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Journal ArticleDOI

Molecular phylogenetics and diagnosis of Anisakis, Pseudoterranova, and Contracaecum from northern Pacific marine mammals.

01 Dec 2005-Journal of Parasitology (American Society of Parasitologists)-Vol. 91, Iss: 6, pp 1413-1429
TL;DR: Phylogenetic analysis of LSU sequences revealed strong support for the monophyly of Anisakinae, Contracaecum plus Phocascaris, Pseudoterranova, and Anisakis, which is primarily consistent with previously published phenograms based on multilocus electrophoretic data.
Abstract: Individual specimens of Anisakis, Pseudoterranova, and Contracaecum collected from marine mammals inhabiting northern Pacific waters were used for comparative diagnostic and molecular phylogenetic analyses. Forty-eight new sequences were obtained for this study of 14 Anisakis taxa, 8 Pseudoterranova taxa, 4 Contracaecum taxa, and 4 outgroup species. Partial 28S (LSU) and complete internal transcribed spacer (ITS-1, 5.8S, ITS-2) ribosomal DNA was amplified by the polymerase chain reaction and sequenced. Sequences of ITS indicated that Pseudoterranova specimens from Zalophus californianus (California sea lion), Mirounga angustirostris (northern elephant seal), Phoca vitulina (harbor seal), Enhydra lutris (sea otter), and Eumetopias jubatus (Steller's sea lion) exactly matched P. decipiens s. str., extending the host and geographic range of this species. Anisakis from northern Pacific marine mammals were most closely related to members of the A. simplex species complex. Comparison of Anisakis ITS sequences diagnosed the presence of A. simplex C in 2 M. angustirostris hosts, which is a new host record. Anisakis specimens from Phocoena phocoena (harbor porpoise), Lissodelphis borealis (Pacific rightwhale porpoise), and E. jubatus included 3 ITS sequences that did not match any known species. Contracaecum adults obtained from Z. californianus were most closely related to C. ogmorhini s.l. and C. rudolphii, but ITS sequences of these Contracaecum specimens did not match C. ogmorhini s. str. or C. margolisi. These novel Anisakis and Contracaecum ITS sequences may represent previously uncharacterized species. Phylogenetic analysis of LSU sequences revealed strong support for the monophyly of Anisakinae, Contracaecum plus Phocascaris, Pseudoterranova, and Anisakis. Phylogenetic trees inferred from ITS sequences yielded robustly supported relationships for Pseudoterranova and Anisakis species that are primarily consistent with previously published phenograms based on multilocus electrophoretic data.

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Citations
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Journal ArticleDOI
TL;DR: The findings of the present study provide a foundation for future investigations of the community composition, life cycles, and distribution of nematode populations in edible fish in Australia and explore and clarify their significance to public health.
Abstract: This study aimed to determine the integrative characterisation of nematodes from three species of edible flathead fishes (Scorpaeniformes: Platycephalidae) in New South Wales, Australia, and describe nematode communities within three species of flatheads. Tiger (Platycephalus richardsoni (Castelnau); n = 20) and sand flatheads (Platycephalus bassensis (Cuvier); n = 20), sourced from the Nelson Bay area, and dusky flathead (Platycephalus fuscus (Cuvier); n = 20) from the Manning River, Taree, were examined for the presence of nematodes. The nematodes were initially classified morphologically as 12 different morphotypes belonging to the families Anisakidae (Anisakis types I, II, and III, Contracaecum type II, Terranova types I and II), Raphidascarididae (Hysterothylacium types IV, VI, VIII, and H. zhoushanense larva), and Gnathostomatidae (Echinocephalus sp. larva), Capillariidae (Capillaria sp.), followed by genetic identification through sequencing of the internal transcribed spacer (ITS-1, 5.8S, ITS-2) regions. Phylogenetic analyses revealed the evolutionary relationship between the identified larval specimens in the present study with available GenBank larval and adult nematodes. Sand flathead was 90% infected with nematodes followed by tiger flathead at 85% and dusky flathead at 15%. Nematodes infecting estuarine dusky and oceanic sand and tiger flatheads contrasted markedly. The analysis of similarities (ANOSIM) showed significant differences (p < 0.001) in the composition of taxa within nematode communities between the three species of flatheads (global R = 0.208) with the highest difference being between sand and dusky flatheads (R = 0.308, p < 0.001). The findings of the present study provide a foundation for future investigations of the community composition, life cycles, and distribution of nematode populations in edible fish in Australia and explore and clarify their significance to public health.

7 citations

Journal ArticleDOI
TL;DR: Molecular phylogenetic analyses supported the validity of Procamallanus spiculogubernaculus and confirmed the paraphyletic status of the members of ProCamallanus, Spirocam allanus, Camallanus and Paracamallanus.
Abstract: Summary The nematode, Procamallanus spiculogubernaculus Agarwal, 1958 was found from the Stinging catfish, Heteropneustes fossilis (Bloch, 1794) from Ghazipur, Delhi, India. Morphological characterization, including scanning electron microscope observation supplemented with DNA sequences is provided. Specimens recently found are characterized by the presence of an unlined buccal capsule having a small basal ring, esophagus muscular and glandular, vulva position is slightly post-equatorial, tail conical, long, and ending in three digit-like processes, phasmids present at about mid-length and cloaca located at the posterior end. In this study the species P. spiculogubernaculus is validated on the basis of molecular data after 47 years from its original description. In the scanning electron microscope examination, the topology of mouth and sensory pits in anterior portion, while the phasmids and digit like processes in posterior portion is clearly observed. Molecular data of the 18S ribosomal RNA and mitochondrial cytochrome c oxidase subunit 1 (cox1) gene were analyzed. Molecular phylogenetic analyses supported the validity of Procamallanus spiculogubernaculus and confirmed the paraphyletic status of the members of Procamallanus, Spirocamallanus, Camallanus and Paracamallanus. Taxonomic status of members of the family Camallanidae are briefly discussed along with the results of the systematic evaluation of P. spiculogubernaculus based on molecular data.

7 citations


Cites methods from "Molecular phylogenetics and diagnos..."

  • ...Molecular tools are frequently used in nematode identifi cation and systematics (Gasser, 2001; Nadler et al., 2005; Mattiucci & Nascetti, 2008; Borges et al., 2012; Jones et al., 2012; Liu et al., 2013; Pekmezci et al., 2014; Di Azevedo et al., 2015; Goswami et al., 2015, 2016)....

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Journal ArticleDOI
TL;DR: Knowing that local populations may be at risk, it is recommended that all prophylactic measures be taken in relation to fish consumption, and the presence of larvae with zoonotic potential of Contracaecum spp.
Abstract: Parasitic nematodes can infect both wild and cultivated fish species and may be the source of many diseases. The consumption of raw fish meat in many countries has been the responsible of nematode related zoonosis. Knowing the risk of consumption of contaminated fish by the local communities, the main goal of this paper is to quantify and report the presence of larvae with zoonotic potential of Contracaecum spp. and Eustrongylides spp. found in two exotic fish species from the Tramandai River Basin in southern Brazil. The sample sites were two lagoons of the basin, the Itapeva lagoon and Palmital lagoon, sampled in the period of April 2018. Forty specimens of Acestrorhynchus pantaneiro and twenty specimens of Trachelyopterus lucenai were examined. A. pantaneiro presented a 58% and 4% prevalence and a mean intensity of 3.17 and 1 for Contracaecum spp. and Eustrongylides spp., respectively. Meanwhile T. lucenai presented a prevalence of 70% and 5% and a mean intensity of 1.92 and 1 of Contracaecum spp. larvae and Eustrongylides spp. larvae, respectively. Although larvae of Contracaeucum spp. are reported only in the literature in experimental infections, they were able to complete their biological cycle in some mammals with certain pathogeneses. However, larvae of Eustrongylides spp. infect humans, as reported in the literature, causing severe damage to the intestinal tract. Knowing that local populations may be at risk, we recommend that all prophylactic measures be taken in relation to fish consumption. This study also contributes to the knowledge concerning the parasitic fauna of the host species studied.

7 citations


Additional excerpts

  • ...(Nadler et al., 2005; Mattiucci and Nascetti, 2007)....

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Journal ArticleDOI
21 Aug 2021-Animal
TL;DR: In this paper, the presence of hybrid genotypes in larvae parasitizing fish caught in sympatric and allopatric Spanish marine waters, the North-East Atlantic and West Mediterranean, respectively, and to study possible differences in the growth behaviour between genotypes.
Abstract: The sibling species Anisakis simplex (s.s.) and Anisakis pegreffii are parasites of marine mammals and fish worldwide and the main causative agents of human anisakiasis. In sympatric areas, a hybrid genotype between the two species has been identified, mainly in third-stage larvae, but rarely in fourth-stage and adult forms. The aim of this study was to confirm the presence of hybrid genotypes in larvae parasitizing fish caught in sympatric and allopatric Spanish marine waters, the North-East Atlantic and West Mediterranean, respectively, and to study possible differences in the growth behaviour between genotypes. Of the 254 molecularly analysed larvae, 18 were identified as hybrids by PCR-RFLP analysis of the rDNA ITS region, 11 of which were subsequently confirmed by EF1 α-1 nDNA gene sequencing. These results therefore indicate an overestimation of hybrid genotypes when identification is based only on the ITS region. We also report the detection of a hybrid specimen in a host from the West Mediterranean, considered an allopatric zone. Additionally, fourth-stage larvae with a hybrid genotype were obtained in vitro for the first time, and no differences were observed in their growth behaviour compared to larvae with A. simplex (s.s.) and A. pegreffii genotypes.

7 citations

Journal ArticleDOI
TL;DR: The model of the environmental niche and distribution of marine, parasitic nematodes from the Pseudoterranova decipiens complex using the software Maxent indicated that biotic variables can help to improve the modelling of data-poor, marine species.
Abstract: Environmental niche modelling is an acclaimed method for estimating species' present or future distributions. However, in marine environments the assembly of representative data from reliable and unbiased occurrences is challenging. Here, we aimed to model the environmental niche and distribution of marine, parasitic nematodes from the Pseudoterranova decipiens complex using the software Maxent. The distribution of these potentially zoonotic species is of interest, because they infect the muscle tissue of host species targeted by fisheries. To achieve the best possible model, we used two different approaches. The land distance (LD) model was based on abiotic data, whereas the definitive host distance (DHD) model included species-specific biotic data. To assess whether DHD is a suitable descriptor for Pseudoterranova spp., the niches of the parasites and their respective definitive hosts were analysed using ecospat. The performance of LD and DHD was compared based on the variables' contribution to the model. The DHD-model clearly outperformed the LD-model. While the LD-model gave an estimate of the parasites' niches, it only showed the potential distribution. The DHD-model produced an estimate of the species' realised distribution and indicated that biotic variables can help to improve the modelling of data-poor, marine species.

7 citations

References
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Journal ArticleDOI
TL;DR: The program MODELTEST uses log likelihood scores to establish the model of DNA evolution that best fits the data.
Abstract: Summary: The program MODELTEST uses log likelihood scores to establish the model of DNA evolution that best fits the data. Availability: The MODELTEST package, including the source code and some documentation is available at http://bioag.byu.edu/zoology/crandall―lab/modeltest.html. Contact: dp47@email.byu.edu.

20,105 citations


"Molecular phylogenetics and diagnos..." refers methods in this paper

  • ...Modeltest Version 3.06 (Posada and Crandall, 1998) was used to compare the fit of nucleotide substitution models for datasets using the Akaike information criterion....

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Journal ArticleDOI
TL;DR: The effects on phylogenetic accuracy of adding characters and/or taxa were explored using data generated by computer simulation using a four-taxon tree representing a difficult phylogenetic problem with an extreme situation of long branch attraction.
Abstract: The effects on phylogenetic accuracy of adding characters and/or taxa were explored using data generated by computer simulation. The conditions of this study were constrained but allowed for systematic investigation of certain parameters. The starting point for the study was a four-taxon tree in the ``Felsenstein zone,'' representing a dif® cult phylogenetic problem with an extreme situation of long branch attraction. Taxa were added sequentially to this tree in a manner speci® cally designed to break up the long branches, and for each tree data matrices of different sizes were simulated. Phylogenetic trees were reconstructed from these data using the criteria of parsimony and maximum likelihood. Phylogenetic accuracy was measured in three ways: (1) proportion of trees that are completely correct, (2) proportion of correctly reconstructed branches in all trees, and (3) proportion of trees in which the original four-taxon statement is correctly reconstructed. Accuracy improved dramatically with the addition of taxa and much more slowly with the addition of characters. If taxa can be added to break up long branches, it is much more preferable to add taxa than characters. (Long branch attraction; parsimony; phylogenetic recon- struction; simulation; taxon sampling.)

687 citations

01 Jan 1998
TL;DR: In this paper, the effects of adding characters and/or taxa on phylogenetic accuracy were explored using data generated by computer simulation using a four-taxon tree in the "Felsenstein zone/7".
Abstract: The effects on phylogenetic accuracy of adding characters and/or taxa were explored using data generated by computer simulation. The conditions of this study were constrained but allowed for systematic investigation of certain parameters. The starting point for the study was a four-taxon tree in the "Felsenstein zone/7 representing a difficult phylogenetic problem with an extreme situation of long branch attraction. Taxa were added sequentially to this tree in a manner specifically designed to break up the long branches, and for each tree data matrices of different sizes were simulated. Phylogenetic trees were reconstructed from these data using the criteria of parsimony and maximum likelihood. Phylogenetic accuracy was measured in three ways: (1) proportion of trees that are completely correct, (2) proportion of correctly reconstructed branches in all trees, and (3) proportion of trees in which the original four-taxon statement is correctly reconstructed. Accuracy improved dramatically with the addition of taxa and much more slowly with the addition of characters. If taxa can be added to break up long branches, it is much more preferable to add taxa than characters. (Long branch attraction; parsimony; phylogenetic recon? struction; simulation; taxon sampling.) It is obvious that the successful recon? struction of phylogenetic relationships re? quires some amount of data sampling from relevant taxa and informative char? acters. Far less clear, however, is how much of each data type is required, and whether one of those sources of data has a greater impact on accuracy than the other. Given limited time and resources, it is important to explore the costs and benefits to phylo? genetic accuracy of adding taxa versus in? creasing the number of characters. For ex? ample, given that one has sufficient time and resources to sequence 10 kilobases (kb) of DNA, would it be better to se? quence, say, 2.5 kb from each of 4 taxa, or 1 kb from each of 10, or 0.25 kb from each of 40?

676 citations

Journal ArticleDOI
15 Apr 1961-Sarsia
TL;DR: More than 260 specimens of fish, belonging to 64 species, have been searched for nematode parasites and 9 species of fish were found to be free of nematodes.
Abstract: The present paper deals with nematode parasites from some Norwegian marine fishes. The major part of the material was collected personally from fishes caught in the fjords near Bergen and Tromso; the minor part of the material was obtained from the zoological museums in Oslo and Bergen and from other sources. 260 specimens of fish, belonging to 64 species, have been searched for nematode parasites. 9 species of fish were found to be free of nematodes.

373 citations


"Molecular phylogenetics and diagnos..." refers background in this paper

  • ...…A. simplex s. str.) A. simplex C); these represent the 3 known species within the A. simplex species complex and are characterized (along with A. typica and A. ziphidarum) by having type I larvae sensu Berland (1961), which may represent the apomorphic (derived) state within An- NADLER ET AL....

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Journal ArticleDOI
TL;DR: The polymorphisms obtained by restriction fragment length polymorphisms have provided a new set of genetic markers for the accurate identification of sibling species and morphospecies.

297 citations