Temperature effects on parasite prevalence in a natural hybrid complex

Both host susceptibility and parasite infectivity commonly have a genetic basis, and can therefore be shaped by coevolution. However, these traits are often sensitive to environmental variation, resulting in genotype-by-environment interactions. We tested the influence of temperature on host–parasite genetic specificity in the Daphnia longispina hybrid complex, exposed to the protozoan parasite Caullerya mesnili . Infection rates were higher at low temperature. Furthermore, significant differences between host clones, but not between host taxa, and a host genotype-by-temperature interaction were observed.

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HOST-PARASITE AND GENOTYPE-BY-ENVIRONMENT INTERACTIONS: TEMPERATURE MODIFIES POTENTIAL FOR SELECTION BY A STERILIZING PATHOGEN

Evolution ◽

10.1554/04-526 ◽

2005 ◽

Vol 59 (1) ◽

pp. 70 ◽

Cited By ~ 7

Author(s):

Suzanne E. Mitchell ◽

Emily S. Rogers ◽

Tom J. Little ◽

Andrew F. Read

Keyword(s):

Genotype By Environment Interactions ◽

Genotype By Environment ◽

Host Parasite

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Prior exposure to long-day photoperiods alters immune responses and increases susceptibility to parasitic infection in stickleback

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2020.1017 ◽

2020 ◽

Vol 287 (1930) ◽

pp. 20201017

Author(s):

James R. Whiting ◽

Muayad A. Mahmud ◽

Janette E. Bradley ◽

Andrew D. C. MacColl

Keyword(s):

Immune Responses ◽

Parasitic Infection ◽

Population Variation ◽

Host Susceptibility ◽

Day Length ◽

Previous Exposure ◽

Parasite Abundance ◽

Susceptibility To Infection ◽

Long Day ◽

Host Parasite

Seasonal disease and parasitic infection are common across organisms, including humans, and there is increasing evidence for intrinsic seasonal variation in immune systems. Changes are orchestrated through organisms' physiological clocks using cues such as day length. Ample research in diverse taxa has demonstrated multiple immune responses are modulated by photoperiod, but to date, there have been few experimental demonstrations that photoperiod cues alter susceptibility to infection. We investigated the interactions among photoperiod history, immunity and susceptibility in laboratory-bred three-spined stickleback (a long-day breeding fish) and its external, directly reproducing monogenean parasite Gyrodactylus gasterostei . We demonstrate that previous exposure to long-day photoperiods (PLD) increases susceptibility to infection relative to previous exposure to short days (PSD), and modifies the response to infection for the mucin gene muc2 and Treg cytokine foxp3a in skin tissues in an intermediate 12 L : 12 D photoperiod experimental trial. Expression of skin muc2 is reduced in PLD fish, and negatively associated with parasite abundance. We also observe inflammatory gene expression variation associated with natural inter-population variation in resistance, but find that photoperiod modulation of susceptibility is consistent across host populations. Thus, photoperiod modulation of the response to infection is important for host susceptibility, highlighting new mechanisms affecting seasonality of host–parasite interactions.

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The mode of host–parasite interaction shapes coevolutionary dynamics and the fate of host cooperation

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2012.0769 ◽

2012 ◽

Vol 279 (1743) ◽

pp. 3742-3748 ◽

Cited By ~ 22

Author(s):

Benjamin J. Z. Quigley ◽

Diana García López ◽

Angus Buckling ◽

Alan J. McKane ◽

Sam P. Brown

Keyword(s):

Stochastic Modelling ◽

Host Population ◽

Social Traits ◽

The Social ◽

Population Structures ◽

Modelling Techniques ◽

Virus Interactions ◽

Host Parasite ◽

The Impact ◽

Genetic Specificity

Antagonistic coevolution between hosts and parasites can have a major impact on host population structures, and hence on the evolution of social traits. Using stochastic modelling techniques in the context of bacteria–virus interactions, we investigate the impact of coevolution across a continuum of host–parasite genetic specificity (specifically, where genotypes have the same infectivity/resistance ranges (matching alleles, MA) to highly variable ranges (gene-for-gene, GFG)) on population genetic structure, and on the social behaviour of the host. We find that host cooperation is more likely to be maintained towards the MA end of the continuum, as the more frequent bottlenecks associated with an MA-like interaction can prevent defector invasion, and can even allow migrant cooperators to invade populations of defectors.

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Sporadic Creutzfeldt-Jakob Disease: Prion Pathology in Medulla Oblongata—Possible Routes of Infection and Host Susceptibility

BioMed Research International ◽

10.1155/2015/396791 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

Diego Iacono ◽

Sergio Ferrari ◽

Matteo Gelati ◽

Gianluigi Zanusso ◽

Sara Mariotto ◽

...

Keyword(s):

Prion Protein ◽

Environmental Exposure ◽

Phenotypic Variability ◽

Host Susceptibility ◽

Motor Nucleus ◽

Host Genotype ◽

Dorsal Motor Nucleus ◽

Jakob Disease ◽

Medullary Nuclei ◽

Codon 129

Sporadic Creutzfeldt-Jakob disease (sCJD), the most frequent human prion disorder, is characterized by remarkable phenotypic variability, which is influenced by the conformation of the pathologic prion protein and the methionine/valine polymorphic codon 129 of the prion protein gene. While the etiology of sCJD remains unknown, it has been hypothesized that environmental exposure to prions might occur through conjunctival/mucosal contact, oral ingestion, inhalation, or simultaneous involvement of the olfactory and enteric systems. We studied 21 subjects with definite sCJD to assess neuropathological involvement of the dorsal motor nucleus of the vagus and other medullary nuclei and to evaluate possible associations with codon 129 genotype and prion protein conformation. The present data show that prion protein deposition was detected in medullary nuclei of distinct sCJD subtypes, either valine homozygous or heterozygous at codon 129. These findings suggest that an “environmental exposure” might occur, supporting the hypothesis that external sources of contamination could contribute to sCJD in susceptible hosts. Furthermore, these novel data could shed the light on possible causes of sCJD through a “triple match” hypothesis that identify environmental exposure, host genotype, and direct exposure of specific anatomical regions as possible pathogenetic factors.

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The impact of environmental change on host–parasite coevolutionary dynamics

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2010.2359 ◽

2010 ◽

Vol 278 (1716) ◽

pp. 2283-2292 ◽

Cited By ~ 48

Author(s):

Rafal Mostowy ◽

Jan Engelstädter

Keyword(s):

Environmental Change ◽

Environmental Changes ◽

Selective Pressure ◽

Time Windows ◽

Gene Interactions ◽

Genotype By Environment ◽

Host Parasite ◽

The Impact ◽

Antagonistic Interactions ◽

Gene For Gene

Environmental factors are known to affect the strength and the specificity of interactions between hosts and parasites. However, how this shapes patterns of coevolutionary dynamics is not clear. Here, we construct a simple mathematical model to study the effect of environmental change on host–parasite coevolutionary outcome when interactions are of the matching-alleles or the gene-for-gene type. Environmental changes may effectively alter the selective pressure and the level of specialism in the population. Our results suggest that environmental change altering the specificity of selection in antagonistic interactions can produce alternating time windows of cyclical allele-frequency dynamics and cessation thereof. This type of environmental impact can also explain the maintenance of polymorphism in gene-for-gene interactions without costs. Overall, our study points to the potential consequences of environmental variation in coevolution, and thus the importance of characterizing genotype-by-genotype-by-environment interactions in natural host–parasite systems, especially those that change the direction of selection acting between the two species.

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Host life-history variation in response to parasitism

Parasitology ◽

10.1017/s0031182000049143 ◽

1985 ◽

Vol 90 (1) ◽

pp. 205-216 ◽

Cited By ~ 270

Author(s):

D. J. Minchella

Keyword(s):

Genetic Variation ◽

Life History ◽

Parasitic Infection ◽

Host Susceptibility ◽

Life History Variation ◽

Susceptible Host ◽

Finite Set ◽

Host Life ◽

Host Parasite ◽

Parasite Populations

Over half of all living species of plants and animals are parasitic, which by definition involves intimate association with and unfavourable impact on hosts (Price, 1980). This paper will only consider parasites whose ‘unfavourable impact’ adversely affects the birth and/or mortality rates of their hosts (Anderson, 1978). Most organisms are potential hosts and must deal with the problem of parasitism. The probability of parasitic infection of a host is influenced by both environmental and genetic factors. Traditionally it was assumed that a host was either resistant or susceptible to a particular parasite and therefore the interaction between a parasite and potential host had only two possible outcomes: either the resistant host rebuffed the parasitic attack and remained uninfected or the parasite successfully invaded and significantly reduced the reproductive success of the susceptible host. This approach, however, ignored the intraspecific genetic variation present within both host and parasite populations (Wakelin, 1978). Since the outcome is determined by the interaction of a finite set of host genes and parasite genes, genetic variation in host susceptibility and parasite infectivity (Richards, 1976; Wakelin, 1978) suggests that more than two outcomes are possible. Variation in host and parasite genomes does not begin and end at the susceptibility/infectivity loci. Other genes may also influence the outcome of host–parasite interactions by altering the life-history patterns of hosts and parasites, and lead to a variety of outcomes.

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Host age modulates within-host parasite competition

Biology Letters ◽

10.1098/rsbl.2015.0131 ◽

2015 ◽

Vol 11 (5) ◽

pp. 20150131 ◽

Cited By ~ 13

Author(s):

Rony Izhar ◽

Jarkko Routtu ◽

Frida Ben-Ami

Keyword(s):

Evolutionary Dynamics ◽

Parasite Prevalence ◽

Host Age ◽

Individual Level ◽

Pasteuria Ramosa ◽

Age Dependent ◽

The Individual ◽

Host Parasite ◽

Parasite Exposure ◽

Age At Exposure

In many host populations, one of the most striking differences among hosts is their age. While parasite prevalence differences in relation to host age are well known, little is known on how host age impacts ecological and evolutionary dynamics of diseases. Using two clones of the water flea Daphnia magna and two clones of its bacterial parasite Pasteuria ramosa , we examined how host age at exposure influences within-host parasite competition and virulence. We found that multiply-exposed hosts were more susceptible to infection and suffered higher mortality than singly-exposed hosts. Hosts oldest at exposure were least often infected and vice versa. Furthermore, we found that in young multiply-exposed hosts competition was weak, allowing coexistence and transmission of both parasite clones, whereas in older multiply-exposed hosts competitive exclusion was observed. Thus, age-dependent parasite exposure and host demography (age structure) could together play an important role in mediating parasite evolution. At the individual level, our results demonstrate a previously unnoticed interaction of the host's immune system with host age, suggesting that the specificity of immune function changes as hosts mature. Therefore, evolutionary models of parasite virulence might benefit from incorporating age-dependent epidemiological parameters.

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Temporal changes in growth, condition and trophic niche in juvenile Cyprinus carpio infected with a non-native parasite

Parasitology ◽

10.1017/s0031182015001237 ◽

2015 ◽

Vol 142 (13) ◽

pp. 1579-1587 ◽

Cited By ~ 6

Author(s):

J. PEGG ◽

D. ANDREOU ◽

C. F. WILLIAMS ◽

J. R. BRITTON

Keyword(s):

Growth Condition ◽

Cyprinus Carpio ◽

Parasite Prevalence ◽

Infected Fish ◽

Trophic Niche ◽

Winter Period ◽

Bothriocephalus Acheilognathi ◽

Native Parasite ◽

Host Parasite ◽

Over Time

SUMMARYIn host–parasite relationships, parasite prevalence and abundance can vary over time, potentially impacting how hosts are affected by infection. Here, the pathology, growth, condition and diet of a juvenile Cyprinus carpio cohort infected with the non-native cestode Bothriocephalus acheilognathi was measured in October 2012 (end of their first summer of life), April 2013 (end of first winter) and October 2013 (end of second summer). Pathology revealed consistent impacts, including severe compression and architectural modification of the intestine. At the end of the first summer, there was no difference in lengths and condition of the infected and uninfected fish. However, at the end of the winter period, the condition of infected fish was significantly reduced and by the end of their second summer, the infected fish were significantly smaller and remained in significantly reduced condition. Their diets were significantly different over time; infected fish consumed significantly higher proportions of food items <53 µm than uninfected individuals, a likely consequence of impaired functional traits due to infection. Thus, the sub-lethal impacts of this parasite, namely changes in histopathology, growth and trophic niche were dependent on time and/or age of the fish.

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Molecular characterization and population genetics of Theileria parva in Burundi’s unvaccinated cattle: Towards the introduction of East Coast fever vaccine

PLoS ONE ◽

10.1371/journal.pone.0251500 ◽

2021 ◽

Vol 16 (5) ◽

pp. e0251500

Author(s):

David Kalenzi Atuhaire ◽

Walter Muleya ◽

Victor Mbao ◽

Joseph Niyongabo ◽

Lionel Nyabongo ◽

...

Keyword(s):

Phylogenetic Analysis ◽

Genetic Differentiation ◽

East Coast ◽

Protozoan Parasite ◽

Parasite Prevalence ◽

East Coast Fever ◽

Theileria Parva ◽

Field Samples ◽

North Eastern ◽

Livestock Development

Theileria parva (T. parva) is a protozoan parasite that causes East Coast fever (ECF). The disease is endemic in Burundi and is a major constraint to livestock development. In this study, the parasite prevalence in cattle in six regions namely; Northern, Southern, Eastern, Western, Central and North Eastern was estimated. Furthermore, the sequence diversity of p67, Tp1 and Tp2 genes was assessed coupled with the population genetic structure of T. parva using five satellite markers. The prevalence of ECF was 30% (332/1109) on microscopy, 60% (860/1431) on ELISA and 79% (158/200) on p104 gene PCR. Phylogenetic analysis of p67 gene revealed that only allele 1 was present in the field samples. Furthermore, phylogenetic analysis of Tp1 and Tp2 showed that the majority of samples clustered with Muguga, Kiambu and Serengeti and shared similar epitopes. On the other hand, genetic analysis revealed that field samples shared only two alleles with Muguga Cocktail. The populations from the different regions indicated low genetic differentiation (FST = 0.047) coupled with linkage disequilibrium and non-panmixia. A low to moderate genetic differentiation (FST = 0.065) was also observed between samples and Muguga cocktail. In conclusion, the data presented revealed the presence of a parasite population that shared similar epitopes with Muguga Cocktail and was moderately genetically differentiated from it. Thus, use of Muguga Cocktail vaccine in Burundi is likely to confer protection against T. parva in field challenge trials.

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The impact of resource provisioning on the epidemiological responses of different parasites

10.1101/2021.05.22.445253 ◽

2021 ◽

Author(s):

Diana Erazo ◽

Amy B Pedersen ◽

Andy Fenton

Keyword(s):

Infectious Diseases ◽

Anthropogenic Activities ◽

Resource Provisioning ◽

Transmission Mode ◽

Host Susceptibility ◽

Host Immune System ◽

Trade Offs ◽

Duration Of Infection ◽

Host Parasite ◽

The Impact

Events such as anthropogenic activities and periodic tree masting can alter resource provisioning in the environment, directly affecting animals, and potentially impacting the spread of infectious diseases in wildlife. The effect of these supplemental resources on infectious diseases can manifest through different pathways, affecting host susceptibility, transmission and host demography. To date however, empirical research has tended to examine these different pathways in isolation, for example by quantifying the effects of provisioning on host behaviour in the wild or changes in immune responses in controlled laboratory studies. Further, while theory has investigated the interactions between these pathways, thus far this work has focussed on a narrow subset of pathogen types, typically directly-transmitted microparasites. Given the diverse ways that provisioning can affect host susceptibility, contact patterns or host demography, we may expect the epidemiological consequences of provisioning to depend on key aspects of parasite life-history, such as the duration of infection and transmission mode. We developed a suite of generic epidemiological models to compare how resource provisioning alters responses for different parasites that vary in their biology (micro- and macro-parasite), transmission mode (direct, environmental, and vector transmitted) and duration of infection (acute, latent, and chronic). Next, we parameterised these different parasite types using data from the diverse parasite community of wild wood mice as a case study. We show there are common epidemiological responses to host resource provisioning across all parasite types examined. In particular, the response to provisioning could be driven in opposite directions, depending on which host pathways (contact rate, susceptibility or host demography) are most altered by the addition of resources to the environment. Broadly, these responses were qualitatively consistent across all parasite types, emphasising the importance of identifying general trade-offs between provisioning-altered parameters. Despite the qualitative consistency in responses to provisioning across parasite types, we found notable quantitative differences between parasites, suggesting specific epidemiological outcomes could strongly depend on parasite type, infection duration and permanency of recovery, and whether the parasite is directly, environmentally, or vector transmitted. These analyses therefore highlight the importance of knowing key specific aspects of host-parasite biology, such as host contact behaviours, parasite interactions with the host immune system, and how resource availability shapes host demographics, in order to understand and predict epidemiological responses to provisioning for any specific host-parasite system.

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