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Manfred E Rau - One of the best experts on this subject based on the ideXlab platform.

  • effects of plagiorchis elegans digenea Plagiorchiidae infection of biomphalaria glabrata pulmonata planorbidae on a challenge infection with schistosoma mansoni digenea schistosomatidae
    Journal of Parasitology, 2003
    Co-Authors: Mahvash Zakikhani, James M Smith, Manfred E Rau
    Abstract:

    Prior exposure of Biomphalaria glabrata to the eggs of an incompatible digenean, Plagiorchis elegans, rendered this snail host less suitable to a compatible species, Schistosoma mansoni. Although P. elegans failed to develop patent infections in B. glabrata, it reduced the production of S. mansoni cercariae by 88%. Concomitantly, host attributes such as reproduction, growth, and survival were compromised. The effect of P. elegans infection was most severe among snails that, in addition, had developed patent schistosome infections. Although few S. mansoni cercariae were produced, egg production by B. glabrata was only 4% of control values. Furthermore, no doubly infected snails survived for more than 3 wk after patency, whereas controls experienced no mortality during the same time period. The above effects were attributable to the establishment and persistence of P. elegans sporocysts in the tissues of the incompatible snail host. Their indirect antagonistic interaction with the larval stages of S. manson...

  • effects of plagiorchis elegans trematoda Plagiorchiidae infection on the carbohydrate metabolism of fourth instar aedes aegypti diptera culicidae
    Journal of Medical Entomology, 2001
    Co-Authors: Rachelle H Wallage, Donald F Niven, Manfred E Rau
    Abstract:

    Infection of fourth-instar Aedes aegypti (L.) with the entomopathogenic digenean Plagiorchis elegans (Rudolphi) alters the carbohydrate metabolism of the insect. Within 24 h of cercarial penetration, total body extracts of infected fourth instars exhibited decreased trehalase activity, increased trehalose-6-phosphatase activity, and a concomitant accumulation of trehalose when compared with uninfected larvae. The amounts of glucose, glycogen and lipids, and the activity of glycogen phosphorylase a were similar in extracts of infected and control larvae. The predominant fatty acids, in both control and infected larvae, were C 18:0, C 18:1, and C 18:3. There were no significant differences in the types or proportions of fatty acids found in control and infected larvae. Parasitic infection is discussed in terms of impaired trehalose metabolism.

  • plagiorchis elegans digenea Plagiorchiidae infections in stagnicola elodes pulmonata lymnaeidae host susceptibility growth reproduction mortality and cercarial production
    Journal of Parasitology, 1999
    Co-Authors: Mahvash Zakikhani, Manfred E Rau
    Abstract:

    Eggs of Plagiorchis elegans were readily ingested by Stagnicola elodes of all ages, but were more infective to immature than mature snails. Infection enhanced the growth of the host in a dose-dependent manner. The number of cercariae released by immature snails increased with the age of the snail host; mature snails yielded fewer cercariae. Heavily infected snails tended to die prematurely, thereby reducing their total production of cercariae to levels below those of more lightly infected individuals. Even light infections castrated the snail host, Snails that acquired the infection as juveniles never produced eggs. Actively reproducing snails ceased egg laying within days of infection and never recovered. All parasite effects on the growth and reproduction of the snail host first manifested themselves during the early stages of infection, long before the development of daughter sporocysts and cercariae, and are therefore attributable to the effects of mother sporocysts. The study provides insight into how this natural enemy of mosquito larvae may be established in natural snail populations by means of strategically timed introductions of parasite eggs, with a goal of maximizing cercarial production for the biological control of sympatric mosquito larvae.

  • effects of plagiorchis elegans digenea Plagiorchiidae infection on the reproduction of biomphalaria glabrata pulmonata planorbidae
    Journal of Parasitology, 1998
    Co-Authors: Mahvash Zakikhani, Manfred E Rau
    Abstract:

    Infection with the digenean parasite Plagiorchis elegans dramatically reduced the reproductive output of Biomphalaria glabrata exposed to the parasite as juveniles or adults. The total number of eggs produced by infected snails was reduced to approximately 7 and 13% of control values, respectively. Parasitic castration was attributed to the presence of mother sporocysts that readily established in the tissues of this incompatible host. Infection did not result in the production of cercariae but significantly shortened the life span of juvenile and adult B. glabrata by approximately 23 and 10%, respectively. Plagiorchis elegans also castrated its compatible host, Stagnicola elodes.

  • selective oviposition by aedes aegypti diptera culicidae in response to a larval parasite plagiorchis elegans trematoda Plagiorchiidae
    Environmental Entomology, 1994
    Co-Authors: Carl Lowenberger, Manfred E Rau
    Abstract:

    A series of biological assays was performed in the laboratory to examine the oviposition response of Aedes aegypti (L.) to sites containing, or which had previously contained, conspecific larvae parasitized by the digenean, Plagiorchis elegans (Rudolphi). Waters containing parasitized larvae received significantly fewer eggs than waters containing unparasitized larvae. Larval holding waters that had previously contained unparasitized larvae received significantly more eggs than either waters that had previously contained no larvae or parasitized larvae. Waters that had contained no larvae received significantly more eggs than larval holding waters that had contained parasitized larvae. When these waters were boiled, treated with antibiotics to curb bacterial growth, or filtered sterilized, larval holding waters that had contained parasitized larvae continued to receive significantly fewer eggs than larval holding waters that had contained unparasitized larvae. We propose that gravid A. aegypti are deterred from ovipositing in response to a chemical found in waters containing parasitized larvae. The ecological implications of this selective oviposition are discussed.

Vasyl V Tkach - One of the best experts on this subject based on the ideXlab platform.

  • molecular phylogenetics and mitogenomics of three avian dicrocoeliids digenea dicrocoeliidae and comparison with mammalian dicrocoeliids
    Parasites & Vectors, 2020
    Co-Authors: Mian Sayed Khan, Vasyl V Tkach, Nehaz Muhammad, Dong Zhang, Xingquan Zhu
    Abstract:

    The Dicrocoeliidae are digenetic trematodes mostly parasitic in the bile ducts and gall bladder of various avian and mammalian hosts. Until recently their systematics was based on morphological data only. Due to the high morphological uniformity across multiple dicrocoeliid taxa and insufficient knowledge of relative systematic value of traditionally used morphological characters, their taxonomy has always been unstable. Therefore, DNA sequence data provide a critical independent source of characters for phylogenetic inference and improvement of the system. We examined the phylogenetic affinities of three avian dicrocoeliids representing the genera Brachylecithum, Brachydistomum and Lyperosomum, using partial sequences of the nuclear large ribosomal subunit (28S) RNA gene. We also sequenced the complete or nearly complete mitogenomes of these three isolates and conducted a comparative mitogenomic analysis with the previously available mitogenomes from three mammalian dicrocoeliids (from 2 different genera) and examined the phylogenetic position of the family Dicrocoeliidae within the order Plagiorchiida based on concatenated nucleotide sequences of all mitochondrial genes (except trnG and trnE). Combined nucleotide diversity, Kimura-2-parameter distance, non-synonymous/synonymous substitutions ratio and average sequence identity analyses consistently demonstrated that cox1, cytb, nad1 and two rRNAs were the most conserved and atp6, nad5, nad3 and nad2 were the most variable genes across dicrocoeliid mitogenomes. Phylogenetic analyses based on mtDNA sequences did not support the close relatedness of the Paragonimidae and Dicrocoeliidae and suggested non-monophyly of the Gorgoderoidea as currently recognized. Our results show that fast-evolving mitochondrial genes atp6, nad5 and nad3 would be better markers than slow-evolving genes cox1 and nad1 for species discrimination and population level studies in the Dicrocoeliidae. Furthermore, the Dicrocoeliidae being outside of the clade containing other xiphidiatan trematodes suggests a need for the re-evaluation of the taxonomic content of the Xiphidiata.

  • characterization of the complete mitochondrial genome of plagiorchis maculosus digenea Plagiorchiidae representative of a taxonomically complex digenean family
    Parasitology International, 2019
    Co-Authors: Mian Sayed Khan, Vasyl V Tkach, Nehaz Muhammad, Dong Zhang, Xingquan Zhu
    Abstract:

    Despite the highly divergent morphology, pathogenicity and worldwide distribution of digenean parasites belonging to one of the largest families, the Plagiorchiidae, there are no complete mitochondrial (mt) genomes published to date for plagiorchiids. In this study, we obtained nuclear ribosomal DNA (ITS region and 28S rDNA) sequences and the complete mt genome sequences of Plagiorchis maculosus (Rudolphi 1802) Braun, 1902, and assessed its phylogenetic relationship with other xiphidiates, based on the mtDNA sequences. The obtained ITS and 28S rDNA sequences were identical to the corresponding sequences of P. maculosus available in GenBank. The complete mitochondrial genome of P. maculosus (14,124 bp) contained 36 genes (atp8 is absent) and a long non-coding region (NCR) with two sets of repeated sequences of 283 nucleotides each. The phylogenetic tree resulting from Bayesian inference (BI) analyses based on concatenated nucleotide sequences of all 36 genes of P. maculosus and other xiphidiates mitochondrial genomes, indicated that P. maculosus (and the Plagiorchiidae) is phylogenetically closest to the Brachycladiidae and Paragonimidae. The present study describes the first mitochondrial genome from the type genus of the family Plagiorchiidae. The overall gene arrangement, nucleotide composition, A + T contents, AT and GC skew and codon usage with relative synonymous codon usage (RSCU) for 12 PCGs are described. Characterization of mitochondrial genomes from additional plagiorchiid taxa is necessary to make further progress in phylogenetic and epidemiological studies of these digeneans as well as accurate diagnostics of these parasites including those parasitic in humans.

  • Vitellogenesis of the digenean Plagiorchis elegans (Rudolphi, 1802) (Plagiorchioidea, Plagiorchiidae).
    Parasitology International, 2014
    Co-Authors: Samuel Greani, Yann Quilichini, Stephen E Greiman, Josephine Foata, Papa Ibnou Ndiaye, Vasyl V Tkach, Bernard Marchand
    Abstract:

    The ultrastructural organization of vitellogenesis of Plagiorchis elegans (Rudolphi, 1802), experimentally obtained from the golden hamster Mesocricetus auratus (Linnaeus, 1758), is described using transmission electron microscopy. This study is the first ultrastructural study of vitellogenesis in a member of the superfamily Plagiorchioidea. The four stages usually observed during vitellogenesis are described: stage I, cytoplasm of the vitellocytes mainly filled with ribosomes and few mitochondria; stage II, beginning of the synthetic activity; stage III, active synthesis of the shell globule clusters; stage IV, vitellocytes are filled with shell globule clusters and contain several lipid droplets, and glycogen granules are grouped around clusters and droplets. Vitellogenesis in P. elegans is compared with that of other Digenea. The differences among P. elegans and previously studied digeneans include, but are not limited to the occurrence of dense coiled endoplasmic reticulum saccules and the concentration of glycogen in the mesenchyme, which may be considered as a fifth stage of maturation of the vitelline glands. This peculiarity was not observed in all trematodes, which clearly indicates differences in the vitellogenesis in various digenean lineages at different stages of maturation of their vitelline cells.

  • phylogeny and classification of the digenea platyhelminthes trematoda
    International Journal for Parasitology, 2003
    Co-Authors: Peter D Olson, Rodney A Bray, Thomas H. Cribb, Vasyl V Tkach, D T J Littlewood
    Abstract:

    Complete small subunit ribosomal RNA gene (ssrDNA) and partial (D1‐ D3) large subunit ribosomal RNA gene (lsrDNA) sequences were used to estimate the phylogeny of the Digenea via maximum parsimony and Bayesian inference. Here we contribute 80 new ssrDNA and 124 new lsrDNA sequences. Fully complementary data sets of the two genes were assembled from newly generated and previously published sequences and comprised 163 digenean taxa representing 77 nominal families and seven aspidogastrean outgroup taxa representing three families. Analyses were conducted on the genes independently as well as combined and separate analyses including only the higher plagiorchiidan taxa were performed using a reduced-taxon alignment including additional characters that could not be otherwise unambiguously aligned. The combined data analyses yielded the most strongly supported results and differences between the two methods of analysis were primarily in their degree of resolution. The Bayesian analysis including all taxa and characters, and incorporating a model of nucleotide substitution (general-time-reversible with among-site rate heterogeneity), was considered the best estimate of the phylogeny and was used to evaluate their classification and evolution. In broad terms, the Digenea forms a dichotomy that is split between a lineage leading to the Brachylaimoidea, Diplostomoidea and Schistosomatoidea (collectively the Diplostomida nomen novum (nom. nov.)) and the remainder of the Digenea (the Plagiorchiida), in which the Bivesiculata nom. nov. and Transversotremata nom. nov. form the two most basal lineages, followed by the Hemiurata. The remainder of the Plagiorchiida forms a large number of independent lineages leading to the crown clade Xiphidiata nom. nov. that comprises the Allocreadioidea, Gorgoderoidea, Microphalloidea and Plagiorchioidea, which are united by the presence of a penetrating stylet in their cercariae. Although a majority of families and to a lesser degree, superfamilies are supported as currently defined, the traditional divisions of the Echinostomida, Plagiorchiida and Strigeida were found to comprise non-natural assemblages. Therefore, the membership of established higher taxa are emended, new taxa erected and a revised, phylogenetically based classification proposed and discussed in light of ontogeny, morphology and taxonomic history. q 2003 Australian Society for Parasitology Inc. Published by Elsevier Science Ltd. All rights reserved.

  • phylogenetic analysis of the suborder plagiorchiata platyhelminthes digenea based on partial lsrdna sequences
    International Journal for Parasitology, 2000
    Co-Authors: Vasyl V Tkach, Jan Pawlowski, Jean Mariaux
    Abstract:

    The phylogenetic relationships and systematic position of the members of the suborder Plagiorchiata, one of the derived and most diverse groups of Digenea, have always been controversial. Here, we present a phylogeny of this group based on the analysis of partial sequences of the lsrDNA in 28 species representing 13 families of Plagiorchiata, as well as four outgroups. Our results show that the Plagiorchiata, as considered by most authors, is not monophyletic, and that the superfamilies Opecoeloidea, and most probably Dicrocoelioidea and Gorgoderoidea, may have to be removed from this suborder. According to our results, the Plagiorchiata includes only parasites of terrestrial vertebrates. We find the Plagiorchiata to be composed of two well-supported clades which can be ranked as superfamilies: (1) Plagiorchioidea, including the Plagiorchiidae, Haematoloechidae, Telorchiidae, Brachycoeliidae and Leptophallidae; and (2) Microphalloidea containing the Microphallidae, Prosthogonimidae, Lecithodendriidae and Pleurogenidae. The genetic analysis also allowed revision of the position of several taxa of Plagiorchiata, including: (1) a confirmation of the position of the Brachycoeliidae within the Plagiorchiata; (2) a close phylogenetic relationships of Macrodera with Paralepoderma, Leptophallus and Metaleptophallus; (3) the grouping of Opisthioglyphe and Telorchis within a distinct and strongly supported clade; and (4) the placement of Allassogonoporus amphoraeformis within the Pleurogenidae, and not close to Lecithodendriidae. Some systematic changes, corresponding to these results, are proposed.

Bernard Marchand - One of the best experts on this subject based on the ideXlab platform.

  • Vitellogenesis of the digenean Plagiorchis elegans (Rudolphi, 1802) (Plagiorchioidea, Plagiorchiidae).
    Parasitology International, 2014
    Co-Authors: Samuel Greani, Yann Quilichini, Stephen E Greiman, Josephine Foata, Papa Ibnou Ndiaye, Vasyl V Tkach, Bernard Marchand
    Abstract:

    The ultrastructural organization of vitellogenesis of Plagiorchis elegans (Rudolphi, 1802), experimentally obtained from the golden hamster Mesocricetus auratus (Linnaeus, 1758), is described using transmission electron microscopy. This study is the first ultrastructural study of vitellogenesis in a member of the superfamily Plagiorchioidea. The four stages usually observed during vitellogenesis are described: stage I, cytoplasm of the vitellocytes mainly filled with ribosomes and few mitochondria; stage II, beginning of the synthetic activity; stage III, active synthesis of the shell globule clusters; stage IV, vitellocytes are filled with shell globule clusters and contain several lipid droplets, and glycogen granules are grouped around clusters and droplets. Vitellogenesis in P. elegans is compared with that of other Digenea. The differences among P. elegans and previously studied digeneans include, but are not limited to the occurrence of dense coiled endoplasmic reticulum saccules and the concentration of glycogen in the mesenchyme, which may be considered as a fifth stage of maturation of the vitelline glands. This peculiarity was not observed in all trematodes, which clearly indicates differences in the vitellogenesis in various digenean lineages at different stages of maturation of their vitelline cells.

  • ultrastructure of the spermatozoon of the digenean plagiorchis elegans rudolphi 1802 plagiorchioidea Plagiorchiidae
    Journal of Morphology, 2013
    Co-Authors: P Ndiaye, Cheikh Tidiane Ba, Yann Quilichini, Stephen E Greiman, Volodymyr V Tkach, Bernard Marchand
    Abstract:

    The ultrastructure of the mature spermatozoon of the type genus of the Plagiorchiidae Plagiorchis elegans (Rudolphi, 1802), a parasite of the Golden hamster, Mesocricetus auratus is described. This study is the first ultrastructural study of the spermatozoon of a Plagiorchis, the second of a plagiorchiid species and only the third in the Plagiorchioidea. Previously data on spermatozoon ultrastructure existed only for the plagiorchiid Enodiotrema reductum and the omphalometrid Rubenstrema exasperatum. The mature spermatozoon of P. elegans exhibited the general pattern described in most digenean species, namely two axonemes of the 9 + "1" Trepaxonemata pattern, nucleus, mitochondria, external ornamentation of the plasma membrane, spine-like bodies, and glycogen granules. However, the rather typical expansion of the plasma membrane is not found in P. elegans. Another peculiarity of the spermatozoon of P. elegans is the presence of a structure called thin cytoplasm termination. Spermatozoon ultrastructure of P. elegans is compared with that of E. reductum and R. exasperatum. Spermatozoon of P. elegans conforms to the general pattern described in E. reductum. Thus, this study further expands our knowledge on the spermatozoon ultrastructure among the members of the Plagiorchioidea, one of the most phylogenetically derived groups of the digenea.

  • ultrastructural study of the spermatozoon of the digenean enodiotrema reductum looss 1901 platyhelminthes plagiorchioidea Plagiorchiidae parasite of the green turtle chelonia mydas linnaeus 1758 in senegal
    Parasitology Research, 2012
    Co-Authors: P Ndiaye, Cheikh Tidiane Ba, Yann Quilichini, Aminata Sene, Volodymyr V Tkach, Bernard Marchand
    Abstract:

    This study describes the ultrastructural organisation of the spermatozoon of a digenean Enodiotrema reductum (Pligiorchiida: Plagiorchiidae) from the green turtle Chelonia mydas (Linnaeus, 1758). This is the first report of E. reductum from Senegal. The mature spermatozoon of E. reductum is filiform and exhibits two axonemes of the 9 + “1” pattern of the Trepaxonemata, a nucleus, parallel cortical microtubules, an extramembranar ornamentation associated with spine-like bodies and granules of glycogen, among other ultrastructural features. The spermatozoon of E. reductum is distinguished by the presence of a moniliform mitochondrion composed of a bulge associated with a long cord and of a central cytoplasmic expansion. This work represents the first utrastructural study of any representative of the large family Plagiorchiidae. Our results are compared with previously published data on spermatozoa of other digenean taxa.

Reinaldo Jose Da Silva - One of the best experts on this subject based on the ideXlab platform.

  • molecular phylogenetic position of haplometroides intercaecalis digenea Plagiorchiidae
    Acta Parasitologica, 2018
    Co-Authors: Maria Isabel Muller, Drausio Honorio Morais, Reinaldo Jose Da Silva
    Abstract:

    Three valid species of Haplometroides Odhner, 1910 parasitise snakes and amphisbaenians from South America. This study provides additional data on morphometric and molecular phylogenetic position inferred from the nuclear ribosomal gene 28S (partial). DNA sequences were isolated from Haplometroides intercaecalis Silva, Ferreira and Strussmann, 2007 found in one specimen of Phalotris matogrossensis Lema, D’Agostini and Cappellari, 2005. Five digenean specimens were recovered from the esophagus of this snake, and four specimens were used for morphometrical studies and one specimen for molecular analysis. Phylogenetic analysis using maximum likelihood and Bayesian methods was conducted with sequences available for the order Plagiorchiida and its phylogenetic position places H. intercaecalis among the brachycoeliids Brachycoelium (Dujardin, 1845) Stiles and Hassall, 1898 and Parabrachycoelium Perez-Ponce de Leon, Mendoza-Garfias, Razo-Mendivil and Parra-Olea, 2011, and the mesocoeliid Mesocoelium Odhner, 1910, not closely related to plagiorchids as expected. Due to morphological differences among these families, it may be necessary to create a new family to accommodate Haplometroides spp. However, more genera/taxa as well as other molecular markers should be added in future studies to confirm our results and resolve this matter. This is the first phylogenetic positioning of digeneans of the genus Haplometroides, contributing to the systematic analysis of the helminthological biodiversity of Neotropical snakes.

  • New record of Haplometroides intercaecalis (Digenea, Plagiorchiidae) infecting a Brazilian snake
    Journal of Venomous Animals and Toxins Including Tropical Diseases, 2008
    Co-Authors: Reinaldo Jose Da Silva, A. F. Béda, Vanda Lúcia Ferreira
    Abstract:

    Phalotris matogrossensis (Serpentes, Colubridae) was reported as a new host for Haplometroides intercaecalis (Digenea, Plagiorchiidae). The host snake was obtained from the municipality of Anastacio, state of Mato Grosso do Sul, Brazil. One specimen of H. intercaecalis was recovered from the esophagus of the host and identified by the intercecal position of the vitellaria in the pre-acetabular region. This paper describes the second report of the occurrence of this trematode in fossorial snakes of the genus Phalotris in the state of Mato Grosso do Sul, Brazil.

  • New reports on parasitism by Haplometroides buccicola (Digenea, Plagiorchiidae) in Brazilian snakes
    Journal of Venomous Animals and Toxins Including Tropical Diseases, 2008
    Co-Authors: Karina Rodrigues Dos Santos, T. H. Barrella, Erica De Oliveira Penha Zica, Reinaldo Jose Da Silva
    Abstract:

    The occurrence of Haplometroides buccicola (Digenea, Plagiorchiidae) in the esophagus of two Brazilian snakes is reported in the present study. The trematodes were collected from one Micrurus corallinus (Elapidae) and one Phalotris lativittatus (Colubridae); both snakes were found in Botucatu city, Sao Paulo State, Brazil. Morphological and morphometric analyses of the trematodes are presented. For the first time Micrurus corallinus has been recorded as a host for H. buccicola and this is the second time that P. lativittatus has been reported as a host for this trematode species.

  • NEW SPECIES OF HAPLOMETROIDES (DIGENEA: Plagiorchiidae) FROM PHALOTRIS NASUTUS (GOMES, 1915) (SERPENTES, COLUBRIDAE)
    Journal of Parasitology, 2007
    Co-Authors: Reinaldo Jose Da Silva, Vanda Lúcia Ferreira, Christine Strüssmann
    Abstract:

    A new species of Haplometroides (Digenea, Plagiorchiidae) is described from a specimen of Phalotris nasutus (Gomes, 1915) (Serpentes, Colubridae). The host snake was obtained in the municipality of Corumba, Mato Grosso do Sul State, Brazil. Trematodes were recovered from esophagus, stomach, and small intestine of the host. The main characteristic of the new species is the vitellaria, which is intercecal, cecal, and extracecal in the preacetabular region. A key for identification of the species in Haplometroides is proposed.

  • Report on the occurrence of Haplometroides buccicola (Trematoda, Digenea, Plagiorchiidae) infecting Phalotris lativittatus (Serpentes, Colubridae) in Brazil
    Journal of Venomous Animals and Toxins Including Tropical Diseases, 2005
    Co-Authors: Reinaldo Jose Da Silva, P. A. Andrade, H. A. Monteiro E Silva, M. Rossellini, T. H. Barrella
    Abstract:

    Haplometroides buccicola (Trematoda, Digenea, Plagiorchiidae) was reported in the mouth and oesophagus of Phalotris lativittatus (Serpentes, Colubridae) from Botucatu, Sao Paulo State, Brazil. This is the first report on the occurrence of H. buccicola parasitizing P. lativittatus. The Haplometroides genus was also discussed and the most important morphological characters for the identification of the species H. buccicola and H. odhneri are presented.

P Ndiaye - One of the best experts on this subject based on the ideXlab platform.