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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.
331

Validação diagnóstica para a detecção de Cryptosporidium spp. em bovinos /

Inácio, Sandra Valéria. January 2016 (has links)
Orientador: Katia Denise Saraiva Bresciani / Banca: Simone Baldini Lucheis / Banca: Valéria Maria Savoya da Silva / Banca: Mônica Regina Vendrame Amarante / Banca: Silvia Helena venturoli Perri / Resumo: A criptosporidiose, tanto humana como animal, tem distribuição cosmopolita. Esse parasito ocasiona diarreia em bezerros, retardo no crescimento, mortalidade e consequentes perdas econômicas. Nós realizamos a viabilização, desenvolvimento, avaliação e validação intralaboratorial de uma nova técnica parasitológica para a análise em microscopia óptica de oocistos de Cryptosporidium spp., denominada de TF-Test Coccidia, em amostras fecais de bezerros do município de Araçatuba, São Paulo. Para o desenvolvimento deste estudo e confirmação da nova técnica diagnóstica TF-Test Coccidia foram empregadas duas metodologias: centrífugo-sedimentação seguida da coloração negativa de verde malaquita (CSN-Malaquita) e Nested-PCR. Amostras positivas e negativas de bezerros foram utilizadas para a confecção e validação do TF-Test Coccidia. Portanto, podemos concluir a eficácia da técnica parasitológica de TF-Test Coccidia, na detecção de oocistos do parasito Cryptosporidium spp. e observamos boa concentração e morfologia das estruturas de eliminação do mencionado parasito, com baixa quantidade de impureza em esfregaço fecal. / Abstract: Cryptosporidiosis, both human and animal, has a worldwide distribution. This parasite causes diarrhea in calves, growth retardation, mortality and consequent economic losses. We performed the feasibility, development, evaluation and within-laboratory validation of a new parasitological technique by optical microscopy analysis of Cryptosporidium spp., Called TF-Test Coccidia in fecal samples of calves in the city of Araçatuba, São Paulo. To develop this study and confirmation of the new diagnostic technique TF-Test Coccidia were employed two methodologies: the centrifugal sedimentation followed by negative staining of malachite green (CSN-Malachite) and nested PCR. Positive and negative samples from calves were used for the preparation and validation of TF-Test Coccidia. Therefore, we conclude the effectiveness of parasitological technique TF-Test Coccidia, on the oocysts detection of the parasite Cryptosporidium spp. and observe good concentration and morphology of eliminated parasitic structures mentioned, with low amount of impurity in fecal smear. / Doutor
332

Parasitas gastrointestinais de Peltocephalus dumerilianus no Parque Nacional do Jaú, Barcelos, Amazonas : taxonomia-alfa e aspectos da relação parasita-hospedeiro /

Ferreira, Luciana Raffi Menegaldo. January 2016 (has links)
Orientador: Estevam Guilherme Lux Hoppe / Banca: Marcos Rogério André / Banca: Adjair Antônio do Nascimento / Banca: Daniel Fontana Ferreira Cardia / Banca: Wilson Gómez Manrique / Resumo: Peltocephalus dumerilianus (Chelonia: Podocnemididae) é um quelônio amplamente distribuído na Bacia Amazônica, encontrado preferencialmente em rios, igapós e lagos de água preta. Ocorrem em simpatria com outros animais da família Podocnemididae, embora sofram menor pressão cinegética por concentrarem seus ninhos em locais mais reclusos, no interior das florestas de igapó. Apesar de sua ampla distribuição e importância como fonte de proteína para os moradores da Amazônia, são raras as pesquisas relacionadas à patógenos desses répteis, inclusive de helmintos parasitos, fato que motivou este projeto. Para o estudo da helmintofauna de P. dumerilianus, 21 espécimes foram obtidos através de caça de subsistência na comunidade Tapiíra, situada às margens do rio Unini e inserida no Parque Nacional do Jaú, Barcelos, Estado do Amazonas, região bastante preservada e caracterizada por diversas Unidades de Conservação de Uso Sustentável e de Uso Integral. Após a colheita do conteúdo gastrointestinal, os helmintos obtidos foram identificados por métodos morfológicos de rotina aliados a estudos com microscopia eletrônica de varredura (MEV). Foram identificados espécies de nematódeos, Ancyracanthus pinnatifidus, Paratractis hystrix, Atractis trematophila, Klossinemella conciliatus, e mais três espécies indeterminadas do gênero Klossinemella. Também foram identificados os digenéticos Nematophila grandis, Helicotrema spirale e Telorchis hagmanni. Os resultados apresentados en... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Peltocephalus dumerilianus (Chelonia: Podocnemididae) is a chelonian widely distributed in the Amazon Basin, preferably found in rivers, flooded forests and black water lakes. Occur sympatric with other animals Podocnemididae family, although they suffer less pressure hunting by concentrating their nests in more prisoners locations within igapó forests. Despite its wide distribution and importance as a protein source for the inhabitants of the Amazon are few studies related to pathogens such animals, including helminth parasites, a fact that motivated this project. For the study of helminth parasites of P. dumerilianus, 21 specimens were obtained through subsistence hunting in Tapiíra community, situated on the banks of the river Unini and inserted in the Jau National Park, Barcelos, State of Amazonas; region well preserved and characterized by several Conservation Units of Sustainable Use and Full Use. After harvesting of gastrointestinal contents, helminths obtained were identified by traditional morphological methods combined with studies with scanning electron microscopy (SEM). Four species of nematodes were identified, Ancyracanthus pinnatifidus, Paratractis hystrix, Atractis trematophila, Klossinemella conciliatus, and more three undetermined species of the genus Klossinemella. Also were identified digeneas Nematophila grandis, Helicotrema spirale and Telorchis hagmanni. The results presented enrich the knowledge of the Amazon parasitic biodiversity and demonstrate aspe... (Complete abstract click electronic access below) / Doutor
333

Střevní paraziti koz ve vybraném chovu / Gut parasites of goats on a chosen farm

VANĚČKOVÁ, Michala January 2011 (has links)
The master thesis is aimed to evaluate intestinal parasites occurrence in a goat breeding. A herd of goats chosen for this survey was kept by a private enterprise focused on milk production. The practical research was conducted during two years, 2009 and 2010. Samples of feaces were collected during that period and analyzed for parasites occurrence. The analyses proved presence of the following parasites: Trichuris ovis, parasites from the order Strongylida, Fasciola hepatica, Dicrocellium lanceatum and coccidia. Total prevalence was significant; 85% of the samples were found to be positive. Species from the order Strongylida were identified as the most often 41,46 %, which meant 199 cases from the total of 509. During the examined period, the highest prevalence of parasites was detected in summer 2009, the second highest then in spring 2010.
334

Viabilidade do parasitismo por Haemonchus placei em caprinos (Capra hircus) experimentalmente infectados /

Santos, Isabella Barbosa dos. January 2018 (has links)
Orientador: Gilson Pereira Oliveira / Coorientador: Alvimar José da Costa / Banca: Adriana Mello Garcia / Banca: Estevam Guilherme Lux Hoppe / Resumo: A caprinocultura é considerada um segmento de grande importância em agronegócios no país, gerando importante fonte de carne e leite, principalmente na região Nordeste. Entretanto, este criatório sofre grandes perdas econômicas devido às parasitoses que acometem o trato digestório. Dentre estas, destaca-se, o gênero Haemonchus, cujas espécies H. contortus e H. placei parasitam abomaso de caprinos e bovinos, respectivamente, havendo possibilidade de infecção cruzada dessas duas espécies helmínticas. O objetivo do presente estudo foi avaliar a viabilidade do parasitismo por H. placei em caprinos e compará-la à patogenicidade por H. contortus. Foram utilizados 14 caprinos, recém-nascidos, mantidos em gaiolas metálicas de piso suspenso, assim distribuídos: GI - quatro cabritos inoculados com 5000 larvas infectantes (L3) de H. placei, GII - quatro infectados com 5000 larvas infectantes (L3) de H. contortus, GIII - quatro animais inoculados com 2500 larvas L3 de H. contortus + 2500 H. placei e GIV - dois cabritos que receberam apenas água (controle). Exames de contagem de ovos de estrongilídeos por grama de fezes (OPG) foram realizados diariamente, após o 7º dia da inoculação. Os períodos pré-patentes foram de 24 dias para H contortus e de 31 dias para H. placei. O grupo inoculado apenas com H. placei apresentou médias de OPG inferiores quando comparado aos demais grupos. Decorridos 42 dias pós-infecção, os 14 caprinos foram eutanasiados e necropsiados, sendo coletados "in totum" os... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Goat breeding is considered a very important segment in Brazilian agribusiness, generating a significant source of meat and milk. However, this industry suffers great economic losses due to parasitic diseases that affect the digestive tract, compromising their development. Among these, the Haemonchus genus stands out, with H. contortus and H. placei parasitizing goats and cattle, respectively, with the possiblity of cross infection between these helminth species in abomasu of hosts. The objective of the present study was to estimate the viability of H. placei parasitism in goats, and compare it with H. contortus pathogenicity. Fourteen newborn goats were used, distributed in the following way: GI - four goats inoculated with infective larvae (L3) of H. placei; GII - four animals infected with infective larvae (L3) of H. contortus; GIII - four caprines inoculated with larvae L3 of H. contortus + H. placei; and GIV - two goats that received only water (control). Each animal received 5000 L3 of Haemonchus species, in a single dose, orally. Egg per Gram of Feces (EPG) exams were performed daily after the 7th day of inoculation, establishing that the pre-patent period of H. contortus was 24 days and H. placei was 31 days. The group inoculated only with H. placei presented lower EPG means when compared to the other groups. After 42 days post-infection, all 14 goats were euthanized and necropsied, and Haemonchus specimens were collected "in totum". Group I presented an average of 25... (Complete abstract click electronic access below) / Mestre
335

Sarconema eurycerca (Wehr) : the heartworm of swans and the role of Trinoton anserinum (F) as an intermediate host

Cohen, Sharon January 1988 (has links)
All filarial nematodes of the family Onchocercidae are parasites of vertebrates and require intermediate insect hosts for completion of their life-cycles. Eighteen genera within this family are known to infect birds but very few of the associated intermediate hosts have been elucidated. Sarconema eurycerca (Wehr) is a filarial nematode of swans and geese. A recent study of S. eurycerca in American Whistling Swans (Cygnus c. columbianus ) has demonstrated that the intermediate insect host is a feather louse, Trinoton anserinum (Fabricius) (Seegar, 1977). The main aim of the present study was to investigate the relationship between S. eurycerca and British swans and to determine whether T. anserinum is the intermediate host of the parasite in this country. A total of 1128 swans (of all species) were examined from sites in Britain, Denmark and Iceland. Infected swans were detected by examining blood samples for larval stages of S. eurycerca (microfilariae) using a new sedimentation technique developed in the study. An overall incidence of 15.0% was recorded with a significantly higher proportion of juvenile swans being infected. The microfilariae of S. eurycerca exhibited a diurnal sub-periodic rhythm within the host, with maximum counts occurring between 11.00 and 19.00 hours in the peripheral blood supply. T. anserinum was found to satisfy all the attributes required of an intermediate insect host. As an obligate ectoparasite, T. anserinum has a close spatial and temporal relationship with the swan. T. anserinum appears to be capable of ingesting microfilarie of S. eurycerca whilst feeding on blood. All developing larval stages of S. eurycerca were found in T. anserinum and the louse was very mobile and capable of transmitting the nematode from one swan to another. Examinations were made of the nematode, its morphology and pathological effects on both heart tissue and blood components of the swan. Significantly higher lymphocyte percentages and lower eosinophil percentages, haematocrit and red blood corpuscle counts were recorded in swans infected with S. eurycerca.
336

Developmental studies of certain South African Ascostromatic ascomycetes

Tim, Stephen K-M January 1971 (has links)
From General Introduction: Toward the last half of the nineteenth century, the structure and mode of development of the ascocarp has aroused much interest. De Bary (1887) recognised the fruiting bodies of the Ascomycetes as 'compound sporophores' made up of interwoven hyphae or of pseudoparenchyma consisting of a peripheral layer separate from an inner tissue. These fruiting bodies included the discocarp or apothecium, the pyrenocarp or perithecium and the cleistocarp or cleistothecium. The name, Pyrenomycetes, has been variously applied to a group of Ascomycetes but mainly to the perithecial types, inclusive of the true perithecia and the loculate forms. The perithecium itself was described as a 'cup-shaped discomycetous' sporocarp with margins incurved to form a pyriform structure (de Bary, 1887). The presence or absence of a stroma had been long considered as a basis for the separation of the major groups of the Ascomycetes. Separation on these grounds was found unacceptable as it grouped together clearly unrelated species or separated related ones. As the subdivisions of the pyrenomycetous Ascomycetes are dependent upon the morphological features of the ascocarp, it would be pertinent to discuss the following: a) The Stroma. b) The various forms of ascocarp which mayor may not be associated with such a stroma. i) Perithecia: free or immersed in a stroma. ii) Uni- or multiloculate stromata. c) The centrum, the details associated with the centrum and the use of these details in the taxonomy of the pyrenomycetes.
337

Inhibition of the histone deacetylase family as a drug target in the human malaria parasite, plasmodium falciparum

Ismail, Nabila January 2014 (has links)
The asexual life cycle of Plasmodium falciparum parasites takes only 48 hours, allowing for rapid replication. The continuous infection, rupturing and re-infection of erythrocytes results in the pathogenicity of this disease. Schizogony (nuclear division) in P. falciparum parasites occurs via alternation between the S and M phases of the cell cycle where DNA synthesis occurs in the mature trophozoite and schizont stages, followed by mitosis to form daughter merozoites. Merozoites then give rise to ring stages after they have infected erythrocytes and the ring stages continue their development to trophozoites. This cyclic development, known as the intraerythrocytic developmental cycle, has a unique transcriptional regulation, which is closely linked to cell cycle regulation. However, the intricacies that these mechanisms are controlled by are still unidentified. One of the means in which the P. falciparum parasite’s complex life cycle is controlled is by means of epigenetics. Epigenetics refers to the heritable changes on a phenotypic level, which are independent of changes on a genetic level. One group of enzymes that participates in the parasite’s epigenetic control is the Plasmodium histone deacetylases. Inhibition of histone deacetylases (HDACs) results in hyperacetylation, which causes aberrant gene transcription and eventually results in parasite death. Comparative analyses of three histone isolation methods and analysis of P. falciparum parasite histones and their post-translational modifications (PTMs) by mass spectrometry techniques identified both epigenetically relevant and novel PTMs in P. falciparum parasite histones and led to the discovery of an adapted histone isolation method for investigation of histone PTM landscapes. When this modified method was used for the investigation of histones that were isolated from P. falciparum parasites treated with HDAC inhibitors compared to untreated parasites, differences were seen in the PTM landscape. Subsequent in silico screening strategies were used to identify ten compounds from the Medicines for Malaria Venture (MMV) Malaria Box, which target the active site of the zinc-requiring PfHDAC1. From these, eight compounds showed inhibition of proliferation of cultured P. falciparum parasites. Ensuing, the adaptation of an HDAC assay to investigate histone deacetylase inhibition was used to validate these compounds as possible PfHDAC1 inhibitors, with at least two of the compounds showing significant inhibition of PfHDAC1 activity, comparable to that of the known HDAC inhibitor, suberoylanilide hydroxamic acid, SAHA. The use of in silico screening of a large library of compounds, such as the MMV Malaria Box, successfully narrows down candidates for possible anti-malarials with drug-like properties by identification of their cellular targets. This work is method-based and facilitates the investigation of the epigenetic landscape of histones, and the identification of novel HDAC inhibitors. / Dissertation (MSc)--University of Pretoria, 2014. / gm2014 / Biochemistry / unrestricted
338

Biodiversity of the fish parasitic Gnathiid isopods from coral reefs

Farquharson, Charon 29 June 2011 (has links)
M.Sc. / Recent years have seen a remarkable increase in scientific research and studies conducted regarding the unique group of parasitic isopods known as gnathiids. The taxonomy of gnathiids are based solely on the morphological characteristics of the free-living adult males, which means that the female and larval life stages are often not collected and described with the males, and when collected it is seldom possible to even identify these stages when not in the company of there adult males. Numerous studies have been conducted in Australia regarding cleaning behaviour of coral reef fishes, where these gnathiid larvae are extremely abundant and are often collected. These types of studies as well as others are increasing all around the world, and because of the fact that the larvae cannot be easily identified, the results and data collected from these various studies are often misinterpreted or inconclusive and makes no sense. The fact that gnathiid larvae may serve as possible vectors for certain fish blood parasites and have various physiological and ecological effects on their fish hosts, which may lead to mortality, can have detrimental economical effects on the fisheries industry. This study was thus conducted to improve the identification methods that are currently applied to the larval life stages of gnathiid isopods through various means including increasing the number of detailed descriptions available, constructing a taxonomic key and lastly conducting a basic phylogenetic analysis of a group of known gnathiid larvae in order to aid researchers with future identifications. It was hypothesised that firstly, although there are some gnathiid descriptions from coral reefs, mostly of adult males, it is likely that there are still a great number of unknown and not yet described gnathiid species, because coral reefs are one of the most highly biodiverse marine ecosystems. Secondly, that the distribution of coral reef gnathiids is much wider than currently known or documented and lastly, that it might be possible to identify gnathiid larvae species in the absence of adult males, through the use of detailed taxonomic descriptions of these larval stages and there live colouration patterns, and to then construct a taxonomic key to aid researchers with future identifications.
339

Aspects of the morphology, parasite host specificity and genetics of selected Labeobarbus polylepis populations

Austin, Amanda 13 April 2011 (has links)
M.Sc. / The Bushveld smallscale yellowfish, Labeobarbus polylepis (Boulenger, 1907), is an ecologically, socially and economically important species. These indigenous freshwater fish are found above an altitude of 600m, and occur in the Inkomati and Phongolo River Systems and the southern tributaries of the Limpopo River System. In the past, it was suspected that morphological differences exist between the different L. polylepis populations, due to the occurrence of the rubberlip formation of individuals from the Elands River. Specimens of five L. polylepis populations were collected from the Phongolo, Assegaai, Elands and Komati rivers and Ngodwana Dam, Mpumalanga, South Africa. A L. natalensis population was collected from the Umvoti River and used as an out-group. Nine meristic counts and 46 morphometric measurements were taken. The measurements were changed into percentage ratios based on the fork length of each individual. The data was statically analysed and includes Multidimensional scaling techniques (MSD’s) and Principle Component Analysis (PCA’s). Statistical analysis split the five populations into three groups. The one group consists of fish from the Phongolo and Assegaai rivers, the second group consists of fish from the Elands River and Ngodwana Dam and the third group is mainly Komati River fish. The third group is the only group that does not overlap with any other group. There were morphological differences between the groups, but they were not significant. The L. natalensis population is morphologically similar to L. polylepis populations obtained from the Phongolo and Assegaai rivers. Twenty enzyme coding loci in two L. polylepis populations from the Phongolo and Elands rivers were analysed by horizontal starch gel-electrophoresis. Electrophoretic analysis of heart, muscle and liver tissue samples revealed genetic variation at 15% (Elands River) and 35% (Phongolo River) of the protein coding loci studied. Average heterozygosity values based on Hardy-Weinberg expectation were 0.019 (Elands River) and 0.059 (Phongolo River), with a genetic distance value of 0.004 between these populations.
340

The biology of Palexorista laxa (Curran) (Diptera : Tachinidae) : an internal larval parasitoid of Heliothis armigera (Hübner) Lepidoptera : Noctuidae)

Van Heerden, Desireé January 1993 (has links)
The Tachinid fly, Palexorista laxa (Curran) is an important parasitoid of Heliothis armigera (Hubner) in Africa and India. The biological characteristics of the parasitoid were studied with an emphasis on its host instar preference, host range, seasonality and percentage parasitism. The developmental stages were also studied and described. A high host mortality (48%-100%) due to parasite attack occurred when small larvae were parasitised (2nd & 3rd instars). A preference for the 4th and 5th host instars was shown by the flies. P. laxa was found to be a non-specific parasitoid and parasitised a number of lepidopterous larvae in the laboratory including Busseola fusca (Fuller), Chilo partellus (Swinhoe) and Eldana saccharina Walker, but preferred Ii. armigera. The percentage parasitism on H. armigera in the field was variable peaking at 48% in 1988/89. Of the various parasitoids recorded from H. armigera on sunflower P. laxa was by far the most abundant. Mating occurred immediately after emergence with the males emerging a day earlier than the females. Males were capable of multiple matings whereas females mated only once in a lifetime. P. laxa females produced incubated macrotype eggs which hatched almost immediately after oviposition. The duration of development of the incubated egg and larval stage was 6,7 days, the pupa 10,4 days for females and 9,4 days for males, and the adult lived up to 50 days at 25°C. A reduction in pupal weight, an increase in the duration of the pupal stage and higher pupal mortality accompanied an increase in density of parasitoids per host. A linear relationship was shown between adult mass and number of ovarioles and eggs in P. laxa females. The oviposition period was 26,9 days with a high variation in daily progeny production. The total fertility per female was 126,3 puparia. "Inexperienced" females deposited incubated eggs on all parts of the host body while "experienced" females confined oviposition to the head and thorax. P. laxa females did not discriminate between previously parasitised and non-parasitised hosts. The effect of temperature on larval and pupal survival and development time was studied at 20°, 22°, 25°, 28°and 30°C. As expected, duration of development decreased with an increase in temperature, and there was a reduction in mortality.

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