Search results for "HOST-PARASITE"
showing 10 items of 355 documents
Establishment and interspecific associations in two species of Ichthyocotylurus (Trematoda) parasites in perch (Perca fluviatilis)
2011
Background: Co-infections of multiple parasite species in hosts may lead to interspecific associations and subsequently shape the structure of a parasite community. However, few studies have focused on these associations in highly abundant parasite species or, in particular, investigated how the associations develop with time in hosts exposed to co-infecting parasite species for the first time. We investigated metacercarial establishment and interspecific associations in the trematodes Ichthyocotylurus variegatus and I. pileatus co-infecting three age cohorts of young perch (Perca fluviatilis). Results: We found that the timing of transmission of the two Ichthyocotylurus species was very si…
The role of maternal effects in host-parasite interactions: examination of the development of the immune defense in a colonial seabird, the black-leg…
2004
One of the main aims of evolutionary biology is to understand the mechanisms responsible for the phenotypic variation on which natural selection can act. Maternal effects occur when a mother's phenotype or her environment influence her offspring's phenotype. Despite the importance of such effects for the ecology of host-parasite interactions, their role has been relatively neglected to date. In this thesis, we examined how mothers influence the immune defense of their young in an environment that varies in space and time. This work has primarily focused on a colonial seabird, the black-legged kittiwake (Rissa tridactyla). Using this model, we have first shown that specific maternal antibodi…
Interactions between two parasites of brown trout (Salmo trutta): Consequences of preinfection
2018
Preinfection by one parasitic species may facilitate or by contrast hamper the subsequent penetration and/or establishment of other parasites in a host. The biology of interacting species, timing of preinfection, and dosage of subsequent parasite exposure are likely important variables in this multiparasite dynamic infection process. The increased vulnerability to subsequent infection can be an important and often overlooked factor influencing parasite virulence. We investigated how the preinfection by freshwater pearl mussel Margaritifera margaritifera glochidia could influence the success of subsequent infection by the common trematode Diplostomum pseudospathaceum in brown trout Salmo tru…
Baseline Gut Microbiota Composition Is Associated With Schistosoma mansoni Infection Burden in Rodent Models
2020
In spite of growing evidence supporting the occurrence of complex interactions between Schistosoma and gut bacteria in mice and humans, no data is yet available on whether worm-mediated changes in microbiota composition are dependent on the baseline gut microbial profile of the vertebrate host. In addition, the impact of such changes on the susceptibility to, and pathophysiology of, schistosomiasis remains largely unexplored. In this study, mice colonized with gut microbial populations from a human donor (HMA mice), as well as microbiota-wild type (WT) animals, were infected with Schistosoma mansoni, and alterations of their gut microbial profiles at 50 days post-infection were compared to …
Antigen-specific T cells and cytokines detection as useful tool for understanding immunity against zoonotic infections.
2012
Zoonoses include a broad range of diseases, that are becoming of great interest, due to the climate changing, that cause the adaptation of vectors to new niches and environments. Host immune responses play a crucial role in determining the outcome of infections, as documented by expansion of antigen-specific T cells during several zoonotic infections. Thus, understanding of the contribution of antigen-specific T-cell subsets in the host immune response is a powerful tool to evaluate the different immunological mechanisms involved in zoonotic infections and for the development of effective vaccines. In this paper we discuss the role of T cells in some eukaryotic and prokaryotic infectious mo…
Parasite presence induces gene expression changes in an ant host related to immunity and longevity
2021
Most species are either parasites or exploited by parasites, making parasite&ndash
Genotype-specific vs. cross-reactive host immunity against a macroparasite
2013
Vertebrate hosts often defend themselves against several co-infecting parasite genotypes simultaneously. This has important implications for the ecological dynamics and the evolution of host defence systems and parasite strategies. For example, it can drive the specificity of the adaptive immune system towards high genotype-specificity or cross-reactivity against several parasite genotypes depending on the sequence and probability of re-infections. However, to date, there is very little evidence on these interactions outside mammalian disease literature. In this study we asked whether genotype-specific or cross-reactive responses dominate in the adaptive immune system of a fish host towards…
Intraguild interactions between egg parasitoids: window of opportunity and fitness costs for a facultative hyperparasitoid.
2013
We investigated intraguild interactions between two egg parasitoids of Nezara viridula (L.) (Heteroptera: Pentatomidae), Ooencyrtus telenomicida (Vassiliev) (Hymenoptera: Encyrtidae) and Trissolcus basalis (Wollaston) (Hymenoptera: Platygastridae), as the former has the potential to be a facultative hyperparasitoid of the latter. We assessed the suitability of N. viridula eggs for the development of O. telenomicida as a function of egg age when they were unparasitized, or had been attacked by T. basalis at different times prior to exposure to O. telenomicida females. Ooencyrtus telenomicida can exploit healthy N. viridula host eggs up to 5 days of age, just prior to the emergence of N. viri…
Intestinal distribution and fecundity of two species ofDiplostomumparasites in definitive hosts
2005
This paper investigated the intestinal distribution and fecundity of 2 species ofDiplostomumparasites,D. spathaceumandD. pseudospathaceum, in 2 species of definitive hosts, herring gull (Larus argentatus) and common gull (L. canus), using both empirical field data and experimental infections. At the level of individual hosts, the parasite species occupied different parts within the intestine, but the fecundity of the worms, measured as the number of eggs in the uterus, did not differ between the parasite species except in wild common gulls. Interestingly, egg numbers in individual hosts were positively correlated between the parasite species suggesting that some birds provided better resour…
Intraguild interactions between two egg parasitoids of a true bug in semi-field and field conditions.
2014
International audience; Research on interspecific competitive interactions among insect parasitoids has often been characterized by laboratory studies in which host insects are exposed to female parasitoids of different species in various sequences and combinations. In the last years, an increasing number of studies have investigated interspecific interactions under field and semi-field conditions although just a few number of works focused on egg parasitoids. In this work, we undertook a two-year study to investigate interspecific interactions between Trissolcus basalis (Wollaston) (Hymenoptera: Platygastridae) and Ooencyrtus telenomicida (Vassiliev) (Hymenoptera: Encyrtidae), two egg para…