Search results for "Parasite"
showing 10 items of 827 documents
Impact of fascioliasis reinfection on Fasciola hepatica egg shedding: relationship with the immune-regulatory response.
2019
Abstract Fascioliasis is a disease caused by liver flukes. In human fascioliasis hyperendemic areas, reinfection and chronicity are the norm. Control strategies in humans require the use of egg count techniques to calculate the appropriate treatment dose for colic risk prevention. The present study investigates how fascioliasis reinfection affects liver fluke egg shedding and its relationship with the immune-regulatory response. The experimental design reproduced the usual reinfection/chronicity conditions in human fascioliasis endemic areas and included Fasciola hepatica primo-infected Wistar rats (PI) and rats reinfected at 4 weeks (R4), 8 weeks (R8), 12 weeks (R12), and negative control …
Disease severity in patients with visceral leishmaniasis is not altered by co-infection with intestinal parasites
2017
Visceral leishmaniasis (VL) is a neglected tropical disease that affects the poorest communities and can cause substantial morbidity and mortality. Visceral leishmaniasis is characterized by the presence of Leishmania parasites in the spleen, liver and bone marrow, hepatosplenomegaly, pancytopenia, prolonged fever, systemic inflammation and low body mass index (BMI). The factors impacting on the severity of VL are poorly characterized. Here we performed a cross-sectional study to assess whether co-infection of VL patients with intestinal parasites influences disease severity, assessed with clinical and haematological data, inflammation, cytokine profiles and BMI. Data from VL patients was s…
Different behavior of myeloperoxidase in two rodent amoebic liver abscess models.
2016
The protozoan Entamoeba histolytica is the etiological agent of amoebiasis, which can spread to the liver and form amoebic liver abscesses. Histological studies conducted with resistant and susceptible models of amoebic liver abscesses (ALAs) have established that neutrophils are the first cells to contact invasive amoebae at the lesion site. Myeloperoxidase is the most abundant enzyme secreted by neutrophils. It uses hydrogen peroxide secreted by the same cells to oxidize chloride ions and produce hypochlorous acid, which is the most efficient microbicidal system of neutrophils. In a previous report, our group demonstrated that myeloperoxidase presents amoebicidal activity in vitro. The ai…
Antibody trapping: A novel mechanism of parasite immune evasion by the trematode Echinostoma caproni
2017
Background Helminth infections are among the most prevalent neglected tropical diseases, causing an enormous impact in global health and the socioeconomic growth of developing countries. In this context, the study of helminth biology, with emphasis on host-parasite interactions, appears as a promising approach for developing new tools to prevent and control these infections. Methods/Principal findings The role that antibody responses have on helminth infections is still not well understood. To go in depth into this issue, work on the intestinal helminth Echinostoma caproni (Trematoda: Echinostomatidae) has been undertaken. Adult parasites were recovered from infected mice and cultured in vi…
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…
Parasite communities in two sparid fishes from the western Mediterranean: a comparative analysis based on samples from three localities off the Alger…
2017
Summary We provide the first known comparative assessment of metazoan parasite communities in two taxonomically and ecologically related sparids, Boops boops and Spicara maena, that are common in the coastal infralittoral habitats in the Mediterranean. Using abundant data for infracommunities in three localities off the Algerian coasts of the Mediterranean, we tested the general prediction that the phylogenetic proximity of the two hosts, their overlapping geographical distribution and habitat occupation, as well as the similar feeding habits and diet would contribute to a homogenization of their parasite community composition and structure. The regional fauna of parasites of B. boops and S…
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…
Mycobacterium avium subsp. paratuberculosis (Map) Fatty Acids Profile Is Strain-Dependent and Changes Upon Host Macrophages Infection
2017
Johne´s disease is a chronic granulomatous enteritis of ruminants caused by the intracellular bacterium Mycobacterium avium subsp. paratuberculosis (Map). We previously demonstrated that Map isolates from sheep persisted within host macrophages in lower CFUs than cattle isolates after 7 days of infection. In the current study, we hypothesize that these phenotypic differences between Map isolates may be driven be the fatty acids (FAs) present on the phosphadidyl-1-myo-inositol mannosides of the Map cell wall that mediate recognition by the mannose receptors of host macrophages. FAs modifications may influence Map´s envelope fluidity ultimately affecting pathogenicity. To test this hypothesis…
Invasive Species as Hosts of Zoonotic Infections: The Case of American Mink (Neovison vison) and Leishmania infantum
2021
Leishmania infantum produces an endemic disease in the Mediterranean Basin that affects humans and domestic and wild mammals, which can act as reservoir or minor host. In this study, we analyzed the presence of the parasite in wild American minks, an invasive species in Spain. We screened for L. infantum DNA by PCR using five primer pairs: Two targeting kinetoplast DNA (kDNA), and the rest targeting the ITS1 region, the small subunit of ribosomal RNA (SSU) and a repetitive sequence (Repeat region). The detection limit was determined for each method using a strain of L. infantum and a bone marrow sample from an infected dog. PCR approaches employing the Repeat region and kDNA (RV1/RV2 primer…
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…