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.
Citations
More filters
TL;DR: Examples in which anisakid nematodes recognized genetically at the species level in definitive and intermediate/paratenic hosts from various geographical areas of the Boreal and Austral regions and their infection levels have been used as biological indicators of fish stocks and food-web integrity in areas at high versus low levels of habitat disturbance are presented.
Abstract: The application of molecular systematics to the anisakid nematodes of the genera Anisakis, Pseudoterranova and Contracaecum, parasites of aquatic organisms, over the last two decades, has advanced the understanding of their systematics, taxonomy, ecology and phylogeny substantially Here the results of this effort on this group of species from the early genetic works to the current status of their revised taxonomy, ecology and evolutionary aspects are reviewed for each of three parasitic groups It has been shown that many anisakid morphospecies of Anisakis, Contracaecum and Pseudoterranova include a certain number of sibling species Molecular genetic markers provided a rapid, precise means to screen and identify several species that serve as definitive and intermediate and or/paratenic hosts of the so far genetically characterized species Patterns of differential distribution of anisakid nematodes in various definitive and intermediate hosts are presented Differences in the life history of related species can be due both to differential host-parasite co-adaptation and co-evolution, and/or to interspecific competition, that can reduce the range of potential hosts in sympatric conditions Phylogenetic hypotheses attempted for anisakid nematodes and the possible evolutionary scenarios that have been proposed inferred from molecular data, also with respect to the phylogeny of their hosts are presented for the parasite-host associations Anisakis-cetaceans and Contracaecum-pinnipeds, showing that codivergence and host-switching events could have accompanied the evolution of these groups of parasites Finally, examples in which anisakid nematodes recognized genetically at the species level in definitive and intermediate/paratenic hosts from various geographical areas of the Boreal and Austral regions and their infection levels have been used as biological indicators of fish stocks and food-web integrity in areas at high versus low levels of habitat disturbance (pollution, overfishing, by-catch) are presented
402 citations
Cites background or methods or result from "Molecular phylogenetics and diagnos..."
...pegreffii is also well supported by a phylogenetic analysis inferred from ITS rDNA sequence data sets (Nadler et al., 2005)....
[...]
...Codes: AN: Antarctica; BE: Bering Sea; BS: Barents Sea; FI: Faeroe Islands; JA: Japan Sea; LS: Labrador Sea; NEA: North-East Atlantic; NEP: North-East Pacific; NWA: NorthWest Atlantic; NWP: North-West Pacific; SEP: South-East Pacific (Chilean coast) (data from George-Nascimento and Llanos, 1995; George-Nascimento and Urrutia, 2000; Mattiucci et al., 1998; Nadler et al., 2005; Paggi et al., 1991, 1998c; Zhu et al., 2002)....
[...]
...) is widespread between 35 N and the Arctic Circle; it is present in both the western and eastern Atlantic and Pacific Oceans (Abe et al., 2005, 2006; Abollo et al., 2001; Mattiucci et al., 1997, 1998; Nadler et al., 2005; Paggi et al., 1998a; Umehara et al., 2006, 2008) (Fig....
[...]
...Parsimony and ML analyses indicated that the Raphidascarididae, Contracaecum plus Phocascaris, and the Anisakinae (here considering only Pseudoterranova and Anisakis) are each monophyletic, the latter two groups with consistently strong bootstrap support at MP and ML analyses (Nadler et al., 2005)....
[...]
...A congruent result was inferred from the ITS rDNA sequence analysis (Nadler et al., 2005) (see Section 4....
[...]
TL;DR: The morphological and morphometric analyses revealed the presence of morphological features that differed among the 3 biological species, and the tree topologies support the finding that A. simplex (s.s.), A. pegreffii, and A. berlandi n.
Abstract: Numerous specimens of the 3 sibling species of the Anisakis simplex species complex (A. pegreffii, A. simplex (senso stricto)), and A. simplex sp. C) recovered from cetacean species stranded within the known geographical ranges of these nematodes were studied morphologically and genetically. The genetic characterization was performed on diagnostic allozymes and sequences analysis of nuclear (internal transcribed spacer [ITS] of ribosomal [r]DNA) and mitochondrial (mitochondrial [mt]DNA cox2 and rrnS) genes. These markers showed (1) the occurrence of sympatry of the 2 sibling species A. pegreffii and A. simplex sp. C in the same individual host, the pilot whale, Globicephala melas Traill, from New Zealand waters; (2) the identification of specimens of A. pegreffii in the striped dolphin, Stenella coeruleoalba (Meyen), from the Mediterranean Sea; and (3) the presence of A. simplex (s.s.) in the pilot whale and the minke whale, Balaenoptera acutorostrata Lacepede, from the northeastern Atlantic wa...
166 citations
Cites background from "Molecular phylogenetics and diagnos..."
...…have confirmed the existence of these 3 cryptic species by using phylogenetic analyses of DNA sequences of mitochondrial (mitochondrial [mt]DNA cox2) and nuclear (internal transcribed spacer [ITS] of ribosomal [r]DNA) genes (Nadler et al., 2005; Mattiucci et al., 2009; Cavallero et al., 2011)....
[...]
TL;DR: This review addresses the biodiversity, biology, distribution, ecology, epidemiology, and consumer health significance of the so far known species of Anisakis, both in their natural hosts and in human accidental host populations, worldwide.
Abstract: This review addresses the biodiversity, biology, distribution, ecology, epidemiology, and consumer health significance of the so far known species of Anisakis, both in their natural hosts and in human accidental host populations, worldwide. These key aspects of the Anisakis species' biology are highlighted, since we consider them as main driving forces behind which most of the research in this field has been carried out over the past decade. From a public health perspective, the human disease caused by Anisakis species (anisakiasis) appears to be considerably underreported and underestimated in many countries or regions around the globe. Indeed, when considering the importance of marine fish species as part of the everyday diet in many coastal communities around the globe, there still exist significant knowledge gaps as to local epidemiological and ecological drivers of the transmission of Anisakis spp. to humans. We further identify some key knowledge gaps related to Anisakis species epidemiology in both natural and accidental hosts, to be filled in light of new 'omic' technologies yet to be fully developed. Moreover, we suggest that future Anisakis research takes a 'holistic' approach by integrating genetic, ecological, immunobiological, and environmental factors, thus allowing proper assessment of the epidemiology of Anisakis spp. in their natural hosts, in human populations, and in the marine ecosystem, in both space and time.
158 citations
TL;DR: It is suggested that anisakiasis in Japan is mainly caused by A. simplex sensu stricto because it penetrates the muscle of the fish at a higher rate than A. pegreffii.
142 citations
TL;DR: This is the first instance of human intestinal anisakiasis diagnosed using PCR of DNA purified from a fixed eosinophilic granuloma embedded in paraffin, reinforcing the pathological significance of the species A. pegreffii to humans.
Abstract: Anisakiasis is an important fish-borne zoonosis provoked by larval stages of nematodes belonging to the genus Anisakis. The detection and identification of human infections is difficult. This is due to: a) the low specificity of the clinical features and symptomatology related to human infections; b) the paucity of diagnostic features of larvae found in granulomatous lesions characteristic of "invasive anisakiasis"; and c) the lack morphological characters diagnostic at the specific level when larvae of Anisakis are detected. Thus, molecular-based diagnostic approaches are warranted. We have developed a PCR method that amplifies the DNA of Anisakis spp. in fixed paraffin-embedded tissues. This method was applied to a granuloma removed from a human case of intestinal anisakiasis in Italy. Specific primers of the mtDNA cox2 gene were used and sequence analysis was performed according to the procedures already established for species of Anisakis. The sequence obtained (629 bp) was compared with those of the other species of Anisakis which have so far been genetically characterized and with sequences obtained from larval stages of Anisakis collected from the Mediterranean fish Engraulis encrasicolus. This enabled the genetic identification of the larva in the human tissue as A. pegreffii. This is the first instance of human intestinal anisakiasis diagnosed using PCR of DNA purified from a fixed eosinophilic granuloma embedded in paraffin. The case of human anisakiasis presented reinforces the pathological significance of the species A. pegreffii to humans. The molecular/genetic methodological approach based on mtDNA cox2 sequence analysis, described here, can allow easy and rapid identification of Anisakis spp. in formalin-fixed and paraffin embedded tissues removed from cases of either gastric or intestinal human anisakiasis.
128 citations
Cites background from "Molecular phylogenetics and diagnos..."
...The systematics of the species of Anisakis has been clarified in recent decades by the application of such molecular methodologies [1,18-34]....
[...]
References
More filters
TL;DR: Stomachs from subadult male northern fur seals (SAMs) (Callorhinus ursinus) from St. Paul Island, Alaska, were examined from 1987 to 1999 for lesions and parasites.
Abstract: Stomachs from subadult male northern fur seals (SAMs) (Callorhinus ursinus) (n = 5,950) from St. Paul Island, Alaska, were examined from 1987 to 1999 for lesions and parasites. On gross examination of these stomachs, parasite nodules were evident in 92% of the stomachs and active and healing ulcers were found in 14% and 10%, respectively. Prevalence of nematodes from 1987 to 1997 was 88% for 5,700 SAMs for which numbers of parasites were estimated but not identified to the genus level. All nematodes recovered from 250 SAMs examined in 1998 (n = 124; 99% infected) and in 1999 (n = 126; 91% infected) were identified and counted. Prevalences in 1998 and 1999 were 5% and 0% for Anisakis spp., 52% and 18% for Contracaecum spp., and 96% and 89% for Pseudoterranova spp., respectively.
16 citations
01 Jan 1998
TL;DR: Molecular studies on anisakid nematodes from the Pacific Boreal region showed that the three taxa detected in this area at the morphological level include at least six reproductively isolated biological species: Anisakis simplex sensu stricto and A. simplex s.
Abstract: Molecular studies were carried out on anisakid nematodes from the Pacific Boreal region, causal agents of human anisakiosis. Genetic markers showed that the three taxa detected in this area at the morphological level include at least six reproductively isolated biological species: Anisakis simplex sensu stricto and A. simplex C, belonging to the A. simplex complex; Contracaecum osculatum A, belonging to the C. osculatum complex; and Pseudoterranova decipiens B, P. bulbosa, and P. azarasi, belonging to the P. decipiens complex. Molecular keys for their routine identification are provided. Genetic relationships among members of the A. simplex, C. osculatum, and P. decipiens complexes are given by unweighted pair group cluster analysis (UPGMA) and multidimensional scaling ordination (MDS). Intermediate/paratenic fish hosts and definitive marine mammal hosts recorded for the considered species are provided: these are benthic-benthopelagic for A. simplex s. s. and C. osculatum C, and specialized benthic for P. bulbosa and P. azarasi. Maps are given showing collecting locations and geographic range of the species studied.
13 citations
TL;DR: Two morphometric keys are proposed for the identification of the three species within Pseudoterranova decipiens (Nematoda: Ascaridida), a parasitic in the digestive tract of seals.
Abstract: Univariate and multivariate statistical analyses have been performed on 19 morphometric variables of adult male specimens belonging to three genetically identified species within Pseudoterranova decipiens (Nematoda: Ascaridida) parasitic in the digestive tract of seals. Two morphometric keys are proposed for the identification of the three species. One key, which uses two variables, determines a frequency of error of 3.8% (3/79). The second key, which uses two canonical discriminant functions based on seven variables previously selected with a “stepwise” procedure, gives 100% (76/76) accurate classification.
11 citations
01 Jan 2011
11 citations