by considering soil biology more holistically can we better understand the functioning of this enigmatic yet critical ecosystem. Knowledge about these interactions could direct how we think about plant-microbe relationships, soil carbon stabilization and the roles of understudied organisms in biogeochemical cycling. The transformation of plant photosynthate into soil organic carbon and its recycling to CO2 by soil microorganisms is one of the central components of the terrestrial carbon cycle. There are currently large knowledge gaps related to which soil-associated microorganisms take up plant carbon in the rhizosphere and the fate of that carbon.
    [Show full text]