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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TL;DR: This mt genome provides novel genetic markers for studying the molecular epidemiology, population genetics, systematics, and biology of pinworm of animals and humans, and should have implications for the diagnosis, prevention, and control of passaluriasis in rabbits and other animals.
Abstract: Passalurus ambiguus (Nematda: Oxyuridae) is a common pinworm which parasitizes in the caecum and colon of rabbits. Despite its significance as a pathogen, the epidemiology, genetics, systematics, and biology of this pinworm remain poorly understood. In the present study, we sequenced the complete mitochondrial (mt) genome of P. ambiguus. The circular mt genome is 14,023 bp in size and encodes of 36 genes, including 12 protein-coding, two ribosomal RNA, and 22 transfer RNA genes. The mt gene order of P. ambiguus is the same as that of Wellcomia siamensis, but distinct from that of Enterobius vermicularis. Phylogenetic analyses based on concatenated amino acid sequences of 12 protein-coding genes by Bayesian inference (BI) showed that P. ambiguus was more closely related to W. siamensis than to E. vermicularis. This mt genome provides novel genetic markers for studying the molecular epidemiology, population genetics, systematics of pinworm of animals and humans, and should have implications for the diagnosis, prevention, and control of passaluriasis in rabbits and other animals.
12 citations
Cites methods from "Molecular phylogenetics and diagnos..."
...According to the previous studies (De Ley and Blaxter 2002; Nadler et al. 2005; Park et al. 2011; Liu et al. 2013a, 2015; Kim et al. 2014) from sequences of nuclear small subunit (SSU) rRNA gene and mt genomes, infraorder Oxyuridomorpha is the monophyly....
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TL;DR: An enhanced risk communication plan focused on control measures, such as removal of anchovy viscera by retailers, and educational campaigns stressing the importance of freezing anchovies that are intended for raw consumption, may clearly contribute to avoid this emergent biohazard in seafood.
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TL;DR: Eustrongylides ignotus and R. gigi in H. transpacificus nipponensis represents a new host record and is recognized as a zoonotic parasite in Japan.
Abstract: As an adult, Eustrongylides ignotus, recognized as a zoonotic parasite, is a parasitic nematode found in the gastrointestinal tract of fish-eating birds. As larvae, they are found in the connective tissue or body cavities of freshwater fish. In Japan, E. ignotus and E. tubifex have been found in three avian species, but their distribution in intermediate and paratenic hosts remains unclear. For this study, 16 commercial raw Japanese smelts, Hypomesus transpacificus nipponensis, were used for parasitological examination. A pinkish red worm collected from the abdominal wall of one smelt (6.3%) was identified as E. ignotus based on the high sequence similarity (99.9%) of the partial 18S ribosomal RNA gene and the morphology of its cephalic and caudal ends. Furthermore, a Raphidascaris-like nematode was found in the intestines of five smelts examined (31.3%) and was identified as R. gigi in view of the absence of lateral cuticular alae. Eustrongylides ignotus and R. gigi have been reported in various freshwater fish, but not in smelts. Therefore, this finding of E. ignotus and R. gigi in H. transpacificus nipponensis represents a new host record.
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Cites methods from "Molecular phylogenetics and diagnos..."
...…RNA gene (LSU rDNA) including the D2 and D3 divergent domains of the Raphidascaris-like nematode were amplified respectively using nemspec18SF, NC5, and NC2 primers, and #391, #390, #538, #501, #93 and #94 primers (Zhu et al. 1998, Szostakowska et al. 2001, Abe et al. 2005, Nadler et al. 2005)....
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TL;DR: A primers/probe system for the identification of five species of anisakid nematodes belonging to the genus Anisakis to be used in a real time polymerase chain reaction (RT-PCR) with specific primers based on the mtDNA cox2 gene may represent a useful tool for future basic and applied research.
12 citations
TL;DR: A new species of Phasmarhabditis was isolated from the slug, Polytoxon robustum, from Nairobi, Kenya, using morphological, morphometric, molecular and phylogenetic analyses.
Abstract:
A new species of Phasmarhabditis was isolated from the slug, Polytoxon robustum, from Nairobi, Kenya. The nematode was identified using morphological, morphometric, molecular and phylogenetic analyses. Phasmarhabditis kenyaensis n. sp. is characterised by an infective juvenile with the longest body length in the genus, measuring 1232 (1107-1336) μm, by the presence of males with a bursa bearing nine bilateral pairs of genital bursal papillae and one pair of papilliform phasmids flanking the tail, cephalate paired spicules, with an arc length of 71 (57-81) μm, as well as by females with a vulva located at the mid-body region and a conoid tail shape, with two phasmids located at ca 40% of the tail length. The molecular phylogeny of the new species, as inferred from its SSU (small subunit) rRNA gene, places P. kenyaensis n. sp. genetically close to undescribed phasmarhabditids from South Africa, suggesting an African grouping, while the D2-D3 (large ribosomal subunit) and ITS region analyses relate P. kenyaensis n. sp. to P. meridionalis, with weak bootstrap support. This is the third new Phasmarhabditis species described from the African continent, the new species bringing the total known complement of the genus to 14 species. A morphometric compendium to all species cultured in vivo is supplied.
12 citations
References
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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
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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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