Search results for "Miasi"
showing 10 items of 123 documents
Human fascioliasis infection: gender differences within school-age children from endemic areas of the Nile Delta, Egypt
2007
Summary Several studies have reported a higher prevalence of infection for human fascioliasis among girls than among boys. To investigate this aspect further a sufficiently large data set was assembled comprising of 21 477 subjects with 932 positive cases. Subjects were primary school children covered by a control programme implemented by the Egyptian Ministry of Health and Population in the Nile Delta from 1988 to 2002. Stool analyses were performed by the Kato–Katz thick smear technique for a quantitative diagnosis on the intensity of infection. Both prevalence and intensity of infection, indirectly measured as mean number of eggs per gram of faeces, were significantly higher among girls …
The effect of glycosylation of antigens on the antibody responses against Echinostoma caproni (Trematoda: Echinostomatidae).
2014
SUMMARYIn the present study, we analyse the effect of glycosylation inEchinostoma caproni(Trematoda: Echinostomatidae) antigens in antibody responses against the parasite in experimentally infected mice. It has been previously demonstrated that the mouse is a host of high compatibility withE. caproniand develops elevated responses of IgG, IgG1, IgG3 and IgM as a consequence of the infection, though the role of glycans in these responses remains unknown. To this purpose, the responses generated in mice against non-treated excretory/secretory antigens ofE. caproniwere compared with those observed after N-deglycosylation, O-deglycosylation and double deglycosylation of the antigens by indirect…
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-…
Echinostomes as experimental models for interactions between adult parasites and vertebrate hosts.
2005
Echinostomes are intestinal trematodes that, for years, have served as experimental models in different areas of parasitology. However, the usefulness of these trematodes in experimental parasitology has been underappreciated. In this article, we examine the characteristics that make echinostomes useful models for analysis of the interactions between adult parasites and vertebrate hosts, particularly in relation to the host-related factors that determine the establishment of the parasites.
ITS-2 rDNA sequencing of Gnathostoma species (Nematoda) and elucidation of the species causing human gnathostomiasis in the Americas.
2000
From several gnathostome species the complete internal transcribed spacer ITS-2 ribosomal DNA (rDNA) repeat sequence and a fragment of the 5.8S rDNA were obtained by direct polymerase chain reaction cycle-sequencing and silver-staining methods. The size of the complete ITS-1 sequence in agarose gel electrophoresis was also obtained. The ITS-2 enabled the differentiation of Gnathostoma spinigerum from Thailand and Gnathostoma binucleatum from Mexico and Ecuador and confirmed the validity of the latter. Gnathostoma turgidum, Gnathostoma sp. I (=Gnathostoma procyonis sensu Almeyda-Artigas et al., 1994), and Gnathostoma sp. II (=G. turgidum sensu Foster, 1939 pro parte), all from Mexico, proved…
Development and pathology of echinostoma caproni in experimentally infected mice
2007
In the present article, several parasitological features of mice, each experimentally infected with 75 metacercariae of Echinostoma caproni (Trematoda: Echinostomatidae), were studied during the first 12 wk postinfection. Moreover, the early pathological responses also were analyzed and compared with data previously published on other host species of E. caproni to gain further insight into the factors determining worm rejection or establishment of chronic infections. The results obtained show that the pattern of E. caproni infection in mice is consistent with a highly compatible host–parasite system. This combination is characterized by a high worm establishment, high egg output, and long s…
Parasite eggs in urine cytology: fact or artifact?
2008
Urine sediment cytology should be done for three main reasons: initial evaluation in symptomatic patients, pursuit of patients with tumoral pathology, and risk population screening. Nevertheless, in the course of microscopic observation it is possible to observe several elements or structures that initially seem unrelated to what we are looking for. Schistosomiasis is an endemic disease affecting humans and animals in tropical countries and the Middle and Far East, but infrequent in the developed countries. Typical eggs from Schistosoma are nonoperculate, embryonated when passed in feces and with transparent shell. The eggs are elongate and large in S. mansoni (114–175 3 40– 70 lm in size),…
Echinostoma caproni: intestinal pathology in the golden hamster, a highly compatible host, and the Wistar rat, a less compatible host.
2005
The histopathological changes induced by Echinostoma caproni (Trematoda: Echinostomatidae) in a high (golden hamster) and a low compatible host (rat) were compared at 15 and 30 days post-infection. Infection of rats was characterized by a progressive increase in erosion of villi and elevated numbers of goblet cells, which could be related to the early expulsion of the parasite in a host of low compatibility. In contrast to rats, the number of goblet cell in E. caproni-infected hamsters was low, but increased numbers of neutrophils and mesenteric inflammatory cells were observed. This indicated that local inflammatory responses in hamsters were greater than in rats. An immunohistochemical st…
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…