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Echinostoma
Published in Dongyou Liu, Handbook of Foodborne Diseases, 2018
Aleksandra Oliveira-Menezes, Júlia Peralta Gonçalves
In addition to its effect on S. mansoni, PZQ causes similar morphological changes in the tegument of other trematodes, like swelling and shortening or loss of superficial spines, the appearance of vesicles around the tubercles, and damage to the oral sucker in S. mekongi112; vesicles, deformities of the spines in the surface, and swelling of the tegument in S. haematobium113; and vacuolization of the tegument of Dicrocoelium dendriticum.110 In C. sinensis, O. viverrini, and S. japonicum, PZQ causes severe vacuolation of their teguments; Paragonimus westermani shows few vacuoles after PZQ treatment.114 In adult E. paraensei recovered after treatment of PZQ, this drug led to changes in the collar of perioral spines, which include the appearance of vesicles and peeling in their tegument, with intense retraction of the spines.107
The Helminths
Published in Donald L. Price, Procedure Manual for the Diagnosis of Intestinal Parasites, 2017
In developing the Key, the author has relied on many reference sources for basic information. Those eggs that are most commonly seen in fecal specimens have been included. Some species, such as Capillaria philippinensis and Ternidens deminutus, seen only in limited geographic areas, have been included because of the ease of travel from those areas. Other species, such as Dicrocoelium dendriticum and the free-living Heterodera sp., seen only as spurious infections, have been included also. Others that are rarely seen, for example Capillaria hepatica and Schistosoma mekongi, have been omitted.
The role of UDP-glycosyltransferases in xenobioticresistance
Published in Drug Metabolism Reviews, 2022
Diana Dimunová, Petra Matoušková, Radka Podlipná, Iva Boušová, Lenka Skálová
Contrary to nematodes, the evidence of UGT activities toward xenobiotics is sporadic in other helminths, such as flukes. In the giant liver fluke (Fascioloides magna), certain activities of glucosyl/glucuronosyl transferases toward model substrate p-nitrophenol were detected in vitro. On the other hand, flukes ex vivo did not conjugate anthelmintics (ABZ, FLU, and TCBZ) with glucose or glucuronic acid (Prchal et al. 2016). Similarly, no formation of the anthelmintics glucosides/glucuronides was detected in the lancet fluke (Dicrocoelium dendriticum), although some activity of UGTs toward p-nitrophenol was observed in vitro (Cvilink, Szotakova, et al. 2009). These results indicate that UGTs do not play a significant role in drug-resistance in flukes.
Extracellular vesicles from parasitic helminths and their potential utility as vaccines
Published in Expert Review of Vaccines, 2018
Gebeyaw Getnet Mekonnen, Mark Pearson, Alex Loukas, Javier Sotillo
The nucleic acid composition of trematode EVs is complex, and different small RNAs and mRNAs have been characterized. Bernal et al. showed that EVs from Dicrocoelium dendriticum contain micro RNAs (miRNAs) (e.g. sma-let-7, sma-miR-2a-3p, emu-miR-71, emu-miR-190, and sma-miR-61), demonstrating for the first time the presence of miRNAs in helminth EVs [28]. Similarly, molecular characterization of Schistosoma mansoni schistosomula (larval stage parasites) revealed 20 tRNAs and 205 miRNAs [29], some of which (sma-bantam, sma-miR-10, sma-miR-3479, and sma-miR-n1) have been detected in sera obtained from chronically infected hosts [46,47] or within EVs from the sera of S. mansoni-infected travelers (bantam and miR-2c-3p) [48]. Likewise, EVs isolated from F. hepatica were shown to contain 42 miRNAs [32], some of which were hypothesized to play a role in host manipulation [32]. In another study, EVs from Schistosoma japonicum adult worms were shown to contain a population of small RNAs associated with host gene regulation. These EVs were internalized by murine liver cells in vitro and could downregulate the expression of the murine genes Gins4, Tysnd1, and Utp3 [34]. S. japonicum egg EVs have also been analyzed, revealing different types of RNAs such as rRNAs, small nuclear RNAs, repeat-associated small RNAs, tRNAs, and miRNAs [35].
Prevalence and associated risk factors of intestinal parasitic infections in Kurdistan province, northwest Iran
Published in Cogent Medicine, 2018
Fares Bahrami, Ali Haghighi, Ghasem Zamini, Mohammad Bagher Khadem-Erfan, Eznolla Azargashb
Dicrocoelium dendriticum, a lanceolate fluke which is found more frequently among ruminants and rarely causes disease in humans. Actually many reported cases of human infection are false parasitism, because eggs can be passed through the intestinal tract and are found in feces as a result of eating liver (Searcey et al., 2013). It is virtually impossible to differentiate true and false human parasitism only through stool exam (Gonçalves, Araújo, & Ferreira, 2003).