1
|
Gladieux P, van Oosterhout C, Fairhead S, Jouet A, Ortiz D, Ravel S, Shrestha RK, Frouin J, He X, Zhu Y, Morel JB, Huang H, Kroj T, Jones JDG. Extensive immune receptor repertoire diversity in disease-resistant rice landraces. Curr Biol 2024; 34:3983-3995.e6. [PMID: 39146939 DOI: 10.1016/j.cub.2024.07.061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 04/19/2024] [Accepted: 07/16/2024] [Indexed: 08/17/2024]
Abstract
Plants have powerful defense mechanisms and extensive immune receptor repertoires, yet crop monocultures are prone to epidemic diseases. Rice (Oryza sativa) is susceptible to many diseases, such as rice blast caused by Magnaporthe oryzae. Varietal resistance of rice to blast relies on intracellular nucleotide binding, leucine-rich repeat (NLR) receptors that recognize specific pathogen molecules and trigger immune responses. In the Yuanyang terraces in southwest China, rice landraces rarely show severe losses to disease whereas commercial inbred lines show pronounced field susceptibility. Here, we investigate within-landrace NLR sequence diversity of nine rice landraces and eleven modern varieties using complexity reduction techniques. We find that NLRs display high sequence diversity in landraces, consistent with balancing selection, and that balancing selection at NLRs is more pervasive in landraces than modern varieties. Notably, modern varieties lack many ancient NLR haplotypes that are retained in some landraces. Our study emphasizes the value of standing genetic variation that is maintained in farmer landraces as a resource to make modern crops and agroecosystems less prone to disease. The conservation of landraces is, therefore, crucial for ensuring food security in the face of dynamic biotic and abiotic threats.
Collapse
Affiliation(s)
- Pierre Gladieux
- Plant Health Institute Montpellier, University of Montpellier, INRAE, CIRAD, IRD, Institut Agro, 34398 Montpellier, France.
| | - Cock van Oosterhout
- School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK
| | - Sebastian Fairhead
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Agathe Jouet
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Diana Ortiz
- Plant Health Institute Montpellier, University of Montpellier, INRAE, CIRAD, IRD, Institut Agro, 34398 Montpellier, France
| | - Sebastien Ravel
- Plant Health Institute Montpellier, University of Montpellier, INRAE, CIRAD, IRD, Institut Agro, 34398 Montpellier, France
| | - Ram-Krishna Shrestha
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Julien Frouin
- CIRAD, UMR AGAP Institut, 34398 Montpellier, France; UMR AGAP Institut, Université de Montpellier, CIRAD, INRAE, Institut Agro, 34398 Montpellier, France
| | - Xiahong He
- School of Landscape and Horticulture, Southwest Forestry University, Kunming 650233, China
| | - Youyong Zhu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming 650201, China; Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University, Kunming 650201, China
| | - Jean-Benoit Morel
- Plant Health Institute Montpellier, University of Montpellier, INRAE, CIRAD, IRD, Institut Agro, 34398 Montpellier, France
| | - Huichuan Huang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming 650201, China; Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University, Kunming 650201, China.
| | - Thomas Kroj
- Plant Health Institute Montpellier, University of Montpellier, INRAE, CIRAD, IRD, Institut Agro, 34398 Montpellier, France.
| | - Jonathan D G Jones
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK.
| |
Collapse
|
2
|
Ramírez Martínez J, Guillou S, Le Prieur S, Di Vittorio P, Bonal F, Taliadoros D, Gueret E, Fournier E, Stukenbrock EH, Valade R, Gladieux P. Deep population structure linked to host vernalization requirement in the barley net blotch fungal pathogen. Microb Genom 2024; 10:001241. [PMID: 38713188 PMCID: PMC11170133 DOI: 10.1099/mgen.0.001241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 04/09/2024] [Indexed: 05/08/2024] Open
Abstract
Invasive fungal pathogens pose a substantial threat to widely cultivated crop species, owing to their capacity to adapt to new hosts and new environmental conditions. Gaining insights into the demographic history of these pathogens and unravelling the mechanisms driving coevolutionary processes are crucial for developing durably effective disease management programmes. Pyrenophora teres is a significant fungal pathogen of barley, consisting of two lineages, Ptt and Ptm, with global distributions and demographic histories reflecting barley domestication and spread. However, the factors influencing the population structure of P. teres remain poorly understood, despite the varietal and environmental heterogeneity of barley agrosystems. Here, we report on the population genomic structure of P. teres in France and globally. We used genotyping-by-sequencing to show that Ptt and Ptm can coexist in the same area in France, with Ptt predominating. Furthermore, we showed that differences in the vernalization requirement of barley varieties were associated with population differentiation within Ptt in France and at a global scale, with one population cluster found on spring barley and another population cluster found on winter barley. Our results demonstrate how cultivation conditions, possibly associated with genetic differences between host populations, can be associated with the maintenance of divergent invasive pathogen populations coexisting over large geographic areas. This study not only advances our understanding of the coevolutionary dynamics of the Pt-barley pathosystem but also prompts further research on the relative contributions of adaptation to the host versus adaptation to abiotic conditions in shaping Ptt populations.
Collapse
Affiliation(s)
- Julie Ramírez Martínez
- PHIM Plant Health Institute, Univ. Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
| | - Sonia Guillou
- PHIM Plant Health Institute, Univ. Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
| | | | - Pauline Di Vittorio
- PHIM Plant Health Institute, Univ. Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
| | - Florelle Bonal
- UMR AGAP (Amélioration génétique et adaptation des plantes), Montpellier, France
| | - Demetris Taliadoros
- Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306, Plön, Germany
- Christian-Albrechts University of Kiel, Am Botanischen Garten 9-11, 24118, Kiel, Germany
| | - Elise Gueret
- MGX-Montpellier GenomiX, University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Elisabeth Fournier
- PHIM Plant Health Institute, Univ. Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
| | - Eva H. Stukenbrock
- Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306, Plön, Germany
- Christian-Albrechts University of Kiel, Am Botanischen Garten 9-11, 24118, Kiel, Germany
| | | | - Pierre Gladieux
- PHIM Plant Health Institute, Univ. Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
| |
Collapse
|
3
|
Muteeb G. Nanotechnology-A Light of Hope for Combating Antibiotic Resistance. Microorganisms 2023; 11:1489. [PMID: 37374990 DOI: 10.3390/microorganisms11061489] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 05/31/2023] [Accepted: 06/01/2023] [Indexed: 06/29/2023] Open
Abstract
Antibiotic usage and resistance are major health concerns. Antibiotic resistance occurs when bacteria evolve to resist the effects of antibiotics, making it impossible to treat infections. The overuse and misuse of antibiotics are the main contributing factors, while environmental stress (such as heavy metals accumulation), unhygienic conditions, illiteracy, and unawareness also contribute to antibiotic resistance. The slow and costly development of new antibiotics has lagged behind the emergence of antibiotic-resistant bacteria, and the overuse of antibiotics leads to negative consequences. The current study used different literature resources to generate an opinion and find a possible solution to antibiotic barriers. Different scientific approaches have been reported to overcome antibiotic resistance. The most useful approach among these is nanotechnology. Nanoparticles can be engineered to disrupt bacterial cell walls or membranes, effectively eliminating resistant strains. Additionally, nanoscale devices enable the real-time monitoring of bacterial populations, allowing for the early detection of resistance emergence. Nanotechnology, along with evolutionary theory offers promising avenues in combating antibiotic resistance. Evolutionary theory helps us understand the mechanisms by which bacteria develop resistance, allowing us to anticipate and counteract their adaptive strategies. By studying the selective pressures that drive resistance, we can therefore design more effective interventions or traps. The synergy between the evolutionary theory and nanotechnology presents a powerful approach to combat antibiotic resistance, offering new avenues for the development of effective treatments and the preservation of our antibiotic arsenal.
Collapse
Affiliation(s)
- Ghazala Muteeb
- Department of Nursing, College of Applied Medical Science, King Faisal University, Al-Ahsa 31982, Saudi Arabia
| |
Collapse
|
4
|
Genotyping and In Silico Analysis of Delmarva (DMV/1639) Infectious Bronchitis Virus (IBV) Spike 1 (S1) Glycoprotein. Genes (Basel) 2022; 13:genes13091617. [PMID: 36140785 PMCID: PMC9498812 DOI: 10.3390/genes13091617] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 09/04/2022] [Accepted: 09/06/2022] [Indexed: 11/17/2022] Open
Abstract
Genetic diversity and evolution of infectious bronchitis virus (IBV) are mainly impacted by mutations in the spike 1 (S1) gene. This study focused on whole genome sequencing of an IBV isolate (IBV/Ck/Can/2558004), which represents strains highly prevalent in Canadian commercial poultry, especially concerning features related to its S1 gene and protein sequences. Based on the phylogeny of the S1 gene, IBV/Ck/Can/2558004 belongs to the GI-17 lineage. According to S1 gene and protein pairwise alignment, IBV/Ck/Can/2558004 had 99.44–99.63% and 98.88–99.25% nucleotide (nt) and deduced amino acid (aa) identities, respectively, with five Canadian Delmarva (DMV/1639) IBVs isolated in 2019, and it also shared 96.63–97.69% and 94.78–97.20% nt and aa similarities with US DMV/1639 IBVs isolated in 2011 and 2019, respectively. Further homology analysis of aa sequences showed the existence of some aa substitutions in the hypervariable regions (HVRs) of the S1 protein of IBV/Ck/Can/2558004 compared to US DMV/1639 isolates; most of these variant aa residues have been subjected to positive selection pressure. Predictive analysis of potential N-glycosylation and phosphorylation motifs showed either loss or acquisition in the S1 glycoprotein of IBV/Ck/Can/2558004 compared to S1 of US DMV/1639 IBV. Furthermore, bioinformatic analysis showed some of the aa changes within the S1 protein of IBV/Ck/Can/2558004 have been predicted to impact the function and structure of the S1 protein, potentially leading to a lower binding affinity of the S1 protein to its relevant ligand (sialic acid). In conclusion, these findings revealed that the DMV/1639 IBV isolates are under continuous evolution among Canadian poultry.
Collapse
|
5
|
Thierry M, Charriat F, Milazzo J, Adreit H, Ravel S, Cros-Arteil S, borron S, Sella V, Kroj T, Ioos R, Fournier E, Tharreau D, Gladieux P. Maintenance of divergent lineages of the Rice Blast Fungus Pyricularia oryzae through niche separation, loss of sex and post-mating genetic incompatibilities. PLoS Pathog 2022; 18:e1010687. [PMID: 35877779 PMCID: PMC9352207 DOI: 10.1371/journal.ppat.1010687] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 08/04/2022] [Accepted: 06/17/2022] [Indexed: 11/18/2022] Open
Abstract
Many species of fungal plant pathogens coexist as multiple lineages on the same host, but the factors underlying the origin and maintenance of population structure remain largely unknown. The rice blast fungus Pyricularia oryzae is a widespread model plant pathogen displaying population subdivision. However, most studies of natural variation in P. oryzae have been limited in genomic or geographic resolution, and host adaptation is the only factor that has been investigated extensively as a contributor to population subdivision. In an effort to complement previous studies, we analyzed genetic and phenotypic diversity in isolates of the rice blast fungus covering a broad geographical range. Using single-nucleotide polymorphism genotyping data for 886 isolates sampled from 152 sites in 51 countries, we showed that population subdivision of P. oryzae in one recombining and three clonal lineages with broad distributions persisted with deeper sampling. We also extended previous findings by showing further population subdivision of the recombining lineage into one international and three Asian clusters, and by providing evidence that the three clonal lineages of P. oryzae were found in areas with different prevailing environmental conditions, indicating niche separation. Pathogenicity tests and bioinformatic analyses using an extended set of isolates and rice varieties indicated that partial specialization to rice subgroups contributed to niche separation between lineages, and differences in repertoires of putative virulence effectors were consistent with differences in host range. Experimental crosses revealed that female sterility and early post-mating genetic incompatibilities acted as strong additional barriers to gene flow between clonal lineages. Our results demonstrate that the spread of a fungal pathogen across heterogeneous habitats and divergent populations of a crop species can lead to niche separation and reproductive isolation between distinct, widely distributed, lineages.
Collapse
Affiliation(s)
- Maud Thierry
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
- CIRAD, UMR PHIM, Montpellier, France
- ANSES Plant Health Laboratory, Mycology Unit, Malzéville, France
| | - Florian Charriat
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
| | - Joëlle Milazzo
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
- CIRAD, UMR PHIM, Montpellier, France
| | - Henri Adreit
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
- CIRAD, UMR PHIM, Montpellier, France
| | - Sébastien Ravel
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
- CIRAD, UMR PHIM, Montpellier, France
| | - Sandrine Cros-Arteil
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
| | - Sonia borron
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
| | - Violaine Sella
- ANSES Plant Health Laboratory, Mycology Unit, Malzéville, France
| | - Thomas Kroj
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
| | - Renaud Ioos
- ANSES Plant Health Laboratory, Mycology Unit, Malzéville, France
| | - Elisabeth Fournier
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
| | - Didier Tharreau
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
- CIRAD, UMR PHIM, Montpellier, France
- * E-mail: (DT); (PG)
| | - Pierre Gladieux
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
- * E-mail: (DT); (PG)
| |
Collapse
|
6
|
Legnardi M, Tucciarone CM, Franzo G, Cecchinato M. Infectious Bronchitis Virus Evolution, Diagnosis and Control. Vet Sci 2020; 7:E79. [PMID: 32580381 PMCID: PMC7356646 DOI: 10.3390/vetsci7020079] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/16/2020] [Accepted: 06/18/2020] [Indexed: 01/09/2023] Open
Abstract
RNA viruses are characterized by high mutation and recombination rates, which allow a rapid adaptation to new environments. Most of the emerging diseases and host jumps are therefore sustained by these viruses. Rapid evolution may also hinder the understanding of molecular epidemiology, affect the sensitivity of diagnostic assays, limit the vaccine efficacy and favor episodes of immune escape, thus significantly complicating the control of even well-known pathogens. The history of infectious bronchitis virus (IBV) fits well with the above-mentioned scenario. Despite being known since the 1930s, it still represents one of the main causes of disease and economic losses for the poultry industry. A plethora of strategies have been developed and applied over time, with variable success, to limit its impact. However, they have rarely been evaluated objectively and on an adequate scale. Therefore, the actual advantages and disadvantages of IBV detection and control strategies, as well as their implementation, still largely depend on individual sensibility. The present manuscript aims to review the main features of IBV biology and evolution, focusing on their relevance and potential applications in terms of diagnosis and control.
Collapse
Affiliation(s)
| | - Claudia Maria Tucciarone
- Department of Animal Medicine, Production and Health, University of Padua, Viale dell’Università, 16, 35020 Legnaro, Italy; (M.L.); (G.F.); (M.C.)
| | | | | |
Collapse
|
7
|
|
8
|
Abstract
Viral quasispecies refers to a population structure that consists of extremely large numbers of variant genomes, termed mutant spectra, mutant swarms or mutant clouds. Fueled by high mutation rates, mutants arise continually, and they change in relative frequency as viral replication proceeds. The term quasispecies was adopted from a theory of the origin of life in which primitive replicons) consisted of mutant distributions, as found experimentally with present day RNA viruses. The theory provided a new definition of wild type, and a conceptual framework for the interpretation of the adaptive potential of RNA viruses that contrasted with classical studies based on consensus sequences. Standard clonal analyses and deep sequencing methodologies have confirmed the presence of myriads of mutant genomes in viral populations, and their participation in adaptive processes. The quasispecies concept applies to any biological entity, but its impact is more evident when the genome size is limited and the mutation rate is high. This is the case of the RNA viruses, ubiquitous in our biosphere, and that comprise many important pathogens. In virology, quasispecies are defined as complex distributions of closely related variant genomes subjected to genetic variation, competition and selection, and that may act as a unit of selection. Despite being an integral part of their replication, high mutation rates have an upper limit compatible with inheritable information. Crossing such a limit leads to RNA virus extinction, a transition that is the basis of an antiviral design termed lethal mutagenesis.
Collapse
Affiliation(s)
- Esteban Domingo
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd) del Instituto de Salud Carlos III, Madrid, Spain
| | - Celia Perales
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd) del Instituto de Salud Carlos III, Madrid, Spain
- Department of Clinical Microbiology, IIS-Fundación Jiménez Díaz, UAM, Madrid, Spain
| |
Collapse
|
9
|
Depotter JRL, Seidl MF, van den Berg GCM, Thomma BPHJ, Wood TA. A distinct and genetically diverse lineage of the hybrid fungal pathogen Verticillium longisporum population causes stem striping in British oilseed rape. Environ Microbiol 2017; 19:3997-4009. [PMID: 28523726 DOI: 10.1111/1462-2920.13801] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 05/11/2017] [Accepted: 05/13/2017] [Indexed: 11/30/2022]
Abstract
Population genetic structures illustrate evolutionary trajectories of organisms adapting to differential environmental conditions. Verticillium stem striping disease on oilseed rape was mainly observed in continental Europe, but has recently emerged in the United Kingdom. The disease is caused by the hybrid fungal species Verticillium longisporum that originates from at least three separate hybridization events, yet hybrids between Verticillium progenitor species A1 and D1 are mainly responsible for Verticillium stem striping. We reveal a hitherto un-described dichotomy within V. longisporum lineage A1/D1 that correlates with the geographic distribution of the isolates with an 'A1/D1 West' and an 'A1/D1 East' cluster. Genome comparison between representatives of the A1/D1 West and East clusters excluded population distinctiveness through separate hybridization events. Remarkably, the A1/D1 West population that is genetically more diverse than the entire A1/D1 East cluster caused the sudden emergence of Verticillium stem striping in the UK, whereas in continental Europe Verticillium stem striping is predominantly caused by the more genetically uniform A1/D1 East population. The observed genetic diversity of the A1/D1 West population argues against a recent introduction of the pathogen into the UK, but rather suggests that the pathogen previously established in the UK and remained latent or unnoticed as oilseed rape pathogen until recently.
Collapse
Affiliation(s)
- Jasper R L Depotter
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, Wageningen, 6708 PB, The Netherlands.,Department of Crops and Agronomy, National Institute of Agricultural Botany, Huntingdon Road, Cambridge, CB3 0LE, UK
| | - Michael F Seidl
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, Wageningen, 6708 PB, The Netherlands
| | - Grardy C M van den Berg
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, Wageningen, 6708 PB, The Netherlands
| | - Bart P H J Thomma
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, Wageningen, 6708 PB, The Netherlands
| | - Thomas A Wood
- Department of Crops and Agronomy, National Institute of Agricultural Botany, Huntingdon Road, Cambridge, CB3 0LE, UK
| |
Collapse
|
10
|
Diard M, Hardt WD. Evolution of bacterial virulence. FEMS Microbiol Rev 2017; 41:679-697. [DOI: 10.1093/femsre/fux023] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 04/24/2017] [Indexed: 12/13/2022] Open
|
11
|
Liao J, Huang H, Meusnier I, Adreit H, Ducasse A, Bonnot F, Pan L, He X, Kroj T, Fournier E, Tharreau D, Gladieux P, Morel JB. Pathogen effectors and plant immunity determine specialization of the blast fungus to rice subspecies. eLife 2016; 5. [PMID: 28008850 PMCID: PMC5182064 DOI: 10.7554/elife.19377] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 12/01/2016] [Indexed: 12/02/2022] Open
Abstract
Understanding how fungi specialize on their plant host is crucial for developing sustainable disease control. A traditional, centuries-old rice agro-system of the Yuanyang terraces was used as a model to show that virulence effectors of the rice blast fungus Magnaporthe oryzaeh play a key role in its specialization on locally grown indica or japonica local rice subspecies. Our results have indicated that major differences in several components of basal immunity and effector-triggered immunity of the japonica and indica rice varieties are associated with specialization of M. oryzae. These differences thus play a key role in determining M. oryzae host specificity and may limit the spread of the pathogen within the Yuanyang agro-system. Specifically, the AVR-Pia effector has been identified as a possible determinant of the specialization of M. oryzae to local japonica rice. DOI:http://dx.doi.org/10.7554/eLife.19377.001 Microbes that cause diseases in plants are a threat to food security. For example, the rice blast fungus Magnaporthe oryzae causes the loss of enough rice to feed 60 million people each year. Disease-causing microbes must overcome the plant’s first line of defense, which includes preformed barriers and antimicrobial responses that are triggered by characteristic molecules found in many different microbes. The microbes that can overcome this first line of defense typically do so with an arsenal of proteins called effectors that interfere with specific biological processes in the plant. To counteract this interference, some plants have evolved genes that encode proteins that detect these effectors and trigger stronger antimicrobial responses. For centuries, farmers and plant breeders have selected for these resistance genes when trying to breed crops that are more resistant to disease. However, over time, disease-causing microbes have lost effectors, which means that several resistance genes have rapidly become ineffective. Some researchers predicted that growing a mixture of varieties of a given crop together might be a better way of protecting crop yields. Over 16 years ago, this idea was proved successful against the rice blast fungus for rice plants grown in China. However, the exact reasons why this strategy worked and its effects on the fungus were not clear. Now Liao, Huang et al. have taken another look at rice varieties grown via the traditional method of terraces of rice paddies in Yuanyang. Some of these varieties had a strong first line of defense and few resistance genes, while others relied much more on resistance genes to protect themselves again the rice blast fungus. Liao, Huang et al. found that growing rice varieties with such different immune systems forces some of the rice blast fungi to accumulate effector proteins to combat the first line of defense, whereas other fungi had to get rid of these effectors to avoid being recognized by the major resistance genes. These two forces led to the evolution of two specialized populations of fungi that can infect specific rice varieties but not others. This means that the fungi cannot spread in the landscape, and so the fields of rice become resistant as a whole. These new findings demonstrate the importance of diversity in rice for sustainable crop protection. The next challenge will be to demonstrate if a similar approach can also protect other major crops grown in different agricultural settings. DOI:http://dx.doi.org/10.7554/eLife.19377.002
Collapse
Affiliation(s)
- Jingjing Liao
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, China.,Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University, Kunming, China
| | - Huichuan Huang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, China.,Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University, Kunming, China
| | - Isabelle Meusnier
- Institut National de la Recherche Agronomique, UMR BGPI, Montpellier, France
| | - Henri Adreit
- Centre de coopération internationale en recherche agronomique pour le développement, UMR BGPI, Montpellier, France
| | - Aurélie Ducasse
- Institut National de la Recherche Agronomique, UMR BGPI, Montpellier, France
| | - François Bonnot
- Centre de coopération internationale en recherche agronomique pour le développement, UMR BGPI, Montpellier, France
| | - Lei Pan
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, China.,Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University, Kunming, China
| | - Xiahong He
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, China.,Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University, Kunming, China
| | - Thomas Kroj
- Institut National de la Recherche Agronomique, UMR BGPI, Montpellier, France
| | - Elisabeth Fournier
- Institut National de la Recherche Agronomique, UMR BGPI, Montpellier, France
| | - Didier Tharreau
- Centre de coopération internationale en recherche agronomique pour le développement, UMR BGPI, Montpellier, France
| | - Pierre Gladieux
- Institut National de la Recherche Agronomique, UMR BGPI, Montpellier, France
| | - Jean-Benoit Morel
- Institut National de la Recherche Agronomique, UMR BGPI, Montpellier, France
| |
Collapse
|
12
|
Franzo G, Tucciarone CM, Cecchinato M, Drigo M. Porcine circovirus type 2 (PCV2) evolution before and after the vaccination introduction: A large scale epidemiological study. Sci Rep 2016; 6:39458. [PMID: 27991573 PMCID: PMC5171922 DOI: 10.1038/srep39458] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 11/21/2016] [Indexed: 01/02/2023] Open
Abstract
Since their commercialization, vaccines against Porcine circovirus type 2 (PCV2) have been the cornerstone control strategy. Nevertheless, the periodic emergence of new genotype waves and the recent reports of vaccine failure outbreaks have raised the question if widespread vaccination strategies could have driven viral evolution and affected different genotype fitness. To investigate this issue an in-deep analysis, based on a bioinformatics and biostatistics approach, has been implemented. ORF2 sequences from vaccinated and non-vaccinated populations (i.e. domestic pigs before and after vaccine introduction and wild boars) were considered. The action of selective forces on PCV2 strains has been analyzed and compared among groups. Remarkable differences were found in the selective forces acting on viral populations circulating in different “immune environments”. Particularly for PCV2a, a directional selection promoting a change in the viral capsid away from the vaccine specific antigenic determinants has been detected after vaccine introduction. Involved amino acids were previously reported to be part of viral epitopes whose variability is responsible of immune escape. Our findings support a change in PCV2 evolutionary pattern after widespread vaccination introduction and stress once more the compulsoriness of a continuous monitoring of PCV2 epidemiology to promptly act in response to the emergence of possible vaccine-escaping mutants.
Collapse
|
13
|
Feurtey A, Gladieux P, Hood ME, Snirc A, Cornille A, Rosenthal L, Giraud T. Strong phylogeographic co-structure between the anther-smut fungus and its white campion host. THE NEW PHYTOLOGIST 2016; 212:668-679. [PMID: 27500396 DOI: 10.1111/nph.14125] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 06/18/2016] [Indexed: 06/06/2023]
Abstract
Although congruence between host and pathogen phylogenies has been extensively investigated, the congruence between host and pathogen genetic structures at the within-species level has received little attention. Using an unprecedented and comprehensive collection of associated plant-pathogen samples, we investigated the degree of congruence between the genetic structures across Europe of two evolutionary and ecological model organisms, the anther-smut pathogen Microbotryum lychnidis-dioicae and its host plant Silene latifolia. We demonstrated a significant and particularly strong level of host-pathogen co-structure, with three main genetic clusters displaying highly similar spatial ranges in Western Europe, Eastern Europe and Italy, respectively. Correcting for the geographical component of genetic variation, significant correlations were still found between the genetic distances of anther-smut and host populations. Inoculation experiments suggested plant local adaptation, at the cluster level, for resistance to pathogens. These findings indicate that the pathogen remained isolated in the same fragmented southern refugia as its host plant during the last glaciation, and that little long-distance dispersal has occurred since the recolonization of Europe for either the plant or the pathogen, despite their known ability to travel across continents. This, together with the inoculation results, suggests that coevolutionary and competitive processes may be drivers of host-pathogen co-structure.
Collapse
Affiliation(s)
- Alice Feurtey
- Ecologie Systématique Evolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Orsay, 91400, France
| | - Pierre Gladieux
- Ecologie Systématique Evolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Orsay, 91400, France
- UMR BGPI, INRA, Montpellier, 34398, France
| | - Michael E Hood
- Department of Biology, Amherst College, Amherst, MA, 01002, USA
| | - Alodie Snirc
- Ecologie Systématique Evolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Orsay, 91400, France
| | - Amandine Cornille
- Ecologie Systématique Evolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Orsay, 91400, France
| | - Lisa Rosenthal
- Department of Biology, Amherst College, Amherst, MA, 01002, USA
| | - Tatiana Giraud
- Ecologie Systématique Evolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Orsay, 91400, France.
| |
Collapse
|
14
|
Ali S, Soubeyrand S, Gladieux P, Giraud T, Leconte M, Gautier A, Mboup M, Chen W, de Vallavieille-Pope C, Enjalbert J. cloncase: Estimation of sex frequency and effective population size by clonemate resampling in partially clonal organisms. Mol Ecol Resour 2016; 16:845-61. [DOI: 10.1111/1755-0998.12511] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 01/29/2016] [Accepted: 02/02/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Sajid Ali
- UMR1290, BIOGER; INRA-AgroParisTech; BP01 78850 Thiverval-Grignon France
- Institute of Biotechnology and Genetic Engineering; the University of Agriculture, Peshawar; 25000 Peshawar Pakistan
| | - Samuel Soubeyrand
- UR546 Biostatistics and Spatial Processes; INRA; 84914 Avignon France
| | - Pierre Gladieux
- Ecologie Systématique Evolution; CNRS; Univ. Paris-Sud; AgroParisTech; Université Paris-Saclay; 91400 Orsay France
- UMR385 Biologie et Génétique des Interactions Plante-Parasite; CIRAD; INRA; F-34398 Montpellier France
| | - Tatiana Giraud
- Ecologie Systématique Evolution; CNRS; Univ. Paris-Sud; AgroParisTech; Université Paris-Saclay; 91400 Orsay France
| | - Marc Leconte
- UMR1290, BIOGER; INRA-AgroParisTech; BP01 78850 Thiverval-Grignon France
| | - Angélique Gautier
- UMR1290, BIOGER; INRA-AgroParisTech; BP01 78850 Thiverval-Grignon France
| | - Mamadou Mboup
- DuPont de Nemours (France) SAS Crop Protection - European Research & Development Center; 24, rue du Moulin 68740 Nambsheim France
| | - Wanquan Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests; Institute of Plant Protection; Chinese Academy of Agricultural Sciences; No. 2 Yuanmingyuan West Road Beijing 100193 China
| | | | - Jérôme Enjalbert
- Ecologie Systématique Evolution; CNRS; Univ. Paris-Sud; AgroParisTech; Université Paris-Saclay; 91400 Orsay France
- GQE - Le Moulon; INRA; Univ. Paris-Sud; CNRS; AgroParisTech; Université Paris-Saclay; F-91190 Gif-sur-Yvette France
| |
Collapse
|
15
|
Trends in Antiviral Strategies. VIRUS AS POPULATIONS 2016. [PMCID: PMC7149557 DOI: 10.1016/b978-0-12-800837-9.00009-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Viral populations are true moving targets regarding the genomic sequences to be targeted in antiviral designs. Experts from different fields have expressed the need of new paradigms for antiviral interventions and viral disease control. This chapter reviews several strategies that aim at counteracting the adaptive capacity of viral quasispecies. The proposed designs are based on combinations of different antiviral drugs and immune modulators, or in the administration of virus-specific mutagenic agents, in an approach termed lethal mutagenesis of viruses. It consists of decreasing viral fitness by an excess of mutations that render viral proteins sub-optimal or non-functional. Viral extinction by lethal mutagenesis involves several sequential, overlapping steps that recapitulate the major concepts of intra-population interactions and genetic information stability discussed in preceding chapters. Despite the magnitude of the challenge, the chapter closes with some optimistic prospects for an effective control of viruses displaying error-prone replication, based on the combined targeting of replication fidelity and the induction of the innate immune response.
Collapse
|
16
|
Lorenzi T, Chisholm RH, Melensi M, Lorz A, Delitala M. Mathematical model reveals how regulating the three phases of T-cell response could counteract immune evasion. Immunology 2015; 146:271-80. [PMID: 26119966 DOI: 10.1111/imm.12500] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 06/21/2015] [Accepted: 06/22/2015] [Indexed: 02/01/2023] Open
Abstract
T cells are key players in immune action against the invasion of target cells expressing non-self antigens. During an immune response, antigen-specific T cells dynamically sculpt the antigenic distribution of target cells, and target cells concurrently shape the host's repertoire of antigen-specific T cells. The succession of these reciprocal selective sweeps can result in 'chase-and-escape' dynamics and lead to immune evasion. It has been proposed that immune evasion can be countered by immunotherapy strategies aimed at regulating the three phases of the immune response orchestrated by antigen-specific T cells: expansion, contraction and memory. Here, we test this hypothesis with a mathematical model that considers the immune response as a selection contest between T cells and target cells. The outcomes of our model suggest that shortening the duration of the contraction phase and stabilizing as many T cells as possible inside the long-lived memory reservoir, using dual immunotherapies based on the cytokines interleukin-7 and/or interleukin-15 in combination with molecular factors that can keep the immunomodulatory action of these interleukins under control, should be an important focus of future immunotherapy research.
Collapse
Affiliation(s)
- Tommaso Lorenzi
- Centre de Mathématiques et de Leurs Applications, ENS Cachan, CNRS, Cachan Cedex, France
| | - Rebecca H Chisholm
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Matteo Melensi
- Department of Health Sciences, A. Avogadro Università del Piemonte Orientale, Novara, Italy
| | - Alexander Lorz
- MAMBA Team, INRIA-Paris-Rocquencourt, Le Chesnay Cedex, France.,Laboratoire Jacques-Louis Lions, Sorbonne Universités, UPMC Univ Paris 06, UMR 7598, Paris, France.,Laboratoire Jacques-Louis Lions, CNRS, UMR 7598, Paris, France
| | - Marcello Delitala
- Department of Mathematical Sciences, Politecnico di Torino, Torino, Italy
| |
Collapse
|
17
|
Long GH, Graham AL. Consequences of immunopathology for pathogen virulence evolution and public health: malaria as a case study. Evol Appl 2015; 4:278-91. [PMID: 25567973 PMCID: PMC3352548 DOI: 10.1111/j.1752-4571.2010.00178.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2010] [Accepted: 12/01/2010] [Indexed: 12/25/2022] Open
Abstract
Evolutionary theories explaining virulence—the fitness damage incurred by infected hosts—often focus on parasite strategies for within-host exploitation. However, much virulence can be caused by the host's own immune response: for example, pro-inflammatory cytokines, although essential for killing malaria parasites, also damage host tissue. Here we argue that immune-mediated virulence, or ‘immunopathology,’ may affect malaria virulence evolution and should be considered in the design of medical interventions. Our argument is based on the ability of immunopathology to disrupt positive virulence-transmission relationships assumed under the trade-off theory of virulence evolution. During rodent malaria infections, experimental reduction of inflammation using reagents approved for field use decreases virulence but increases parasite transmission potential. Importantly, rodent malaria parasites exhibit genetic diversity in the propensity to induce inflammation and invest in transmission-stage parasites in the presence of pro-inflammatory cytokines. If immunopathology positively correlates with malaria parasite density, theory suggests it could select for relatively low malaria virulence. Medical interventions which decrease immunopathology may therefore inadvertently select for increased malaria virulence. The fitness consequences to parasites of variations in immunopathology must be better understood in order to predict trajectories of parasite virulence evolution in heterogeneous host populations and in response to medical interventions.
Collapse
Affiliation(s)
- Gráinne H Long
- Department of Epidemiology and Public Health, London School of Hygiene and Tropical Medicine London, UK
| | - Andrea L Graham
- Institutes of Evolution, Immunology and Infection Research, School of Biological Sciences, University of Edinburgh Edinburgh, UK ; Department of Ecology and Evolutionary Biology, Princeton University Princeton, NJ, USA
| |
Collapse
|
18
|
Ford BE, Sun B, Carpino J, Chapler ES, Ching J, Choi Y, Jhun K, Kim JD, Lallos GG, Morgenstern R, Singh S, Theja S, Dennehy JJ. Frequency and fitness consequences of bacteriophage φ6 host range mutations. PLoS One 2014; 9:e113078. [PMID: 25409341 PMCID: PMC4237377 DOI: 10.1371/journal.pone.0113078] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 10/15/2014] [Indexed: 11/19/2022] Open
Abstract
Viruses readily mutate and gain the ability to infect novel hosts, but few data are available regarding the number of possible host range-expanding mutations allowing infection of any given novel host, and the fitness consequences of these mutations on original and novel hosts. To gain insight into the process of host range expansion, we isolated and sequenced 69 independent mutants of the dsRNA bacteriophage Φ6 able to infect the novel host, Pseudomonas pseudoalcaligenes. In total, we found at least 17 unique suites of mutations among these 69 mutants. We assayed fitness for 13 of 17 mutant genotypes on P. pseudoalcaligenes and the standard laboratory host, P. phaseolicola. Mutants exhibited significantly lower fitnesses on P. pseudoalcaligenes compared to P. phaseolicola. Furthermore, 12 of the 13 assayed mutants showed reduced fitness on P. phaseolicola compared to wildtype Φ6, confirming the prevalence of antagonistic pleiotropy during host range expansion. Further experiments revealed that the mechanistic basis of these fitness differences was likely variation in host attachment ability. In addition, using computational protein modeling, we show that host-range expanding mutations occurred in hotspots on the surface of the phage's host attachment protein opposite a putative hydrophobic anchoring domain.
Collapse
Affiliation(s)
- Brian E. Ford
- Biology Department, Queens College of the City University of New York, New York, New York, United States of America
- The Graduate Center of the City University of New York, New York, New York, United States of America
| | - Bruce Sun
- Biology Department, Queens College of the City University of New York, New York, New York, United States of America
| | - James Carpino
- Biology Department, Queens College of the City University of New York, New York, New York, United States of America
| | - Elizabeth S. Chapler
- Biology Department, Queens College of the City University of New York, New York, New York, United States of America
| | - Jane Ching
- Biology Department, Queens College of the City University of New York, New York, New York, United States of America
| | - Yoon Choi
- Biology Department, Queens College of the City University of New York, New York, New York, United States of America
| | - Kevin Jhun
- Biology Department, Queens College of the City University of New York, New York, New York, United States of America
| | - Jung D. Kim
- Biology Department, Queens College of the City University of New York, New York, New York, United States of America
| | - Gregory G. Lallos
- Biology Department, Queens College of the City University of New York, New York, New York, United States of America
| | - Rachelle Morgenstern
- Biology Department, Queens College of the City University of New York, New York, New York, United States of America
| | - Shalini Singh
- Biology Department, Queens College of the City University of New York, New York, New York, United States of America
| | - Sai Theja
- Biology Department, Queens College of the City University of New York, New York, New York, United States of America
| | - John J. Dennehy
- Biology Department, Queens College of the City University of New York, New York, New York, United States of America
- * E-mail:
| |
Collapse
|
19
|
Akala HM, Achieng AO, Eyase FL, Juma DW, Ingasia L, Cheruiyot AC, Okello C, Omariba D, Owiti EA, Muriuki C, Yeda R, Andagalu B, Johnson JD, Kamau E. Five-year tracking of Plasmodium falciparum allele frequencies in a holoendemic area with indistinct seasonal transitions. J Multidiscip Healthc 2014; 7:515-23. [PMID: 25395861 PMCID: PMC4227620 DOI: 10.2147/jmdh.s67252] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND The renewed malaria eradication efforts require an understanding of the seasonal patterns of frequency of polymorphic variants in order to focus limited funds productively. Although cross-sectional studies in holoendemic areas spanning a single year could be useful in describing parasite genotype status at a given point, such information is inadequate in describing temporal trends in genotype polymorphisms. For Plasmodium falciparum isolates from Kisumu District Hospital, Plasmodium falciparum chloroquine-resistance transporter gene (Pfcrt-K76T) and P. falciparum multidrug resistance gene 1 (PfMDR1-N86Y), were analyzed for polymorphisms and parasitemia changes in the 53 months from March 2008 to August 2012. Observations were compared with prevailing climatic factors, including humidity, rainfall, and temperature. METHODS Parasitemia (the percentage of infected red blood cells per total red blood cells) was established by microscopy for P. falciparum malaria-positive samples. P. falciparum DNA was extracted from whole blood using a Qiagen DNA Blood Mini Kit. Single nucleotide polymorphism identification at positions Pfcrt-K76T and PfMDR1-N86Y was performed using real-time polymerase chain reaction and/or sequencing. Data on climatic variables were obtained from http://www.tutiempo.net/en/. RESULTS A total of 895 field isolates from 2008 (n=169), 2009 (n=161), 2010 (n=216), 2011 (n=223), and 2012 (n=126) showed large variations in monthly frequency of PfMDR1-N86Y and Pfcrt-K76T as the mutant genotypes decreased from 68.4%±15% and 38.1%±13% to 29.8%±18% and 13.3%±9%, respectively. The mean percentage of parasitemia was 2.61%±1.01% (coefficient of variation 115.86%; n=895). There was no correlation between genotype or parasitemia and climatic factors. CONCLUSION This study shows variability in the frequency of Pfcrt-K76T and PfMDR1-N86Y polymorphisms during the study period, bringing into focus the role of cross-sectional studies in describing temporal genotype trends. The lack of correlation between genotypes and climatic changes, especially precipitation, emphasizes the cost of investment in genotype change.
Collapse
Affiliation(s)
- Hoseah M Akala
- Global Emerging Infections Surveillance Program, United States Army Medical Research Unit-Kenya, Kenya Medical Research Institute, Walter Reed Project, Kisumu and Nairobi, Kenya
| | - Angela O Achieng
- Global Emerging Infections Surveillance Program, United States Army Medical Research Unit-Kenya, Kenya Medical Research Institute, Walter Reed Project, Kisumu and Nairobi, Kenya
| | - Fredrick L Eyase
- Global Emerging Infections Surveillance Program, United States Army Medical Research Unit-Kenya, Kenya Medical Research Institute, Walter Reed Project, Kisumu and Nairobi, Kenya
| | - Dennis W Juma
- Global Emerging Infections Surveillance Program, United States Army Medical Research Unit-Kenya, Kenya Medical Research Institute, Walter Reed Project, Kisumu and Nairobi, Kenya
| | - Luiser Ingasia
- Global Emerging Infections Surveillance Program, United States Army Medical Research Unit-Kenya, Kenya Medical Research Institute, Walter Reed Project, Kisumu and Nairobi, Kenya
| | - Agnes C Cheruiyot
- Global Emerging Infections Surveillance Program, United States Army Medical Research Unit-Kenya, Kenya Medical Research Institute, Walter Reed Project, Kisumu and Nairobi, Kenya
| | - Charles Okello
- Global Emerging Infections Surveillance Program, United States Army Medical Research Unit-Kenya, Kenya Medical Research Institute, Walter Reed Project, Kisumu and Nairobi, Kenya
| | - Duke Omariba
- Global Emerging Infections Surveillance Program, United States Army Medical Research Unit-Kenya, Kenya Medical Research Institute, Walter Reed Project, Kisumu and Nairobi, Kenya
| | - Eunice A Owiti
- Global Emerging Infections Surveillance Program, United States Army Medical Research Unit-Kenya, Kenya Medical Research Institute, Walter Reed Project, Kisumu and Nairobi, Kenya
| | - Catherine Muriuki
- Global Emerging Infections Surveillance Program, United States Army Medical Research Unit-Kenya, Kenya Medical Research Institute, Walter Reed Project, Kisumu and Nairobi, Kenya
| | - Redemptah Yeda
- Global Emerging Infections Surveillance Program, United States Army Medical Research Unit-Kenya, Kenya Medical Research Institute, Walter Reed Project, Kisumu and Nairobi, Kenya
| | - Ben Andagalu
- Global Emerging Infections Surveillance Program, United States Army Medical Research Unit-Kenya, Kenya Medical Research Institute, Walter Reed Project, Kisumu and Nairobi, Kenya
| | - Jacob D Johnson
- Global Emerging Infections Surveillance Program, United States Army Medical Research Unit-Kenya, Kenya Medical Research Institute, Walter Reed Project, Kisumu and Nairobi, Kenya
| | - Edwin Kamau
- Global Emerging Infections Surveillance Program, United States Army Medical Research Unit-Kenya, Kenya Medical Research Institute, Walter Reed Project, Kisumu and Nairobi, Kenya
| |
Collapse
|
20
|
Walker AS, Gladieux P, Decognet V, Fermaud M, Confais J, Roudet J, Bardin M, Bout A, C. Nicot P, Poncet C, Fournier E. Population structure and temporal maintenance of the multihost fungal pathogenBotrytis cinerea: causes and implications for disease management. Environ Microbiol 2014; 17:1261-74. [DOI: 10.1111/1462-2920.12563] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 07/04/2014] [Indexed: 01/02/2023]
Affiliation(s)
- Anne-Sophie Walker
- INRA, UR 1290 BIOGER-CPP; Avenue Lucien Brétignières Thiverval-Grignon F-78850 France
| | - Pierre Gladieux
- CNRS, UMR 8079 Ecologie Systématique Evolution; Bâtiment 360 Orsay F-91405 France
- University of Paris-Sud; Orsay F-91405 France
- Department of Plant and Microbial Biology; University of California; Berkeley CA 94720 USA
| | - Véronique Decognet
- INRA, UR 407 Plant Pathology Unit; Domaine Saint Maurice; Montfavet F-84143 France
| | - Marc Fermaud
- INRA UMR 1065 SAVE; ISVV; 71 Avenue Edouard Bourlaux Villenave d'Ornon F-33882 France
| | - Johann Confais
- INRA, UR 1290 BIOGER-CPP; Avenue Lucien Brétignières Thiverval-Grignon F-78850 France
| | - Jean Roudet
- INRA UMR 1065 SAVE; ISVV; 71 Avenue Edouard Bourlaux Villenave d'Ornon F-33882 France
| | - Marc Bardin
- INRA, UR 407 Plant Pathology Unit; Domaine Saint Maurice; Montfavet F-84143 France
| | - Alexandre Bout
- INRA, UMR 1355 ISA, TEAPEA; Sophia-Antipolis F-06903 France
| | - Philippe C. Nicot
- INRA, UR 407 Plant Pathology Unit; Domaine Saint Maurice; Montfavet F-84143 France
| | | | - Elisabeth Fournier
- INRA, UMR BGPI; TA A 54/K; Campus International de Baillarguet Montpellier F-34398 France
| |
Collapse
|
21
|
Carter LM, Schneider P, Reece SE. Information use and plasticity in the reproductive decisions of malaria parasites. Malar J 2014; 13:115. [PMID: 24670151 PMCID: PMC3986881 DOI: 10.1186/1475-2875-13-115] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 03/23/2014] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Investment in the production of transmissible stages (gametocytes) and their sex ratio are malaria parasite traits that underpin mosquito infectivity and are therefore central to epidemiology. Malaria parasites adjust their levels of investment into gametocytes and sex ratio in response to changes in the in-host environment (including red blood cell resource availability, host immune responses, competition from con-specific genotypes in mixed infections, and drug treatment). This plasticity appears to be adaptive (strategic) because parasites prioritize investment (in sexual versus asexual stages and male versus female stages) in manners predicted to maximize fitness. However, the information, or 'cues' that parasites use to detect environmental changes and make appropriate decisions about investment into gametocytes and their sex ratio are unknown. METHODS Single genotype Plasmodium chabaudi infections were exposed to 'cue' treatments consisting of intact or lysed uninfected red blood cells, lysed parasitized RBCs of the same clone or an unrelated clone, and an unmanipulated control. Infection dynamics (proportion of reticulocytes, red blood cell and asexual stage parasite densities) were monitored, and changes in gametocyte investment and sex ratio in response to cue treatments, applied either pre- or post-peak of infection were examined. RESULTS AND CONCLUSIONS A significant reduction in gametocyte density was observed in response to the presence of lysed parasite material and a borderline significant increase in sex ratio (proportion of male gametocytes) upon exposure to lysed red blood cells (both uninfected and infected) was observed. Furthermore, the changes in gametocyte density and sex ratio in response to these cues depend on the age of infection. Demonstrating that variation in gametocyte investment and sex ratio observed during infections are a result of parasite strategies (rather than the footprint of host physiology), provides a foundation to investigate the fitness consequences of plasticity and explore whether drugs could be developed to trick parasites into making suboptimal decisions.
Collapse
Affiliation(s)
- Lucy M Carter
- Institute of Evolutionary Biology, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, UK
| | - Petra Schneider
- Institute of Evolutionary Biology, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, UK
| | - Sarah E Reece
- Institute of Evolutionary Biology, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, UK
- Centre for Immunity, Infection & Evolution, Institutes of Evolution, Immunology and Infection Research, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, UK
| |
Collapse
|
22
|
Frequent gene fissions associated with human pathogenic bacteria. Genomics 2014; 103:65-75. [DOI: 10.1016/j.ygeno.2014.02.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 01/21/2014] [Accepted: 02/01/2014] [Indexed: 01/05/2023]
|
23
|
Carter LM, Kafsack BF, Llinás M, Mideo N, Pollitt LC, Reece SE. Stress and sex in malaria parasites. EVOLUTION MEDICINE AND PUBLIC HEALTH 2013; 2013:135-47. [PMID: 24481194 PMCID: PMC3854026 DOI: 10.1093/emph/eot011] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
For vector-borne parasites such as malaria, how within- and between-host processes interact to shape transmission is poorly understood. In the host, malaria parasites replicate asexually but for transmission to occur, specialized sexual stages (gametocytes) must be produced. Despite the central role that gametocytes play in disease transmission, explanations of why parasites adjust gametocyte production in response to in-host factors remain controversial. We propose that evolutionary theory developed to explain variation in reproductive effort in multicellular organisms, provides a framework to understand gametocyte investment strategies. We examine why parasites adjust investment in gametocytes according to the impact of changing conditions on their in-host survival. We then outline experiments required to determine whether plasticity in gametocyte investment enables parasites to maintain fitness in a variable environment. Gametocytes are a target for anti-malarial transmission-blocking interventions so understanding plasticity in investment is central to maximizing the success of control measures in the face of parasite evolution.
Collapse
Affiliation(s)
- Lucy M. Carter
- Institute of Evolutionary Biology, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, UK; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA; Department of Molecular Biology, 246 Carl Icahn Lab, Washington Road, Princeton University, Princeton, NJ, USA; Center for Infectious Disease Dynamics, Departments of Biology and Entomology, Pennsylvania State University, Millennium Science Complex, University Park, PA, USA and Centre for Immunity, Infection & Evolution. Institutes of Evolution, Immunology and Infection Research, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, UK
- *Corresponding author. Institute of Evolutionary Biology, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, EH9 3JT, UK. Tel: +44 131 650 7706; Fax: +44 131 650 6564; E-mail:
| | - Björn F.C. Kafsack
- Institute of Evolutionary Biology, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, UK; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA; Department of Molecular Biology, 246 Carl Icahn Lab, Washington Road, Princeton University, Princeton, NJ, USA; Center for Infectious Disease Dynamics, Departments of Biology and Entomology, Pennsylvania State University, Millennium Science Complex, University Park, PA, USA and Centre for Immunity, Infection & Evolution. Institutes of Evolution, Immunology and Infection Research, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, UK
| | - Manuel Llinás
- Institute of Evolutionary Biology, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, UK; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA; Department of Molecular Biology, 246 Carl Icahn Lab, Washington Road, Princeton University, Princeton, NJ, USA; Center for Infectious Disease Dynamics, Departments of Biology and Entomology, Pennsylvania State University, Millennium Science Complex, University Park, PA, USA and Centre for Immunity, Infection & Evolution. Institutes of Evolution, Immunology and Infection Research, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, UK
| | - Nicole Mideo
- Institute of Evolutionary Biology, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, UK; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA; Department of Molecular Biology, 246 Carl Icahn Lab, Washington Road, Princeton University, Princeton, NJ, USA; Center for Infectious Disease Dynamics, Departments of Biology and Entomology, Pennsylvania State University, Millennium Science Complex, University Park, PA, USA and Centre for Immunity, Infection & Evolution. Institutes of Evolution, Immunology and Infection Research, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, UK
| | - Laura C. Pollitt
- Institute of Evolutionary Biology, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, UK; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA; Department of Molecular Biology, 246 Carl Icahn Lab, Washington Road, Princeton University, Princeton, NJ, USA; Center for Infectious Disease Dynamics, Departments of Biology and Entomology, Pennsylvania State University, Millennium Science Complex, University Park, PA, USA and Centre for Immunity, Infection & Evolution. Institutes of Evolution, Immunology and Infection Research, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, UK
| | - Sarah E. Reece
- Institute of Evolutionary Biology, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, UK; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA; Department of Molecular Biology, 246 Carl Icahn Lab, Washington Road, Princeton University, Princeton, NJ, USA; Center for Infectious Disease Dynamics, Departments of Biology and Entomology, Pennsylvania State University, Millennium Science Complex, University Park, PA, USA and Centre for Immunity, Infection & Evolution. Institutes of Evolution, Immunology and Infection Research, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, UK
| |
Collapse
|
24
|
Hawley DM, Osnas EE, Dobson AP, Hochachka WM, Ley DH, Dhondt AA. Parallel patterns of increased virulence in a recently emerged wildlife pathogen. PLoS Biol 2013; 11:e1001570. [PMID: 23723736 PMCID: PMC3665845 DOI: 10.1371/journal.pbio.1001570] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 04/17/2013] [Indexed: 11/18/2022] Open
Abstract
A bacterial pathogen of wild songbirds evolved higher virulence following its emergence in two separate regions of the host range. The evolution of higher virulence during disease emergence has been predicted by theoretical models, but empirical studies of short-term virulence evolution following pathogen emergence remain rare. Here we examine patterns of short-term virulence evolution using archived isolates of the bacterium Mycoplasma gallisepticum collected during sequential emergence events in two geographically distinct populations of the host, the North American house finch (Haemorhous [formerly Carpodacus] mexicanus). We present results from two complementary experiments, one that examines the trend in pathogen virulence in eastern North American isolates over the course of the eastern epidemic (1994–2008), and the other a parallel experiment on Pacific coast isolates of the pathogen collected after M. gallisepticum established itself in western North American house finch populations (2006–2010). Consistent with theoretical expectations regarding short-term or dynamic evolution of virulence, we show rapid increases in pathogen virulence on both coasts following the pathogen's establishment in each host population. We also find evidence for positive genetic covariation between virulence and pathogen load, a proxy for transmission potential, among isolates of M. gallisepticum. As predicted by theory, indirect selection for increased transmission likely drove the evolutionary increase in virulence in both geographic locations. Our results provide one of the first empirical examples of rapid changes in virulence following pathogen emergence, and both the detected pattern and mechanism of positive genetic covariation between virulence and pathogen load are consistent with theoretical expectations. Our study provides unique empirical insight into the dynamics of short-term virulence evolution that are likely to operate in other emerging pathogens of wildlife and humans. A long-standing paradox in the study of infectious diseases is why pathogens evolve to cause harm to the very hosts they depend on to survive and reproduce. Research over several decades suggests that this harm, or virulence, is an inevitable by-product of the pathogen replication needed to maximize the chance that a given pathogen will be transmitted to another host. Here we demonstrate that a recently emerged bacterial pathogen of a North American songbird species has gradually become more virulent during each of two emergence events in different regions of the host range. This evolution of higher virulence appears to have been driven by selection for high rates of pathogen replication, because bacterial isolates that are more virulent in finches also attain the highest loads in infected host tissues. Overall, our results indicate that emerging pathogens can evolve to become more virulent in their hosts, at least in the short term, when an increase in the pathogen's ability to replicate is linked with higher virulence. Our findings have important implications for understanding and predicting the severity of disease caused by emerging pathogens in wildlife, domestic animals, and humans.
Collapse
Affiliation(s)
- Dana M Hawley
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA.
| | | | | | | | | | | |
Collapse
|
25
|
The evolutionary consequences of alternative types of imperfect vaccines. J Math Biol 2013; 68:969-87. [PMID: 23455568 DOI: 10.1007/s00285-013-0654-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 01/20/2013] [Indexed: 10/27/2022]
Abstract
The emergence and spread of mutant pathogens that evade the effects of prophylactic interventions, including vaccines, threatens our ability to control infectious diseases globally. Imperfect vaccines (e.g. those used against influenza), while not providing life-long immunity, confer protection by reducing a range of pathogen life-history characteristics; conversely, mutant pathogens can gain an advantage by restoring the same range of traits in vaccinated hosts. Using an SEIR model motivated by equine influenza, we investigate the evolutionary consequences of alternative types of imperfect vaccination, by comparing the spread rate of three types of mutant pathogens, in response to three types of vaccines. All mutant types spread faster in response to a transmission-blocking vaccine, relative to vaccines that reduce the proportion of exposed vaccinated individuals becoming infectious, and to vaccines that reduce the length of the infectious period; this difference increases with increasing vaccine efficacy. We interpret our results using the first published Price equation formulation for an SEIR model, and find that our main result is explained by the effects of vaccines on the equilibrium host distribution across epidemiological classes. In particular, the proportion of vaccinated infectious individuals among all exposed and infectious hosts, which is relatively higher in the transmission-blocking vaccine scenario, is important in explaining the faster spread of mutant strains in response to that vaccine. Our work illustrates the connection between epidemiological and evolutionary dynamics, and the need to incorporate both in order to explain and interpret findings of complicated infectious disease dynamics.
Collapse
|
26
|
Pathogen-host-environment interplay and disease emergence. Emerg Microbes Infect 2013; 2:e5. [PMID: 26038452 PMCID: PMC3630490 DOI: 10.1038/emi.2013.5] [Citation(s) in RCA: 148] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 12/07/2012] [Accepted: 01/07/2013] [Indexed: 12/13/2022]
Abstract
Gaining insight in likely disease emergence scenarios is critical to preventing such events from happening. Recent focus has been on emerging zoonoses and on identifying common patterns and drivers of emerging diseases. However, no overarching framework exists to integrate knowledge on all emerging infectious disease events. Here, we propose such a conceptual framework based on changes in the interplay of pathogens, hosts and environment that lead to the formation of novel disease patterns and pathogen genetic adjustment. We categorize infectious disease emergence events into three groups: (i) pathogens showing up in a novel host, ranging from spill-over, including zoonoses, to complete species jumps; (ii) mutant pathogens displaying novel traits in the same host, including an increase in virulence, antimicrobial resistance and host immune escape; and (iii) disease complexes emerging in a new geographic area, either through range expansion or through long distance jumps. Each of these categories is characterized by a typical set of drivers of emergence, matching pathogen trait profiles, disease ecology and transmission dynamics. Our framework may assist in disentangling and structuring the rapidly growing amount of available information on infectious diseases. Moreover, it may contribute to a better understanding of how human action changes disease landscapes globally.
Collapse
|
27
|
Aktipis CA, Nesse RM. Evolutionary foundations for cancer biology. Evol Appl 2013; 6:144-59. [PMID: 23396885 PMCID: PMC3567479 DOI: 10.1111/eva.12034] [Citation(s) in RCA: 142] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 10/12/2012] [Indexed: 12/16/2022] Open
Abstract
New applications of evolutionary biology are transforming our understanding of cancer. The articles in this special issue provide many specific examples, such as microorganisms inducing cancers, the significance of within-tumor heterogeneity, and the possibility that lower dose chemotherapy may sometimes promote longer survival. Underlying these specific advances is a large-scale transformation, as cancer research incorporates evolutionary methods into its toolkit, and asks new evolutionary questions about why we are vulnerable to cancer. Evolution explains why cancer exists at all, how neoplasms grow, why cancer is remarkably rare, and why it occurs despite powerful cancer suppression mechanisms. Cancer exists because of somatic selection; mutations in somatic cells result in some dividing faster than others, in some cases generating neoplasms. Neoplasms grow, or do not, in complex cellular ecosystems. Cancer is relatively rare because of natural selection; our genomes were derived disproportionally from individuals with effective mechanisms for suppressing cancer. Cancer occurs nonetheless for the same six evolutionary reasons that explain why we remain vulnerable to other diseases. These four principles-cancers evolve by somatic selection, neoplasms grow in complex ecosystems, natural selection has shaped powerful cancer defenses, and the limitations of those defenses have evolutionary explanations-provide a foundation for understanding, preventing, and treating cancer.
Collapse
Affiliation(s)
- C Athena Aktipis
- Center for Evolution and Cancer, University of California San Francisco, CA, USA ; Department of Psychology, Arizona State University Tempe, AZ, USA
| | | |
Collapse
|
28
|
Abstract
Felix d'Herelle proposed the use of bacteriophages for the therapy of human and animal bacterial infections at the beginning of the 20th century. This approach, however, was not widely accepted in the West. After the emergence of antibiotics in 1940s, phage research was diverted to a more fundamental level. At the same time, phage therapy was widely practiced in the Soviet Union due to collaboration of Felix d'Herelle with his Georgian colleagues. The majority of the articles dedicated to this subject are from the 1930s and 1940s. The old Soviet literature indicates that phage therapy was used extensively to treat a wide range of bacterial infections in the areas of dermatology (Beridze, 1938), ophthalmology (Rodigina, 1938), urology (Tsulukidze, 1938), stomatology (Ruchko and Tretyak, 1936), pediatrics (Alexandrova et al., 1935; Lurie, 1938), otolaryngology (Ermolieva, 1939), and surgery (Tsulukidze, 1940, 1941). These articles were published in Russian and thus were not readily available to Western scientists. The Western skepticism toward phage therapy itself was again followed by renewed interest and reappraisal, mainly due to the emergence of drug-resistant bacteria. Often the experiments described in the old Soviet articles were not designed properly: the use of placebos and the coding of preparations were absent from most of the studies, number of patients in the experimental and control groups was unequal or missing, sometimes no control groups were used at all, or patients treated previously unsuccessfully with antibiotics were employed as an experimental group and as control. The results obtained and the efficiency of phage prophylaxis were estimated by comparing with results obtained in previous years. In most publications, phage titers and descriptions of methods used for evaluation of the results are not specified. Nevertheless, past experience indicates some effectiveness of phage therapy and prophylaxis. Therefore, these clinical results should not be neglected when designing any future studies.
Collapse
|
29
|
Schneider P, Bell AS, Sim DG, O'Donnell AJ, Blanford S, Paaijmans KP, Read AF, Reece SE. Virulence, drug sensitivity and transmission success in the rodent malaria, Plasmodium chabaudi. Proc Biol Sci 2012; 279:4677-85. [PMID: 23015626 PMCID: PMC3479731 DOI: 10.1098/rspb.2012.1792] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Here, we test the hypothesis that virulent malaria parasites are less susceptible to drug treatment than less virulent parasites. If true, drug treatment might promote the evolution of more virulent parasites (defined here as those doing more harm to hosts). Drug-resistance mechanisms that protect parasites through interactions with drug molecules at the sub-cellular level are well known. However, parasite phenotypes associated with virulence might also help parasites survive in the presence of drugs. For example, rapidly replicating parasites might be better able to recover in the host if drug treatment fails to eliminate parasites. We quantified the effects of drug treatment on the in-host survival and between-host transmission of rodent malaria (Plasmodium chabaudi) parasites which differed in virulence and had never been previously exposed to drugs. In all our treatment regimens and in single- and mixed-genotype infections, virulent parasites were less sensitive to pyrimethamine and artemisinin, the two antimalarial drugs we tested. Virulent parasites also achieved disproportionately greater transmission when exposed to pyrimethamine. Overall, our data suggest that drug treatment can select for more virulent parasites. Drugs targeting transmission stages (such as artemisinin) may minimize the evolutionary advantage of virulence in drug-treated infections.
Collapse
Affiliation(s)
- Petra Schneider
- Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, UK.
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Abstract
Evolution of RNA viruses occurs through disequilibria of collections of closely related mutant spectra or mutant clouds termed viral quasispecies. Here we review the origin of the quasispecies concept and some biological implications of quasispecies dynamics. Two main aspects are addressed: (i) mutant clouds as reservoirs of phenotypic variants for virus adaptability and (ii) the internal interactions that are established within mutant spectra that render a virus ensemble the unit of selection. The understanding of viruses as quasispecies has led to new antiviral designs, such as lethal mutagenesis, whose aim is to drive viruses toward low fitness values with limited chances of fitness recovery. The impact of quasispecies for three salient human pathogens, human immunodeficiency virus and the hepatitis B and C viruses, is reviewed, with emphasis on antiviral treatment strategies. Finally, extensions of quasispecies to nonviral systems are briefly mentioned to emphasize the broad applicability of quasispecies theory.
Collapse
Affiliation(s)
- Esteban Domingo
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), C/ Nicolás Cabrera, Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain.
| | | | | |
Collapse
|
31
|
Mideo N, Reece SE. Plasticity in parasite phenotypes: evolutionary and ecological implications for disease. Future Microbiol 2012; 7:17-24. [DOI: 10.2217/fmb.11.134] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Preventing disease is a major goal of applied bioscience and explaining variation in the harm caused by parasites, and their infectiousness, are major goals of evolutionary biology. The emerging field of evolutionary medicine integrates these two ambitions to inform the development of control strategies that retard or withstand unfavorable parasite evolution. However, as parasites live in hostile and changeable environments – the bodies of other organisms – the success of integrating evolutionary biology with medicine requires a better understanding of how natural selection has solved the problems parasites face. There is increasing appreciation that natural selection shapes parasite strategies to survive in the host and transmit between hosts through facultative (plastic) shifts in parasite traits expressed during infections and in different hosts. This article describes how integrating parasite plasticity into biomedical thinking is central to explaining disease outcomes and transmission patterns, as well as predicting the success of control measures.
Collapse
Affiliation(s)
- Nicole Mideo
- Centre for Immunity, Infection & Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, UK
| | - Sarah E Reece
- Institutes of Evolution, Immunity & Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, UK
| |
Collapse
|
32
|
Molecular evidence for zoonotic transmission of an emergent, highly pathogenic Campylobacter jejuni clone in the United States. J Clin Microbiol 2011; 50:680-7. [PMID: 22189122 DOI: 10.1128/jcm.06167-11] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Campylobacter jejuni is a major zoonotic pathogen. A highly virulent, tetracycline-resistant C. jejuni clone (clone SA) has recently emerged in ruminant reservoirs and has become the predominant cause of sheep abortion in the United States. To determine whether clone SA is associated with human disease, we compared the clinical isolates of clone SA from sheep abortions with the human isolates of the PulseNet National Campylobacter databases at the CDC and the FDA using pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and serotyping. The combined SmaI and KpnI PFGE pattern designations of clone SA from sheep were indistinguishable from those of 123 (9.03%) human C. jejuni isolates (total, 1,361) in the CDC database, among which 56 were associated with sporadic infections and 67 were associated with outbreaks that occurred in multiple states from 2003 to 2010. Most of the outbreaks were attributed to raw milk, while the sources for most of the sporadic cases were unknown. All clone SA isolates examined, including PFGE-matched human isolates, belong to sequence type 8 (ST-8) by MLST and serotype HS:1,8, further indicating the clonality of the related isolates from different host species. Additionally, C. jejuni clone SA was identified in raw milk, cattle feces, the feces and bile of healthy sheep, and abortion cases of cattle and goats, indicating the broad distribution of this pathogenic clone in ruminants. These results provide strong molecular and epidemiological evidence for zoonotic transmission of this emergent clone from ruminants to humans and indicate that C. jejuni clone SA is an important threat to public health.
Collapse
|
33
|
Carroll SP. Conciliation biology: the eco-evolutionary management of permanently invaded biotic systems. Evol Appl 2011; 4:184-99. [PMID: 25567967 PMCID: PMC3352563 DOI: 10.1111/j.1752-4571.2010.00180.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 12/20/2010] [Indexed: 12/18/2022] Open
Abstract
Biotic invaders and similar anthropogenic novelties such as domesticates, transgenics, and cancers can alter ecology and evolution in environmental, agricultural, natural resource, public health, and medical systems. The resulting biological changes may either hinder or serve management objectives. For example, biological control and eradication programs are often defeated by unanticipated resistance evolution and by irreversibility of invader impacts. Moreover, eradication may be ill-advised when nonnatives introduce beneficial functions. Thus, contexts that appear to call for eradication may instead demand managed coexistence of natives with nonnatives, and yet applied biologists have not generally considered the need to manage the eco-evolutionary dynamics that commonly result from interactions of natives with nonnatives. Here, I advocate a conciliatory approach to managing systems where novel organisms cannot or should not be eradicated. Conciliatory strategies incorporate benefits of nonnatives to address many practical needs including slowing rates of resistance evolution, promoting evolution of indigenous biological control, cultivating replacement services and novel functions, and managing native-nonnative coevolution. Evolutionary links across disciplines foster cohesion essential for managing the broad impacts of novel biotic systems. Rather than signaling defeat, conciliation biology thus utilizes the predictive power of evolutionary theory to offer diverse and flexible pathways to more sustainable outcomes.
Collapse
Affiliation(s)
- Scott P Carroll
- Institute for Contemporary Evolution Davis, CA, USA ; Department of Entomology, University of California Davis, CA, USA
| |
Collapse
|
34
|
de Roode JC, de Castillejo CLF, Faits T, Alizon S. Virulence evolution in response to anti-infection resistance: toxic food plants can select for virulent parasites of monarch butterflies. J Evol Biol 2011; 24:712-22. [PMID: 21261772 DOI: 10.1111/j.1420-9101.2010.02213.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Host resistance to parasites can come in two main forms: hosts may either reduce the probability of parasite infection (anti-infection resistance) or reduce parasite growth after infection has occurred (anti-growth resistance). Both resistance mechanisms are often imperfect, meaning that they do not fully prevent or clear infections. Theoretical work has suggested that imperfect anti-growth resistance can select for higher parasite virulence by favouring faster-growing and more virulent parasites that overcome this resistance. In contrast, imperfect anti-infection resistance is thought not to select for increased parasite virulence, because it is assumed that it reduces the number of hosts that become infected, but not the fitness of parasites in successfully infected hosts. Here, we develop a theoretical model to show that anti-infection resistance can in fact select for higher virulence when such resistance reduces the effective parasite dose that enters a host. Our model is based on a monarch butterfly-parasite system in which larval food plants confer resistance to the monarch host. We carried out an experiment and showed that this environmental resistance is most likely a form of anti-infection resistance, through which toxic food plants reduce the effective dose of parasites that initiates an infection. We used these results to build a mathematical model to investigate the evolutionary consequences of food plant-induced resistance. Our model shows that when the effective infectious dose is reduced, parasites can compensate by evolving a higher per-parasite growth rate, and consequently a higher intrinsic virulence. Our results are relevant to many insect host-parasite systems, in which larval food plants often confer imperfect anti-infection resistance. Our results also suggest that - for parasites where the infectious dose affects the within-host dynamics - vaccines that reduce the effective infectious dose can select for increased parasite virulence.
Collapse
Affiliation(s)
- J C de Roode
- Biology Department, Emory University, Atlanta, GA 30322, USA.
| | | | | | | |
Collapse
|
35
|
Pirnay JP, De Vos D, Verbeken G, Merabishvili M, Chanishvili N, Vaneechoutte M, Zizi M, Laire G, Lavigne R, Huys I, Van den Mooter G, Buckling A, Debarbieux L, Pouillot F, Azeredo J, Kutter E, Dublanchet A, Górski A, Adamia R. The phage therapy paradigm: prêt-à-porter or sur-mesure? Pharm Res 2010; 28:934-7. [PMID: 21063753 DOI: 10.1007/s11095-010-0313-5] [Citation(s) in RCA: 182] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 10/27/2010] [Indexed: 11/30/2022]
Affiliation(s)
- Jean-Paul Pirnay
- Laboratory for Molecular and Cellular Technology, Burn Wound Centre, Queen Astrid Military Hospital, 1120, Brussels, Belgium
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|