scholarly journals Evolutionary epidemiology of a zoonosis

2021 ◽  
Author(s):  
Giulia I Corsi ◽  
Swapnil Tichkule ◽  
Anna Rosa Sannella ◽  
Paolo Vatta ◽  
Francesco Asnicar ◽  
...  
Keyword(s):  
Nucleotide Diversity ◽  
Virulence Genes ◽  
Population Admixture ◽  
Genome Sequences ◽  
Host Parasite Interactions ◽  
Geographic Origins ◽  
Evolutionary Epidemiology ◽  
Evolutionary Consequences ◽  
Host Parasite

Cryptosporidium parvum is a global zoonoses and a major cause of diarrhoea in humans and ruminants. The parasite's life cycle comprises an obligatory sexual phase, during which genetic exchanges can occur between previously isolated lineages. Here, we compare 32 whole genome sequences from human- and ruminant-derived parasite isolates collected across Europe, Egypt and China. We identify three strongly supported clusters that comprise a mix of isolates from different host species, geographic origins, and subtypes. We show that: (1) recombination occurs between ruminant isolates into human isolates; (2) these recombinant regions can be passed on to other human subtypes through gene flow and population admixture; (3) there have been multiple genetic exchanges, and all are likely recent; (4) putative virulence genes are significantly enriched within these genetic exchanges, and (5) this results in an increase in their nucleotide diversity. We carefully dissect the phylogenetic sequence of two genetic exchanges, illustrating the long-term evolutionary consequences of these events. Our results suggest that increased globalisation and close human-animal contacts increase the opportunity for genetic exchanges between previously isolated parasite lineages, resulting in spillover and spillback events. We discuss how this can provide a novel substrate for natural selection at genes involved in host-parasite interactions, thereby potentially altering the dynamic coevolutionary equilibrium in the Red Queens arms race.

scholarly journals Spatial evolutionary epidemiology of spreading epidemics

2016 ◽  
Vol 283 (1841) ◽  
pp. 20161170 ◽  
Author(s):  
S. Lion ◽  
S. Gandon
Keyword(s):  
Evolutionary Dynamics ◽  
Spatial Models ◽  
Spatial Differentiation ◽  
Spatial Moment ◽  
Novel Approach ◽  
Evolutionary Epidemiology ◽  
Pathogen Populations ◽  
Evolutionary Consequences ◽  
Host Parasite

Most spatial models of host–parasite interactions either neglect the possibility of pathogen evolution or consider that this process is slow enough for epidemiological dynamics to reach an equilibrium on a fast timescale. Here, we propose a novel approach to jointly model the epidemiological and evolutionary dynamics of spatially structured host and pathogen populations. Starting from a multi-strain epidemiological model, we use a combination of spatial moment equations and quantitative genetics to analyse the dynamics of mean transmission and virulence in the population. A key insight of our approach is that, even in the absence of long-term evolutionary consequences, spatial structure can affect the short-term evolution of pathogens because of the build-up of spatial differentiation in mean virulence. We show that spatial differentiation is driven by a balance between epidemiological and genetic effects, and this quantity is related to the effect of kin competition discussed in previous studies of parasite evolution in spatially structured host populations. Our analysis can be used to understand and predict the transient evolutionary dynamics of pathogens and the emergence of spatial patterns of phenotypic variation.

Generation of Murine Growth Factor-Dependent Long-Term Dendritic Cell Lines to Investigate Host-Parasite Interactions

2009 ◽  
pp. 17-27 ◽  
Author(s):  
Alessandra Mortellaro ◽  
Matteo Urbano ◽  
Stefania Citterio ◽  
Maria Foti ◽  
Francesca Granucci ◽  
...  
Keyword(s):  
Dendritic Cell ◽  
Growth Factor ◽  
Cell Lines ◽  
Host Parasite Interactions ◽  
Host Parasite

scholarly journals Ligula intestinalis (Cestoda: Pseudophyllidea): an ideal fish-metazoan parasite model?

Parasitology ◽  
2010 ◽  
Vol 137 (3) ◽  
pp. 425-438 ◽  
Author(s):  
D. HOOLE ◽  
V. CARTER ◽  
S. DUFOUR
Keyword(s):  
Ecological Studies ◽  
Biological Factors ◽  
Ligula Intestinalis ◽  
Metazoan Parasite ◽  
Host Parasite Interactions ◽  
Parasite Ecology ◽  
Host Parasite ◽  
Scientific Tool

SUMMARYSince its use as a model to study metazoan parasite culture and in vitro development, the plerocercoid of the tapeworm, Ligula intestinalis, has served as a useful scientific tool to study a range of biological factors, particularly within its fish intermediate host. From the extensive long-term ecological studies on the interactions between the parasite and cyprinid hosts, to the recent advances made using molecular technology on parasite diversity and speciation, studies on the parasite have, over the last 60 years, led to significant advances in knowledge on host-parasite interactions. The parasite has served as a useful model to study pollution, immunology and parasite ecology and genetics, as well has being the archetypal endocrine disruptor.

Evolutionary epidemiology theory of vaccination

Pertussis ◽  
2018 ◽  
pp. 133-143 ◽  
Author(s):  
Sylvain Gandon
Keyword(s):  
Theoretical Framework ◽  
Host Population ◽  
Phenotypic Traits ◽  
High Coverage ◽  
Evolutionary Epidemiology ◽  
Short And Long Term ◽  
Evolutionary Consequences ◽  
Parasite Populations ◽  
Specific Parasite

The aim of vaccination is to prevent or limit the risk of pathogen infections for individual hosts but large vaccination coverage often has dramatic epidemiological consequences at the scale of the whole host population. This massive perturbation of the ecology and transmission of the pathogen can also have important evolutionary effects. In particular, vaccine-driven evolution may lead to the spread of new pathogen variants that may erode the benefits of vaccination. This chapter presents a theoretical framework for modelling the short- and long-term epidemiological and evolutionary consequences of vaccination. This framework can be used to make quantitative predictions about the speed of such evolutionary processes. This work helps identify the relevant phenotypic traits that need to be measured in specific parasite populations in order to evaluate the potential evolutionary consequences of vaccination. In particular, this may help in the debate regarding the involvement of evolution in the re-emergence of pertussis in spite of the high coverage of vaccination.

scholarly journals The evolutionary epidemiology of vaccination

2007 ◽  
Vol 4 (16) ◽  
pp. 803-817 ◽  
Author(s):  
Sylvain Gandon ◽  
Troy Day
Keyword(s):  
Fitness Costs ◽  
Parasite Fitness ◽  
Different Types ◽  
Evolutionary Epidemiology ◽  
Short And Long Term ◽  
Parasite Evolution ◽  
Evolutionary Consequences ◽  
Parasite Populations ◽  
Specific Parasite

Vaccination leads to dramatic perturbations of the environment of parasite populations and this can have both demographic and evolutionary consequences. We present a theoretical framework for modelling the short- and long-term epidemiological and evolutionary consequences of vaccination. This framework integrates previous theoretical studies of vaccine-induced parasite evolution, and it allows one to make some useful qualitative predictions regarding the outcome of the competition between different types of vaccine-favoured variants. It can also be used to make quantitative predictions about the speed of such evolutionary processes. This work may help define the relevant parameters that need to be measured in specific parasite populations in order to evaluate the potential evolutionary consequences of vaccination. In particular, we argue that more work should be done evaluating the nature and magnitude of parasite fitness costs associated with adaptation to vaccinated hosts.

scholarly journals Long‐term dynamics in local host–parasite interactions linked to regional population trends

Ecosphere ◽  
2016 ◽  
Vol 7 (8) ◽  
Author(s):  
Zachary S. Ladin ◽  
Vincent D'Amico ◽  
Jan M. Baetens ◽  
Roland R. Roth ◽  
W. Gregory Shriver
Keyword(s):  
Population Trends ◽  
Host Parasite Interactions ◽  
Local Host ◽  
Regional Population ◽  
Host Parasite

scholarly journals The Price equation and evolutionary epidemiology

2020 ◽  
Vol 375 (1797) ◽  
pp. 20190357 ◽  
Author(s):  
Troy Day ◽  
Todd Parsons ◽  
Amaury Lambert ◽  
Sylvain Gandon
Keyword(s):  
Evolutionary Biology ◽  
Transmission Rate ◽  
Price Equation ◽  
Demographic Stochasticity ◽  
Widespread Application ◽  
Disease Evolution ◽  
Price’S Equation ◽  
Evolutionary Epidemiology ◽  
Evolutionary Consequences

The Price equation has found widespread application in many areas of evolutionary biology, including the evolutionary epidemiology of infectious diseases. In this paper, we illustrate the utility of this approach to modelling disease evolution by first deriving a version of Price’s equation that can be applied in continuous time and to populations with overlapping generations. We then show how this version of Price’s equation provides an alternative perspective on pathogen evolution by considering the epidemiological meaning of each of its terms. Finally, we extend these results to the case where population size is small and generates demographic stochasticity. We show that the particular partitioning of evolutionary change given by Price’s equation is also a natural way to partition the evolutionary consequences of demographic stochasticity, and demonstrate how such stochasticity tends to weaken selection on birth rate (e.g. the transmission rate of an infectious disease) and enhance selection on mortality rate (e.g. factors, like virulence, that cause the end of an infection). In the long term, if there is a trade-off between virulence and transmission across parasite strains, the weaker selection on transmission and stronger selection on virulence that arises from demographic stochasticity will tend to drive the evolution of lower levels of virulence. This article is part of the theme issue ‘Fifty years of the Price equation’.

Living with Two Genomes: Grafting and Its Implications for Plant Genome-to-Genome Interactions, Phenotypic Variation, and Evolution

2019 ◽  
Vol 53 (1) ◽  
pp. 195-215 ◽  
Author(s):  
Brandon S. Gaut ◽  
Allison J. Miller ◽  
Danelle K. Seymour
Keyword(s):  
Host Resistance ◽  
Arms Race ◽  
Plant Genome ◽  
Long Term Effects ◽  
Evolutionary Innovation ◽  
Host Parasite Interactions ◽  
Artificial Grafts ◽  
Genome Interactions ◽  
Host Parasite

Plant genomes interact when genetically distinct individuals join, or are joined, together. Individuals can fuse in three contexts: artificial grafts, natural grafts, and host–parasite interactions. Artificial grafts have been studied for decades and are important platforms for studying the movement of RNA, DNA, and protein. Yet several mysteries about artificial grafts remain, including the factors that contribute to graft incompatibility, the prevalence of genetic and epigenetic modifications caused by exchanges between graft partners, and the long-term effects of these modifications on phenotype. Host–parasite interactions also lead to the exchange of materials, and RNA exchange actively contributes to an ongoing arms race between parasite virulence and host resistance. Little is known about natural grafts except that they can be frequent and may provide opportunities for evolutionary innovation through genome exchange. In this review, we survey our current understanding about these three mechanisms of contact, the genomic interactions that result, and the potential evolutionary implications.

scholarly journals Nutrient stoichiometry shapes microbial coevolution

2017 ◽  
Author(s):  
Megan L. Larsen ◽  
Steven W. Wilhelm ◽  
Jay T. Lennon
Keyword(s):  
Arms Race ◽  
Lytic Phage ◽  
Nutrient Stoichiometry ◽  
P Limitation ◽  
Host Parasite Interactions ◽  
Negative Frequency Dependent Selection ◽  
Selection For ◽  
The Stability ◽  
Host Parasite

ABSTRACTCoevolution is a force contributing to the generation and maintenance of biodiversity. It is influenced by environmental conditions including the scarcity of essential resources, which can drive the evolution of defense and virulence traits. We conducted a long-term chemostat experiment where the marine cyanobacterium Synechococcus was challenged with a lytic phage under nitrogen (N) or phosphorus (P) limitation. This manipulation of nutrient stoichiometry altered the stability of host-parasite interactions and the underlying mode of coevolution. By assessing infectivity with >18,000 pairwise challenges, we documented directional selection for increased phage resistance, consistent with arms-race dynamics while phage infectivity fluctuated through time, as expected when coevolution is driven by negative frequency-dependent selection. The resulting infection networks were 50 % less modular under N-versus P-limitation reflecting host-range contraction and asymmetric coevolutionary trajectories. Nutrient stoichiometry affects eco-evolutionary feedbacks in ways that may alter the dynamics and functioning of environmental and host-associated microbial communities.

scholarly journals EPNs Exhibit Repulsion to Prenol in Pluronic Gel Assays

Insects ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 457
Author(s):  
Tiffany Baiocchi ◽  
Chunjie Li ◽  
Adler R. Dillman
Keyword(s):  
Behavioral Ecology ◽  
Storage Time ◽  
Entomopathogenic Nematodes ◽  
Long Term Storage ◽  
Host Parasite Interactions ◽  
Host Seeking ◽  
Successful Infection ◽  
Host Parasite ◽  
Term Storage

Entomopathogenic nematodes (EPNs) are lethal parasites of insects that have become valuable in biological control and as a model system for studying host–parasite interactions, behavioral ecology, neurobiology, and genomics, among other fields. Their ability to locate hosts is paramount to successful infection and host seeking has been extensively studied in many species in the lab. Here, we explored the usefulness of pluronic gel as a medium to assess EPN host seeking in the lab by characterizing the response of Steinernema carpocapsae, S. feltiae, S. glaseri, S. riobrave, Heterorhabditis bacteriophora, and H. indica to the odor prenol. We found that the infective juveniles (IJs) of these species were repelled by prenol in pluronic gel. We then evaluated how storing the IJs of S. carpocapsae, S. feltiae, and S. glaseri for different amounts of time affected their behavioral responses to prenol. The response of S. carpocapsae was significantly affected by the storage time, while the responses of S. feltiae and S. glaseri were unaffected. Our data support the notion that pluronic gel is a useful medium for studying EPN behavior and that the response of S. carpocapsae to informative odors is significantly affected by long-term storage.

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