The Experts below are selected from a list of 258 Experts worldwide ranked by ideXlab platform
C Gonzalezlanza - One of the best experts on this subject based on the ideXlab platform.
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strategic control of Dicrocoelium dendriticum digenea egg excretion by naturally infected sheep
Veterinarni Medicina, 2018Co-Authors: M Y Mangagonzalez, C Gonzalezlanza, H Quirozromero, B Minambres, P OchoaAbstract:The aim of this study was to determine the most appropriate months for applying albendazole (ABZ; oral suspension dose 20 mg/kg body weight) to sheep naturally infected with Dicrocoelium dendriticum and kept at pasture, in order to reduce parasite egg shedding to a minimum, mainly during the cold months and, as a result, decrease pasture contamination by viable eggs. Five animal groups (G), homogeneous as regards the number of eggs per gram (EPG) in faeces, were established. The treatment months were: G1, November and January; G2, November and February; G3, November and April; G4, January; and G5 (control), April. Ten samplings (S1-S10) were carried out every 35 to 45 days to collect faecal samples from the rectum of each animal in the five groups. The sedimentation technique and McMaster egg counting chambers were used to analyze the faecal samples. Due to the effect of albendazole (ABZ) treatments, the five groups behaved differently with regard to EPG reduction and the percentage of samples positive for D. dendriticum eggs. Using the Kruskal-Wallis test, statistically signifi- cant differences (Pwere observed between the EPG values obtained in G5 and the rest of the groups from November to May, but not from May onwards. The biggest reduction in egg excretion was obtained in G1, mainly in the cold period when elimination is highest and egg survival greatest, so G1 gave the best result, followed by G2, G4, G3 and finally G5 in descending order.
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proteomic analysis of the tegument and excretory secretory products of Dicrocoelium dendriticum digenea adult worms
Experimental Parasitology, 2013Co-Authors: A M Martinezibeas, C Gonzalezlanza, M Y MangagonzalezAbstract:Dicrocoeliosis, caused by Dicrocoelium dendriticum, is an important hepatic parasitosis in ruminants, whose immunological diagnosis and control remain unsatisfactory. There are very few studies on the antigens of this trematode and molecular knowledge about it is practically nil. Therefore the aim of this study was to identify the major antigenic proteins in the tegument (TG) and excretory–secretory (ES) antigenic extracts of D. dendriticum. The separation conditions of the protein extracts were optimized using 2-D PAGE; the gels were stained with colloidal Coomassie or transferred to carry out immunodetection with anti-Dicrocoelium dendriticum sera. The proteins of interest excised from the gels were identified by mass spectrometry (MALDI). The proteomic maps of the TG and ES extracts of D. dendriticum were defined first, detecting 332 spots in the TG and 284 in the ES, with a similar distribution in both. A quantity of 29 proteins in the excretion-secretion products and 43 in the teguments were identified first in D. dendriticum, 23 of them antigenic, involved in various processes such as: metabolism, detoxification, chaperone, transport or structural molecules. These results could help us to understand the complex parasite-host relationships, improve the diagnosis of dicroceliosis and help to produce possible vaccines to control it.
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immunohistochemical study of the local immune response in lambs experimentally infected with Dicrocoelium dendriticum digenea
Parasitology Research, 2007Co-Authors: Carmen M Ferrerasestrada, C Gonzalezlanza, Raquel Del Campo, Valentin Perez Perez, J F Garciamarin, M Y MangagonzalezAbstract:Phenotypic expression of inflammatory cells in liver and hepatic lymph nodes (HLN) has been examined in lambs experimentally infected with Dicrocoelium dendriticum using immunohistochemical techniques. Thirty-two lambs, 12 infected with 1,000 D. dendriticum metacercariae, 12 with 3,000, and 8 controls were used. Half the lambs in each group were slaughtered on days 60 and 180 post-infection (p.i.), respectively. Primary antibodies (Abs) against T cell epitopes (CD3+, CD4+, CD8+ and WC1+ γδ), B cell epitopes (CD79αcy+, CD45R+), immunoglobulin (IgG)-bearing plasma cells, macrophages (CD14+, VPM32+) and major histocompatibility complex (MHC) class IIβ antigen were used. T lymphocytes (CD3+, CD4+ and CD8+) and B lymphocytes (CD79αcy+ and CD45R+) with diffuse pattern or forming lymphoid aggregates and follicles surrounded the septal bile ducts (SBD) and inter-lobular bile ducts, whereas the WC1 γδ T cells were scattered. Numerous IgG+ plasma cells were observed around SBD. CD14 and VPM32+ macrophages intermingled with lymphocytes were immunostained by the anti-MHC class IIβ. This Ab also reacted with lymphoid cells. Likewise, increased positive immunostaining for all Abs used was observed in the HLN of infected lambs. There was no qualitative difference regarding the phenotype expression of inflammatory cells between the lambs infected with D. dendriticum. The humoral and cell-mediated local immune responses observed were similar in the two groups of lambs infected with different doses.
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preliminary protective capacity study of a Dicrocoelium dendriticum antigenic protein in hamsters
Parasitology Research, 2006Co-Authors: C Gonzalezlanza, M Y Mangagonzalez, B RevillanuinAbstract:The purpose of this study was to evaluate the protective capacity of 130 kDa Dicrocoelium dendriticum protein in hamsters experimentally infected with this parasite. Forty hamsters divided into four groups of ten animals each were used: G1 (control), G2 (infected), G3 (immunized with Freund’s adjuvant and infected), G4 (130 kDa protein vaccinated + adjuvant and infected). Infection with 40 metacercariae/hamster was carried out 4 weeks after the last immunization. Parasitological studies [number of eggs per gram (epg) and worm burden] and biochemical parameters (total proteins, albumin, and total bilirubin), hepatic enzymes [aspartate aminotransferase (AST) and alanine aminotransferase (ALT)], and total IgG levels were determined. A reduction in epg in G3 and G4 was observed 16 weeks postinfection with the higher reduction percentage in the latter (25.2%). No statistically significant differences were detected in the number of recovered worms among groups, although the mean was slightly less in G4 (12.2±2.08, mean±SE) than in G2 (15.4±2.90). In G4, global protection was 20.9% and an increase in AST and ALT levels was observed. Total IgG levels were similar in the three infected groups. The protection obtained was inadequate, so the antigen dose, immunization–infection period, adjuvants, and immunization route must be optimized.
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partial characterization and isolation of 130 kda antigenic protein of Dicrocoelium dendriticum adults
Veterinary Parasitology, 2005Co-Authors: B Revillanuin, M Y Mangagonzalez, B Minambres, C GonzalezlanzaAbstract:Abstract The study focused on characterizing and isolating Dicrocoelium dendriticum antigens or their fractions that could be used for the immunological diagnosis of dicrocoeliosis. Somatic (SoAg) and excretory–secretory antigens (ESAg) were analyzed by SDS-PAGE and their specificity was evaluated by Western blot with homologous and heterologous sera. The antigens were partially purified by chromatographic techniques of gel-filtration (Sephacryl S-300) and ion exchange (Hitrap–DEAE–Sepharose). Western blot analysis using sera of ovine infected with D. dendriticum revealed eight main antigenic polypeptides ranging from 24 to 205 kDa for SoAg and seven for ESAg with apparent molecular mass in the range of 26–205 kDa. We detected a specific parasite protein with an approximate molecular weight of 130 kDa in SDS-PAGE gels, arranged as a 450 kDa tetramer in native conditions. It also showed strong immunoreactivity by Western blot against ovine sera experimentally infected with D. dendriticum. Gel filtration chromatography (Sephacryl S-300) also showed other specific proteins, one of about 24 kDa in SoAg and another of about 42 kDa in ESAg. The elution conditions of 450 kDa protein (130 kDa monomer) by DEAE chromatography were similar to those from the somatic antigen (pH 7.2, 0.1 M NaCl, in 29–34 ml fractions) and from the excretion–secretion antigen (pH 8.0, 0.1 M NaCl, in 29–35 ml fractions). The suitability of 130 kDa polypeptide for D. dendriticum infection diagnosis was confirmed by Western blot using a pool of sera as well as individual serum samples from experimentally infected sheep. The sequence of amino termini of 130 kDa polypeptide from both fractions was the same and identical to that reported for a peptide from D. dendriticum described as a globin. This sequence also revealed an appreciable similarity with the amino end of globins from some phylogenetically related worms.
M Y Mangagonzalez - One of the best experts on this subject based on the ideXlab platform.
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strategic control of Dicrocoelium dendriticum digenea egg excretion by naturally infected sheep
Veterinarni Medicina, 2018Co-Authors: M Y Mangagonzalez, C Gonzalezlanza, H Quirozromero, B Minambres, P OchoaAbstract:The aim of this study was to determine the most appropriate months for applying albendazole (ABZ; oral suspension dose 20 mg/kg body weight) to sheep naturally infected with Dicrocoelium dendriticum and kept at pasture, in order to reduce parasite egg shedding to a minimum, mainly during the cold months and, as a result, decrease pasture contamination by viable eggs. Five animal groups (G), homogeneous as regards the number of eggs per gram (EPG) in faeces, were established. The treatment months were: G1, November and January; G2, November and February; G3, November and April; G4, January; and G5 (control), April. Ten samplings (S1-S10) were carried out every 35 to 45 days to collect faecal samples from the rectum of each animal in the five groups. The sedimentation technique and McMaster egg counting chambers were used to analyze the faecal samples. Due to the effect of albendazole (ABZ) treatments, the five groups behaved differently with regard to EPG reduction and the percentage of samples positive for D. dendriticum eggs. Using the Kruskal-Wallis test, statistically signifi- cant differences (Pwere observed between the EPG values obtained in G5 and the rest of the groups from November to May, but not from May onwards. The biggest reduction in egg excretion was obtained in G1, mainly in the cold period when elimination is highest and egg survival greatest, so G1 gave the best result, followed by G2, G4, G3 and finally G5 in descending order.
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proteomic analysis of the tegument and excretory secretory products of Dicrocoelium dendriticum digenea adult worms
Experimental Parasitology, 2013Co-Authors: A M Martinezibeas, C Gonzalezlanza, M Y MangagonzalezAbstract:Dicrocoeliosis, caused by Dicrocoelium dendriticum, is an important hepatic parasitosis in ruminants, whose immunological diagnosis and control remain unsatisfactory. There are very few studies on the antigens of this trematode and molecular knowledge about it is practically nil. Therefore the aim of this study was to identify the major antigenic proteins in the tegument (TG) and excretory–secretory (ES) antigenic extracts of D. dendriticum. The separation conditions of the protein extracts were optimized using 2-D PAGE; the gels were stained with colloidal Coomassie or transferred to carry out immunodetection with anti-Dicrocoelium dendriticum sera. The proteins of interest excised from the gels were identified by mass spectrometry (MALDI). The proteomic maps of the TG and ES extracts of D. dendriticum were defined first, detecting 332 spots in the TG and 284 in the ES, with a similar distribution in both. A quantity of 29 proteins in the excretion-secretion products and 43 in the teguments were identified first in D. dendriticum, 23 of them antigenic, involved in various processes such as: metabolism, detoxification, chaperone, transport or structural molecules. These results could help us to understand the complex parasite-host relationships, improve the diagnosis of dicroceliosis and help to produce possible vaccines to control it.
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immunohistochemical study of the local immune response in lambs experimentally infected with Dicrocoelium dendriticum digenea
Parasitology Research, 2007Co-Authors: Carmen M Ferrerasestrada, C Gonzalezlanza, Raquel Del Campo, Valentin Perez Perez, J F Garciamarin, M Y MangagonzalezAbstract:Phenotypic expression of inflammatory cells in liver and hepatic lymph nodes (HLN) has been examined in lambs experimentally infected with Dicrocoelium dendriticum using immunohistochemical techniques. Thirty-two lambs, 12 infected with 1,000 D. dendriticum metacercariae, 12 with 3,000, and 8 controls were used. Half the lambs in each group were slaughtered on days 60 and 180 post-infection (p.i.), respectively. Primary antibodies (Abs) against T cell epitopes (CD3+, CD4+, CD8+ and WC1+ γδ), B cell epitopes (CD79αcy+, CD45R+), immunoglobulin (IgG)-bearing plasma cells, macrophages (CD14+, VPM32+) and major histocompatibility complex (MHC) class IIβ antigen were used. T lymphocytes (CD3+, CD4+ and CD8+) and B lymphocytes (CD79αcy+ and CD45R+) with diffuse pattern or forming lymphoid aggregates and follicles surrounded the septal bile ducts (SBD) and inter-lobular bile ducts, whereas the WC1 γδ T cells were scattered. Numerous IgG+ plasma cells were observed around SBD. CD14 and VPM32+ macrophages intermingled with lymphocytes were immunostained by the anti-MHC class IIβ. This Ab also reacted with lymphoid cells. Likewise, increased positive immunostaining for all Abs used was observed in the HLN of infected lambs. There was no qualitative difference regarding the phenotype expression of inflammatory cells between the lambs infected with D. dendriticum. The humoral and cell-mediated local immune responses observed were similar in the two groups of lambs infected with different doses.
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preliminary protective capacity study of a Dicrocoelium dendriticum antigenic protein in hamsters
Parasitology Research, 2006Co-Authors: C Gonzalezlanza, M Y Mangagonzalez, B RevillanuinAbstract:The purpose of this study was to evaluate the protective capacity of 130 kDa Dicrocoelium dendriticum protein in hamsters experimentally infected with this parasite. Forty hamsters divided into four groups of ten animals each were used: G1 (control), G2 (infected), G3 (immunized with Freund’s adjuvant and infected), G4 (130 kDa protein vaccinated + adjuvant and infected). Infection with 40 metacercariae/hamster was carried out 4 weeks after the last immunization. Parasitological studies [number of eggs per gram (epg) and worm burden] and biochemical parameters (total proteins, albumin, and total bilirubin), hepatic enzymes [aspartate aminotransferase (AST) and alanine aminotransferase (ALT)], and total IgG levels were determined. A reduction in epg in G3 and G4 was observed 16 weeks postinfection with the higher reduction percentage in the latter (25.2%). No statistically significant differences were detected in the number of recovered worms among groups, although the mean was slightly less in G4 (12.2±2.08, mean±SE) than in G2 (15.4±2.90). In G4, global protection was 20.9% and an increase in AST and ALT levels was observed. Total IgG levels were similar in the three infected groups. The protection obtained was inadequate, so the antigen dose, immunization–infection period, adjuvants, and immunization route must be optimized.
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partial characterization and isolation of 130 kda antigenic protein of Dicrocoelium dendriticum adults
Veterinary Parasitology, 2005Co-Authors: B Revillanuin, M Y Mangagonzalez, B Minambres, C GonzalezlanzaAbstract:Abstract The study focused on characterizing and isolating Dicrocoelium dendriticum antigens or their fractions that could be used for the immunological diagnosis of dicrocoeliosis. Somatic (SoAg) and excretory–secretory antigens (ESAg) were analyzed by SDS-PAGE and their specificity was evaluated by Western blot with homologous and heterologous sera. The antigens were partially purified by chromatographic techniques of gel-filtration (Sephacryl S-300) and ion exchange (Hitrap–DEAE–Sepharose). Western blot analysis using sera of ovine infected with D. dendriticum revealed eight main antigenic polypeptides ranging from 24 to 205 kDa for SoAg and seven for ESAg with apparent molecular mass in the range of 26–205 kDa. We detected a specific parasite protein with an approximate molecular weight of 130 kDa in SDS-PAGE gels, arranged as a 450 kDa tetramer in native conditions. It also showed strong immunoreactivity by Western blot against ovine sera experimentally infected with D. dendriticum. Gel filtration chromatography (Sephacryl S-300) also showed other specific proteins, one of about 24 kDa in SoAg and another of about 42 kDa in ESAg. The elution conditions of 450 kDa protein (130 kDa monomer) by DEAE chromatography were similar to those from the somatic antigen (pH 7.2, 0.1 M NaCl, in 29–34 ml fractions) and from the excretion–secretion antigen (pH 8.0, 0.1 M NaCl, in 29–35 ml fractions). The suitability of 130 kDa polypeptide for D. dendriticum infection diagnosis was confirmed by Western blot using a pool of sera as well as individual serum samples from experimentally infected sheep. The sequence of amino termini of 130 kDa polypeptide from both fractions was the same and identical to that reported for a peptide from D. dendriticum described as a globin. This sequence also revealed an appreciable similarity with the amino end of globins from some phylogenetically related worms.
Barbora Szotakova - One of the best experts on this subject based on the ideXlab platform.
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the inability of tapeworm hymenolepis diminuta and fluke Dicrocoelium dendriticum to metabolize praziquantel
Veterinary Parasitology, 2012Co-Authors: Ivan Vokřal, Hana Bartikova, Lenka Skalova, J Lamka, Robert Jirasko, Veronika Jedlickova, Michal Holcapek, Barbora SzotakovaAbstract:Abstract Biotransformation enzymes can, to a certain extent, protect parasitic worms against the toxic effects of anthelmintics and can contribute to drug-resistance development. The objective of our work was (1) to find and identify phase I and II metabolites of the anthelmintic praziquantel (PZQ) formed by the lancet fluke (Dicrocoelium dendriticum) and the rat tapeworm (Hymenolepis diminuta) and (2) to compare PZQ metabolites in helminths with PZQ biotransformation in rat as host species. Ultra high performance liquid chromatography/tandem mass spectrometry (UHPLC/MS/MS) was used for this purpose. During in vitro incubations, mitochondria-like and microsomes-like fractions (prepared from homogenates of adult worms or from rat liver homogenate) were incubated with 10 and 100 μM PZQ. Liquid/liquid extraction was used for samples during in vitro experiments. In the ex vivo study, living D. dendriticum and H. diminuta adults were incubated in RPMI-1640 medium in the presence of 50 nM or 100 nM PZQ for 24 h. After incubation, the worms were removed from the medium and homogenized. Homogenates of worms, medium from the incubation of worms or rat hepatocytes and rat urine (collected during 24 h after oral PZQ administration) were separately extracted using solid-phase extraction. The results showed that both D. dendriticum and H. diminuta enzymatic systems are not able to metabolize PZQ. On the other hand, thirty one different phase I and four phase II PZQ metabolites were detected in rat samples using UHPLC/MS/MS analyses. These results show that our experimental helminths, as the members of tapeworm and fluke groups of parasites, are not able to deactivate PZQ, and that the biotransformation enzymes of the studied helminths do not contribute to PZQ-resistance.
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the transport of albendazole and albendazole sulphoxide in the lancet fluke Dicrocoelium dendriticum
Veterinary Parasitology, 2011Co-Authors: Hana Bartikova, Ivan Vokřal, Veronika Forstovakřižova, Lenka Skalova, J Lamka, Barbora SzotakovaAbstract:Abstract Albendazole (ABZ) is one of the most important benzimidazole compounds possessing high activity against the lancet fluke, Dicrocoelium dendriticum. ABZ sulphoxide (ABZ.SO) is the main molecule present in the bloodstream of an ABZ-treated host. The aim of this study was to characterise the pattern of ex vivo uptake of ABZ and ABZ.SO by lancet flukes and the export of both anthelmintics from these parasites. Transport of these anthelmintics in both living and dead flukes was compared. The adult flukes were collected from mouflons (Ovis musimon) which had been infected naturally. Results showed that more lipophilic ABZ was imported to a higher extent than ABZ.SO, and that significantly higher concentrations of ABZ were detected within living flukes as compared to dead ones. The same pattern was revealed in the study of ABZ and ABZ.SO export from the flukes’ bodies. In addition to passive diffusion, active ABZ uptake and active efflux of ABZ and ABZ.SO in D. dendriticum could be assumed.
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in vitro oxidative metabolism of xenobiotics in the lancet fluke Dicrocoelium dendriticum and the effects of albendazole and albendazole sulphoxide ex vivo
Xenobiotica, 2010Co-Authors: Hana Bartikova, Ivan Vokřal, Lenka Skalova, J Lamka, Barbora SzotakovaAbstract:Dicrocoeliosis, a parasitic infection caused by Dicrocoelium dendriticum (lancet fluke), is often treated by the anthelmintic drug albendazole (ABZ). In the lancet fluke, ABZ metabolism via enzymatic sulphoxidation was found, but no information about ABZ oxidases has been available.The aim of our project was to find out which enzyme of the lancet fluke is responsible for ABZ sulphoxidation, as well as to assay the activities of oxidation enzymes. We also studied whether ex vivo 24-h exposures of flukes to ABZ or its sulphoxide (ABZ.SO) would alter ABZ sulphoxidation rate and the activities of tested enzymes.In subcellular fractions from flukes, marked activities of peroxidase (Px), glutathione Px (GPx), catalase (CAT), superoxide dismutase, and thioredoxin glutathione reductase were found. Using specific inhibitors, the participation of flavine monooxygenases in ABZ-oxidation was found.The ex vivo exposition of flukes to ABZ or ABZ.SO did not change the rate of ABZ sulphoxidation in vitro, but the ex vivo...
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liquid chromatography mass spectrometric identification of benzimidazole anthelminthics metabolites formed ex vivo by Dicrocoelium dendriticum
Rapid Communications in Mass Spectrometry, 2009Co-Authors: V Cvilink, Hana Bartikova, Barbora Szotakova, Ivan Vokral, Jiri Lamka, Lenka SkalovaAbstract:With further use of chemical agents in the control of parasitic infections, an increased number of drug resistance occurrences to antiparasitic drugs has been reported. Induction of enzymes responsible for detoxification of given drugs can contribute to drug resistance development in a parasitic organism. The identification of formed metabolites allows the characterization of the enzymes participating in biotransformation and possibly in drug resistance development. The objective of our work was to find and identify phase I and phase II metabolites of the anthelminthic drugs albendazole, flubendazole and mebendazole formed in ex vivo incubations by the parasitic helminth Dicrocoelium dendriticum, a parasite of ruminants and other grazing animals, using liquid chromatography/mass spectrometric (LC/MS) techniques. In the ex vivo study, approximately 50 living D. dendriticum adults were incubated in 5 mL RPMI-1640 medium in the presence of 10.0 µmol L−1 benzimidazole drug (5% CO2, 38°C) for 24 h. The bodies of the parasite were then removed from the medium. After homogenization of parasites, both parasite homogenates and medium from the incubation were separately extracted using solid-phase extraction. The extracts were analyzed using LC/MS with electrospray ionization. The results showed that D. dendriticum enzymatic systems are capable of phase I oxidation and reduction as well as phase II conjugation reactions. Detected phase I metabolites comprised albendazole sulfoxide, reduced flubendazole and reduced mebendazole. As for phase II metabolites, methyl derivatives of both reduced flubendazole and reduced mebendazole were observed. Copyright © 2009 John Wiley & Sons, Ltd.
Cameron P Goater - One of the best experts on this subject based on the ideXlab platform.
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life cycle host utilization and ecological fitting for invasive lancet liver fluke Dicrocoelium dendriticum emerging in southern alberta canada
Journal of Parasitology, 2017Co-Authors: Bradley J Van Paridon, John S Gilleard, Douglas D Colwell, Cameron P GoaterAbstract:Abstract The expansion of parasite distributions outside of their native host and geographical ranges has occurred repeatedly over evolutionary time. Contemporary examples include emerging infectious diseases (EIDs), many of which pose threats to human, domestic animal, and wildlife populations. Theory predicts that parasites with complex life cycles will be rare as EIDs due to constraints imposed by host specialization at each life-cycle stage. In contrast to predictions of this theory, we report 2 new intermediate hosts in the 3-host life cycle of the liver fluke Dicrocoelium dendriticum in Cypress Hills Provincial Park, Alberta, Canada. Results of sequence analysis of the cytochrome oxidase 1 (cox1) mitochondrial gene identified the terrestrial snail Oreohelix subrudis and the ant Formica aserva as first and second intermediate hosts, respectively, in the region. Neither of these intermediate hosts, nor their suite of domestic and wild mammalian grazers used in the life cycle, occurs within the native ...
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characterization of nine microsatellite loci for Dicrocoelium dendriticum an emerging liver fluke of ungulates in north america and their use to detect clonemates and random mating
Molecular and Biochemical Parasitology, 2016Co-Authors: Bradley J Van Paridon, John S Gilleard, Cameron P Goater, Charles D CriscioneAbstract:Abstract This study characterizes polymorphic microsatellite loci from adults of the liver fluke Dicrocoelium dendriticum sampled from a population of sympatric beef cattle and wapiti in a region of emergence in southern Alberta, Canada. We also scrutinized the markers to validate their use in studying the population genetics of this complex life cycle parasite. Among the nine loci described, four deviated significantly from Hardy Weinberg Equilibrium (HWE) due to technical artefacts. The remaining five loci were in HWE. These five provided sufficient resolution to identify clonemates produced from the obligate asexual reproduction phase of the life cycle in snails and to assess the impact of non-random transmission of clonemates on measures of FIS, FST and genotypic disequilibrium. Excluding clonemates, we show that the sub-population of worms was in HWE, that average FIS within hosts was 0.003 (p = 0.4922) and that there was no population genetic structure among hosts FST = 0.001 (p = 0.3243). These markers will be useful for studies of Dicrocoelium dendriticum ecology, transmission, and evolution.
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comparative recruitment morphology and reproduction of a generalist trematode Dicrocoelium dendriticum in three species of host
Parasitology, 2015Co-Authors: Melissa A Beck, Cameron P Goater, Douglas D ColwellAbstract:Epidemiological rate parameters of host generalist parasites are difficult to estimate, especially in cases where variation in parasite performance can be attributed to host species. Such cases are likely common for generalist parasites of sympatric grazing mammals. In this study, we combined data from experimental exposures in cattle and sheep and natural infections in elk to compare the recruitment, morphology and reproduction of adult Dicrocoelium dendriticum, a generalist trematode that has emerged in sympatric grazing hosts in Cypress Hills Provincial Park, Alberta. Overall, there were no significant differences in the recruitment of metacercariae and in the pre-patency period of adults in experimentally exposed cattle and sheep. All flukes reached reproductive maturity and the degree of reproductive inequality between individual flukes within each infrapopulation was moderate and approximately equal among the three host species. Neither fluke size nor per capita fecundity was constrained by density dependence. Thus, fitness parameters associated with growth and reproduction were approximately equivalent among at least three species of definitive host, two of which are sympatric on pastures in this Park. The generalist life-history strategy of this trematode, which is known to extend to other stages of its life cycle, has likely contributed to its invasion history outside its native range in Europe.
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Dicrocoelium dendriticum in cattle from cypress hills canada humoral response and preliminary evaluation of an elisa
Veterinary Parasitology, 2010Co-Authors: Douglas D Colwell, Cameron P GoaterAbstract:Apparent changes in the distribution of Dicrocoelium dendriticum in western Canada and the absence of other liver flukes in the area prompted an examination of the humoral responses in naturally infected cattle sharing pasture with heavily infected wild cervids. Western blots using sera from the infected cattle indicated that the cattle had antibodies to various fluke antigens, however the pattern of response varied among isotypes. Isotype analysis indicated that Dicrocoelium-infected cattle produced IgG1, and IgM antibodies, but not IgG2 antibodies. Subsequent comparison of the efficiency of coprological and serological approaches for diagnosis showed that while 43.5% of a separate group of 26 yearlings had eggs in their faeces, the immunoblots indicated that all had detectable antibodies. A group of cattle necropsied for confirmation of fluke status was used to evaluate humoral immune responses and to provide baseline information in the preliminary development of an indirect ELISA for detection of anti-fluke antibodies.
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epidemiological characteristics of an invading parasite Dicrocoelium dendriticum in sympatric wapiti and beef cattle in southern alberta canada
Journal of Parasitology, 2007Co-Authors: Cameron P Goater, Douglas D ColwellAbstract:Previous surveys of wild ungulates indicate that the liver fluke, Dicrocoelium dendriticum, was rare in the Cypress Hills area of southeastern Alberta. However, 41 of 59 wapiti (Cervus elaphus) sampled during the 2003 and 2004 hunting seasons from this region were infected, with 7 hosts containing >1,000 worms. Prevalence and mean intensity were similarly high in sympatric beef cattle and mule deer. Worm abundance in wapiti was age related, with calves containing significantly higher numbers of worms (mean ± SD abundance = 825 ± 1,098) than adults (107 ± 259). This pattern with host age was not evident in beef cattle, although the smaller sample sizes may be a contributing factor. These results indicate that D. dendriticum is now well established in Cypress Hills Park, circulating between at least 3 species of sympatric ungulates, including beef cattle.
Douglas D Colwell - One of the best experts on this subject based on the ideXlab platform.
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life cycle host utilization and ecological fitting for invasive lancet liver fluke Dicrocoelium dendriticum emerging in southern alberta canada
Journal of Parasitology, 2017Co-Authors: Bradley J Van Paridon, John S Gilleard, Douglas D Colwell, Cameron P GoaterAbstract:Abstract The expansion of parasite distributions outside of their native host and geographical ranges has occurred repeatedly over evolutionary time. Contemporary examples include emerging infectious diseases (EIDs), many of which pose threats to human, domestic animal, and wildlife populations. Theory predicts that parasites with complex life cycles will be rare as EIDs due to constraints imposed by host specialization at each life-cycle stage. In contrast to predictions of this theory, we report 2 new intermediate hosts in the 3-host life cycle of the liver fluke Dicrocoelium dendriticum in Cypress Hills Provincial Park, Alberta, Canada. Results of sequence analysis of the cytochrome oxidase 1 (cox1) mitochondrial gene identified the terrestrial snail Oreohelix subrudis and the ant Formica aserva as first and second intermediate hosts, respectively, in the region. Neither of these intermediate hosts, nor their suite of domestic and wild mammalian grazers used in the life cycle, occurs within the native ...
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comparative recruitment morphology and reproduction of a generalist trematode Dicrocoelium dendriticum in three species of host
Parasitology, 2015Co-Authors: Melissa A Beck, Cameron P Goater, Douglas D ColwellAbstract:Epidemiological rate parameters of host generalist parasites are difficult to estimate, especially in cases where variation in parasite performance can be attributed to host species. Such cases are likely common for generalist parasites of sympatric grazing mammals. In this study, we combined data from experimental exposures in cattle and sheep and natural infections in elk to compare the recruitment, morphology and reproduction of adult Dicrocoelium dendriticum, a generalist trematode that has emerged in sympatric grazing hosts in Cypress Hills Provincial Park, Alberta. Overall, there were no significant differences in the recruitment of metacercariae and in the pre-patency period of adults in experimentally exposed cattle and sheep. All flukes reached reproductive maturity and the degree of reproductive inequality between individual flukes within each infrapopulation was moderate and approximately equal among the three host species. Neither fluke size nor per capita fecundity was constrained by density dependence. Thus, fitness parameters associated with growth and reproduction were approximately equivalent among at least three species of definitive host, two of which are sympatric on pastures in this Park. The generalist life-history strategy of this trematode, which is known to extend to other stages of its life cycle, has likely contributed to its invasion history outside its native range in Europe.
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Dicrocoelium dendriticum in cattle from cypress hills canada humoral response and preliminary evaluation of an elisa
Veterinary Parasitology, 2010Co-Authors: Douglas D Colwell, Cameron P GoaterAbstract:Apparent changes in the distribution of Dicrocoelium dendriticum in western Canada and the absence of other liver flukes in the area prompted an examination of the humoral responses in naturally infected cattle sharing pasture with heavily infected wild cervids. Western blots using sera from the infected cattle indicated that the cattle had antibodies to various fluke antigens, however the pattern of response varied among isotypes. Isotype analysis indicated that Dicrocoelium-infected cattle produced IgG1, and IgM antibodies, but not IgG2 antibodies. Subsequent comparison of the efficiency of coprological and serological approaches for diagnosis showed that while 43.5% of a separate group of 26 yearlings had eggs in their faeces, the immunoblots indicated that all had detectable antibodies. A group of cattle necropsied for confirmation of fluke status was used to evaluate humoral immune responses and to provide baseline information in the preliminary development of an indirect ELISA for detection of anti-fluke antibodies.
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epidemiological characteristics of an invading parasite Dicrocoelium dendriticum in sympatric wapiti and beef cattle in southern alberta canada
Journal of Parasitology, 2007Co-Authors: Cameron P Goater, Douglas D ColwellAbstract:Previous surveys of wild ungulates indicate that the liver fluke, Dicrocoelium dendriticum, was rare in the Cypress Hills area of southeastern Alberta. However, 41 of 59 wapiti (Cervus elaphus) sampled during the 2003 and 2004 hunting seasons from this region were infected, with 7 hosts containing >1,000 worms. Prevalence and mean intensity were similarly high in sympatric beef cattle and mule deer. Worm abundance in wapiti was age related, with calves containing significantly higher numbers of worms (mean ± SD abundance = 825 ± 1,098) than adults (107 ± 259). This pattern with host age was not evident in beef cattle, although the smaller sample sizes may be a contributing factor. These results indicate that D. dendriticum is now well established in Cypress Hills Park, circulating between at least 3 species of sympatric ungulates, including beef cattle.