Search results for " tropi"
showing 10 items of 405 documents
No pre-zygotic isolation mechanisms between Schistosoma haematobium and Schistosoma bovis parasites: From mating interactions to differential gene ex…
2021
Species usually develop reproductive isolation mechanisms allowing them to avoid interbreeding. These preventive barriers can act before reproduction, “pre-zygotic barriers”, or after reproduction, “post-zygotic barriers”. Pre-zygotic barriers prevent unfavourable mating, while post-zygotic barriers determine the viability and selective success of the hybrid offspring. Hybridization in parasites and the underlying reproductive isolation mechanisms maintaining their genetic integrity have been overlooked. Using an integrated approach this work aims to quantify the relative importance of pre-zygotic barriers in Schistosoma haematobium x S. bovis crosses. These two co-endemic species cause sch…
Predicting the spatial abundance of Ixodes ricinus ticks in southern Scandinavia using environmental and climatic data
2019
AbstractRecently, focus on tick-borne diseases has increased as ticks and their pathogens have become widespread and represent a health problem in Europe. Understanding the epidemiology of tick-borne infections requires the ability to predict and map tick abundance. We measured Ixodes ricinus abundance at 159 sites in southern Scandinavia from August-September, 2016. We used field data and environmental variables to develop predictive abundance models using machine learning algorithms, and also tested these models on 2017 data. Larva and nymph abundance models had relatively high predictive power (normalized RMSE from 0.65–0.69, R2 from 0.52–0.58) whereas adult tick models performed poorly …
Temporal dynamics of the tick Ixodes ricinus in northern Europe : epidemiological implications
2017
Background Tick-borne pathogens pose an increasing threat to human and veterinary health across the northern hemisphere. While the seasonal activity of ticks is largely determined by climatic conditions, host-population dynamics are also likely to affect tick abundance. Consequently, abundance fluctuations of rodents in northern Europe are expected to be translated into tick dynamics, and can hence potentially affect the circulation of tick-borne pathogens. We quantified and explained the temporal dynamics of the tick Ixodes ricinus in the northernmost part of its European geographical range, by estimating (i) abundance in vegetation and (ii) infestation load in the most common rodent speci…
Oestrus ovis external ophtalmomyiasis : a case report in Burgundy France
2018
Background External ophtalmomyiasis (EOM) is a zoonosis related to the presence of Oestrus ovis larvae at the ocular level in small ruminants (i.e. ovine, caprine). In humans, EOM is a rare cosmopolitan disorder, mostly described in warm and dry rural areas in patients living close to livestock areas. In metropolitan France (excluding Corsica), EOM is an exceptional disease with less than 25 cases recorded since 1917. Case presentation We report a case of EOM in a 19-years old man in the last week of September 2016 in Burgundy. Conclusion The diagnosis of an EOM in Burgundy, a French region described as cold and humid, is surprising and could be due to a more marked climatic warming during …
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…
Fasciola hepatica reinfection potentiates a mixed Th1/Th2/Th17/Treg response and correlates with the clinical phenotypes of anemia.
2016
Background: Fascioliasis is a severe zoonotic disease of worldwide extension caused by liver flukes. In human fascioliasis hyperendemic areas, reinfection and chronicity are the norm and anemia is the main sign. Herein, the profile of the Th1/Th2/Th17/Treg expression levels is analyzed after reinfection, correlating them with their corresponding hematological biomarkers of morbidity. Methodology/Principal findings: The experimental design reproduces the usual reinfection/chronicity conditions in human fascioliasis endemic areas and included Fasciola hepatica primo-infected Wistar rats (PI) and rats reinfected at 8 weeks (R8), and at 12 weeks (R12), and negative control rats. In a cross-sect…
Hepatitis E virus-induced primary cutaneous CD30(+) T cell lymphoproliferative disorder.
2017
International audience; BACKGROUND & AIM:Several types of unexplained extra-hepatic manifestations, including haematological disorders, have been reported in the context of hepatitis E virus (HEV) infection. However, the underlying mechanism(s) of these manifestations are unknown. We provide evidence that HEV has an extra-hepatic endothelial tropism that can engage cutaneous T cells towards clonality.METHODS:A patient with a CD30(+) cutaneous T cell lymphoproliferative disorder (T-LPD) and biopsy-proven chronic HEV infection received three rounds of oral ribavirin treatment, administered either without or with interferon, and eventually achieved a sustained virologic response (SVR). Patholo…
Taeniasis vs cysticercosis infection routes
2016
Although cysticercosis caused by Taenia solium ( T. soliu ) is considered a neglected disease, its life cycle has been well known for more than two centuries. T. solium not only causes cysticercosis but also taeniasis in humans. These two diseases have totally different infection routes. To acquire taeniasis (the presence of the adult stage of T. solium in the intestine), humans have to ingest the larval stage (cysticercus) that infects a variety of organs and viscera in pigs, its intermediate hosts. Therefore, taeniasis is acquired when eating raw or undercooked infected pork. The adult stage in the human intestine release eggs that contain a hexacanth embryo, the oncosphere. If humans acc…
Monitoring campaign over an edible dormouse population (Glis glis; rodentia: Gliridae) in Sicily: First report of mesocestodiasis
2021
Simple Summary In Nebrodi Park (Sicily, Italy), live many wild mammal species that move closer to human beings every day. The edible dormouse (Glis glis), in 2017 and 2018, was responsible for nut crop damage in the area. For this reason, a sanitary monitoring campaign involving 30 dormice was carried out by collecting rectal and conjunctival swabs and fur and nest content, which were then processed for laboratory examinations. A large presence of fleas belonging to Monopsyllus sciurorum was found. Necropsy of a dead dormouse revealed an infection of Mesocestoides lineatus, whose cysts were found in the abdomen cavity and on the liver; this is the first report of this in this species. Furth…
Seroprevalence of Borrelia burgdorferi in Stray Dogs from Southern Italy
2020
Borrelia burgdorferi is a bacterial pathogen transmitted by Ixodes ticks and is responsible for Lyme disease in both humans and dogs. The aim of this work was to evaluate B. burgdorferi diffusion among stray dogs in Palermo (Sicily, Italy) by serological methods in order to study the risk factors associated with the infection. Serum and blood samples of 316 dogs were collected from a shelter in Palermo, and were analyzed for the presence of antibodies against B. burgdorferi by indirect immunofluorescence assay (IFA), and of the ospA gene by real-time PCR, respectively. Seventeen sera (5.4%) were positive for the antibodies via IFA and one blood (0.3%) for ospA via real time PCR. On the basi…