Showing papers on "Anisakis published in 2011"

First molecular identification of the zoonotic parasite Anisakis pegreffii(Nematoda: Anisakidae) in a paraffin-embedded granuloma taken from a case of human intestinal anisakiasis in Italy

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.

Anisakid Nematode (Ascaridoidea) Life Cycles and Distribution: Increasing Zoonotic Potential in the Time of Climate Change?

Abstract: Parasitic nematodes are known as important pathogens that cause problems for human and animal health. Some of them naturally inhabit the marine environment, where they are widespread and can be found in a variety of different hosts. Food-borne zoonoses via aquatic animals are most often linked to anisakid nematodes of the genera Anisakis Dujardin, 1845, Contracaecum Railliet and Henry, 1912, and Pseudoterranova Mozgovoi, 1951. These are commonly found in the digestive tract of marine mammals, and infect aquatic invertebrates and vertebrates as intermediate hosts. The most widely distributed whale worms Anisakis spp. involve cetaceans as final and planktonic copepods, euphausiids, squids and teleosts as intermediate or paratenic hosts. Painful infections of the digestive tract in humans originate through consumption of raw or semi-raw fisheries products, for example fish and squid. Recent molecular studies revealed the existence of morphologically similar but genetically different cryptic species (‘sibling species’) within the anisakids. Among these, A. simplex (s.s.) is responsible for the highest number of recorded human infections. Molecular studies of Anisakis larvae from various parts of the world Oceans demonstrate an uneven species distribution, with A. simplex (s.s.) being limited to the northern hemisphere. Another species, A. typica, has not yet been connected to this disease, and seems to be restricted to the tropical regions. This chapter presents the present state of knowledge about this widespread group of fish parasites, including the importance as human pathogens, their life cycle biology, biogeography and phylogeny. The distribution of the currently recognized Anisakis species is summarized and combined with the number of known cases of human anisakiasis. We suggest that pathogenicity for humans is different among the Anisakis siblings, providing a possible explanation for uneven disease records worldwide. The possibility of a changing risk of anisakidosis in the time of climate change is discussed.

Adaptive Radiation within Marine Anisakid Nematodes: A Zoogeographical Modeling of Cosmopolitan, Zoonotic Parasites

Abstract: Parasites of the nematode genus Anisakis are associated with aquatic organisms. They can be found in a variety of marine hosts including whales, crustaceans, fish and cephalopods and are known to be the cause of the zoonotic disease anisakiasis, a painful inflammation of the gastro-intestinal tract caused by the accidental consumptions of infectious larvae raw or semi-raw fishery products. Since the demand on fish as dietary protein source and the export rates of seafood products in general is rapidly increasing worldwide, the knowledge about the distribution of potential foodborne human pathogens in seafood is of major significance for human health. Studies have provided evidence that a few Anisakis species can cause clinical symptoms in humans. The aim of our study was to interpolate the species range for every described Anisakis species on the basis of the existing occurrence data. We used sequence data of 373 Anisakis larvae from 30 different hosts worldwide and previously published molecular data (n = 584) from 53 field-specific publications to model the species range of Anisakis spp., using a interpolation method that combines aspects of the alpha hull interpolation algorithm as well as the conditional interpolation approach. The results of our approach strongly indicate the existence of species-specific distribution patterns of Anisakis spp. within different climate zones and oceans that are in principle congruent with those of their respective final hosts. Our results support preceding studies that propose anisakid nematodes as useful biological indicators for their final host distribution and abundance as they closely follow the trophic relationships among their successive hosts. The modeling might although be helpful for predicting the likelihood of infection in order to reduce the risk of anisakiasis cases in a given area.

Molecular characterization and phylogeny of anisakid nematodes from cetaceans from southeastern Atlantic coasts of USA, Gulf of Mexico, and Caribbean Sea

Abstract: In the present study, 407 anisakid nematodes, collected from 11 different species of cetaceans of the families Delphinidae, Kogiidae, Physeteridae, and Ziphiidae, from the southeastern Atlantic coasts of USA, the Gulf of Mexico, and the Caribbean Sea, were examined morphologically and genetically characterized by PCR restriction fragment length polymorphism to identify them to species level, assess their relative frequencies in definitive hosts, and determine any host preference. Sequence data from nuclear ribosomal internal transcribed spacer and mitochondrial cox2 genes were analysed by maximum parsimony and Bayesian inference methods, as separate and combined datasets, to evaluate phylogenetic relationships among taxa. The results revealed a highly diverse ascaridoid community. Seven Anisakis species and Pseudoterranova species were recovered as adult parasites. Larval forms of Contracaecum multipapillatum were also found in a coastal population of bottlenose dolphins. The phylogenetic trees obtained from the combined dataset (and most individual datasets) revealed the existence of distinct clades, the first including species of the Anisakis simplex complex (A. simplex s.s., Anisakis pegreffii, A. simplex C), (Anisakis nascettii, Anisakis ziphidarum) and the second including Pseudoterranova ceticola ((Anisakis paggiae, (Anisakis physeteris, Anisakis brevispiculata)). This finding, excluding the relationship of P. ceticola, is consistent with the morphology of adult and larval specimens. Considering the presence versus absence of an intestinal cecum, the relationship of P. ceticola with the members of the second clade of Anisakis appears inconsistent with morphological evidences but consistent with host preference. The position of Anisakis typica as the sister group to the two main anisakid clades indicates that it represents a third distinct lineage.

Anisakis hypersensitivity in Italy: prevalence and clinical features: a multicenter study

Abstract: Background: Anisakis simplex (As), a parasite in fish, is able to sensitize humans via the alimentary tract. The prevalence of hypersensitivity and allergy to As outside the Iberian peninsula has not been investigated so far. We investigated Anisakis hypersensitivity in different areas of Italy. Methods: Consecutive subjects seen at 34 Italian allergy centers from October to December 2010 were investigated both by specific interview and by skin prick test (SPT) with As extract. Results: A total of 10 570 subjects were screened, of which 474 (4.5%) scored positive on Anisakis SPT and 66 of these (14% of those sensitized; 0.6% of the studied population) had a history of As allergy. Marinated anchovies were the most frequent cause of allergic reactions. Thirty-four (52%) patients were monosensitized to Anisakis. Sensitization rate showed marked geographic differences (range: 0.4‐12.7%), being highest along the Adriatic and Tyrrhenian coasts, where homemade marinated anchovies are an age-old tradition. In inland centers in northern Italy, the prevalence was directly related to the number of inhabitants. The analysis of the impact of immigration on the prevalence of Anisakis hypersensitivity showed that about 60% of sensitized subjects in Milano and Torino came from southern Italy or from non-European countries. Conclusions: Anisakis hypersensitivity and allergy are mainly a matter of dietary habits. Areas where marinated anchovies are popular can be considered as ‘endemic’ for this type of food allergy, whereas immigration and, possibly, new or imported trendy food styles, such as eating raw fish carpaccios or sushi, are a major causative factor in big cities of inland zones.

Occurrence and abundance of anisakid nematode larvae in five species of fish from southern Australian waters.

Abstract: The aim of the present study was to conduct, in southern Australian waters, a preliminary epidemiological survey of five commercially significant species of fish (yellow-eye mullet, tiger flathead, sand flathead, pilchard and king fish) for infections with anisakid nematodes larvae using a combined morphological–molecular approach With the exception of king fish, which was farmed and fed commercial pellets, all other species were infected with at least one species of anisakid nematode, with each individual tiger flathead examined being infected Five morphotypes, including Anisakis, Contracaecum type I and II and Hysterothylacium type IV and VIII, were defined genetically using mutation scanning and targeted sequencing of the second internal transcribed spacer of nuclear ribosomal DNA The findings of the present study provide a basis for future investigations of the genetic composition of anisakid populations in a wide range of fish hosts in Australia and for assessing their public health significance

Population Structure of Three Species of Anisakis Nematodes Recovered From Pacific Sardines (Sardinops sagax) Distributed Throughout the California Current System

Abstract: Members of the Anisakidae are known to infect over 200 pelagic fish species and have been frequently used as biological tags to identify fish populations. Despite information on the global distribution of Anisakis species, there is little information on the genetic diversity and population structure of this genus, which could be useful in assessing the stock structure of their fish hosts. From 2005 through 2008, 148 larval anisakids were recovered from Pacific sardine (Sardinops sagax) in the California Current upwelling zone and were genetically sequenced. Sardines were captured off Vancouver Island, British Columbia in the north to San Diego, California in the south. Three species, Anisakis pegreffii, Anisakis simplex 'C', and Anisakis simplex s.s., were identified with the use of sequences from the internal transcribed spacers (ITS1 and ITS2) and the 5.8s subunit of the nuclear ribosomal DNA. The degree of nematode population structure was assessed with the use of the cytochrome c oxidase 2 (cox2) mitochondrial DNA gene. All 3 Anisakis species were distributed throughout the study region from 32u Nt o 50uN latitude. There was no association between sardine length and either nematode infection intensity or Anisakis species recovered. Larval Anisakis species and mitochondrial haplotype distributions from both parsimony networks and analyses of molecular variance revealed a panmictic distribution of these parasites, which infect sardines throughout the California Current ecosystem. Panmictic distribution of the larval Anisakis spp. populations may be a result of the presumed migratory pathways of the intermediate host (the Pacific sardine), moving into the northern portion of the California Current in summer and returning to the southern portion to overwinter and spawn in spring. However, the wider geographic range of paratenic (large piscine predators), and final hosts (cetaceans) can also explain the observed distribution pattern. As a result, the recovery of 3 Anisakis species and a panmictic distribution of their haplotypes could not be used to confirm or deny the presence of population subdivision of Pacific sardines in the California Current system.

Occurrence and identification of Anisakis spp. (Nematoda: Anisakidae) isolated from chum salmon (Oncorhynchus keta) in Korea.

Abstract: The prevalence of infection and the identification of anisakid larvae in chum salmon (Oncorhynchus keta) from the Namdae River, the east coast of Korea, were investigated. In total, 8,358 larvae were collected from 120 fish samples (male = 58 fish, female = 62 fish) in 2008. Fish samples were collected during October and November 2008. All the chum salmon samples (120/120, 100%) caught were infected with anisakid larvae with a high intensity (69.65 ± 48.58 larvae/host). They were mostly found in muscles (98.00%). Based on the morphological and the molecular analysis of PCR-RFLP and sequencing of mitochondrial DNA cox2 gene markers, these nematodes were identified as Anisakis simplex (sensu stricto) third-stage larvae. This is the first report on the molecular identification of anisakid worms from salmonid fishes in Korea. The high occurrence of anisakid worms in chum salmon may pose considerable food safety problems if they were consumed as raw or undercooked, although their commercial value is relatively lower than other salmonid species.

Anisakis simplex (s.s.) larvae in wild Alaska salmon: no indication of post-mortem migration from viscera into flesh.

Abstract: The prevalence, mean intensity and distribution of Anisakis nematode third-stage larvae (L3) in the muscle and viscera of wild-caught chum salmon Oncorhynchus keta, pink salmon O. gorbuscha and sockeye salmon O. nerka were compared immediately after catch. Salmon were collected during the fishing season in July 2007 in Bristol Bay and Prince William Sound close to Cordova, Alaska (USA). All fish were infected, and more than 90% of the nematode larvae were found in the edible muscle meat. The isolated anisakid L3 were genetically identified as A. simplex (s.s.). The distribution of nematodes in the muscle meat of fresh-caught salmon was examined in 49 O. keta, 50 O. nerka and 12 O. gorbuscha from Cordova. Most of the larvae were detected in the muscle parts around the body cavity, but nematodes were also found in the tail meat and epaxial muscle (loins). The mean intensity of Anisakis larvae in the edible part was 21 individuals for O. gorbuscha, 62 individuals for O. keta and 63 individuals for O. nerka. No difference in the intensity of Anisakis larvae in the hypaxial muscle was found between fresh-caught and immediately gutted salmon and individuals stored ungutted for 24 h either on ice or in refrigerated sea water.

Molecular characterization of anisakis larvae from fish caught

Abstract: Anisakis spp. larvae are parasitic, and potentially zoonotic, nematodes transmitted by marine fish and cephalopods, which are the main intermediate hosts of the third larval stage. The accidental consumption of infected raw or poorly cooked fish may cause gastroenteric diseases and allergies in humans. The aim of the present study was to use polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to define the occurrence, species variability, and host preferences of Anisakis spp. larvae in fish caught off the coast of Sardinia. Necropsy was used on 285 samples; 552 Anisakis spp. L3 larvae were isolated from 87 fish that tested positive for this nematode. Anisakis pegreffii was most frequently encountered (90.6%), with a primary preference for Scomber scombrus, Zeus faber, and Trachurus mediterraneus. In contrast, the prevalence of Anisakis physeteris was only 1.3%. A hybrid genotype of Anisakis simplex sensu stricto and Anisakis pegreffii was also observed, which confirms the results of previous studies carried out in the western Mediterranean. Interestingly, no Anisakis simplex s.s. larvae were recovered. These results indicate that the diversity of Anisakis species is low in Sardinia waters, probably because of its geographic position.

Molecular Characterization of Anisakis Larvae from Fish Caught Off Sardinia

Abstract: Anisakis spp. larvae are parasitic, and potentially zoonotic, nematodes transmitted by marine fish and cephalopods, which are the main intermediate hosts of the third larval stage. The accidental consumption of infected raw or poorly cooked fish may cause gastroenteric diseases and allergies in humans. The aim of the present study was to use polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) to define the occurrence, species variability, and host preferences of Anisakis spp. larvae in fish caught off the coast of Sardinia. Necropsy was used on 285 samples; 552 Anisakis spp. L3 larvae were isolated from 87 fish that tested positive for this nematode. Anisakis pegreffii was most frequently encountered (90.6%), with a primary preference for Scomber scombrus, Zeus faber, and Trachurus mediterraneus. In contrast, the prevalence of Anisakis physeteris was only 1.3%. A hybrid genotype of Anisakis simplex sensu stricto and Anisakis pegreffii was also observed, which confirms ...

Deep-water life cycle of Anisakis paggiae (Nematoda: Anisakidae) in the Irminger Sea indicates kogiid whale distribution in north Atlantic waters

Abstract: The study of the beryciform Anoplogaster cornuta from the Irminger Sea (north Atlantic) revealed the presence of the anisakid nematode Anisakis paggiae inside the body cavity, representing a new host and locality record. This deep-sea fish was infected with Anisakis larvae at a prevalence of 57.1% and a mean intensity of 2.2, with no correlation between the fish standard length and the number of accumulated A. paggiae. Kogiid whales (Kogia breviceps, K. sima), the typical final hosts of this parasitic nematode, have not yet been recorded so far in the north. Because A. cornuta does not migrate outside the Irminger Sea, and by using the parasite as an indicator for the presence of the final hosts, A. paggiae must have been introduced through migratory kogiid final hosts. This would extend their range of distribution into the Irminger Sea. The depth range of the meso- and bathypelagic A. cornuta and the frequent occurrence of Anisakis inside this deep-sea fish demonstrate an oceanic deep-water life cycle for A. paggiae in the north Atlantic.

Anisakis simplex larvae: infection status in marine fish and cephalopods purchased from the Cooperative Fish Market in Busan, Korea.

Abstract: The infection status of marine fish and cephalopods with Anisakis simplex third stage larva (L3) was studied over a period of 1 year. A total of 2,537 specimens, which consisted of 40 species of fish and 3 species of cephalopods, were purchased from the Cooperative Fish Market in Busan, Korea, from August 2006 to July 2007. They were examined for A. simplex L3 from the whole body cavity, viscera, and muscles. A. simplex L3 were confirmed by light microscopy. The overall infection rate reached 34.3%, and average 17.1 larvae were parasitized per infected fish. Fish that recorded the highest infection rate was Lophiomus setigerus (100%), followed by Liparis tessellates (90%), Pleurogrammus azonus (90%), and Scomber japonicus (88.7%). The intensity of infection was the highest in Gadus macrocephalus (117.7 larvae per fish), followed by S. japonicus (103.9 larvae) and L. setigerus (54.2 larvae). Although abundance of A. simplex L3 was not seasonal in most of the fish species, 10 of the 16 selected species showed the highest abundance in February and April. A positive correlation between the intensity of L3 infection and the fish length was obvious in S. japonicus and G. macrocephalus. It was likely that A. simplex L3 are more frequently infected during the spring season in some species of fish. Our study revealed that eating raw or undercooked fish or cephalopods could still be a source of human infection with A. simplex L3 in Korea.

Seroprevalence of Antibodies against Anisakis simplex Larvae among Health-Examined Residents in Three Hospitals of Southern Parts of Korea

Abstract: The present study was performed to estimate the seroprevalence of larval Anisakis simplex infection among the residents health-examined in 3 hospitals in southern parts of Korea. A total of 498 serum samples (1 serum per person) were collected in 3 hospitals in Busan Metropolitan city, Masan city, and Geoje city in Gyeongsangnam-do (Province) and were examined by IgE-ELISA and IgE-western blotting with larval A. simplex crude extract and excretory-secretory products (ESP). The prevalence of antibody positivity was 5.0% and 6.6% with ELISA against crude extracts and ESP, respectively. It was also revealed that infection occurred throughout all age groups and higher in females than in males. A specific protein band of 130 kDa was detected from 10 patients with western blot analysis against crude extract and ESP among those who showed positive results by ELISA. Our study showed for the first time the seroprevalence of anisakiasis in Korea. The allergen of 130 kDa can be a candidate for serologic diagnosis of anisakiasis.

Synergism between prior Anisakis simplex infections and intake of NSAIDs, on the risk of upper digestive bleeding: a case-control study.

Abstract: Background The aim of this study was to investigate the relationship between prior Anisakis infections and upper gastrointestinal bleeding (UGIB), and its interaction with non-steroidal anti-inflammatory drug (NSAID) intake. Methods/Principal Findings We conducted a hospital-based case-control study covering 215 UGIB cases and 650 controls. Odds ratios (ORs) with their confidence intervals (95% CIs) were calculated, as well as the ratio of the combined effects to the sum of the separate effects of Anisakis allergic sensitization and NSAIDs intake. Prior Anisakis infections were revealed by the presence of anti-Anisakis IgE antibodies specific to the recombinant Ani s 1 and Ani s 7 allergens used as the targets in indirect ELISA. Prior Anisakis infections (OR 1.74 [95% CI: 1.10 to 2.75]) and the intake of NSAIDs (OR 6.63 [95% CI: 4.21 to 10.43]) increased the risk of bleeding. Simultaneous NSAIDs intake and Anisakis allergic sensitization increased the risk of UGIB 14-fold (OR = 14.46 [95% CI: 6.08 to 34.40]). This interaction was additive, with a synergistic index of 3.01 (95% CI: 1.18–7.71). Conclusions Prior Anisakis infection is an independent risk factor for UGIB, and the joint effect with NSAIDs is 3 times higher than the sum of their individual effects.

Parasite structure of the Ocean Whitefish Caulolatilus princeps from Baja California, México (East Pacific)

Abstract: The metazoan parasite fauna of Caulolatilus princeps from northern Baja California, Mexico is quantitatively described for the first time. Further, the ecological aspects of prevalence, abundance, and intensity of infection are examined through an annual cycle. Six parasite species were recorded; 2 ectoparasites (1 monogenean and 1 copepod) and 4 endoparasites (2 digeneans and 2 nematodes). The digeneans Choanodera caulolatili and Bianium plicitum, the nematodes Anisakis sp. and Hysterothylacium sp., and the copepod Hatschekia sp. set new geographical and host records. The highest values of prevalence and abundance were in Anisakis sp. (prevalence = 93.3%, abundance = 12.4 ± 4.7 ind/host) and in Hysterothylacium sp. (prevalence = 86.6%, abundance = 16.5 ± 3.4 ind/host). The mean intensity of infection showed maximum values in summer (August = 14.2) and minimums in winter (February = 4.2). The mean intensity was higher in Hatschekia sp. (20.3 ± 7.8) followed by Hysterothylacium sp. (18.6 ± 1.4) and Anisakis sp. (12.9 ± 2.2). Larval stages of Anisakis and Hysterothylacium were particularly important due to their high abundance and prevalence, because they represent a human health risk (anisakiasis). In addition, the relationships between the metazoan parasites of C. princeps and host size and weight, fish condition and water temperature (bottom) are discussed.

Infection of Anisakids Larvae in Long Tail Tuna (Thunnus tonggol) In North Persian Gulf

Abstract: Background : The aim of this paper was to study the prevalence and intensity of Anisakids lar­vae in the long tail tuna fish captured from Iranian shores of Persian Gulf Methods : Different organs including skin, abdominal cavity, stomach and intestinal contents, stom­ach sub serous tissues, liver, spleen, gonads and 20 grams of muscles of 100 long tail tuna fish ( Thannus tonggol ) caught from waters of the north parts of Persian Gulf were searched for anisakid nematodes larvae Twenty grams of around the body cavity muscles were digested in artificial gastric juice Different organs and digested muscles were examined with naked eyes for the presence of anisakids larvae The collected larvae were preserved in 70% alcohol containing 5% glycerin, and cleared in lactophenol for identification Results : Our findings revealed that 89% of fish harbored 3 rd stage larvae of Anisakis sp of which 2% were infected with both Anisakis and Raphidascaris All inspected organs except that of skin were found to be infected, while stomach sub serous tissues were the most infected organ (80%) followed by abdominal cavity (10%), liver (4%), testicle (3%), stomach contents and spleen (2%) and intestinal contents (1%) Intestine and abdominal cavity were the organs har­bored Raphidascaris sp Digested muscles were free of parasite Mean intensity was low for both spe­cies and ranged between 15 for Raphidascaris sp and 367 for Anisaki sp Conclusion : Anisakids larvae especially Anisakis are very prevalent in some fish including tunas of Persian Gulf, and consumption of infected fish if it is not properly cooked may lead to human anisakiasis