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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A multidisciplinary approach to tackle the problem of the zoonotic parasite Anisakis in fish

Bao Dominguez, Miguel January 2017 (has links)
No description available.
2

Taxonomia integrada de nematóides anisaquídeos parasitos de cetáceos da costa do nordeste do Brasil

Di Azevedo, Maria Isabel Nogueira January 2012 (has links)
Made available in DSpace on 2015-10-21T12:19:28Z (GMT). No. of bitstreams: 2 maria_azevedo_ioc_mest_2012.pdf: 3920589 bytes, checksum: 4c33d4d2ace8f5e6b7d0c7c657da00d3 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2015-05-21 / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil / Nematóides da família Anisakidae tem como principais representantes espécies dos gêneros AnisakisDujardin, 1845, PseudoterranovaKrabbe, 1878 e Contracaecum Railliet e Henry, 1913. Apresentam um ciclo de vida indireto em ecossistemas aquáticos, tendo mamíferos marinhos como hospedeiros definitivos e peixes e crustáceos como hospedeiros intermediários, estando relacionado a quadros patológicos em ambos. O homem pode infectar-se ao ingerir o pescado de forma crua ou mal-cozida, e desenvolver uma patologia gastrointestinal denominada anisaquidose. A identificação acurada de anisaquídeos em qualquer estágio do ciclo de vida é crucial para o melhor entendimento da ecologia e epidemiologia destes nematódeos, assim como para o diagnóstico e controle da anisaquíase humana e monitoramento da qualidade do pescado. A identificação em nível de espécie baseado na morfologia é difícil, devido aos limitados caracteres de importância taxonômica. Abordagens moleculares e genéticas são capazes de fornecer uma identificação precisa dos anisaquídeos, possibilitando um melhor entendimento de sua sistemática. O objetivo deste trabalho é identificar, através da taxonomia integrada com base em análises morfológica e genética, as espécies de nematódeos da família Anisakidae parasitos de mamíferos marinhos provenientes do litoral do nordeste brasileiro. Os parasitos (n=195) foram coletados de 54 cetáceos encalhados ao longo do litoral de seis estados do nordeste do Brasil A análise morfológica revelou 60 espécimes como sendo Anisakis sp. clado I, 24 Anisakissp. clado II e 4 como Pseudoterranovasp. A espécie A. paggiaefoi identificada em Kogiabreviceps, constituindo a pimeira descrição austral da espécie. O gênero Pseudoterranova é identificado pela primeira vez infectando o golfinho-rotator, Stenella longirostris.Devido à natureza do material, fixado em formalina, etanol, ou AFA, diferentes métodos e kits de extração de DNA foram empregados, e a metodologia de pré-tratamento com CTAB e extração com o kit comercial QIAamp® DNA Investigator(Qiagen) apresentou o melhor desempenho. Para amplificação do DNA, a técnica de Polimerização Reconstrutora se mostrou eficaz na optimização da PCR. O gene mtDNA cox2 foi avaliado comobarcodeda família Anisakidae e se mostrou eficiente. Dezesseis espécimes, de hospedeiros distintos, foram geneticamente identificados como A. typica, confirmando esta espécie como a mais circulante no Brasil. Em Stenella frontalis, Lagenodelphis hosei e Globicephala macrorhyncus, a espécie é relatada pela primeira vez em águas do litoral brasileiro. A espécie A. nascettiifoi identificada em um hospedeiro ainda não relatado, Mesoplodon europaus, a baleia bicuda de Gervais, e sua distribuição também expandida para águas do Atlântico sudoeste / Anisakids are mainly represented by species of the genus Anisakis Dujardin, 1845, Pseudoterranova Krabbe, 1878 e Contracaecum Railliet and Henry, 1913. They display indirect life cycles in aquatic ecosystems. Marine mammals act as definitive hosts and fishes as intermediate hosts, being anisakids associated to pathological conditions on both. Human can become infected when ingesting raw or undercooked seafood, acquiring anisakidosis. The accurate identification of anisakids at any life cycle stage is crucial for better understanding the ecology and epidemiology of these nematodes, as well for diagnosis and control of human anisakidosis and monitoring the seafood quality. Identification at species level based on morphology is difficulty, due to limited characters of taxonomic importance. Molecular and genetic approaches are able to provide a precise identification of anisakids, enabling a better knowledge about their systematics. The objective of the present study was to identify, through the integrated taxonomy based on morphological and genetic data, the nematodes species of the Anisakidae family, parasites of marine mammals caught on the northeastern coast off Brazil. Parasites (n=195) were collected from 57 cetaceans stranded along the coast of six states of the Northeastern of Brazil. Morphological analysis revealed 60 specimens as Anisakis sp. clade I , 24 as Anisakis sp. clade II e 4 as Pseudoterranova sp. The species A. paggiae was identified in K. breviceps , constituting the first austral description of the species. The genera Pseudoterranova was identified for the first time infecting the spinner-dolphin, Stenella longirostris. Due to material conditions, fixed in formalin, ethanol or AFA, different methods and extractions kits were applied, and the pre-treatment with CTAB solution and posterior extraction with the commercial kit comercial QIAamp® DNA Investigator (Qiagen) , showed the best performance. For DNA amplification, the Reconstructive Polymerization method was efficient in PCR optimization. The gene mtDNA cox 2 was evaluated as barcode to Anisakidae and it was effective. Sixteen specimens, from different hosts, were genetically identified as A. typica , confirming this species as the most circulating in Brazil. In Stenella frontalis , Lagenodelphis hosei and Globicephala macrorhyncus, the species was reported for the first time in Brazilian waters. The species A. nascettii was identified in an unreported host, Mesoplodon europaus, the Gervais beaked whale, expanding its distribution to Southwest Atlantic waters
3

Population dynamics of Anisakis simplex in harbour porpoise (Phocoena Phocoena) from the Gulf of St. Lawrence

Simard, Manon. January 1997 (has links)
A prevalence of 76% and a mean intensity of 42.7 Anisakis simplex was found in harbour porpoises (Phocoena phocoena) (N = 78) by-caught in cod gill nets set by fishers from the Gaspe area in summer 1993. No young-of-the-year porpoises (N = 12) were infected. Prevalence and mean intensity among immature and adult porpoises as well as between sexes and length-classes were not significantly different. Anisakis simplex was present in the three stomach compartments of harbour porpoises. Adult stages were proportionately less abundant in the main and pyloric stomachs than the forestomach. Percent intensity of A. simplex was influenced by maturity of harbour porpoises. Gravid female A. simplex contained up to 818,000 eggs. Egg number was highly correlated with worm uttering volume. Density effects were not demonstrated, possibly due to high variability of egg number, total length, uterine and total worm volume between parasites from each stomach and between stomachs of harbour porpoise.
4

Estudio de la presencia de nematodos anisákidos en distintas especies acuícolas producidas en el litoral español

López Ramon, Jordi 07 January 2016 (has links)
[EN] The main objective of this study has been to determine the presence or absence of anisakid nematodes in aquaculture fish from the Spanish coast. For the study, it has been used different detection techniques: direct visualization, acid digestion and UV visualization. It has been studied a total of 4,080 samples from fish farms on the Spanish coast in a study divided into two phases. In addition, it has been also performed an study to determine the presence of anisakid nematodes in fish from fisheries of Valencia Region. In this work 217 samples were studied by the technique of direct visualization. The obtained results by the diagnostic techniques used indicate no anisakid larvae in aquaculture fish bred in Spain, independently of the production system, geographic location and season. From aquaculture samples, it has been analyzed the following species: gilthead seabream (1.741), european sea bass (907), european eel (601), rainbow trout (441), meagre (246) and turbot (144). Similar results has been obtained from other authors previously (Kapota, 2012; Peñalver et al., 2010). The processing methods for raw materials utilized to the manufature of extruded aquaculture feed, mainly those used to the production of fish meal and oils, prevent the transfer of viable anisakid through the extruded feed. However, in fish from fisheries, comparable to synanthropic species of fish farms, the prevalence was 5.53 %. The hypothesis that the breeding and food techniques used in Spain minimizes the possibility of the presence of anisakid nematodes on this fishes is confirmed, so the risk of human transmission of these parasites through fish aquaculture consumption is negligible. The conditions that would be necessary for the presence of anisakid nematodes in fish occur in fish farms on the Spanish coast: presence of definitive hosts of anisakid nematodes; presence of anisakid nematode paratenic hosts; presence of intermediate hosts, because the life cycle of the parasite is closed; breeding of susceptible species in aquaculture facilities of the Spanish coast. However, it has not been found anisakid larvae, so it can be concluded that the absence of anisakid larvae nematodes is not due to species kept are not affected, or the absence of nematodes in waters where they are raised, as there are definitive, intermediate and paratenic hosts, but growing and feed conditions feed used in Spanish fish farms. Although the presence of anisakid larvae can not completely be discarded, in the fish farming conditions that currently are used in Spain, the probability of finding anisakid larvae in these fish is negligible. Therefore, consumption of fish from spanish aquaculture does not represent a significant risk to consumer of infection by anisakid larvae and reduces the risk of sensitization to the parasite. / [ES] El principal objetivo de este trabajo ha sido la determinación de la presencia o ausencia de nematodos anisákidos en pescado proveniente de la acuicultura del litoral español. Para el estudio se han utilizado diferentes técnicas de detección: visualización directa, digestión ácida y visualización con UV. Se han estudiado un total de 4.080 muestras de pescados procedentes de granjas del litoral español en un estudio dividido en dos fases. Además, se ha realizado un estudio para la determinación de la presencia de nematodos anisákidos en pescado procedente de la pesca extractiva de la Comunitat Valenciana. En este trabajo se han estudiado 217 individuos mediante la técnica de la visualización directa. Los resultados obtenidos, mediante las técnicas diagnósticas utilizadas, indican la ausencia de larvas de anisákidos en los pescados de acuicultura criados en España, independientemente del sistema de producción, de la localización geográfica y la estación del año. De las muestras provenientes de la acuicultura se han analizado las siguientes especies: dorada (1.741), lubina (907), anguila (601), trucha arco iris (441), corvina (246) y rodaballo (144). Similares resultados han sido obtenido por otros autores con anterioridad (Kapota, 2012; Peñalver et al., 2010). Los métodos de procesado de las materias primas utilizadas en la fabricación de los piensos extrusionados para acuicultura, principalmente las utilizadas para la producción de harinas y aceites de pescado, impiden la transferencia de anisákidos viables a través de los piensos extrusionados. Sin embargo, en el pescado proveniente de la pesca extractiva, asimilable a las especies sinantrópicas de las granjas acuícolas, la prevalencia ha sido del 5,53 %. Se confirma la hipótesis que la forma de cría y alimentación de los pescados criados en España minimiza la posibilidad de la presencia de nematodos anisákidos en los mismos, por lo que el riesgo de una transmisión al ser humano de estos parásitos por el consumo de pescado de acuicultura es insignificante. En las granjas de acuicultura del litoral español se dan las condiciones que serían necesarias para la presencia de nematodos anisákidos en el pescado: presencia de hospedadores definitivos de nematodos anisákidos; presencia de hospedadores paraténicos de nematodos anisákidos; presencia de hospedadores intermediarios, dado que se cierra el ciclo biológico del parásito; cría de especies sensibles en las instalaciones de acuicultura del litoral español. Sin embargo, no se han encontrado larvas de anisákidos, por lo que se puede concluir que la ausencia de larvas de nematodos anisákidos no es debida a que las especies de cultivo criadas no sean sensibles, ni a la ausencia de nematodos en las aguas donde se crían, ya que existen hospedadores definitivos, intermediarios y paraténicos, sino a las condiciones de cultivo y de alimentación utilizadas en las granjas marinas del litoral español. Aunque no se puede descartar totalmente su presencia, en las condiciones de cría de pescado actualmente utilizadas en España, la probabilidad de encontrar larvas de anisákidos en estos pescados es prácticamente nula. Por tanto, el consumo de pescado procedente de acuicultura española no representa un riesgo significativo de infección del consumidor por larvas de anisákidos y disminuye el riesgo de sensibilización al parásito. / [CAT] El principal objectiu d'aquest treball ha sigut la determinació de la presència o absència de nematodes anisàkids en peix provinent de l'aqüicultura del litoral espanyol. Per a l'estudi s'han utilitzat diferents tècniques de detecció: visualització directa, digestió àcida i visualització amb UV. S'han estudiat un total de 4.080 mostres de peix provinent de granges del litoral espanyol en un estudi dividit en dues fases. A més, s'ha realitzat un estudi per la determinació de la presència de nematodes anisàkids en peix provinent de la pesca extractiva de la Comunitat Valenciana. A aquest treball s'han estudiat 217 individus mitjançant la tècnica de la visualització directa. Els resultats obtinguts, mitjançant les tècniques diagnòstiques utilitzades, indiquen l'absència de larves d'anisàkids als peixos d'aqüicultura criats a Espanya, independentment del sistema de producció, la localització geogràfica i l'estació de l'any. De les mostres provinents de l'aqüicultura s'han analitzat les següents espècies: orada (1.741), llobarro (907), anguila (601), truita arc de Sant Martí (441), corball (246) i rèmol empetxinat (144). Semblants resultats han sigut obtinguts per altres autors amb anterioritat (Kapota, 2012; Peñalver et al., 2010). Els mètodes de processat de les matèries primes utilitzades a la fabricació dels pinsos extrusionats per a l'aqüicultura, principalment les utilitzades per la fabricació de farines i olis de peix, impedeixen la transferència d'anisàkids viables mitjançant els pinsos extrusionats. No obstant això, al peix provinent de la pesca extractiva, assimilable a les espècies sinantròpiques de les granges aqüícoles, la prevalència ha sigut del 5,53 %. Es confirma la hipòtesi que la forma de cria i alimentació dels peixos criats a Espanya minimitza la possibilitat de la presència de nematodes anisàkids en els mateixos, de manera que el risc d'una transmissió a l'ésser humà d'aquests paràsits pel consum de peix d'aqüicultura es insignificant. A les granges d'aqüicultura del litoral espanyol es donen les condicions que serien necessàries per la presència de nematodes anisàkids al peix: presència de hospedadors definitius de nematodes anisàkids; presència de hospedadors paratènics de nematodes anisàkids; presència d'hospedadors intermediaris, ja que es tanca el cicle del paràsit; cria d'espècies sensibles a les instal·lacions del litoral espanyol. Malgrat això, no s'han trobat larves d'anisàkids, pel que es pot concloure que l'absència de larves de nematodes anisàkids no es deguda a que les espècies de cultiu criades no són sensibles, ni a l'absència de nematodes a les aigües on es crien, ja que hi han hospedadors definitius, intermediaris i paratènics, sinó a les condicions de cultiu i d'alimentació utilitzades a les granges marines del litoral espanyol. Tot i que no es pot descartar totalment la seua presència, en les condicions de cria de peix actualment utilitzades a Espanya, la probabilitat de trobar larves d'anisàkids a aquestos peixos es pràcticament nul·la. Per tant, el consum de peix provinent de l'aqüicultura espanyola no representa un risc significatiu d'infecció del consumidor per larves d'anisàkids i disminueix el risc de sensibilització al paràsit. / López Ramón, J. (2015). Estudio de la presencia de nematodos anisákidos en distintas especies acuícolas producidas en el litoral español [Tesis doctoral no publicada]. Universitat Politècnica de València. doi:10.4995/Thesis/10251/59406. / TESIS
5

Symbionts in Mesozooplankton Communities from NE Atlantic Ocean: Ecology and Recruitment of Parasites to the Marine Trophic Web

Gregori Casamayor, Maria Dolors 15 July 2014 (has links)
Beca JAE-Predoctoral CISC; Proyecto LARECO CTM2011-25929
6

Einfluss des Ausnehmens auf die sensorische und hygienische Beschaffenheit von eisgelagerten Zandern (Sander lucioperca) und Regenbogenforellen (Oncorhynchus mykiss)

Sipos, Gyopar 24 April 2003 (has links)
Die Bedingungen für die Vermarktung von Fischereierzeugnissen sind streng geregelt. Die Deutsche Fisch-Hygiene-Verordnung (VO) schreibt in den §§ 4 (1) und 6 vor, dass alle Fische unverzüglich nach dem Fang und der Tötung ausgenommen werden müssen. In diesem Punkt ist die deutsche VO strenger als das europäische Gemeinschaftsrecht (RL 91/493/EWG). Sowohl durch die in einzelnen Bundesländern unterschiedliche Auslegung des Begriffes "unverzüglich" als auch durch die in anderen EU-Ländern erlassenen Vorschriften ergibt sich eine gewisse Rechtsunsicherheit bei der Vermarktung von Ganzfischen. Im Gegensatz zu Seefischen gibt es bei Süßwasserfischen nur wenige Untersuchungen zum Vergleich der sensorischen und hygienischen Parameter von ausgenommen und unausgenommen gelagerten Fischen. Ziel der Untersuchungen war es daher, an den zwei Modellfischarten Regenbogenforelle (Oncorhynchus mykiss) und Ostsee-Zander (Sander lucioperca) gesundheitlich-hygienische als auch qualitative Gründe für bzw. gegen das Ausnehmen von Süßwasserfischen zu ermitteln. Zum einen wurde während der Lagerung bis zum Verderb wiederholt der Keimstatus der Fische bestimmt, wobei sowohl die Verderbsorganismen als auch potentiell humanpathogene Keime (Vibrio spp., Aeromonas spp., Clostridium spp., Salmonella spp., Listeria spp.) im Fischgewebe erfasst wurden. Zum anderen wurden fischartspezifische Frischegrad- und Kochprobenschemata entwickelt, die den Verderbsprozessen der beiden Süßwasserfischarten während der Lagerung angepasst sind und für eine Bestimmung der sensorischen Eigenschaften angewendet werden können. Darüber hinaus erfolgte bei den Zandern eine Untersuchung der Muskulatur und der Eingeweide auf einen Befall mit humapathogenen Nematoden und eine Bestimmung von flüchtigen Basenstickstoff (TVB-N) in der Filetmuskulatur. Die vorliegenden Ergebnisse lassen den Schluss zu, dass unausgenommene Fische, sofern eine optimale Lagerung gewährleistet ist, hygienisch unbedenklich sind und für einen Zeitraum von einigen Tagen qualitativ gleichwertig mit ausgenommenen Fischen bleiben, bevor autolytische Bauchhöhlenprozesse die Qualität des Ganzfisches beeinträchtigen. Dabei hängt der Zeitraum unter anderem von der Fischart und dem Nüchterungsgrad ab. Mikrobiologische Gründe sprechen eher gegen ein frühzeitiges Ausnehmen, da die bakterielle Belastung der Bauchhöhle durch die Schlachtung höher ausfällt als bei unausgenommen gelagerten Fischen. Demnach kann durch ein spätes Ausnehmen zwar ein schnellerer Qualitätsverlust bei Ganzfischen auftreten, aber aus hygienischer Sicht, auch im Zusammenhang mit humanpathogenen Keimen, ist eine erhöhte Gesundheitsgefährdung des Verbrauchers nicht zu erwarten. / Conditions for the marketing of fishery products are strictly regulated. In Germany, the fish hygiene regulations (§§ 4(1) and 6) demand the gutting of all fishes immediately after the catch. This regulation is more restrictive than the corresponding EU-legislation (RL 91/493/EWG). But several German counties interprete the term "immediately" differently, and most other EU-countries have more permitting regulations, thus creating legal ambiguities in the marketing of whole fishes. Unlike the situation in seafish there are only few surveys in fresh water fish comparing possible sensoric and hygienic effects of gutted and ungutted storage. The aim of this study therefore was to examine health and hygiene related as well as qualitative reasons for or against an immediate gutting of freshwater fish, using aquaculture rainbow trout (Oncorhynchus mykiss) and pike-perch (Sander lucioperca) from the Baltic Sea as model fish species. The bacterial load in several tissues of gutted and ungutted fish, spoilage organisms as well as potentially pathogenic bacteria (Vibrio spp., Aeromonas spp., Clostridium spp., Salmonella spp., Listeria spp), were determined repeatedly throughout the storage period and statistically compared. Furthermore, species-specific grading schemes for the whole fish as well as for steamed fillets were developed that allowed the assessment of spoilage and of the sensoric characteristics of gutted and ungutted fishes. In pike-perch, muscle tissue and guts were examined for pathogenic nematode larvae and the fillet content of total volatile basic nitrogen was determined. The results of this study lead to the conclusion that ungutted fish, as long as optimal storage conditions are guaranteed, bear no special hygienic risks and keep a quality comparable to gutted fish for at least some days before autolytic processes in the body cavity compromise the quality of the whole fish. The length of this storage period depends mainly on the fish species and the filling of the digestive tract. From a microbiological point of view early gutting is not advisable because the gutting process itself results in a higher bacterial contamination of the body cavity than that found in fish stored ungutted. Therefore, a later gutting may lead to a faster loss of quality in whole fish but a higher hygienic risk for the consumer, even in connection with bacteria pathogenic for humans, can not be stated.

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