Nematode Anisakis Research Articles

Seroreactivity to Anisakis spp. in the perinatal period.

This study had sought to assess the seroreactivity to the fish nematode Anisakis spp. in a puerperal population, as well as to ascertain whether a correlation exists between maternal and cord blood levels. Blood samples were obtained from puerperal women and cord blood to measure specific anti-Anisakis antigen IgG and IgE by ELISA. Non-parametric tests were used to compare two or more independent and related samples. Of the 99 maternal serum samples assessed, 21 were positive on ELISA (21.2%). There were no significant differences in the mean ranks of IgG optical density levels between women who ate fish and those who did not (p = 0.456), those who ate raw fish and those who did not (p = 0.479), or between those who had allergic complaints and those who did not (p = 0.431). Transplacental passage of antibodies occurred, leading to moderate correlation between maternal and cord blood serum levels.

Parásitos del pez luna Mola mola (Pisces: Molidae). Primer registro en aguas de la costa centro sur de Chile

In this study, we report parasitological findings in one Mola mola specimen examined and collected as by catch-off Tome, south central Chile, during october 2014. Adult stages of digeneans, Accacladium serpentulum and Accacladocoelium macrocotyle, cestode Anchistrocephalus microcephalus, and copepod Cecrops latreillii were isolated. Besides, at the larval stage, the third larval stage (L3) of nematode Anisakis sp. Type I, sensu Berland, 1961, and plerocerci larvae of cestode Molicola horridus were also observed. The results demonstrated the participation of M. mola as a definitive and intermediate or paratenic host in the life cycles of different parasites identified in the present study.

The parasite community of Phycis blennoides (Brünnich, 1768) from the Balearic Sea in relation to diet, biochemical markers, histopathology and environmental variables

The greater forkbeard Phycis blennoides is a benthopelagic fish distributed in the Mediterranean and NE Atlantic. The main goal of this study is to describe the complete parasite community of this species, which is at present unknown. A total of 188 specimens of P. blennoides were captured in the Balearic Sea (NW Mediterranean Sea) at 550–1250m depth during the four seasons of 2007, in summer of 2010 and in summer and autumn of 2011 at five distinct localities off the mainland slope off Catalonia coasts and off the insular slope off the Balearic Islands. Environmental and fish biological, parasitological, dietary, enzymatic and histological data were obtained and the relationships among them tested. A total of 20 different parasites were recovered, of which 11 constitute new host records. The most important parasites were the monogenean Diclidophora phycidis, the digeneans Bathycreadium brayi and Lepidapedon spp., the nematodes Capillaria gracilis, Collarinema collaris, Cucullanus sp. and Hysterothylacium aduncum, and the copepod Clavella alata. Overall, the parasite community of P. blennoides was characterized by high abundance, richness and diversity. Significant differences in the structure of the parasite community were detected between samples from <1000 to >1000m depth and between samples from off the mainland and insular slopes. Significant seasonal and/or geographical differences were found for some specific parasites. Abundance of the nematode C. collaris was associated to high levels of turbidity and O2 concentrations near the bottom. Abundances of H. aduncum, D. phycidis, B. brayi and Lepidapedon spp. were linked to high near-bottom temperature and salinity. Dietary analyses evidenced the role as potential intermediate hosts in parasite transmission by some prey (e.g. the teleost Gaidropsarus biscayensis for the cestode Grillotia cf. erinaceus and the nematodes Anisakis spp. or the euphausiid Meganyctiphanes norvegica for the acanthocephalan Echinorhynchus sp.). While the abundance of B. brayi, C. collaris, Cucullanus sp. and Echinorhynchus sp. was negatively linked to acetylcholinesterase activity (AChE), the abundance of Echinorhynchus sp. and H. aduncum correlated positively with lipid peroxidation levels. Cysts of unknown etiology in fish gills were detected at higher prevalence than in any other fish from the same area. Number and area of hepatic macrophage centres varied significantly among seasonal and geographical groups and seemed not significantly influenced by parasite infection levels.

Cytokine Profile in Patients Infected with Anisakis simplex in Endemic Areas: Dietary Intervention with Polyphenols: A Working Hypothesis.

Anisakiasis is a zoonosis due to infection with the nematode Anisakis (A.) simplex. Humans represent an accidental host after ingesting raw fish infected with A. simplex. A. simplex larvae lead to a robust host immune response mostly at gastro-intestinal level and, usually, T helper (h)2 lymphocytes play a protective against this nematode. However, larvae can elude immunity triggering activation of T regulatory (Treg) cells, which, in turn, suppress Th2 responses via production of interleukin (IL)-10. According to our own experience in the area of Bari (south Italy) where anisakiasis is endemic, chronic urticaria (CU) is very often associated to A. simplex infection. The cytokine profile in CU patients with Anisakis infection is characterized by an elevated release of interferon-γ and IL-17, while IL-10 production is very low. This pattern of pro-inflammatory cytokine response was consistently detectable in patients who underwent a raw fish free diet regimen over a period of six months. In the light of the above considerations, we hypothesize that treating these patients with polyphenols it may be beneficial in terms of activation of Treg cell function. In fact, polyphenols have the capacity to expand Treg cell response in vitro. In this regard, activation of human Treg cells, by analogy to other helminthiasis, may lead to a reduction of allergic/inflammatory reaction in the course of human anisakiasis.

Endoparasitic Diseases in Relation to Heavy Metal Pollution among Some Marine Fishes in Port-Said Governorate

This study was carried out to detect the endoparasites affecting Pomatomus saltatrix, Caranx rhonchus,Platycephalus indicus and Epinephelus aeneus collected from Port Said Province at different seasons. The highest infestation rate was in P. saltatrix(89%) followed by C. rhonchus (75%), P. indicus(68%) and E. aeneus (57%). The isolated parasites were represented as nematodes (Anisakis simplex, Hysterothylacium aduncum and Philometra saltatrix), cestodes (Plerocercoides of Scolex pleuronectis) and acanthocephalan parasites (Andracantha tandemtesticulata and Hesterosentismongcia). Seasonal prevalence, detection of iron, lead and copper in water and histopathological picture were also recorded and discussed.

Eumetazoan parasites of two marine fish species from Baja California, Mexico:Sebastes miniatus(Jordan &amp; Gilbert, 1880) andCaulolatilus princeps(Jenyns, 1840)

It is hypothesized that two fish species sharing a same demersal habitat might show a similar community of parasites. The aim of this study was to compare the parasite community component of of two marine fishes on the northwest coast of México of economical interest, the vermilion rockfish Sebastes miniatus and the ocean whitefish Caulolatilus princeps. From February to December 2005, 210 specimens of S. miniatus (85–550 mm total length TL) and 91 C. princeps (85–550 mm TL) were obtained from the San Quintín sportfishing catch, at Pacific Baja California. Skin, eyes, fins and gill cavity were examined in situ, and their internal organs removed for later analysis, including a portion of flesh. In S. miniatus, 12 parasite taxa were identified as belonging to Monogenea, Digenea, Cestoda, Nematoda, Acanthocephala and Copepoda; the stomach, pyloric caeca, and intestine (digestive tract) were the most parasitized organs with seven of the 12 species. In S. miniatus, the most abundant parasite was Parabothriocephalus sagitticeps (80.8 individuals/host ± 33.4 SE: standard error), highest prevalence was Microcotyle sebastis (92.6%), and the highest average intensity of infection was the cestode P. sagitticeps (190.4 ± 48.1 SE). The C. princeps showed six species belonging to Monogenea, Digenea, Nematoda and Copepoda; the digestive tract presented the greatest infestation, with four of the six species recorded. The most abundant nematode was Hysterothylacium aduncum (16.5 ± 3.5 individuals/host), the main prevalent species was Anisakis sp., and the highest value of infection intensity was by Hatschekia sp. The nematodes Anisakis sp. and H. aduncum were shared between the two host fishes, and are a zoonotic risk to humans if the fishes are not cooked properly.

Inactivation of Anisakis simplex L3 in the flesh of white spotted conger (Conger myriaster) by high hydrostatic pressure and its effect on quality

ABSTRACTKoreans consume much seafood; the country is surrounded on the east, west and south by the sea. Koreans have eaten raw sashimi for a long time. However, a concern in the raw sea food industry is that the parasitic nematode Anisakis simplex L3 occurs naturally in marine fish. Thus, the fishery industry needs a non-thermal processing method. High hydrostatic pressure (HPP) has been demonstrated to be effective. White spotted conger flesh containing 20 live larvae was exposed to different pressures (150 and 200 MPa for 1 and 5 min; 250 and 300 MPa each for 1 min). The viability of A. simplex L3 was significantly (p < 0.05) reduced in the flesh of white spotted conger by the stepwise increase of high pressure and time. The conditions required to eliminate A. simplex L3 were as follows: 200 MPa for 5 min or 300 MPa for 1 min. The flesh of the white spotted conger treated at 300 MPa for 1 min was whiter and yellower than untreated controls or that treated at 200 MPa for 5 min. No significant changes (p > 0.05) in any of the Hunter colour (‘L’, ‘a’ and ‘b’) values were found after HPP at 200 MPa for 5 min. The fresh treated at 300 MPa for 1 min scored < 4.0 (the defect limit of quality) of flavour, texture and overall acceptability in untrained sensory evaluation using a seven-point hedonic scale. However, the flesh treated at 200 MPa for 5 min scored > 5.0 (‘like’) for all sensory parameters. This study suggested that HPP at 200 MPa for 5 min could potentially be used for the inactivation of A. simplex L3 in raw fishery food products without any concomitant changes in their colour or sensory qualities.

Molecular Cloning and Expression of a New Major Allergen, Ani s 14, from Anisakis simplex.

The nematode Anisakis simplex is a representative parasite infecting marine animals. When third stage larvae of A. simplex infecting fish and squids are ingested by humans, individuals previously sensitized by this parasite may experience IgE-mediated allergic reactions. So far, as many as 13 kinds of proteins (Ani s 1-13) have been identified as A. simplex allergens but several more unknown allergens are suggested to exist. In this study, therefore, chemiluminescent immunoscreening of an expression cDNA library constructed from the third stage larvae was conducted to identify a new allergen. As a result, an IgE-positive clone coding for a 23.5 kDa protein (named Ani s 14) composed of 217 amino acid residues was isolated. The regions 4-147 and 34-123 of Ani s 14 share 31% identity with the region 796-940 of Ani s 7 and 32% identity with the region 2-91 of Ani s 12, respectively. Recombinant Ani s 14 was successfully expressed in Escherichia coli as a His-tagged protein and shown to be IgE reactive to 14 (54%) of 26 sera from Anisakis-allergic patients. In conclusion, Ani s 14 is a new major allergen of A. simplex that is specific to Anisakis-allergic patients.

Clinical Presentation of Gastrointestinal Anisakiasis: A Comparison Between Gastric and Small Intestinal Anisakiasis

Introduction: Today sushi is popular in many countries. However, some fish harbor the nematode Anisakis simplex, which often causes damage to the gastrointestinal tract when ingested. In this study, we elucidated differences in the clinical features and treatment methods between the two types of anisakiasis. Methods: Subjects were 29 patients who were diagnosed with gastric or intestinal anisakiasis at Kyorin University Hospital between April 2012 and March 2015. Gastric anisakiasis was diagnosed upon confirmation of the nematode on upper gastrointestinal endoscopy. Intestinal anisakiasis was diagnosed based on the seroprevalence of anti-Anisakis IgE antibodies. The clinical features and treatment methods noted in the medical records were retrospectively compared between the groups. Results: One patient had anisakiasis infection in both the stomach and small intestine. The clinical picture of 14 patients with gastric anisakiasis alone was (1) 41 years of age(mean), (2) 1.4 days between the consumption of fish and hospital visit(mean), (3) 0.1 mg/dl of C-reactive protein (CRP) at initial examination(mean), (4) no ascites accumulation in any of 8 patients who had undergone computed tomography (CT), and (5) no hospital admission. The clinical picture of 14 patients with intestinal anisakiasis alone were (1) 56 years of age(mean), (2) 2.1 days between fish consumption and hospital visit(mean) (a history of fish consumption was unclear in 1 patient), (3) 4.8 mg/dl of CRP at initial examination(mean), (4) ascites accumulation in 11 of the 14 patients who had undergone CT, and (5) hospital stay of 9.4 days. With regard to treatment methods, the nematode was endoscopically removed in patients with gastric anisakiasis. Whereas we did not find the nematode in the small intestine in any of the patients. To treat ileus, neither gastric tube nor ireus tube were needed in 7 patients. Conclusion: Comparison of the two groups showed that patients with gastric anisakiasis tended to be young and have early onset, whereas those with intestinal anisakiasis were characterized by ascites accumulation and CRP positivity. CT was useful in the diagnosis of the latter group. Half the patients with intestinal anisakiasis did not require decompression of the intestinal tract, but all patients were required for hospitalization. For diagnosis of gastrointestinal anisakiasis, it was proved that clinical history taking, CRP, serum Anisakis IgE antibody testing, and CT was useful.

Parasitation of sea trout (Salmo trutta trutta L.) from the spawning ground and German coastal waters off Mecklenburg-Western Pomerania, Baltic Sea.

A total of 52 sea trouts, Salmo trutta trutta, were studied for parasites, originating from German freshwater streams and coastal waters of the Baltic Sea. While 35 specimens were caught mainly close to the shoreline in the Baltic Sea, 17 were sampled during their spawning migration in Warnow River and other neighboring rivers in Mecklenburg-Western Pomerania. A total of 12 different metazoan parasite species were found in sea trout originating from the Baltic Sea, including five digeneans, two cestodes, three nematodes, and two acanthocephalans. Marine and freshwater species were found. In the migratory trout, seven different parasite species were recorded (one digenean, two cestodes, one nematode, and one acanthocephalan), demonstrating lower parasite diversity and load during the spawning migration compared with the fish from the Baltic Sea. The anisakid nematodes Anisakis simplex (sensu stricto), Contraceacum rudolphii, and Hysterothylacium aduncum were identified by molecular analyses of the ITS-1, 5.8S, ITS-2, and flanking sequences of the rDNA. Together with the digenean Derogenes varicus, Hemiurus communis and H. luehei, and the cestode Diphyllobothrium dendriticum seven new host records for sea trout from the German part of the Baltic Sea are made.

Role of biogenic amines in the post-mortem migration of Anisakis pegreffii (Nematoda: Anisakidae Dujardin, 1845) larvae into fish fillets

Infective third-stage larvae (L3) of nematode Anisakis spp. have been recognized as one of the major food-borne threats in lightly processed fish products in Europe, particularly in the Mediterranean region. Therefore, the effect of different storage temperatures of fish on larval post-mortem migration from visceral cavity into fillets is an important parameter to take into account when evaluating the risk for consumer safety. The European anchovy (Engraulis encrasicolus) were caught during fishing season, a subsample of fillets was checked for the presence of Anisakis larvae at capture (mean abundance=0.07), and the rest was stored at four different temperatures (−18, 0, 4 and 22°C) in order to count migrating larvae and measure the production of biogenic amines over a period of time. Larvae were identified by morphological features and molecular tools. Post-mortem migration was observed in fillets stored at 0 and 4°C after three and five days, respectively, but not at 22 and −18°C. In case of storage at 22°C for two days, at the onset of putrefaction of the visceral organs, larvae migrated out of the visceral cavity towards the fish surface. Measured pH and biogenic amine profile during storage indicated that certain biochemical conditions trigger larval migration into fillets. Likewise, migration was observed at pH ~6.4 when sensory degradation of the fish was markedly visible. Although larval migration was delayed for approximately four days at a temperature of <4°C the correlation between pH and abundance of A. pegreffii larvae in the fillet was high and statistically significant at both 0 (r=0.998, p<0.01) and 4°C (r=0.946, p<0.05). Out of eight biogenic amines measured, cadaverine and putrescine levels correlated the most with the post-mortem migration at 4°C, while tyramine levels were significant at both temperatures.

Expression patterns and structural modelling of Hsp70 and Hsp90 in a fish-borne zoonotic nematode Anisakis pegreffii

Heat shock proteins (HSPs) are essential molecular chaperones that are highly conserved across organisms. They have a pivotal function in responding to thermal stress and are responsible for many cellular functions. Here, we aimed to elucidate the possible roles of Hsp70 and Hsp90 in the life cycle of the parasitic nematode Anisakis, particularly third- and fourth-stage larvae, from cold-blooded fish to warm-blooded marine mammals or accidentally to human hosts. We examined the expression profiles of Hsp70 and Hsp90 in different developmental stages of Anisakis pegreffii. The open reading frame of Hsp70 of A. pegreffii was 1950bp, and deduced amino acid sequence showed high homology with those of other nematodes. Heatmap analysis revealed sequence identity of Hsp70 and Hsp90 in 13 important parasitic species, human and yeast. On heatmap and phylogenetic analysis, ApHsp70 and ApHsp90 shared the highest amino acid sequence identity with other nematodes and formed a monophyletic clade. The three-dimensional (3D) structure prediction of the newly characterized ApHsp70 and known ApHsp90 gene showed highly conserved motifs between A. pegreffii and other species. Quantitative real-time PCR and western blot analysis revealed higher mRNA and protein expression for ApHsp70 and ApHsp90 in fourth- than third-stage larvae, with higher mRNA and protein expression for ApHsp70 than ApHsp90. ApHsp70 and ApHsp90 may play important roles in Anisakis in response to thermal stress and might be important molecules in the development of A. pegreffii, which has implications for its control.

The rate of infection of the Pacific herring Clupea pallasii Valenciennes, 1847 (Clupeiformes: Clupeidae) with larval Anisakis simplex (Rudolphi, 1809) (Nematoda: Ascaridata)

Data on the interannual and seasonal variations in the rate of infection of Pacific herring with larval nematodes Anisakis simplex in some waters of the Far Eastern seas are considered. A total of 5076 fish were examined. An analysis of dynamics in the infection rate showed its reduction from the spawning to feeding seasons. The relative abundance of infected fish that remained after spawning is estimated for various waters. The ways in which parasites are removed from fish and also the level of threat that this infection poses to humans are discussed.

Updates on Aquatic Parasites in Fisheries: Implications to Food Safety, Food Security and Environmental Protection

Cheap protein sources from fishery products comes from both capture fishery and aquaculture industries. Despite the available technologies that help increase wild catch and aquaculture production, our food security is being threatened by several factors including parasitic infections. Zoonotic parasites infecting our fishery products are one of the several concerns in our food safety. Among these include the infections with the nematode Anisakis among marine fishes and cephalopods causing human anisakiasis and/or allergy-associated health risks, the nematode Gnathostoma causing gnathostomiasis, and food poisoning due to the myxozoan infection of the genus Kudoa. On the other hand, the increasing human population, dwindling fish catch from the wild, degradation of aquatic environment, and declining or slow growth of aquaculture sector due to parasitic diseases are all posing global threat to the security and sustainability of fish supplies. The wild fish populations are affected by the parasitic diseases that directly and indirectly affect fish reproduction, growth and survival, whereas intensifications of aquaculture operations cause fish health problems associated to parasitic diseases resulting to decline in production. Despite these negative impacts of parasites, there are several parasite groups that are used as biological indicators for food chain structure, heavy metal contamination, environmental pollutions and fish stock assessment (i.e., nematodes Anisakis, Hysterothylacium, Anguillicola, Spirophilometra, Raphidascaris and Philometra; acanthocephalans Pomphorhynchus, Serrasentis and Acanthocephalus; cestodes Bothriocephalus, Monobothrium and Ligula; monogenean Pseudorhabdosynochus; and digenean Didymodiclinus), as well as reducer of heavy metal accumulation in the body of their host fish (i.e., acanthocephalans Pomphorhynchus and Acanthocephalus). The use of these parasites for proper management of fishery resources can be of help in addressing food safety, fish security and food sustainability while at the same time managing our fishery resources. As we are addressing these global issues, these parasites that we are considering as threat can be of useful value to attain sustainable development.

Pathogenic potential of two sibling species, Anisakis simplex (s.s.) and Anisakis pegreffii (Nematoda: Anisakidae): in vitro and in vivo studies.

The pathogenic potentials of two sibling nematodes Anisakis simplex sensu stricto (s.s.) and A. pegreffii were compared by in vitro and in vivo studies. Live third-stage larvae of each species were subjected to agar blocks made using PBS or RPMI-1640, overlaid with different supernatants (artificial gastric juice, PBS, and RPMI-1640), and their penetration ability was compared. Their tolerance of artificial gastric juice was also tested. Further, they were introduced into rats by gastric intubation, and the in vivo locations of them were investigated. A. pegreffii showed higher penetration ability than A. simplex (s.s.) in most of the experimental conditions, except for the RPMI-1640 agar block overlaid with artificial gastric juice. In an acid tolerance test, the mean survival times were 6.1 days for A. simplex (s.s.) and 4.2 days for A. pegreffii. In an animal experiment, A. simplex (s.s.) stayed for a shorter time in the stomachs of rats than A. pegreffii. Some A. pegreffii and A. simplex (s.s.) were embedded in the gastric mucosa or freely existed in the abdominal cavity. All of these results suggest that A. pegreffii has the pathogenic potential to cause anisakidosis in humans when ingested, as does A. simplex (s.s.).

Anisakis Infection and Allergy in Humans

Compared with other well-studied parasitic diseases, fish-borne parasitic zoonoses do not get enough attention, especially because these zoonoses have been limited for the most part to populations living in low- and middle-income countries in Europe. Human fishery product-borne parasitic diseases caused by nematodes are the results of infection following ingestion of viable parasites, or as allergic reactions against parasite antigens. With the globalization of the seafood industry, the risk of humans acquiring anisakiasis in developed countries appears to be underestimated. For allergy, the only implicated parasite in fishery products is the nematode Anisakis simplex.

A man with unsuspected marine eosinophilic gastritis

A 49-year-old man with a history of hypertension and type 2 diabetes mellitus was referred for an internal medicine consultation because of worsening heartburn for the past 3 months. The patient regularly ate pickled anchovies (raw anchovies in vinegar sauce). His overall health was good, and fi ndings from physical examination were unexceptional. Laboratory results showed peripheral eosinophilia (1·7 × 103 cells per μL, normal 0·5 × 103 cells per μL) but were otherwise unremarkable. Upper gastrointestinal endoscopy showed characteristic fi ndings of gastro-oesophageal refl ux disease and Barrett’s oesophagus (confi rmed by pathological study); an isolated, thickened gastric fold (which was biopsied; fi gure); and no macroscopic evidence of erythema, oedema, erosive gastritis, ulcerations, tumour-like nodules, or worms. Nevertheless, histological assessment showed a striking eosinophilic infl ammatory infi ltrate and a sectioned larva of the nematode Anisakis simplex embedded in the gastric mucosa (fi gure). Additionally, serum IgE specifi c for A simplex was increased. We gave the patient omeprazole to treat his gastro-oesophageal refl ux disease and specifi c preventive recommendations to avoid ingestion of potentially contaminated seafood (eg, by freezing or suitably heating fi sh) and decrease the risk of anaphylaxis due to A simplex. 10 months after the diagnosis of anisakidosis was made, his blood eosinophil count was within normal limits, and both gastroscopy and examination of gastric biopsy samples showed no abnormalities. Anisakidosis, a disease caused by any member of the family Anisakidae that occurs worldwide, usually results from consumption of raw or undercooked marine fi sh or squid contaminated with the larvae of A simplex or Pseudoterranova decipiens. Although symptomatic gastrooesophageal, intestinal, ectopic, and allergic diseases are the most common clinical presentations in human beings, this case shows that symptomless eosinophilic gastritis with secondary eosinophilia can also develop. In view of the popularity of raw seafood consumption, clinicians should keep anisakidosis high on their list of diff erential diagnoses for a wide range of disorders, especially in patients known to have these dietary habits. Lancet Infect Dis 2015; 15: 248

Detection of Proteins from the Fish Parasite Anisakis simplex in Norwegian Farmed Salmon and Processed Fish Products

Wild-caught marine fish are potentially carrying parasites. Larvae of the nematode Anisakis simplex (herring or whale worm) occur in almost all commercially exploited fish stocks in temperate seas. The presence of A. simplex in fish and fish products is not only an economic concern but represents a significant consumer health risk. Anisakiasis, human infection with live larvae, can occur by consuming raw or undercooked fish while allergy symptoms can also be elicited by the presence of A. simplex proteins in processed seafood. The European Food Safety Authority (EFSA) has concluded in a scientific opinion that routine testing of seafood products for A. simplex is needed. In the present study, we have determined A. simplex proteins in farmed salmon intended for use in sushi and fish products from the Norwegian market by quantitative sandwich ELISA, immunostaining and mass spectrometry. Analytical methods detecting anisakid proteins at the single-digit milligram level appear to be sufficiently sensitive for the protection of allergic consumers. Only trace amounts (<10 mg/kg) were detected in a few samples showing that contamination with A. simplex is apparently not an immediate health problem given the results from this survey.

Characterisation of potential novel allergens in the fish parasite Anisakis simplex

The parasitic nematode Anisakis simplex occurs in fish stocks in temperate seas. A. simplex contamination of fish products is unsavoury and a health concern considering human infection with live larvae (anisakiasis) and allergic reactions to anisakid proteins in seafood. Protein extracts of A. simplex produce complex band patterns in gel electrophoresis and IgE-immunostaining. In the present study potential allergens have been characterised using sera from A. simplex-sensitised patients and proteome data obtained by mass spectrometry. A. simplex proteins were homologous to allergens in other nematodes, insects, and shellfish indicating cross-reactivity. Characteristic marker peptides for relevant A. simplex proteins were described.

Changes in the Anatomical Organization ofContracaecum multipapillatumL3 sensu lato (Nematoda: Anisakidae) Larvae Subjected to Different Culinary Treatments in La Paz, Baja California Sur, Mexico

Anisakidosis is a disease caused by the nematodes Anisakis simplex, Pseudoterranova decipiens (sensu lato), Contracaecum sp., and Hysterothylacium following larval consumption in raw or undercooked fish. The mullets Mugil curema and Mugil cephalus along the coast of La Paz, Baja California Sur, Mexico, have high prevalences and mean intensities of Contracaecum multipapillatum sensu lato L3 larvae, which could increase the risk of acquiring the disease for people eating ceviche (raw fish marinated in lemon juice) or undercooked fish tacos. This study shows the effects of different culinary treatments on the anatomical organization of C. multipapillatum s. lat. L3 larvae. We collected 709 larvae from 58 M. curema from Estero Zacatecas and Balandra. Groups of nematodes were exposed to different treatment regimes involving storage in pure lemon juice, 4% acetic acid (vinegar), and 0.9% saline solution at room temperature, or refrigeration, and fillets were cooked in a microwave oven, cooked foil wrapped, or fried on a conventional stove. We observed fish frozen at −20°C to −30°C that were destined for supermarket distribution. Helminths survived from 2 to 40 d, except those that were subjected to cooking and freezing, which died immediately. Treatments with lemon, vinegar, and cooking caused more serious lesions and anatomical disruption, which could decrease infectivity of the larvae when exposure time to these treatments lasted more than 2 d. Since fish meat preparation and exposure time to lemon or vinegar are typically from 8 to 10 hr, nematode viability might not be affected in case of accidental ingestion. Therefore, it is recommended to either cook fish or freeze them at −20°C to −30°C for more than 1 wk prior to ingestion.