Search results for "Host-parasite interactions"
showing 10 items of 330 documents
Morphology, performance and attachment function in Corynosoma spp. (Acanthocephala)
2018
Background: Functional inference on the attachment of acanthocephalans has generally been drawn directly from morphology. However, performance of structures is often non-intuitive and context-dependent, thus performance analysis should be included whenever possible to improve functional interpretation. In acanthocephalans, performance analysis of attachment is available only for Acanthocephalus ranae, a species that solely relies on the proboscis to attach. Here we compare body morphology and muscle arrangement in 13 species of Corynosoma, which use their spiny body as a fundamental holdfast. A basic performance analysis using live cystacanths of two representative species is also provided.…
From mammals back to birds: Host-switch of the acanthocephalan Corynosoma australe from pinnipeds to the Magellanic penguin Spheniscus magellanicus.
2017
Trophically-transmitted parasites are regularly exposed to potential new hosts through food web interactions. Successful colonization, or switching, to novel hosts, occur readily when ?donor? and ?target? hosts are phylogenetically related, whereas switching between distantly related hosts is rare and may result from stochastic factors (i.e. rare favourable mutations). This study investigates a host-switching event between a marine acanthocephalan specific to pinnipeds that is apparently able to reproduce in Magellanic penguins Spheniscus magellanicus from Brazil. Detailed analysis of morphological and morphometrical data from acanthocephalans from penguins indicates that they belong to Cor…
Helminths, hosts, and their microbiota: new avenues for managing gastrointestinal helminthiases in ruminants
2020
Evidence is emerging of complex interactions occurring between gastrointestinal (GI) parasites of ruminants and the resident gut flora, with likely implications for the pathophysiology of worm infection and disease. Similarly, recent data point toward the occurrence of a GI nematode (GIN)-specific microbiota, with potential roles in worm fundamental physiology and reproduction. Parasite-microbiota relationships might represent potential targets for the development of novel parasiticides.In this article, we review current knowledge of the role(s) that host- and helminth-associated microbiota play in ruminant host-parasite relationships, and outline potential avenues for the control of GIN of…
Age reduces resistance and tolerance in malaria-infected mice.
2021
7 pages; International audience; Once infected, hosts can rely on two strategies to cope with parasites: fight them (resist the infection) or minimize the damage they induce (tolerate the infection). While there is evidence that aging reduces resistance, how tolerance varies as hosts become old has been barely studied. Here, we used a rodent malaria parasite (Plasmodium yoelii) to investigate whether 2- and 12-month old house mice differ in their capacity to resist and tolerate the infection. We found that 12-month old mice harbored higher parasitemia, showing that age reduces resistance to malaria. Infection-induced deterioration of host health was assessed using red blood cell and body ma…
Perils and Promises of Pathogenic Protozoan Extracellular Vesicles
2020
Extracellular vesicles (EVs) are membranous structures formed during biological processes in living organisms. For protozoan parasites, secretion of EVs can occur directly from the parasite organellar compartments and through parasite-infected or antigen-stimulated host cells in response to in vitro and in vivo physiological stressors. These secreted EVs characteristically reflect the biochemical features of their parasitic origin and activating stimuli. Here, we review the species-specific morphology and integrity of parasitic protozoan EVs in concurrence with the origin, functions, and internalization process by recipient cells. The activating stimuli for the secretion of EVs in pathogeni…
Extracellular non-coding RNA signatures of the metacestode stage of Echinococcus multilocularis
2020
Extracellular RNAs (ex-RNAs) are secreted by cells through different means that may involve association with proteins, lipoproteins or extracellular vesicles (EV). In the context of parasitism, ex-RNAs represent new and exciting communication intermediaries with promising potential as novel biomarkers. In the last years, it was shown that helminth parasites secrete ex-RNAs, however, most work mainly focused on RNA secretion mediated by EV. Ex-RNA study is of special interest in those helminth infections that still lack biomarkers for early and/or follow-up diagnosis, such as echinococcosis, a neglected zoonotic disease caused by cestodes of the genus Echinococcus. In this work, we have char…
Drivers of parasite community structure in fishes of the continental shelf of the Western Mediterranean: the importance of host phylogeny and autecol…
2019
15 pages, 5 figures, 6 tables, supplementary data https://doi.org/10.1016/j.ijpara.2019.04.004
On the presence and immunoregulatory functions of extracellular microRNAs in the trematode Fasciola hepatica.
2017
Summary Liver flukes represent a paraphyletic group of endoparasitic flatworms that significantly affect man either indirectly due to economic damage on livestock or directly as pathogens. A range of studies have focussed on how these macroscopic organisms can evade the immune-system and live inside a hostile environment such as the mammalian liver and bile-ducts. Recently, microRNAs, a class of short non-coding gene-regulators, have been proposed as likely candidates to play roles in this scenario. MicroRNAs (miRNAs) are key players in development and pathogenicity and are highly conserved between metazoans: identical miRNAs can be found in flatworms and mammalians. Interestingly, miRNAs a…
Towards a Unified Functional Trait Framework for Parasites
2019
Trait-based research holds high potential to unveil ecological and evolutionary processes. Functional traits are fitness-related characteristics of individuals, which are measured at individual level and defined without using information external to the individual. Despite the usefulness of the functional approach to understand the performance of individuals in ecosystems, and parasitism being the most common life-history strategy on Earth, studies based on functional traits of parasites are still scarce. Since the choice of functional traits is a critical step for any study, we propose a core list of seven functional traits of metazoan parasites, related to three universal challenges faced…
Life history adjustments to intestinal inflammation in a gut nematode.
2017
ABSTRACT Many parasitic nematodes establish chronic infections. This implies a finely tuned interaction with the host immune response in order to avoid infection clearance. Although a number of immune interference mechanisms have been described in nematodes, how parasites adapt to the immune environment provided by their hosts remains largely unexplored. Here, we used the gastrointestinal nematode Heligmosomoides polygyrus to investigate the plasticity of life history traits and immunomodulatory mechanisms in response to intestinal inflammation. We adopted an experimental model of induced colitis and exposed worms to intestinal inflammation at two different developmental stages (larvae and …