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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

Immunological and ultrastructural studies of Strongyloides ratti (Nematoda: Rhabditoidea)

McHugh, Timothy Daniel January 1989 (has links)
No description available.
2

Brood size and offspring sex ratio of the intertidal amphipod, Corophium volutator (Pallas): apparent effects of a novel microsporidian /

Cook, Kathleen A., January 1900 (has links)
Thesis (M.Sc.) - Carleton University, 2006. / Includes bibliographical references (p. 54-74). Also available in electronic format on the Internet.
3

Associa??o entre Amblyomma cajennense e Boophilus microplus em Infesta??o Simult?nea de Bovinos Holand?s - Zebu / Association between Amblyomma cajennense and Boophilus microplus in simultaneus infestation of Holstein Gir Cattle

Fernandez, Ruth Miriam Alva 10 May 1990 (has links)
Made available in DSpace on 2016-04-28T20:15:23Z (GMT). No. of bitstreams: 1 1990-Ruth Miriam Alva Fernandez.pdf: 795004 bytes, checksum: 0fa06a19352e7709d3b42d96b1490723 (MD5) Previous issue date: 1990-05-10 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Steers were used as experimental host for Amblyomma cajennense and Boophilus microplus during simultaneous infections on ears and quarters. Thus, the study shows especifically teleoginas and quenoginas weight, egg production, eclodibility and oviposition period. The ticks were held in laboratoryconditions at 27?C and 70% UR. It was observed that teleoginas collected from the ears were lighter than those collected from hind quarters. Egg production index (EPI) and nutrient efficiency index (NEI) for A. cajennense was 45,74% and 60,36%, respectively, and for B. microplus was 42,58% and 59,51%, respectively. The eclodibility index from simultaneous infection was lower than individual infections. The correlation between teleogina weight and egg production for both ticks specie showed that the number of eggs was influenced by teleogina weight. The interaction between A. cajennense and B. microplus is reported for simultaneous infection on bovine. / Utilizando bovinos como hospedeiros, avaliou-se o comportamento de Amblyomma cajennense e Boophilus microplus em infesta??es simult?neas na orelha e anca, essa em ?reas de aproximadamente 60 cm2. O estudo focalizou prioritariamente o peso das tele?ginas, das quen?ginas, a produ??o de ovos, o tempo de ovipostura e a eclodibilidade. Os carrapatos foram criados em laborat?rio em estufa do tipo B.O.D. com temperatura controlada de 27? C e unidade relativa de 70 ? 10%, e mantidos isoladamente ap?s desprendimento do hospedeiro nas mesmas condi??es laboratoriais. As tele?ginas que ingurgitaram na orelha pesaram menos que as alimentadas nas ancas em ambas as esp?cies; o ?ndice de produ??o de ovos (IPO) e o ?ndice de efici?ncia nutricional (IEN) para A. cajennense e B. microplus foram 45,74 e 42,58%, e 60,36 e 59,5%, respectivamente. As taxas de eclodibilidade foram menores que as j? assinaladas para infesta??es individuais nas duas esp?cies. A correla??o entre o peso da tele?gina das duas esp?cies e a produ??o de ovos foi significativa, comprovando ser o n?mero de ovos ovipostos fun??o do peso da f?mea antes do ?nicio da postura. Concluindo-se haver intera??o entre A. cajennense e B. microplus em infesta??o simult?nea em bovinos.
4

Mathematical models for investigating the long-term impact of Gyrodactylus salaris infections on Atlantic salmon populations

Denholm, Scott J. January 2013 (has links)
Gyrodactylus salaris Malmberg, 1957, is a notifiable freshwater ecto-parasite that infects both wild and farmed populations of Atlantic salmon (Salmo salar, L.). It has caused catastrophic damage to wild salmon stocks in Norway since its accidental introduction in 1975, reducing salmon density in some rivers by 98% over a period of five years. It is estimated that G. salaris has cost the Norwegian salmon industry more than 500 million EUR. Currently the UK has G. salaris free status under EU law, however, it is believed that if G. salaris emerged in the UK the impact would be similar to that witnessed in Norway. The aim of this thesis is to develop mathematical models that describe the salmon-G. salaris system in order to gain a greater understanding of the possible long-term impact the parasite may have on wild populations of Atlantic salmon in G. salaris-free territories such as the UK. Mathematical models, including deterministic, Leslie matrix and individual based models, were used to investigate the impact of G. salaris on Atlantic salmon at the individual and population level. It is known that the Atlantic strain of Atlantic salmon, examples of which occur naturally in Norway and the UK, does not have any resistance to G. salaris infections and the parasite population is able to quickly grow to epidemic levels. In contrast, the Baltic strain of Atlantic salmon, examples of which occur naturally in Sweden and Russia, exhibits some form of resistance and the parasite is unable to persist. Thus, baseline models were extended to include immunity to infection, a trade-off on salmon reproductive rate, and finally, to consider interactions between populations of G. salaris and multiple strains of salmon exhibiting varying levels of immunity from fully susceptible to resistant. The models proposed predict that in the absence of host resistance or an immune response infections by G. salaris will result in an epidemic followed by the extinction of the salmon host population. Models also predict that if salmon are able to increase their resistance to G. salaris infections through mutations, salmon population recovery after the epidemic is indeed possible within 10-15 years post introduction with low level parasite coexistence. Finally, models also highlight areas where additional information is needed in order to improve predictions and enable the estimation of important parameter values. Model predictions will ultimately be used to assist in future contingency planning against G. salaris outbreaks in the UK and possibly as a basis for future models describing other fish/ecto-parasite systems.
5

Infecção experimental de Mazana gouazoubira (Ficher, 1814) (Cervidae: Odocoileinae) com Haemonchus contortus (Rudolphi, 1803) (Nematoda: Trichostrongyloidea)

Hoppe, Estevam Guilherme Lux [UNESP] 08 February 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:32:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-08Bitstream added on 2014-06-13T19:22:39Z : No. of bitstreams: 1 hoppe_egl_dr_jabo.pdf: 1540256 bytes, checksum: 5f7596806464f080af8ea17e52f8fafd (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A adequada compreensão dos mecanismos fisiopatológicos das doenças que afetam os animais silvestres contribui positivamente para a melhoria das condições de manutenção desses animais em cativeiro e fornece subsídios para a elaboração de planos de conservação de animais de vida livre. Diversos relatos de Haemonchus contortus em cervídeos de cativeiro e vida livre, bem como a importância desse nematódeo para a ovinocultura, motivaram o presente estudo. Inicialmente, foram determinados valores de normalidade para os parâmetros hematológicos e bioquímicos, bem como testada possível influência do sexo sobre eles. Num segundo momento, os animais foram separados em grupos e infectados experimentalmente. O processo infeccioso foi monitorado por um período de 60 dias, ao final do qual os animais foram submetidos à eutanásia e necropsiados. O processo infeccioso estabelecido, em intensidade parasitária similar à observada em animais de vida livre, não foi capaz de suscitar alterações hematológicas, bioquímicas ou anátomo-patológicas relevantes, tampouco interferir na ingestão de alimentos, sugerindo que, apesar da possibilidade de parasitismo, a infecção por H. contortus, nos níveis deste experimento, não provocam doença clínica nos animais. À luz dos dados morfométricos e parasitológicos, sugere-se uma má adaptação do H. contortus aos veados-catingueiros, apesar da possibilidade de manutenção do parasita nestes animais. / The comprehension of the pathophysiological aspects concerning wild animals’ diseases contributes favourably to the improvement of captive rearing of these animals, and also to the elaboration of conservation action plans for free-ranging animals. The diverse reports on deer parasitism by Haemonchus contortus and the importance of this nematode for sheep production motivated this research. First, reference values for haematological and biochemical parameters were determined for this species and the gender influence on them was tested. Then, the animals were divided in groups and infected. The infectious process was monitored over a 60 days period, and then the animals were killed and necropsied. The established infection, similar to natural acquired infections, was insufficient to lead to haematological, biochemical or pathological changes or interfere with food uptake. Based on this, despite the possibility of infection, H. contortus did not cause clinical disease in gray-brocket deer. Moreover, the morphometric and parasitological data suggest a maladaptation of H. contortus in this host species.
6

Myxozoa parasitos de Pseudoplatystoma corruscans (pintado), Salminus franciscanus (dourado) e Brycon orthotaenia (matrinxã) oriundos da bacia do rio São Francisco, MG / Myxozoa parasites of Pseudoplatystoma corruscans (pintado), Salminus franciscanus (dourado) and Brycon orthotaenia (matrinxã) from the São Francisco river basin, MG

Naldoni, Juliana, 1986- 12 October 2014 (has links)
Orientador: Edson Aparecido Adriano / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-26T12:26:07Z (GMT). No. of bitstreams: 1 Naldoni_Juliana_D.pdf: 10311500 bytes, checksum: a497c164e89d09cfdbe8ccfcf87ef274 (MD5) Previous issue date: 2014 / Resumo: Mixosporídeos são cosmopolitas e infectam peixes em diversas regiões do mundo. Atualmente são conhecidas cerca de 2.400 espécies, das quais a grande maioria é parasito de peixes, tanto de ambiente natural como de sistemas de criação, sendo algumas espécies responsáveis por altas taxas de mortalidade em várias partes do mundo. Este trabalho teve como objetivo o estudo da diversidade de mixosporídeos parasitos de Pseudoplatystoma corruscans (pintado), Salminus franciscanus (dourado) e Brycon orthotaenia (matrinxã) da bacia do rio são Francisco, município de Pirapora, MG, Brasil. Foram realizados estudos morfológicos, ultraestruturais, histotológicos e moleculares de cinco novas espécies de mixosporídeos, sendo uma do gênero Henneguya em pintado, duas do gênero Myxobolus infectando dourado e duas infectando matrinxã. Henneguya sp. n. 1 apresentou plasmódios brancos e alongados no tecido conjuntivo das brânquias de pintado. A análise ultraestrutual revelou a parede plasmodial com delicadas projeções em direção aos tecidos do hospedeiro e a presença de uma fina camada de material finamente granular isolando o parasito do contato com o tecido do hospedeiro. A análise histológica revelou que o desenvolvimento do plasmódio causou a compressão no tecido conjuntivo e epitelial, deformação dos filamentos e a fusão lamelar. A análise filogenética, baseada no gene 18S rDNA e utilizando somente espécies dos gêneros Henneguya e Myxobolus parasitos de siluriformes, revelou o agrupamento de acordo com a família dos peixes hospedeiros. Myxobolus sp. n. 1 apresentou plasmódios brancos e arredondados entre os raios da nadadeira de dourado. A análise ultraestrutural revelou uma camada de fibroblastos circundando o plasmódio, impedindo o contato com as células do hospedeiro. Myxobolus sp. n. 2 apresentou plasmódios brancos e arredondados no fígado de dourado. Myxobolus sp. n. 3 e Myxobolus sp. n. 4 apresentaram plasmódios brancos e arredondados, sendo que a primeira ocorreu no baço e a segunda no rim de matrinxã. A análise ultraestrutural de Myxobolus sp. n. 2, Myxobolus sp. n. 3 e Myxobolus sp. n. 4 revelou o contato direto entre a parede do plasmódio do parasito e o tecido dos hospedeiros. As paredes dos plasmódios das cinco espécies aqui estudadas foram compostas por membrana simples. O processo de esporogênese das cinco espécies foi assincrônico, com células germinativas e jovens estágios de desenvolvimento dos esporos ocorrendo na periferia do plasmódio e esporos imaturos e maduros foram observados na região central. A análise filogenética, baseado no gene 18S rDNA e usando somente espécies dos gêneros Henneguya e Myxobolus parasitos de peixes da América do Sul mais as quatro novas espécies de Myxobolus parasitas de briconídeos, mostrou a especificidade de hospedeiro e a afinidade de órgão/tecido, como um importante sinal evolutivo para Myxobolus/Henneguya / Abstract: Myxosporeans are cosmopolitan parasites and infect fish in various regions of the world. So far, are known about 2,400 species, of which the vast majority are parasites of fishes, from natural environment and fish farms, and some species responsible for high mortality rates in various parts of the world. This work aimed to study the diversity of myxosporeans of Pseudoplatystoma corruscans (pintado), Salminus franciscanus (dourado) and Brycon orthotaenia (matrinxã) from the São Francisco River, municipality of Pirapora, MG, Brazil. Morphological, ultrastructural, histological and molecular studies of five new species of myxosporeans were performed, being one species of the genus Henneguya infecting pintado, two of the genus Myxobolus infecting dourado and two infecting matrinxã. Henneguya sp. n. 1 had white and elongated plasmodia in the connective tissue of the gill filaments. The ultrastructural analysis revealed the plasmodial wall with delicate projections towards the tissues of the host, and the presence of a thin layer of fibrous material isolating the parasite of the contact with the host tissue. Histological analysis revealed that the development of the plasmodium caused compression of the connective and epithelial tissue, deformation of the filament and lamellar fusion. Phylogenetic analysis, based on 18S rDNA gene, and using only Henneguya and Myxobolus parasites of siluriformes revealed clustering according to the family of the host fish. Myxobolus sp. n. 1 had white and rounded plasmodia that developed between the fin rays of dourado. The ultrastructural analysis showed a fibroblast layer surrounding the plasmodium, preventing contact of the parasite with the host tissues. Myxobolus sp. n. 2 had white and rounded plasmodia that developed in the liver also of dourado. Myxobolus sp. n. 3 and Myxobolus sp. n. 4 infected matrinxã, being that the first had white and rounded plasmodia in the spleen and the second in the kidney. The ultrastructural analyses of Myxobolus sp. n. 2, Myxobolus sp. n. 3 and Myxobolus sp. n. 4 revealed direct contact between the plasmodial wall and the host tissue. The plasmodial wall of the five myxosporeans species subject of this study was composed by single membrane. The process of sporogenesis in these five species was asynchronous, with germ cells and young development stages of spores occurring in the periphery of the plasmodia and immature and mature spores in the central region. Phylogenetic analysis based on 18S rDNA gene and using only Henneguya and Myxobolus parasites of fish from South America plus the four new Myxobolus species parasites of bryconids, shows host specificity and organs/tissue affinity as important evolutionary signs to Myxobolus/Henneguya / Doutorado / Parasitologia / Doutora em Parasitologia
7

The structure and function of the attachment organs in Cotylurus variegatus Creplin, 1825 (Odening, 1969) (Trematoda: Strigeida).

Haight, Murray Ellis 10 1900 (has links)
<p> Previous studies dealing with the structure and function of the attachment organs in the strigeid trematodes have neglected to describe the processes involved in the formation of attachment. A knowledge of these processes is necessary to promote the understanding of the host-parasite relationship. </p> <p> In the present study, specimens of developing Cotylurus variegatus were examined using light and electron microscopic techniques. It seemed relevant to consider not only the sequence of attachment events, but the growth and structure of the attachment organs in relation to the total parasite body growth and structure. This of course, has led to considerations of the reputative functions of these structures. </p> / Thesis / Master of Science (MSc)
8

Infecção experimental de Mazana gouazoubira (Ficher, 1814) (Cervidae: Odocoileinae) com Haemonchus contortus (Rudolphi, 1803) (Nematoda: Trichostrongyloidea) /

Hoppe, Estevam Guilherme Lux. January 2010 (has links)
Orientador: Adjair Antônio do Nascimento / Banca: Milton Hissashi Yamamura / Banca: Alessandro Francisco Talamini do Amarante / Banca: Flavio Ruas de Moraes / Banca: Rosemeri de Oliveira Vasconcelos / Resumo: A adequada compreensão dos mecanismos fisiopatológicos das doenças que afetam os animais silvestres contribui positivamente para a melhoria das condições de manutenção desses animais em cativeiro e fornece subsídios para a elaboração de planos de conservação de animais de vida livre. Diversos relatos de Haemonchus contortus em cervídeos de cativeiro e vida livre, bem como a importância desse nematódeo para a ovinocultura, motivaram o presente estudo. Inicialmente, foram determinados valores de normalidade para os parâmetros hematológicos e bioquímicos, bem como testada possível influência do sexo sobre eles. Num segundo momento, os animais foram separados em grupos e infectados experimentalmente. O processo infeccioso foi monitorado por um período de 60 dias, ao final do qual os animais foram submetidos à eutanásia e necropsiados. O processo infeccioso estabelecido, em intensidade parasitária similar à observada em animais de vida livre, não foi capaz de suscitar alterações hematológicas, bioquímicas ou anátomo-patológicas relevantes, tampouco interferir na ingestão de alimentos, sugerindo que, apesar da possibilidade de parasitismo, a infecção por H. contortus, nos níveis deste experimento, não provocam doença clínica nos animais. À luz dos dados morfométricos e parasitológicos, sugere-se uma má adaptação do H. contortus aos veados-catingueiros, apesar da possibilidade de manutenção do parasita nestes animais. / Abstract: The comprehension of the pathophysiological aspects concerning wild animals' diseases contributes favourably to the improvement of captive rearing of these animals, and also to the elaboration of conservation action plans for free-ranging animals. The diverse reports on deer parasitism by Haemonchus contortus and the importance of this nematode for sheep production motivated this research. First, reference values for haematological and biochemical parameters were determined for this species and the gender influence on them was tested. Then, the animals were divided in groups and infected. The infectious process was monitored over a 60 days period, and then the animals were killed and necropsied. The established infection, similar to natural acquired infections, was insufficient to lead to haematological, biochemical or pathological changes or interfere with food uptake. Based on this, despite the possibility of infection, H. contortus did not cause clinical disease in gray-brocket deer. Moreover, the morphometric and parasitological data suggest a maladaptation of H. contortus in this host species. / Doutor
9

Macroparasite transmission and dynamics in Apodemus flavicollis

Ferrari, Nicola January 2005 (has links)
This thesis examines the parasite dynamics and the mechanisms affecting parasite load and transmission focalising on the role played by host and habitat heterogeneities. This study is based on the gastrointestinal nematode Heligmosomoides polygyrus and the small mammal yellow necked mouse and uses data gathered from experimental field manipulations of parasites intensities and data gathered from trapping monitoring. Initially the parasite community of yellow-necked mouse (Apodemus flavicollis) was explored in North-Eastern Italian Alps with the aim to describe the major patterns and identify the factors affecting parasite community structure. Despite the observed spatial variability it has been found that differences within the host population such age and secondly sex and breeding conditions, were the major factors acting on parasite occurrence and intensity. Habitat differences had a less apparent effect on parasite community structure. The consequences of H. polygyrus infection on other parasite species infections have been analysed, in specific the infestation of the tick Ixodes ricinus in populations of A. flavicollis. H. polygyrus load and tick infestation were monitored as well as were carried out field manipulations of H. polygyrus intensity and were monitored changes in tick infestation. It has been found that H. polygyrus load was negatively related to I. ricinus infestations. Host factors mediated the H. polygyrus-I. ricinus interaction such that young and non-breeding mice exhibited higher I. ricinus to H. polygyrus intensity respect breeding adults. The role of host sex on parasite abundance was then investigated carrying out a field experiment where the H. polygyrus intensity were manipulated in relation to mice gender. In specific, H. polygyrus was removed alternately from either sexes and the parasite load was analysed in the untreated sex. It was found that males mice were responsible to drive parasite transmission in the host population and this was observed in absence of sex-bias in parasite infection, suggesting that this pattern was not a mere consequence of quantitative differences in parasite loads between sexes. To disentangle the possible mechanism causing this sex bias in parasite transmission mathematical simulations based on parameters obtained for the field experiment were used. Two non mutually exclusive hypotheses causing sex bias in parasite transmission were tested: a- males immune response is less efficient and this causes the development of more successful parasite infective stages or b-males behaviours allow them to be more efficient is spreading in more exposed areas parasite infective stages. Multi-host models were developed and simulations were compared with field results. While it was not disentangled the most dominant mechanism causing sex bias in parasite transmission this study underlined the importance of host sexes in affecting parasite dynamics and host-parasite interaction. In conclusion this thesis highlighted the importance of considering host and environmental differences when investigating host parasite interactions. This finding could be extremely important when planning measured of disease control or to avoid disease outbreak. Controlling target group of individuals host could avoid economical losses and a more effective measure of intervention.
10

Angiostrongylus cantonensis (Nematoda): estudo comparativo dos efeitos da infec??o sobre o metabolismo de Biomphalaria straminea e Biomphalaria tenagophila (Mollusca) / Angiostrongylus cantonensis (Nematoda): Comparative study of infection effects on the metabolism of Biomphalaria straminea and Biomphalaria tenagophila (Mollusca).

Lima, Mariana Gomes 23 February 2016 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-03-22T13:55:27Z No. of bitstreams: 1 2016 - Mariana Gomes Lima.pdf: 3236185 bytes, checksum: 3517b88022c7943663ae0274085cc96a (MD5) / Made available in DSpace on 2017-03-22T13:55:27Z (GMT). No. of bitstreams: 1 2016 - Mariana Gomes Lima.pdf: 3236185 bytes, checksum: 3517b88022c7943663ae0274085cc96a (MD5) Previous issue date: 2016-02-23 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / The nematode Angiostrongylus cantonensis has gained notoriety under the public health point of view out of its endemic area in Asia, since in recent years cases of eosinophilic meningoencephalitis have been reported in other continents, such as in the Americas. In Brazil over thirty cases of this zoonotic disease have been recorded and there are reports of the presence of this nematode in 11 states. In its life cycle A. cantonensis has, along their development, need for intermediate and final host, involving predominantly molluscs and rodents, respectively, and different paratenic hosts, humans are accidental hosts. They can also infect a rich variety of terrestrial and aquatic molluscs and in this study, there were used specimens of neotropical planorbids transmitters of schistosomiasis, Biomphalaria straminea and Biomphalaria tenagophila, born and reared in the laboratoryfor experimental infection by A. cantonensis. In order to characterize the resulting physiological profile that host-parasite relationship, the host molluscs were separated into groups of infected and uninfected containing thirty molluscs per group, all made in triplicates. The investigation lasted 21 days, after the pre-patent period molluscs were dissected to collect hemolymph, removal of tissues and use the shell for calcium concentration check. The reproductive biology of both species was observed on the viability of the eggs, as well as (A) Number of eggs/ eggs mass; (B) Number of eggs/mollusc; (C) Number of eggs mass/mollusc and (D) Number of hatched molluscs/mollusc. In the hemolymph there were quantified total protein, glucose, uric acid, urea, the activity of transaminases AST and ALT, lactate dehydrogenase - LDH, and organic acids (oxalic, pyruvic, succinic and lactic). In the cephalopedal mass and digestive gland the glycogen content was measured and in the albumen gland, it was measured the galactogen. The results showed that the snails infected, of both species showed significant reduction in the viability of eggs, 50% for B. straminea and 10% for B. tenagophila. The metabolic status was also strongly affected, with mobilization of glycogen and hemolymph glucose reduction of 68% to B. straminea and 6.48% for B. tenagophila, followed by anincrease of LDH activity of 518.25% to 320.14% B. straminea and to B. tenagophila as well as the concentration of lactic acid, 5,7mM to B. straminea and 0.34 mM for B. tenagophila, and reduction in the concentration of pyruvic and succinic acids. The intense release of gluconeogenic amino acids from protein catabolism reversed the excretory pattern from uricotelic to ureotelic in both B. tenagophila and B. straminea. The tissue injury showed increase of 69% in the concentration of total proteins in the hemolymph of B. straminea and the intense activity of aminotransferases, ALT and AST, an increase of 241.26% and 360%, respectively, compared to the control group. The infection reduced by 51.57% the concentration of total circulating proteins to B. tenagophila, and increased ALT and AST activity at 310% and 280% compared to uninfected snails. The results of this study indicate that the energetic and structural metabolism of both species is strongly affected by the infection, showing the activation of an anaerobic to compensate for the depletion of glicidics stores as well as the change in the excretory pattern depending on the use of substrates protein for the production of ATP. Although studies on clinical, pathological and epidemiological neural angiostrongyliasis have been extensively carried xiii out, data on the metabolic and reproductive profile of snails infected by A. cantonensis are scarce. This pioneering study focused on species of host-parasite relationship certainly contribute to the knowledge of this interaction, as well as to the epidemiology of transmission A. cantonensis in addition to providing new subsidies which can be used in prevention and control of eosinophilic meningitis, zoonosis considered emerging in Brazil. / O nemat?deo Angiostrongylus cantonensis tem ganhado notoriedade sob o ponto de vista da sa?de p?blica fora de sua ?rea end?mica na ?sia, uma vez que nos ?ltimos anos casos de meningoencefal?te eosinof?lica v?m sendo reportados em outros continentes, como nas Am?ricas. No Brasil mais de trinta casos dessa zoonose j? foram registrados e h? relatos da presen?a desse nemat?deo em 11 estados. Em seu ciclo de vida heteroxeno A. cantonensis tem, ao longo do seu desenvolvimento, a necessidade de hospedeiro intermedi?rio e definitivo, envolvendo predominantemente, moluscos e roedores, respectivamente, al?m de v?rios hospedeiros parat?nicos, sendo o homem um hospedeiro acidental. Pode infectar uma rica variedade de moluscos terrestres e aqu?ticos e neste estudo, foram utilizadas para infec??o experimental popula??es nascidas e criadas em laborat?rio de duas esp?cies de planorb?deos neotropicais transmissores da esquistossomose mans?nica, Biomphalaria straminea e Biomphalaria tenagophila. Com a finalidade de caracterizar o perfil fisiol?gico resultante dessa rela??o hospedeiro-parasito, os moluscos hospedeiros foram separados em grupos de infectados e n?o infectados, contendo trinta moluscos por grupo, todos feitos em triplicatas. A investiga??o durou 21 dias, ao fim do per?odo pr?-patente os moluscos foram dissecados para a coleta de hemolinfa, retirada de tecidos e utiliza??o da concha para verifica??o de concentra??o de c?lcio. A oviposi??o dos moluscos de ambas as esp?cies foi observada quanto ? viabilidade dos ovos, assim como (A) N?mero de massas ov?geras/molusco; (B) N?mero de ovos/molusco; (C) N?mero de ovos/massa ov?gera e (D) N?mero de moluscos eclodidos/molusco. Na hemolinfa foram quantificadas as prote?nas totais, glicose, ?cido ?rico, ureia, a atividade das transaminases ALT e AST, lactato desidrogenase - LDH, e os ?cidos org?nicos (ox?lico, pir?vico, succ?nico e l?tico). Na massa cefalopediosa e gl?ndula digestiva, foram mensurados os conte?dos de glicog?nio e na gl?ndula de alb?men, foi mensurado o galactog?nio. Os resultados obtidos mostraram que os moluscos infectados, de ambas as esp?cies, apresentaram redu??o significativa na viabilidade dos ovos, de 50% para B. straminea e de 10% para B. tenagophila. O estado energ?tico tamb?m foi vigorosamente afetado, com mobiliza??o das reservas de glicog?nio, e queda da glicemia de 68% para B. straminea e de 6,48% para B. tenagophila, seguida de uma eleva??o na atividade da LDH de 518,25% para B. straminea e 320,14% para B. tenagophila, bem como na concentra??o do ?cido l?tico, 5,7mM para B. straminea e 0,34 mM para B. tenagophila, e redu??o na concentra??o dos ?cidos pir?vico e succ?nico. A intensa libera??o de amino?cidos gliconeog?nicos a partir do catabolismo proteico inverteu o padr?o excretor de uricot?lico para ureot?lico tanto em B. tenagophila quanto em B. straminea. A les?o tecidual mostrou eleva??o de 69% na concentra??o das prote?nas totais na hemolinfa de B. straminea, bem como a intensa atividade das aminotransferases, AST e ALT, com aumento de 241,26% e 360%, respectivamente, em rela??o ao grupo controle. A infec??o reduziu em 51,57% a concentra??o de prote?nas totais circulantes para B. tenagophila, e elevou a atividade de ALT e AST em 310% e xi 280% em compara??o com os moluscos n?o infectados. Os resultados observados neste estudo indicam que o metabolismo energ?tico e estrutural de ambas as esp?cies foi vigorosamente afetado pela infec??o, mostrando a ativa??o de uma via anaer?bia para compensar a exaust?o das reservas glic?dicas, assim como a mudan?a no padr?o excretor em fun??o da utiliza??o de substratos proteicos para produ??o de ATP. Embora, estudos sobre aspectos cl?nicos, patol?gicos e epidemiol?gicos da angiostrongil?ase neural t?m sido extensivamente realizados, dados acerca do perfil metab?lico e reprodutivo de moluscos infectados por A. cantonensis s?o escassos. Este estudo pioneiro na rela??o parasito-hospedeiro das esp?cies focadas seguramente contribuir? tanto para o conhecimento dessa intera??o, quanto da epidemiologia da transmiss?o de A. cantonensis, al?m de fornecer novos subs?dios que poder?o ser utilizados em medidas de preven??o e controle da meningite eosinof?lica, zoonose considerada emergente no Brasil

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