Search results for "HELMINTHS"
showing 10 items of 202 documents
Echinostoma caproni (Trematoda): differential in vivo mucin expression and glycosylation in high- and low-compatible hosts.
2014
Enhanced mucus production and release appears to be a common mechanism for the clearance of intestinal helminths, and this expulsion is normally mediated by Th2-type immune responses. To investigate the factors determining the expulsion of intestinal helminths, we have analysed in vivo expression of mucin genes at the site of infection in two host species displaying different compatibility with Echinostoma caproni (Trematoda). Surprisingly, a general down-regulation on mucin mRNA expression was detected in low-compatible hosts (rats) coinciding with the development of Th2/Th17 responses and the early rejection of the worms from the intestinal lumen. This suggests the existence of a mechanis…
Th17 responses in Echinostoma caproni infections in hosts of high and low compatibility.
2011
In order to investigate the factors determining the expulsion of intestinal helminths, we have analyzed the in vivo expression of IL-17, TGF-β and IL-23 in several tissues of two host species displaying different compatibility with Echinostoma caproni (Trematoda). We did not observe upregulation of these cytokines in any of the tissues of the high compatible host (mice). In contrast, the responses in the host of low compatibility (rats) with the parasite were markedly different. Significant increases in the expression of IL-17 and TGF-β were observed in the Peyer's patches and the intestine from the 2 to 8 weeks post-infection. The expression of IL-23 was upregulated from 2 to 4 weeks post-…
High fascioliasis infection in children linked to a man-made irrigation zone in Peru.
2002
We detected 10 protozoan and nine helminth species in surveys of 338 5-15 year-old Quechua schoolchildren in three communities of the Asillo zone of the Puno region, located at a very high altitude of 3910 m in the Peruvian Altiplano. The area proved to be hyperendemic for human fascioliasis with a 24.3% overall mean prevalence of Fasciola hepatica, local prevalences ranging between 18.8 and 31.3%, and infection intensities of up to 2496 eggs per gram of faeces (epg), with 196-350 epg (mean: 279 epg) and 96-152 epg (123 epg) as arithmetic and geometric means, respectively. Prevalences did not significantly vary between schools and in relation to sex. No statistical differences were found in…
Molecular and morphological evidence for three species of Diplostomum (Digenea: Diplostomidae), parasites of fishes and fish-eating birds in Spain
2014
Background Recent molecular studies have revealed high species diversity of Diplostomum in central and northern Europe. However, our knowledge of the distribution of Diplostomum spp. in the southern distributional range in Europe of the snail intermediate hosts (Lymnaea stagnalis and Radix spp.) is rather limited. This study aims to fill this gap in our knowledge using molecular and morphological evidence. Methods Nineteen fish species and six fish-eating bird species were sampled opportunistically in three regions (Catalonia, Extremadura and Aragon) in Spain. All isolates of Diplostomum spp. were characterised morphologically and molecularly. Partial sequences of the barcode region of the …
Analysis of the tegument of Zygocotyle lunata (Trematoda: Paramphistomidae) adults by scanning electron microscopy.
2012
Paramphistomiasis is a parasitic disease caused by various species of the Paramphistomidae. These species mainly affect domestic and wild ruminants; the economic impact of these diseases is often underestimated. Traditionally, the identification of paramphistomes has been difficult and has been based on morphological aspects such as the body shape, the position of the esophagus and cecae, or the tegumental papillae. Despite the many investigations regarding the tegumental papillae for other paramphistomes, very few efforts have been made using Zygocotyle lunata, partly because many authors differ with respect to the importance of papillae in the classification of paramphistomids. Herein, we…
Proximate factors affecting the larval life history of Acanthocephalus lucii (Acanthocephala).
2007
The growth and eventual size of larval helminths in their intermediate hosts presumably has a variety of fitness consequences. Therefore, elucidating the proximate factors affecting parasite development within intermediate hosts should provide insight into the evolution of parasite life histories. An experimental infection that resulted in heavy intensities of an acanthocephalan (Acanthocephalus lucii) in its isopod intermediate host (Asellus aquaticus) permitted the examination of parasite developmental responses to variable levels of resource availability and intraspecific competition. Isopods were infected by exposure to egg-containing fish feces, and larval infrapopulations were monitor…
Lung-worms (Nematoda: Pseudaliidae) of harbour porpoises (Phocoena phocoena) in Norwegian waters: patterns of colonization
1994
SUMMARYWe studied the component community of lung-worms of the harbour porpoise, attempting to establish the relative importance of ecological and evolutionary factors on its development. The lungs of 64 porpoises by-caught in Norwegian waters were examined for helminths. Three pseudaliid species were detected. The porpoises appear to be readily colonized by lung-worms, the structure of the component community of calves being fairly similar to that of the remainder. Prenatal and/or transmammary infections might partly account for these early infections. However, host age was correlated with the number of lung-worm species, suggesting that the lung-worms may have heteroxenous cycles similar …
Hepatic parasitosis in two wood mice, Apodemus sylvaticus (Rodentia: Muridae), due to Aonchotheca annulosa (Nematoda: Trichuridae), and Eucoleus baci…
2014
AbstractAonchotheca annulosa and Eucoleus bacillatus are two capillariin nematodes parasitizing the intestinal and stomach mucosa, respectively, of various rodent species, and two, among others, component species of the helminth fauna of the wood mouse, Apodemus sylvaticus. A capillariin each was found in the liver parenchyma of two wood mice in a post-fire regeneration enclave in Serra Calderona Natural Park (Valencian Community, Spain). Due to their location, the preliminary identification of the helminths corresponded to Calodium hepaticum, a hepatic capillariin with rodents as its main host. So far, this species had never been found in Serra Calderona. To verify the preliminary identifi…
Finding of Parastrongylus cantonensis (Chen, 1935) in Rattus rattus in Tenerife, Canary Islands (Spain).
2010
Parastrongylus cantonensis is a parasite of murid rodents that can infect humans and cause health problems as eosinophilic meningitis. Although it is endemic in south Asia, the Pacific islands, Australia, USA, and a few Caribbean islands, it has been extended to new geographical regions. In the Canary Islands (Spain) a survey of helminths of Rattus rattus, Rattus norvegicus and Mus musculus domesticus was carried out. Furthermore, five species of molluscs were examined for nematode larvae to determine whether they are potential intermediate hosts of P. cantonensis. Nematodes were found in the lungs of 15% of 67 R. rattus examined in Tenerife, one of the four studied islands, with a prevalen…
Morphological and genomic characterisation of the Schistosoma hybrid infecting humans in Europe reveals admixture between Schistosoma haematobium and…
2021
Schistosomes cause schistosomiasis, the world’s second most important parasitic disease after malaria in terms of public health and social-economic impacts. A peculiar feature of these dioecious parasites is their ability to produce viable and fertile hybrid offspring. Originally only present in the tropics, schistosomiasis is now also endemic in southern Europe. Based on the analysis of two genetic markers the European schistosomes had previously been identified as hybrids between the livestock- and the human-infective species Schistosoma bovis and Schistosoma haematobium, respectively. Here, using PacBio long-read sequencing technology we performed genome assembly improvement and annotati…