Horizontal transmission of a parasite is influenced by infected host phenotype and density

Parasitology ◽  
2014 ◽  
Vol 142 (2) ◽  
pp. 395-405 ◽  
Author(s):  
K. E. ROBERTS ◽  
W. O. H. HUGHES
Keyword(s):  
Control Strategies ◽  
Horizontal Transmission ◽  
Population Level ◽  
Pathogen Transmission ◽  
Parasite Transmission ◽  
Microsporidian Parasite ◽  
Female Workers ◽  
Host Parasite Interactions ◽  
The Social ◽  
Host Parasite

SUMMARYTransmission is a key determinant of parasite fitness, and understanding the dynamics of transmission is fundamental to the ecology and evolution of host–parasite interactions. Successful transmission is often reliant on contact between infected individuals and susceptible hosts. The social insects consist of aggregated groups of genetically similar hosts, making them particularly vulnerable to parasite transmission. Here we investigate how the ratio of infected to susceptible individuals impacts parasite transmission, using the honey bee, Apis mellifera and its microsporidian parasite Nosema ceranae. We used 2 types of infected hosts found simultaneously in colonies; sterile female workers and sexual males. We found a higher ratio of infected to susceptible individuals in groups resulted in a greater proportion of susceptibles becoming infected, but this effect was non-linear and interestingly, the ratio also affected the spore production of infected individuals. The transmission level was much greater in an experiment where the infected individuals were drones than in an experiment where they were workers, suggesting drones may act as intracolonial ‘superspreaders’. Understanding the subtleties of transmission and how it is influenced by the phenotype of the infected/susceptible individuals is important for understanding pathogen transmission at population level, and for optimum targeting of parasite control strategies.

Evolution and function of tandem repeats in the major surface protein 1a of the ehrlichial pathogenAnaplasma marginale

2001 ◽  
Vol 2 (2) ◽  
pp. 163-174 ◽  
Author(s):  
José de la Fuente ◽  
Jose C. Garcia-Garcia ◽  
Edmour F. Blouin ◽  
Sergio D. Rodríguez ◽  
Migel A. García ◽  
...  
Keyword(s):  
Tandem Repeats ◽  
Control Strategies ◽  
Surface Protein ◽  
Single Copy ◽  
Major Surface Protein ◽  
Host Parasite Interactions ◽  
Major Surface ◽  
And Function ◽  
Host Parasite ◽  
Bovine Erythrocytes

AbstractThe major surface protein (MSP) 1a of the ehrlichial cattle pathogenAnaplasma marginale, encoded by the single-copy genemsp1α, has been shown to have a neutralization-sensitive epitope and to be an adhesin for bovine erythrocytes and tick cells.msp1αhas been found to be a stable genetic marker for the identification of geographic isolates ofA. marginalethroughout development in acutely and persistently infected cattle and in ticks. The molecular weight of MSP1a varies among geographic isolates ofA. marginalebecause of a varying number of tandemly repeated peptides of 28–29 amino acids. Variation in the sequence of the tandem repeats occurs within and among isolates, and may have resulted from evolutionary pressures exerted by ligand–receptor and host–parasite interactions. These repeated sequences include markers for tick transmissibility that may be important in the identification of ehrlichial pathogens because they may influence control strategies and the design of subunit vaccines.

Genetic differences in the interactions of a microsporidian parasite and four clones of its cyclically parthenogenetic host

Parasitology ◽  
1994 ◽  
Vol 108 (1) ◽  
pp. 11-16 ◽  
Author(s):  
D. Ebert
Keyword(s):  
Body Length ◽  
Multiplication Rate ◽  
Juvenile Growth ◽  
Size At Maturity ◽  
Age At Maturity ◽  
Microsporidian Parasite ◽  
Host Parasite Interactions ◽  
Parasite Multiplication ◽  
Host Parasite ◽  
Host Clone

SUMMARYHost–parasite interactions were studied for the microsporidium Pleistophora intestinalis and its host, Daphnia magna. Two host clones were established from the same population from which the parasites were taken (home-1 and 2), and two clones from two other ponds (neighbour and Munich clone). With increasing clutch number infected females from home-1 clone produced relatively smaller clutches than uninfected females. Age and body length at maturity were not affected by the infection, but body length of the sixth adult instar was reduced. In an experiment including all four host clones, the parasite reproduced well in the two home clones and in the neighbour clone, but poorly in the Munich clone. Juvenile growth and age at maturity was not affected in the two home clones, but for the neighbour and the Munich clone age was delayed by 2·2 days and 4·1 days, and juvenile growth reduced by 16 and 23%, respectively. Significant host-clone x parasite-treatment interactions were also found for size at maturity and clutch size. This pattern of host-parasite interactions suggests that there is no general positive relation between disease severity and parasite multiplication rate.

scholarly journals Neurophysiological Changes Induced by Chronic Toxoplasma gondii Infection

2017 ◽  
Author(s):  
Ellen Tedford ◽  
Glenn McConkey
Keyword(s):  
Toxoplasma Gondii ◽  
Neurological Diseases ◽  
Behavioral Changes ◽  
Cns Infection ◽  
Parasite Transmission ◽  
Hormonal Responses ◽  
Host Parasite Interactions ◽  
Host Parasite ◽  
Neurological Infection ◽  
Host Brain

Although the parasite Toxoplasma gondii is one of the most pervasive neurotropic pathogens in the world, the host-parasite interactions during CNS infection and consequences of neurological infection are just beginning to be unraveled. The chronic stages of infection have been considered dormant, although several studies have found correlations of infection with an array of host behavioral changes. These may facilitate parasite transmission and impact neurological diseases. During infection, in addition to the presence of the parasites within neurons, host-mediated neuroimmune and hormonal responses to infection are also present. T. gondii induces numerous changes to host neurons during infection and globally alters host neurological signaling pathways, as discussed in this review. Understanding the neurophysiological changes in the host brain is imperative to understanding the parasitic mechanisms and to delineate the effects of this single-celled parasite on health and its contribution to neurological disease.

Co-evolution between mosquitoes and microsporidian transmission strategies

2018 ◽  
Author(s):  
◽  
Giacomo Zilio
Keyword(s):  
Evolutionary Dynamics ◽  
Horizontal Transmission ◽  
Life History Evolution ◽  
Induced Response ◽  
Ecological Conditions ◽  
Transmission Strategy ◽  
Host Parasite Interactions ◽  
Key Aspects ◽  
Host Parasite ◽  
The Impact

Parasite and host impose strong selection on each other. The first causes damages and mortality to the host, while the second responds by reducing the detrimental effects and the intensity and/or success of infection. The resulting co-evolutionary dynamics are profoundly affected by the ecological conditions, for these may influence many aspects of host-parasite interactions including life history evolution, virulence and transmission. It is therefore essential to study and incorporate environmental variation in the field of parasitology to gain an exhaustive understanding of how host and parasite evolve. In this thesis, a single generation and an evolutionary experimental approach were used to investigate the impact of the ecological and epidemiological conditions on several aspects of host-parasite interactions, with the main focus on parasite transmission strategies. Firstly, it was examined the effect of the availability of resources for the host, timing of infection, and co-infection on the virulence and transmission success of two parasites with conflicting transmission strategy. Next, it was tested how the environment influenced the trade-off between vertical and horizontal transmission in a parasite with a mixed mode of transmission and it was assessed the genetic contribution of the host to its transmission mode. Whether the vertical and horizontal component of this parasite and the associated virulence responded to restriction opportunities, represented by different availability of resources over several generations, was investigated with an evolutionary experiment. Finally, the presence of a plastically parasite-induced response on the recombination rate of the host as a potential cross-generational defence mechanism was explored. The experiments cover many key aspects of host-parasite interactions and emphasize the role of the ecological conditions on shaping these relationships. The results and their implications are discussed in detail throughout the thesis. Overall, this work highlights the dependence of crucial aspects of host-parasite interactions from the epidemiological and ecological conditions. Disentangling the various forces surrounding these interactions may help us to acquire a better knowledge of how a changing environment may drive the evolution of both host and parasite.

scholarly journals Host-Parasite Interactions and Purifying Selection in a Microsporidian Parasite of Honey Bees

PLoS ONE ◽  
2016 ◽  
Vol 11 (2) ◽  
pp. e0147549 ◽  
Author(s):  
Qiang Huang ◽  
Yan Ping Chen ◽  
Rui Wu Wang ◽  
Shang Cheng ◽  
Jay D. Evans
Keyword(s):  
Honey Bees ◽  
Purifying Selection ◽  
Microsporidian Parasite ◽  
Host Parasite Interactions ◽  
Host Parasite

scholarly journals A multi-scale epidemic model of Salmonella infection with heterogeneous shedding

2020 ◽  
Vol 67 ◽  
pp. 261-284
Author(s):  
Simon Labarthe ◽  
Béatrice Laroche ◽  
Thi Nhu Tao Nguyen ◽  
Bastien Polizzi ◽  
Florian Patout ◽  
...  
Keyword(s):  
Control Strategies ◽  
Food Poisoning ◽  
Population Level ◽  
Pathogen Transmission ◽  
Modeling Framework ◽  
Multi Scale ◽  
Multiscale Modeling Framework ◽  
The Individual ◽  
Random Fluctuations ◽  
The Impact

Salmonella strains colonize the digestive tract of farm livestock, such as chickens or pigs, without affecting them, and potentially infect food products, representing a threat for human health ranging from food poisoning to typhoid fever. It has been shown that the ability to excrete the pathogen in the environment and contaminate other animals is variable. This heterogeneity in pathogen carriage and shedding results from interactions between the host’s immune response, the pathogen and the commensal intestinal microbiota. In this paper we propose a novel generic multiscale modeling framework of heterogeneous pathogen transmission in an animal population. At the intra-host level, the model describes the interaction between the commensal microbiota, the pathogen and the inflammatory response. Random fluctuations in the ecological dynamics of the individual microbiota and transmission at between-host scale are added to obtain a drift-diffusion PDE model of the pathogen distribution at the population level. The model is further extended to represent transmission between several populations. The asymptotic behavior as well as the impact of control strategies including cleaning and antimicrobial administration are investigated through numerical simulation.

scholarly journals Four QTL underlie resistance to a microsporidian parasite that may drive genome evolution in its Daphnia host

2019 ◽  
Author(s):  
Devon Keller ◽  
Devin Kirk ◽  
Pepijn Luijckx
Keyword(s):  
Immune Response ◽  
Daphnia Magna ◽  
Genetic Architecture ◽  
Pivotal Role ◽  
Parasite Resistance ◽  
Microsporidian Parasite ◽  
Ecological Processes ◽  
Host Parasite Interactions ◽  
Host Parasite ◽  
General Immune Response

AbstractDespite its pivotal role in evolutionary and ecological processes the genetic architecture underlying host-parasite interactions remains understudied. Here we use a quantitative trait loci approach to identify regions in the Daphnia magna genome that provide resistance against its microsporidium parasite Ordospora colligata. The probability that Daphnia became infected was affected by a single locus and an interaction between two additional loci. A fourth locus influenced the number of spores that grew within the host. Comparing our findings to previously published genetic work on Daphnia magna revealed that two of these loci may be the same as detected for another microsporidium parasite, suggesting a general immune response to this group of pathogens. More importantly, this comparison revealed that two regions previously identified to be under selection coincided with parasite resistance loci, highlighting the pivotal role parasites may play in shaping the host genome.

scholarly journals Genomic evidence for population-specific responses to coevolving parasites in a New Zealand freshwater snail

2016 ◽  
Author(s):  
Laura Bankers ◽  
Peter Fields ◽  
Kyle E. McElroy ◽  
Jeffrey L. Boore ◽  
John M. Logsdon ◽  
...  
Keyword(s):  
Natural Populations ◽  
Primary Source ◽  
Population Level ◽  
Freshwater Snail ◽  
Sequence Evolution ◽  
Specific Host ◽  
Host Parasite Interactions ◽  
Evolutionary Trajectories ◽  
Host Parasite ◽  
Genomic Basis

AbstractReciprocal coevolving interactions between hosts and parasites are a primary source of strong selection that can promote rapid and often population- or genotype-specific evolutionary change. These host-parasite interactions are also a major source of disease. Despite their importance, very little is known about the genomic basis of coevolving host-parasite interactions in natural populations, especially in animals. Here, we use gene expression and sequence evolution approaches to take critical steps towards characterizing the genomic basis of interactions between the freshwater snail Potamopyrgus antipodarum and its coevolving sterilizing trematode parasite, Microphallus sp., a textbook example of natural coevolution. We found that Microphallus-infected P. antipodarum exhibit systematic downregulation of genes relative to uninfected P. antipodarum. The specific genes involved in parasite response differ markedly across lakes, consistent with a scenario where population-level coevolution is leading to population-specific host-parasite interactions and evolutionary trajectories. We also used an FST-based approach to identify a set of loci that represent promising candidates for targets of parasite-mediated selection across lakes as well as within each lake population. These results constitute the first genomic evidence for population-specific responses to coevolving infection in the P. antipodarum-Microphallus interaction and provide new insights into the genomic basis of coevolutionary interactions in nature.

scholarly journals Parasite-infected sticklebacks increase the risk-taking behaviour of uninfected group members

2018 ◽  
Vol 285 (1881) ◽  
pp. 20180956 ◽  
Author(s):  
Nicolle Demandt ◽  
Benedikt Saus ◽  
Ralf H. J. M. Kurvers ◽  
Jens Krause ◽  
Joachim Kurtz ◽  
...  
Keyword(s):  
Risk Taking ◽  
Gasterosteus Aculeatus ◽  
Social Dynamics ◽  
Final Host ◽  
Infected Group ◽  
Host Parasite Interactions ◽  
The Social ◽  
Group Members ◽  
Host Parasite ◽  
Behavioural Manipulation

Trophically transmitted parasites frequently increase their hosts' risk-taking behaviour, to facilitate transmission to the next host. Whether such elevated risk-taking can spill over to uninfected group members is, however, unknown. To investigate this, we confronted groups of 6 three-spined sticklebacks, Gasterosteus aculeatus , containing 0, 2, 4 or 6 experimentally infected individuals with a simulated bird attack and studied their risk-taking behaviour. As a parasite, we used the tapeworm Schistocephalus solidus , which increases the risk-taking of infected sticklebacks, to facilitate transmission to its final host, most often piscivorous birds. Before the attack, infected and uninfected individuals did not differ in their risk-taking. However, after the attack, individuals in groups with only infected members showed lower escape responses and higher risk-taking than individuals from groups with only uninfected members. Importantly, uninfected individuals adjusted their risk-taking behaviour to the number of infected group members, taking more risk with an increasing number of infected group members. Infected individuals, however, did not adjust their risk-taking to the number of uninfected group members. Our results show that behavioural manipulation by parasites does not only affect the infected host, but also uninfected group members, shedding new light on the social dynamics involved in host–parasite interactions.

scholarly journals Next-generation tools to control biting midge populations and reduce pathogen transmission

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Phillip Shults ◽  
Lee W. Cohnstaedt ◽  
Zach N. Adelman ◽  
Corey Brelsfoard
Keyword(s):  
Control Strategies ◽  
Population Level ◽  
Larval Habitat ◽  
Pathogen Transmission ◽  
Next Generation ◽  
Biting Midges ◽  
Biting Midge ◽  
Generation Control ◽  
Population Suppression ◽  
Transmit Disease

AbstractBiting midges of the genus Culicoides transmit disease-causing agents resulting in a significant economic impact on livestock industries in many parts of the world. Localized control efforts, such as removal of larval habitat or pesticide application, can be logistically difficult, expensive and ineffective if not instituted and maintained properly. With these limitations, a population-level approach to the management of Culicoides midges should be investigated as a means to replace or supplement existing control strategies. Next-generation control methods such as Wolbachia- and genetic-based population suppression and replacement are being investigated in several vector species. Here we assess the feasibility and applicability of these approaches for use against biting midges. We also discuss the technical and logistical hurdles needing to be addressed for each method to be successful, as well as emphasize the importance of addressing community engagement and involving stakeholders in the investigation and development of these approaches.

Sign in / Sign up

Export Citation Format

Share Document