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At least 19 recordsLinked to original sources
PubMed2001

Genetic divergence and reproductive isolation between Anisakis brevispiculata and Anisakis physeteris (Nematoda: Anisakidae)s.

In order to assess the taxonomic status of Anisakis brevispiculata Dollfus, 1966 population samples of this taxon from central and south-eastern Atlantic ocean were compared at 22 enzymatic loci with samples belonging to Anisakis physeteris Baylis, 1923 from the Mediterranean sea and central-eastern Atlantic ocean. Very low interpopulational genetic divergence was observed both within A. brevispiculata (average D(Nei) = 0.008) and within A. physeteris (D(Nei) = 0.009) despite the geographic distance among the samples, indicating high levels of gene flow in both taxa. On the other hand, the average genetic distance between A. brevispiculata and A. physeteris was found to be D(Nei) = 0.80, a value generally observed between well differentiated congeneric species. The reproductive isolation between A. brevispiculata and A. physeteris is indicated by the following observations: (1) no F(1) hybrids or recombinant genotypes were until now observed; and (2) the two Anisakis species do not seem to share their definitive hosts. The main definitive host of A. brevispiculata is the pygmy sperm whale (Kogia breviceps), while for A. physeteris it is the sperm whale (Physeter catodon). Only adult males differ slightly in spicule length, while females and larval stages are not differentiated morphologically. Both A. brevispiculata and A.physeteris show a type II larva. The correct recognition of A. brevispiculata from A. physeteris and from other Anisakis species studied, in either sexes and at any life stage, is made easy by allozyme markers (e.g. Icdh, Gapdh, Sod-1, Np, Aat-2, Adk-2, fEst-2, PepB, PepC-2, Mpi). Diagnostic keys, which can be used for routine identification in the field of these Anisakis worms, based on genetic markers, are given.

Animals↗
PubMed2002

Genetic markers in the study of Anisakis typica (Diesing, 1860): larval identification and genetic relationships with other species of Anisakis Dujardin, 1845 (Nematoda: Anisakidae).

Genetic variation at 21 gene-enzyme systems was studied in a sample of an adult population of Anisakis typica (Diesing, 1860) recovered in the dolphin Sotalia fluviatilis from the Atlantic coast of Brazil. The characteristic alleles, detected in this population, made it possible to identify as A. typica, Anisakis larvae with a Type I morphology (sensu Berland, 1961) from various fishes: Thunnus thynnus and Auxis thazard from Brazil waters, Trachurus picturatus and Scomber japonicus from Madeiran waters, Scomberomorus commerson, Euthynnus affinis, Sarda orientalis and Coryphaena hippurus from the Somali coast of the Indian Ocean, and Merluccius merluccius from the Eastern Mediterranean. Characteristic allozymes are given for the identification, at any life-stage and in both sexes, of A. typica and the other Anisakis species so far studied genetically. The distribution of A. typica in warmer temperate and tropical waters is confirmed; the definitive hosts so far identified for this species belong to delphinids, phocoenids and pontoporids. The present findings represent the first established records of intermediate/paratenic hosts of A. typica and extend its range to Somali waters of the Indian Ocean and to the Eastern Mediterranean Sea. A remarkable genetic homogeneity was observed in larval and adult samples of A. typica despite their different geographical origin; interpopulation genetic distances were low, ranging from D(Nei)=0.004 (Eastern Mediterranean versus Somali) to D(Nei)=0.010 (Brazilian versus Somali). Accordingly, indirect estimates of gene flow gave a rather high average value of Nm = 6.00. Genetic divergence of A. typica was, on average, D(Nei)=1.12 from the members of the A. simplex complex (A. simplex s.s, A. pegreffii, A. simplex C) and D(Nei)=1.41 from A. ziphidarum, which all share Type I larvae; higher values were found from both A. physeteris (D(Nei)=2.77)

Alleles↗
PubMed1978

Anisakis and eosinophil. I. Detection of a soluble factor selectively chemotactic for eosinophils in the extract from Anisakis larvae.

Studies were undertaken in order to determine if Anisakis larva itself has the ability to attract eosinophils. Extracts from Anisakis larvae were examined for both neutrophil and eosinophil chemotactic activities with both in vivo and in vitro assay systems. When the soluble extract was injected intradermally into normal guinea pigs, a profound accumulation of eosinophils was observed at the injection site. The cells started to accumulate at the site within 1 hr and the number of eosinophils at the site reached its peak at 8 hr after the injection of the extract. Such eosinophilic accumulation was enhanced in a dose-response fashion over the range of 0.5 to 50 micrograms protein. The strong chemotatic activity of the Anisakis extract for eosinophils was confirmed when in vitro chemotaxis assays were performed with Boyden chemotatic chambers. Interestingly, no chemotactic activity for neutrophils was found at those concentrations of the extract with which the eosinophil effect was observed. These results indicate that the factor described here, in addition to the various known immunologic factors, may play an important role in the development of eosinophilia in anisakiasis.

Animals↗
PubMed2004

Evaluation by the skin prick test of Anisakis simplex antigen purified by affinity chromatography in patients clinically diagnosed with Anisakis sensitization.

Anisakis simplex crude extracts (CE) (IPI, ASAC and ALK-ABELLO), A. simplex larval antigens purified using a column of IgG anti-A. simplex (PAK) or a column of IgG anti-Ascaris suum (PAS), antigen eluted from columns of IgG anti-A. suum (EAS) and an A. suum adult CE were assayed by the skin prick test. Thirty percent of assayed patients showed a negative reaction in the Anisakis skin prick test. Of 70% positives, two patients had a weal greater than that produced by histamine with the A. simplex extract from ABELLO and IPI. The A. suum skin prick test was positive in 35% of patients, with a lower reaction than that observed with the A. simplex extract from IPI in 57% of the sera and a higher reaction in 28% of the sera. All patients with positive reactions with the crude extract also showed positive weals with the two purified antigens, PAK and PAS. All patients, except three, with a reaction to A. suum antigen, were positive to the EAS antigen. In five patients the weal size produced by PAS was greater than that observed with PAK, whereas in another six patients the contrary was observed. Only one of these six patients did not react to EAS antigen, coincident with the patient showing only a slight increase (7%) in the weal size induced by PAK vs. PAS. When the EAS antigen was tested on patients positive to both PAK and PAS, six patients presented a weal size of >30% and only three patients who were positive to PAS did not react to the EAS antigen. These three patients were also negative against the A. suum CE. Purification by affinity chromatography eliminates from the PAS antigen the proteins responsible for producing cross-reactions with Ascaris (present in the EAS antigen).

Adolescent↗
PubMed1986

Genetic structure of Anisakis physeteris, and its differentiation from the Anisakis simplex complex (Ascaridida: Anisakidae).

The genetic structure of Anisakis physeteris from the Mediterranean Sea has been analysed electrophoretically at 22 enzyme loci. The samples studied, although differing in the life-stage (larvae and adults), and in the host (the fishes Micromesistius poutassou and Trachurus trachurus, and the sperm whale Physeter macrocephalus) were genetically homogeneous. Of these loci 11 (Ldh, Sod, Np, Adk-2, Pgm-1, Est-1, Est-2, Acph-1, Acph-2, Lap-2 and Ca) were found to be monomorphic, while the other 11 (Sdh, Mdh, Idh, 6-Pgdh, G3pdh, Got, Adk-1, Pgm-2, Lap-1, Mpi and Gpi) showed from 2 to 7 alleles. The following values of genetic variability were estimated: He = 0.11, P = 0.50, A = 1.95. Distinct alleles were found between A. physeteris and the A. simplex complex at 19 out of the 22 loci studied, and only few rare alleles were shared at the remaining 3 loci. The genetic divergence between A. physeteris and A. simplex A and B is therefore very high, the values of Nei's index D being 7.384 and 6.443 respectively (I = 0.001 and 0.002). The assignation of A. physeteris and the A. simplex complex to two distinct subgenera, Skrjabinisakis and Anisakis, as proposed by Mosgovoy on a morphological basis, appears to be fully justified according to our genetic data.

Alleles↗
PubMed2006

Molecular identification of Anisakis simplex sensu stricto and Anisakis pegreffii (Nematoda: Anisakidae) from fish and cetacean in Japanese waters.

Parasites morphologically consistent with Anisakis simplex sensu lato collected from the coast of Japan and Western North Pacific Ocean were examined by PCR-RFLP of the ITS region (ITS1, 5.8 subunit rRNA gene and ITS2) and mtDNA cox1. The RFLP patterns of rDNA generated by HinfI and HhaI showed that 100% of the larvae collected from Hokkaido and 94% of adults collected from Western North Pacific Ocean were identified as A. simplex sensu stricto. On the other hand, 97% of the larvae collected from Fukuoka prefecture were identified as A. pegreffii. A hybrid genotype was found in adults in Western North Pacific Ocean and larva in Fukuoka prefecture. These findings revealed that A. simplexs. str. is primarily distributed in the North Pacific Ocean and A. pegreffii is primarily distributed in the southern Sea of Japan. RFLP analysis of mtDNA cox1 showed different patterns between A. simplex s. str. and A. pegreffii after digestion with HinfI. This polymorphism obtained by RFLP analysis of mtDNA cox1 proved the usefulness as new genetic markers to distinguish two sibling species.

Animals↗
PubMed2003

Occurrence of recombinant genotypes of Anisakis simplex s.s. and Anisakis pegreffii (Nematoda: Anisakidae) in an area of sympatry.

The anisakid nematode populations collected from fish and stranded cetaceans along from Iberian Peninsula waters were morphologically identified as corresponding to the Anisakis simplex complex. In order to realise their molecular identification and to analyse the extent of genetic variation, the entire ITS (ITS1, 5.8S rDNA gene and ITS2) and the mitochondrial small subunit of rRNA were pcr-amplified and sequenced. Digestions of the amplified its region with HinfI and HhaI allowed the identification of three different genotypes, belonging to A. simplex s.s., A. pegreffii and a yet not described recombinant genotype. The ITS sequences of the recombinant genotypes showed the presence of heterozygotes C/T at position 240 and 256 of the aligned sequence. Otherwise, the analysis of mtDNA sequences showed the existence of a different parental origin for recombinant genotypes. In order to check if they can be the products of a polymorphism normally occurring both in A. pegreffii and in A. simplex s.s., and/or the existence of an incomplete concerted evolution, three samples were also collected as controls in isolated geographic areas, where sympatric coexistence between A. simplex s.s. and A. pegreffii does not occur. The results supports the hypothesis that the recombinant individuals may be a product of interspecific hybridisation, and describe the Iberian Peninsula waters as a hybrid zone for the two sibling species.

Animals↗
PubMed1992

The identity of Anisakis type II larvae with Anisakis physeteris confirmed by restriction fragment length polymorphism analysis of genomic DNA.

The identity of Anisakis type II larvae with adult A. physeteris was confirmed by comparison of restriction fragment length polymorphisms (RFLPs) of 25S ribosomal DNA (rDNA). Patterns of RFLPs in larvae were almost identical with those in adult worms. Directly labelled 25S rDNA might serve as an appropriate probe with highly specific activity for examining RFLPs of larvae and adult worms.

Animals↗
PubMedDate not supplied

Anisakis, anisakiasis and IgE-mediated immunity to Anisakis simplex.

Anisakis simplex is a common parasite in fish and cephalopods and is not only capable of causing anisakiasis in humans through visceral invasion of the third-stage larvae but can also cause anaphylactic reactions, as has recently been demonstrated. We present the clinical case of a 56-year-old man who initially presented anaphylactic reactions related to eating fish. Shortly afterwards, he began to experience self-limiting recurrences of very intense epigastric pain, nausea and vomiting. Skin tests for immediate hypersensitivity (prick tests) with a commercial extract as well as the determination of specific IgE in the patient's serum were clearly positive for A. simplex. The hemogram did not show eosinophilia. Copro-cultures and parasites in the patient's feces were repeatedly negative. Gastroscopy was normal. The intestinal tract showed contrast flocculation and dilation of ansas in the distal duodenum and proximal jejunum. Biopsy samples of gastric and distal duodenum mucous showed an active process of chronic inflammation with a predominance of eosinophils in the lamina propria. After subjecting the patient to a fish and cephalopod-free diet and treating him with thiabendazole 350 mg every 12 hours for 6 days, he showed no sign of symptoms while awaiting new tests. Even though the diagnosis of IgE-mediated allergy caused by A. simplex offers no room for doubt, we are unable to present a firm diagnosis of anisakiasis as no larva has been seen. Nevertheless, the clinical pattern, the image of the intestinal tract, the eosinophilic infiltrate in the biopsies and the good response to thiabendazole all lead to the suspected existence of anisakiasis in this patient coexisting with IgE-mediated allergy to this parasite.

Anaphylaxis↗
PubMed2006

Exposure to the fish parasite Anisakis causes allergic airway hyperreactivity and dermatitis.

BACKGROUND: Several case reports show allergy and anaphylactic reactions to the fish parasite Anisakis in the domestic and occupational setting. Further research is needed on the prevalence and mechanisms of disease. OBJECTIVE: To determine the prevalence of Anisakis sensitization and related symptoms among workers in 2 fish-processing factories, and to use gene-deficient mice to determine the working mechanisms of Anisakis allergy. METHODS: A modified version of the European Community Respiratory Health Survey was used to interview 578 South African fish-processing workers. Sensitization to Anisakis, seafood, and common aeroallergens was determined by skin prick test. Lung function was measured by spirometry and methacholine challenge. Serum eicosapentaenoic acid levels were used as an index of seafood consumption. Sensitized wild-type, IL-4, or IL-4 receptor alpha-deficient mice were challenged orally with Anisakis extract. Allergic reactions, lung pathology, antibodies, cytokines, mast cell proteases, and histamine were evaluated. RESULTS: The prevalence of sensitization to Anisakis was higher than the prevalence of sensitization to fish (8% vs 6%). Anisakis-specific IgE reactivity was associated with bronchial hyperreactivity and dermatitis, and significantly increased with fish consumption. In mice, Anisakis infective larvae (L3) induced a striking T(H)2/type 2 response. Food-allergic-type reactions induced by oral challenge with Anisakis extract were absent in IL-4 receptor alpha knockout mice. CONCLUSION: Anisakis sensitization in fish-processing workers is associated with allergic symptoms and correlates with high levels of fish consumption. Anisakis proteins induce allergic reactions in sensitized mice by IL-4/IL-13-mediated mechanisms. CLINICAL IMPLICATIONS: Anisakis allergy should be considered in fish-processing workers with allergic symptoms.

Administration, Oral↗
PubMed2000

Usefulness of currently available methods for the diagnosis of Anisakis simplex allergy.

BACKGROUND: Serodiagnosis of anisakiosis and Anisakis allergy is difficult since many Anisakis antigens show cross-reactivity complications. In the present study, we assess the usefulness of the major immunologic methods currently available for the diagnosis of Anisakis allergy. METHODS: Four tests (skin prick test, CAP-FEIA system, Western blotting, and an antigen-capture ELISA using O-deglycosylated antigen bound by the monoclonal antibody UA3) were applied to Anisakis-free subjects and subjects with confirmed Anisakis allergy. RESULTS: The skin prick test, CAP-FEIA, and the antigen-capture ELISA identified Anisakis allergy sera with 100% sensitivity, while Western blotting showed 96%/ sensitivity. The antigen-capture ELISA also showed 100% specificity, but CAP-FEIA showed a specificity of only 50%. In Western blotting, none of the bands detected were specific for either Anisakis-free or Anisakis allergy subjects. The skin prick test was not applied to the Anisakis-free subjects, so its specificity could not be determined. CONCLUSIONS: On the basis of these results, we suggest that the most appropriate procedure for diagnosis of Anisakis allergy suspected on clinical grounds is the antigen-capture ELISA using UA3, or, alternatively, a preliminary skin prick test with a positive result subsequently confirmed by UA3-ELISA.

Adolescent↗
PubMed2000

O-glycans as a source of cross-reactivity in determinations of human serum antibodies to Anisakis simplex antigens.

BACKGROUND: Anisakis simplex is a seafood-borne parasite that may both infect humans and cause allergy. Serodiagnosis of anisakiasis and allergy caused by this nematode is difficult since most Anisakis antigens show cross-reactivity problems. OBJECTIVE: To analyse the possible role of sugar epitopes contained in Anisakis simplex antigens as causes of false-positive results in serodiagnostic assays. METHODS: The antigens UA2R and UA3R recognized by two anti-Anisakis monoclonal antibodies were used in this study. Capture ELISA techniques were used to compare the reactivities with native or O-deglycosylated antigens of sera from Anisakis-free children (most of them infected by several other parasites) and from Anisakis allergy patients. O-deglycosylation was done by mild alkali treatment with NaOH. SDS-PAGE and immunoblotting were used to characterize the effects of NaOH or N-glycanase F treatment on UA3R. RESULTS: Native UA2R was recognized by IgG1 and IgM antibodies in the sera of both Anisakis-free subjects and allergy patients. Native UA3R was recognized by most sera from allergy patients (92% considering immunoglobulin (Ig) G1, 100% considering IgE), but also by a significant proportion of sera from Anisakis-free subjects (36% considering IgG1, 14% considering IgE). O-deglycosylation of UA3R greatly improved specificity: none of the sera from Anisakis-free patients showed either IgG1 or IgE reactivity with O-deglycosylated UA3R, while the proportion of sera from allergy patients showing IgE reactivity with this antigen was practically unaffected. O-deglycosylation of UA2R did not improve the specificity of assays using this antigen. Our results also show that the protein core of glycoproteins may be altered by even very mild alkali treatment, depending on the nature of the protein. CONCLUSION: Native glycoproteins of A. simplex should not be used for diagnostic purposes. O-deglycosylated UA3R seems to be an excellent candidate for use as target antigen in the serodiagnosis of anisakiasis and A. simplex allergy.

Animals↗
PubMed2005

Evidence for a new species of Anisakis Dujardin, 1845: morphological description and genetic relationships between congeners (Nematoda: Anisakidae).

In the present study, a new biological species of Anisakis Dujardin, 1845, was detected in Kogia breviceps and K. sima from West Atlantic waters (coast of Florida) on the basis of 19 (nuclear) structural genes studied by multilocus allozyme electrophoresis. Fixed allele differences at 11 enzyme loci were found between specimens of both adults and larvae of the new species and the other Anisakis spp. tested. Reproductive isolation from A. brevispiculata Dollfus, 1968 was demonstrated by the lack of hybrid or recombinant genotypes in mixed infections in K. breviceps. Genetic distance of the new species from its closest relative, A. brevispiculata, was D(Nei)=0.79. The new species is morphologically different from the other species which have been genetically characterised and from the other Anisakis retained by Davey (1971) as valid or as species inquirendae: the name of Anisakis paggiae n. sp. is proposed for the new taxon. Anisakis Type II larvae (sensu Berland, 1961) from the European hake Merluccius merluccius in the northeastern Atlantic Ocean (Galician coast) and from the scabbard fish Aphanopus carbo in Central Atlantic waters (off Madeira), were identified as A. paggiae n. sp. Its genetic relationships with respect to the seven species previously characterised (A. simplex (Rudolphi, 1809) sensu stricto), A. pegreffii Campana-Rouget & Biocca, 1955, A. simplex, (A. typica (Diesing, 1860), A. ziphidarum Paggi et al., 1998, A. physeteris Baylis, 1923 and A. brevispiculata) were also inferred. Overall, a low genetic identity was detected at allozyme level between the eight Anisakis species. Interspecific genetic identity ranged from I(Nei)=0.68, between the sibling species of the A. simplex complex, to I(Nei)=0.00 (no alleles shared at the considered loci) when A. physeteris, A. brevispiculata and the new species were compared with the other species of the genus. Concordant topologies were obtained using both UPGMA and NJ tree analyses for the considered species. In both analyses, A. paggiae n. sp. clustered with A. brevispiculata. They also indicated two main clades, the first including A. physeteris, A. brevispiculata and A. paggiae n. sp., the second containing all of the remaining species (i.e. A. simplex (s.s.), A. pegreffii, A. simplex, A. typica and A. ziphidarum). A deep separation between these two main Anisakis clades, also supported by high bootstrap values at the major nodes, was apparent. This is also supported by differences in adult and larval morphology, as well as with respect to their main definitive hosts. A morphological key for distinguishing adult A. paggiae n. sp., A. physeteris and A. brevispiculata is presented. Allozyme markers for the identification of any life-history stage of the Anisakis spp. so far studied, as well as ecological data on their definitive host preferences and geographical distribution, are updated.

Alleles↗
PubMed2005

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

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.

Animals↗