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Dissertations / Theses on the topic 'Parasites Parasitology'

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Published: 4 June 2021
Last updated: 25 January 2023

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1

Renteria, Flores Axel. "Novel drugs against protozoan parasites." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=116979.

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Cryptosporidium parvum and Trypanosoma brucei are two protozoan parasites that can cause life-threatening illnesses in humans. Over 70 million people on the African continent are at risk of contracting T.brucei. In the case of C.parvum, infections are cosmopolitan, and a major problem is that it can be acquired very easily and requires only an infectious dose of 10 oocysts to cause the illness. If released in the public water supplies, C.parvum can endanger entire cities. This is one reason why C.parvum is categorized as a Class B bioterrorist weapon. Despite the threat C.parvum poses and the severe illness T.brucei causes, current treatments against these parasites are insufficient. These treatments fail to consistently eliminate the parasites and cause many adverse side effects. Furthermore, no significant improvements to the efficacy of these currently available treatments have been made. Given the need to find new drugs against these parasites and improve treatments, we tested the anti-parasitic activity of two compounds against T.brucei and C.parvum, respectively. First, we looked at the in vivo activity of TH-III-149, a cyclopropyl-indol, against T. brucei and then the in vitro and in vivo activity of oleyl-PC, a phosphocholine analog, against C. parvum. To begin, we looked at the effects of TH-III-149 against T.brucei by using a CD1 mouse model of infection. We demonstrated that an 8mg/kg treatment of TH-III-149 for three days resulted in a significant decrease in parasite replication rates compared to non-treated mice. By real-time PCR quantification of blood parasitemia, we showed that non-treated, T.brucei-infected mice had a thousand-fold increase in parasite burden between day 2 and 4 of infection. In comparison, only a 7.5-fold increase in parasite burden was observed in mice treated with TH-III-149. Results from blood smears and microscopy also confirmed this reduction in the replication rate of parasites. The treatment of infected mice with TH-III-149 delayed the patent period (appearance of parasites in the blood smear) by two days when compared to non-treated mice. In non-treated mice, parasite in the blood smears appeared at day 4 of the infection, while TH-III-149-treated mice only exhibited parasites in the blood smears at day 6. In addition, this compound showed minimal signs of toxicity, as non-infected mice treated with 8mg/kg of TH-III-149 for three days did not exhibit weight loss, hepatomegaly or splenomegaly. Therefore, our results support the development of TH-III-149 as a new treatment against T.brucei. In parallel, we also tested oleyl-PC against C.parvum. We showed that in vitro oleyl-PC has an IC50 of 22.9nM against C.parvum. Toxicity was evaluated using human ileocecal adenocarcinoma cells (HCT-8 cells) and was not significant at concentrations below 100µM (TC50=153.7 µM). The ratio between the TC50 and the IC50 allowed us to calculate a therapeutic index of 6.7x103. The in vivo animal study confirmed the activity of oleyl-PC previously seen in vitro. Treating C57BL/6 IFNγR-KO mice with 40mg/kg of oleyl-PC for ten days resulted in the cure (clearance of blood parasitemia) in 75% of the mice and a percent survival of 100% after 30 days (P < 0.001). In contrast, all of the non-treated mice succumbed to C. parvum infection and died by day 11. Using real-time PCR, oleyl-PC-treated mice showed no detectable levels of parasitic DNA in their intestines 30 days post infection, which indicates that these mice successfully cleared their parasitic infections. These results were confirmed by histological analysis of sections of the ileum which were clear of C.parvum oocysts. Furthermore, after ten days of treatment with 40mg/kg of oleyl-PC, no signs of toxicity were seen in treated mice; non-infected oleyl-PC-treated mice were monitored for visible behavioral changes and weight loss. Therefore, our results support the development of oleyl-PC as a new safe and effective treatment against C.parvum.
Cryptosporidium parvum et Trypanosoma brucei sont deux parasites protozoaires qui peuvent causer des maladies mortelles chez les humains. Confinées au continent africain, les infections dues à T.brucei affectent plus de 70 millions d'habitants. Dans le cas de C.parvum, les infections qui sont cosmopolites causent un problème majeur puisque la dose infectieuse n'est que de 10 oocysts. De plus, ce parasite peut être obtenu facilement et peut mettre en danger plusieurs villes, s'il est relâché dans les eaux potables. C'est un des raisons pourquoi ce parasite a été catégorisé comme une arme bio-terroriste de classe B. Malgré les risques majeurs associés à C.parvum et la maladie sévère de T.brucei, aucun progrès n'a été fait pour améliorer les traitements actuels. Ceux-ci n'ont toujours pas réussi à démontrer leur efficacité en plus de causer des effets secondaires sérieux. Vu le besoin urgent de trouver de meilleurs traitements, nous avons testé l'activité de TH-III-149, un indole-cyclopropane, contre T.brucei dans une étude in vivo ainsi que le oleyl-PC, un analogue de la phosphocholine, contre C.parvum dans des études in vitro et in vivo. Pour commencer, nous avons observé les effets du TH-III-149 contre T.brucei dans un modèle de souris CD1. Les résultats in vivo ont démontré qu'un traitement de trois jours en utilisant 8 mg/kg cause une réduction significative dans le taux de réplication du parasite en comparaison aux souris non-traitées. En utilisant le PCR en temps réel comme méthode de quantification, nous avons démontré que la charge en parasite dans le sang des souris non-traitées a augmenté de mille fois entre les jours 2 et 4, tandis qu'elle n'a augmenté que de 7.5 fois dans les souris qui ont été traitées. Les résultats des frottis sanguins ont confirmé cette réduction dans le taux de réplication des parasites. En effet, l'apparition de parasites dans les frottis sanguins a été observée dès le jour 4 de l'infection dans les souris non-traitées, tandis qu'elle n'a pu être observée qu'à partir du jour 6 dans les souris traitées avec le TH-III-149. De plus, ce composé n'a pas révélé de signes de toxicité car les groupes de souris non-infectées traitées pendant trois jours avec 8 mg/kg n'ont pas démontré de splénomégalie, d'hépatomégalie ni de perte de poids. Donc, nos résultats supportent le développement de TH-III-149 en tant que nouveau traitement contre les infections de T.brucei. En parallèle, nous avons aussi testé l'oleyl-PC contre C.parvum. Nos résultats in vitro démontrent que la concentration nécessaire pour réduire de 50% le taux de réplication du parasite (IC50) est de 25nM. La toxicité a été évaluée en utilisant une culture entérique humaine en couche monocellulaire (HCT-8). Les résultats de celle-ci démontrent que les premiers signes de toxicité apparaissent à partir de 100µM (TC50=123µM). Le ratio entre le TC50 et le IC50 a permis de calculer un index thérapeutique de 5x103. Les résultats in vivo ont servis à confirmer l'activité in vitro de oleyl-PC. En effet, le traitement de dix jours des souris C57BL/6 IFNγR-KO avec 40mg/kg de oleyl-PC a réussi à guérir (absence de parasitémie sanguine) 75% des souris, tout en gardant un taux de survie de 100% après le jour 30 (P<0.001). En contraste, toutes les souris non-traitées ont succombées à l'infection à la fin du jour 11. En utilisant le PCR en temps réel, aucune trace d'ADN provenant de C.parvum n'a pu être détectée dans les intestins de ces souris 30 jours après l'infection. Ces résultats ont été confirmés par l'analyse des lamelles histologique de l'ilium de ces souris où l'absence d'oocyst de C.parvum a été observée. De plus, chez les souris non-infectées, un traitement de dix jours avec 40 mg/kg de oleyl-PC n'a pas causé d'effets secondaires visibles tels qu'une perte de poids. Donc, nos résultats supportent le développement de l'oleyl-PC en tant que nouveau traitement sécuritaire et efficace contre les infections de C.parvum.
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2

Dallarés, Villar Sara Maria. "Twenty thousand parasites under the sea: a multidisciplinary approach to parasite communities of deep-dwelling fishes from the slopes of the Balearic Sea (NW Mediterranean)." Doctoral thesis, Universitat Autònoma de Barcelona, 2017. http://hdl.handle.net/10803/402224.

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El Mar Mediterráneo profundo permanece en gran parte inexplorado, y, específicamente, las comunidades parásitas de los peces mediterráneos de aguas profundas son mayormente desconocidas. El principal objetivo de la presente tesis es caracterizar las comunidades parásitas de las importantes especies ícticas de aguas profundas siguientes: Mora moro (Risso, 1810), Phycis blennoides (Brünnich, 1768), Galeus melastomus Rafinesque, 1810, Scyliorhinus canicula (Linnaeus, 1758), Etmopterus spinax (Linnaeus, 1758) y Centroscymnus coelolepis Barbosa du Bocage and de Brito Capello, 1864. Otro propósito importante es evaluar la respuesta de estas comunidades a gradientes y variables ambientales, a la dieta y a la ecología trófica de los hospedadores y su posible impacto en el estado de salud de estos últimos. En los capítulos tercero a sexto se describen las comunidades parásitas de las especies mencionadas en diferentes estaciones, estratos de profundidad y localidades de las vertientes continental e insular del Mar Balear. Mientras que las comunidades parásitas de M. moro, P. blennoides y G. melastomus se caracterizaron por altos valores abundancia, riqueza y diversidad, las de S. canicula, E. spinax y C. coelolepis eran comparativamente más pobres y menos diversas. Diferencias ontogénicas, batimétricas, estacionales y geográficas se detectaron en las comunidades parásitas de las especies tratadas, en todos los casos asociadas a las dinámicas alimentarias (a su vez asociadas a la disponibilidad de presas a lo largo de los gradientes mencionados, en la mayoría de casos) de sus hospedadores. Se hallaron relaciones detalladas entre parásitos y presas ingeridas por los diferentes hospedadores, permitiendo confirmar las vías de transmisión ya conocidas para algunos parásitos y sugiriendo nuevas vías de infección para otros. La mayoría de parásitos se asociaron a altos niveles de O2 y turbidez del agua. Mientras que los primeros favorecen la abundancia de parásitos con ciclos indirectos como resultado de la proliferación del zooplancton y la agregación de hospedadores intermediarios potenciales asociada, los segundos favorecen la transmisión de parásitos y aumentan la carga parasitaria debido a un incremento del zooplancton y de las comunidades de invertebrados suprabentónicos a causa de una mayor disponibilidad de nutrientes. Altos niveles de salinidad del agua parecieron estar asociados a mayores abundancias de los nematodos Hysterothylacium aduncum y Proleptus obtusus, probablemente porque la salinidad se correlaciona con la abundancia de decápodos y misidáceos, entre otros, que son utilizados por esos nematodos como hospedadores intermediarios. A su vez, altos niveles de temperatura del agua se asociaron a la abundancia de parásitos monogeneos, probablemente debido a un mayor éxito de eclosión de los huevos y a una reducción del tiempo de maduración reproductiva a mayores temperaturas, como ya había sido demostrado para estos parásitos. Se detectaron una inhibición de la enzima acetilcolinesterasa y mayores niveles de peroxidación de lípidos, ambos posiblemente asociados a estrés por las infecciones parasitarias, en varias especies de peces. En general, la carga parasitaria no tuvo un impacto significativo en los índices de condición generales de los peces, ni en el número y/o área de centros macrofágicos o melanomacrofágicos esplénicos en el caso de teleósteos, o en el número de melanomacrófagos hepáticos en el caso de G. melastomus. En el séptimo capítulo se aportan datos morfológicos, moleculares y ecológicos de diferentes estadíos de desarrollo del cestodo Ditrachybothridium macrocephalum en su hospedador definitivo, G. melastomus, y en el Mar Mediterráneo por primera vez. En el octavo capítulo la familia de cestodos Sphyriocephalidae es revisada. Se describe la nueva especie Heterosphyriocephalus encarnae n. sp., y dos especies ya existentes, Sphyriocephalus viridis y Sphyriocephalus tergestinus, se redescriben a partir de datos morfológicos y moleculares de nuevo material recolectado y de material de museo.
The Mediterranean deep-sea remains mostly unexplored and, specifically, the parasite communities of Mediterranean deep-dwelling fishes are largely unknown. The central purpose of the present thesis is to characterize the parasite communities infecting the following important deep-dwelling ichthyc species in the Balearic Sea: Mora moro (Risso, 1810), Phycis blennoides (Brünnich, 1768), Galeus melastomus Rafinesque, 1810, Scyliorhinus canicula (Linnaeus, 1758), Etmopterus spinax (Linnaeus, 1758) and Centroscymnus coelolepis Barbosa du Bocage and de Brito Capello, 1864. Another main objective is to assess the responsiveness of these parasite communities to environmental gradients and variables, to host diet and trophic ecology and their possible impact on host health condition. In the third to sixth chapters, the parasite communities of the mentioned species are described on different seasons, depth strata and localities from the mainland and insular slopes of the Balearic Sea. While parasite communities of M. moro, P. blennoides and G. melastomus were characterized by high abundance, richness and diversity values, those of S. canicula, E. spinax and C. coelolepis were comparatively poorer and less diverse. Ontogenic, bathymetric, seasonal and geographic differences in the parasite communities of the different species addressed were detected, in all cases linked to the feeding dynamics (in turn linked to prey availability across the mentioned gradients, in most cases) of their hosts. Detailed relationships were found between parasite taxa and prey ingested by the different hosts, allowing confirmation of the transmission pathways known for some parasites and suggesting new ways of infection in others. Most parasites were linked to high O2 and turbidity levels. While the former enhances the abundance of parasites with indirect life cycles as a result of zooplankton proliferation and the associated aggregation of potential intermediate hosts, the latter favours parasite transmission and increases parasite loads due to an increase of zooplankton and suprabenthic invertebrate communities linked to higher nutrient availability. High water salinity levels seemed to be linked to higher abundance of the nematodes Hysterothylacium aduncum and Proleptus obtusus, probably because salinity correlates with the abundance of decapods and mysids, among others, which are used by these nematodes as intermediate hosts. In turn, high water temperature levels correlated with the abundance of monogenean parasites, likely due to enhanced egg hatching success and reduced time to maturity, as previously reported for these parasites. An inhibition of acetylcholinesterase activity and increased lipid peroxidation levels were detected in different fish species, possibly associated to infection-related stress. In general, parasite burden did not have a significant effect on fish general condition indices or on the number and/or surface of splenic melano-macrophage or macrophage centres in the case of teleosts, or on the number of hepatic melano-macrophages in the case of G. melastomus. In the seventh chapter, morphological, molecular and ecological data of different developmental stages of the cestode Ditrachybothridium macrocephalum are provided for the first time from its definitive host, G. melastomus, in the Mediterranean Sea. In the eighth chapter, the cestode family Sphyriocephalidae is revised. The new species Heterosphyriocephalus encarnae n. sp. is described, and two already existing species, Sphyriocephalus viridis and Sphyriocephalus tergestinus are further redescribed based on morphological and molecular data of newly-collected and museum material.
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3

Constantine, Clare Colleen. "Molecular markers, analysis and the population genetics of parasites." Thesis, Constantine, Clare Colleen (2002) Molecular markers, analysis and the population genetics of parasites. PhD thesis, Murdoch University, 2002. https://researchrepository.murdoch.edu.au/id/eprint/662/.

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In this study different molecular techniques are contrasted (RAPD's, allozyme, sequencing mtDNA, sequencing ribosomal spacers) and appropriate analytical methods (allelic and infinite-sites approaches; inbreeding and coalescent models) used for estimating population genetic parameters in parasites. A range of population genetic questions at different scales were chosen to emphasise the importance of tailoring techniques and analytical methods to the particular question being investigated. The realisation that each question formulated has a particular scale means the appropriate technique and markers must be useful at that scale to attempt to answer the question. The useful scale of a technique depends several factors including the region of DNA examined, the density of sampling of the technique, and the mode of evolution of the markers. Each technique will produce a useful range of variability. Below the lower limit there is no variation, above the upper limit the variation is too high to produce useful comparisons. Parasites are of interest for many reasons, primarily because they can cause disease and thus impact on their host's population dynamics. They are often closely associated with their hosts and may undergo co-evolution, as well as causing an ongoing immunological "arms race" with their hosts. The parasitic mode of live is found throughout nearly all taxonomic groupings and thus classical models of population genetics based on sexual, diploid vertebrates do not fit well with the entire diversity of parasite groups. Genetic diversity within and among populations of Echinococcus granulosus was examined contrasting a RAPD dataset with an allozyme dataset. Two models of variation in Echinococcus have been proposed, those of Smyth and Rausch, and the expected genetic structure from each was compared to the observed genetic structure. The premise of Smyth's model, predominant self-fertilisation, was supported, but the resultant pattern of genetic variation followed Rausch's model. RAPD data, being dominant, present challenges to analysis. An approach to overcome this dominance problem and allow standard allelic frequency analysis is described using the selfing rate estimated from allozyme data. The RAPD data were also analysed using both band-sharing and nucleotide diversity approaches. A population genetic study of Ostertagia ostertagi in the USA was extended to two different scales: within an Australian state and between the USA and Australian continents. Three alternative explanations for the observed discrepancy between genetic structure and differentiation in an important biological trait, hypobiosis, were explored. A number of programs and analyses were compared including coalescent geneflow estimates. Variation among multiple copies of two spacer regions of rDNA was examined within individuals of Ostertagia ostertagi. Both the intergenic spacer and internal transcribed spacer 1 regions were found to include repeat regions, with different numbers of repeats creating length differences in clones from the same worm. Multi-copy genes present extra challenges in analysis to ensure that only homologous copies are being compared. Many studies fail to look for variation within populations or within individuals. The two major conclusions from these examples are that: 1). The study of variation necessarily involves an implicit scale, and markers must be chosen that are appropriate to the question being explored. 2). Using several methods of analysis of genetic data allows contrasts to be made, and if different methods produce similar results gives much more confidence in the conclusions drawn. Incongruence in results leads to new questions and reexamination of the assumptions of each analysis.
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4

Constantine, Clare Colleen. "Molecular markers, analysis and the population genetics of parasites /." Access via Murdoch University Digital Theses Project, 2002. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20050817.102006.

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5

Dale, Denver Dudley Stanton. "Parasites and host nutrition." Thesis, University of Oxford, 1993. http://ora.ox.ac.uk/objects/uuid:5bc8aebc-fcfa-4301-8d04-4ebc89fb1c8a.

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6

Adams, Peter John. "Parasites of feral cats and native fauna from Western Australia: the application of molecular techniques for the study of parasitic infections in Australian wildlife." Thesis, Adams, Peter John (2003) Parasites of feral cats and native fauna from Western Australia: the application of molecular techniques for the study of parasitic infections in Australian wildlife. PhD thesis, Murdoch University, 2003. https://researchrepository.murdoch.edu.au/id/eprint/29/.

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A survey of gastro-intestinal parasites was conducted on faecal samples collected from 379 feral cats and 851 native fauna from 16 locations throughout Western Australia. The prevalence of each parasite species detected varied depending upon the sampling location. Common helminth parasites detected in feral cats included Ancylostoma spp. (29.8%), Oncicola pomatostomi (25.6%), Spirometra erinaceieuropaei (14%), Taenia taeniaeformis (4.7%), Physaloptera praeputialis (3.7%) and Toxocara cati (2.6%). The most common protozoan parasites detected in feral cats were Isospora rivolta (16.9%) and I. felis (4.5%). The native mammals were predominately infected with unidentified nematodes of the order Strongylida (59.1%), with members of the orders Rhabditida, Spirurida and Oxyurida also common. Oxyuroid nematodes were most common in the rodents (47.9%) and western grey kangaroos (27.8%). Several species of Eimeria were detected in the marsupials whilst unidentified species of Entamoeba and coccidia were common in most of the native fauna. Primers anchored in the first and second internal transcribed spacers (ITS1 and ITS2) of the ribosomal DNA (rDNA) were used to develop a polymerase chain reaction-linked restriction fragment length polymorphism (PCR-RFLP) technique to differentiate the species of Ancylostoma detected in feral cats. Amplification of the ITS+ region (ITS1, ITS2 and 5.8S gene) followed by digestion with the endonuclease RsaI produced characteristic patterns for A. tubaeforme, A. ceylanicum and A. caninum, which were detected in 26.6%, 4.7% and 0% of feral cats respectively. Giardia was detected in a cat, dingo, quenda and two native rodents. Sequence analysis at the small subunit rDNA gene (SSU-rDNA) identified the cat and dingo as harbouring G.duodenalis infections belonging to the genetic assemblages A and D respectively. Subsequent analysis of the SSU-rDNA and elongation factor 1 alpha (ef1[alpha]) identified a novel species of Giardia occurring in the quenda. Attempts to genetically characterise the Giardia in the two native rodents were unsuccessful. Serological detection of Toxoplasma gondii was compared to a one tube hemi-nested PCR protocol to evaluate its sensitivity. PCR was comparable to serology in detecting T. gondii infections, although PCR was a much more definitive and robust technique than serology for large numbers of samples. Amplification of T. gondii DNA detected infections in 4.9% of feral cats and 6.5% of native mammals. The distribution of T. gondii does not appear to be restricted by environmental factors, which implies that vertical transmission is important for the persistence of T. gondii infections in Western Australia. These results demonstrate that cats carry a wide range of parasitic organisms, many of which may influence the survival and reproduction of native mammals. As such, the large-scale conservation and reintroduction of native fauna in Western Australia must not disregard the potential influence parasites can have on these populations.
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Adams, Peter John. "Parasites of feral cats and native fauna from Western Australia : the application of molecular techniques for the study of parasitic infections in Australian wildlife /." Adams, Peter John (2003) Parasites of feral cats and native fauna from Western Australia: the application of molecular techniques for the study of parasitic infections in Australian wildlife. PhD thesis, Murdoch University, 2003. http://researchrepository.murdoch.edu.au/29/.

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A survey of gastro-intestinal parasites was conducted on faecal samples collected from 379 feral cats and 851 native fauna from 16 locations throughout Western Australia. The prevalence of each parasite species detected varied depending upon the sampling location. Common helminth parasites detected in feral cats included Ancylostoma spp. (29.8%), Oncicola pomatostomi (25.6%), Spirometra erinaceieuropaei (14%), Taenia taeniaeformis (4.7%), Physaloptera praeputialis (3.7%) and Toxocara cati (2.6%). The most common protozoan parasites detected in feral cats were Isospora rivolta (16.9%) and I. felis (4.5%). The native mammals were predominately infected with unidentified nematodes of the order Strongylida (59.1%), with members of the orders Rhabditida, Spirurida and Oxyurida also common. Oxyuroid nematodes were most common in the rodents (47.9%) and western grey kangaroos (27.8%). Several species of Eimeria were detected in the marsupials whilst unidentified species of Entamoeba and coccidia were common in most of the native fauna. Primers anchored in the first and second internal transcribed spacers (ITS1 and ITS2) of the ribosomal DNA (rDNA) were used to develop a polymerase chain reaction-linked restriction fragment length polymorphism (PCR-RFLP) technique to differentiate the species of Ancylostoma detected in feral cats. Amplification of the ITS+ region (ITS1, ITS2 and 5.8S gene) followed by digestion with the endonuclease RsaI produced characteristic patterns for A. tubaeforme, A. ceylanicum and A. caninum, which were detected in 26.6%, 4.7% and 0% of feral cats respectively. Giardia was detected in a cat, dingo, quenda and two native rodents. Sequence analysis at the small subunit rDNA gene (SSU-rDNA) identified the cat and dingo as harbouring G.duodenalis infections belonging to the genetic assemblages A and D respectively. Subsequent analysis of the SSU-rDNA and elongation factor 1 alpha (ef1[alpha]) identified a novel species of Giardia occurring in the quenda. Attempts to genetically characterise the Giardia in the two native rodents were unsuccessful. Serological detection of Toxoplasma gondii was compared to a one tube hemi-nested PCR protocol to evaluate its sensitivity. PCR was comparable to serology in detecting T. gondii infections, although PCR was a much more definitive and robust technique than serology for large numbers of samples. Amplification of T. gondii DNA detected infections in 4.9% of feral cats and 6.5% of native mammals. The distribution of T. gondii does not appear to be restricted by environmental factors, which implies that vertical transmission is important for the persistence of T. gondii infections in Western Australia. These results demonstrate that cats carry a wide range of parasitic organisms, many of which may influence the survival and reproduction of native mammals. As such, the large-scale conservation and reintroduction of native fauna in Western Australia must not disregard the potential influence parasites can have on these populations.
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8

Langridge, Susan A. "Studies of the susceptibility of cattle nematode parasites to morantel tartrate." Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/47147.

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9

Sarkari, Bahador. "Immunological and biochemical characterization of a urinary antigen in visceral leishmaniasis." Thesis, University of Liverpool, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343644.

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10

Hahn, Michael Leonhard. "Studies on the biochemical, biological and molecular diversity of Radopholus similis (Cobb, 1893) Thorne, 1949." Thesis, University of London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339137.

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11

Douglas, Polly Joanne. "Studies on Entobdella hippoglossi (Muller, 1776) (Monogenea) and Lepeophtheirus hippoglossi (Kroyer, 1837) (Copepoda) : ectoparasites of Atlantic halibut (Hippoglossus hippoglossus L., 1758)." Thesis, University of Stirling, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391470.

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12

Whiteman, Noah Kerness. "Evolutionary epidemiology of endemic Galápagos birds and their parasites." Diss., St. Louis, Mo. : University of Missouri--St. Louis, 2005. http://etd.umsl.edu/r1081.

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13

Schleppe, Jason L., and University of Lethbridge Faculty of Arts and Science. "The ecology of two larval parasites in fathead minnows." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 2002, 2002. http://hdl.handle.net/10133/198.

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The population dynamics and life histories of two larval parasites of fathead minnows were investigated, together with their effects on host reproduction in natural populations. In two lakes in northern Alberta, Canada, 100% of fathead minnows (Pimephales promelas) are infected with larval trematodes (Ornithodiplostomum ptychcocheilus and Posthodiplostomum minimum) that encyst in their brains and mesentaries, respectively. The numbers of parasites in individual adult minnows varied extensively between and within two different lakes. Parallel laboratory studies indicated that selection imposed by common hosts in the life cycles of these species have shaped broadly similar life histories. Field collections of male minnows indicated that early in the breeding season, breeding males were longer than non-breeding males. Furthermore, breeding males had larger girths (independent of total length) and contained fewer numbers of three of 4 common larval trematodes than non-breeding males throughout the breeding season. These parasites most likely affect a male's ability to compete for or defend a nest.
vi, 99 leaves : ill. ; 28 cm.
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14

Lacey, S. M. "Some studies on parasites of the alimentary tract of the European eel Anguilla anguilla (L.)." Thesis, University of Hull, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381874.

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15

Shuang, Liang. "New Approach To DNA Transfection And Genetics In Schistosome Parasites." Case Western Reserve University School of Graduate Studies / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=case1424201510.

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16

Clease, Derek Fraser. "Evolutionary divergence in Philonema (Nematoda; Philometridae) parasites of B.C. salmonids." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/28942.

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Philonema (Nematoda; Philometridae) from anadromous hosts, sockeye salmon (Oncorhynchus nerka), and non-anadromous hosts, rainbow trout (Oncorhynchus mykiss) , were studied in order to determine if hosts with different life histories were infected with the same or different species of Philonema. Worms from the two host species were morphologically indistinguishable. However, electrophoretic banding patterns produced by restriction enzyme digestion of DNA extracted from Philonema demonstrated the presence of two genetic types corresponding to the two host species. This supports the idea that at least two species of Philonema are endemic in British Columbia. Philonema oncorhynchi Kuitunen-Ekbaum, 1933 is a parasite of sockeye salmon which undergo a long ocean migration before returning to freshwater to spawn, while P. agubernaculum Simon and Simon, 1936 is a parasite of rainbow trout (and other salmonids) which live in lakes. Kokanee (O. nerka kennerlyi), a non-anadromous offshoot of sockeye, were infected with the same worm as sockeye probably because the two hosts have similar life histories. Steelhead smolts, anadromous O. mykiss, contained worms identified as P. agubernaculum. This likely represented an accidental infection because steelhead do not usually contact Philonema. Philonema were examined from various localities in B.C. Philonema agubernaculum showed population divergence corresponding to the different geographic localities from which it was collected. This likely reflects the isolation of these parasite populations in unconnected watersheds. Philonema oncorhynchi showed polymorphisms spread throughout many of the populations. The lack of population divergence probably results from gene flow between parasite populations brought about by wandering hosts.
Science, Faculty of
Zoology, Department of
Graduate
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17

Kvasager, Danielle Kay. "Prevalence, Statistical Trends and Phylogenetics of Blood Parasites (Haemosporidia| Haemoproteus, Plasmodium and Leucocytozoon) in Songbird Passerines from Grasslands of northwest Minnesota." Thesis, The University of North Dakota, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10003494.

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Passerine birds that primarily use grassland habitats are rarely the focus of a parasite study. With many rapidly declining bird populations that breed at even faster decreasing grassland habitat, it is important to know the potential risks to the birds posed by blood parasites. During the breeding seasons of 2009-2011, 150 samples from 148 individual birds (fourteen species) were collected from five grassland sites in northwest Minnesota, USA and surveyed for blood parasites using microscopy and molecular methods. Eighty-five (56.67%) of the 150 samples were infected with at least one of three haemosporidian genera: Haemoproteus, Plasmodium and Leucocytozoon. Seventy (46.67%) of the 150 samples were infected with either Haemoproteus or Plasmodium (fourteen infections were Haemoproteus, forty were Plasmodium and sixteen were undetermined due to dual infections or lack of sequences) and 41 samples (27.33%) were infected with Leucocytozoon, for a total of 111 infections. Plasmodium infections in two juvenile bobolinks provide evidence of active transmission within the study area. Haemoproteus/Plasmodium prevalence was significantly higher in May and June than in later collection months (July-Sept.) and dual infections were significantly higher in June compared with other sampling months. Of the three bird species that were sampled most, clay-colored sparrows (Spizella pallida) had significantly more Haemoproteus infections than savannah sparrows (Passerculus sandwichensis) and bobolinks (Dolichonyx oryzivorus). Only bobolinks were classified based on sex and/or age and adult males had significantly more Leucocytozoon and dual infections than adult females or juveniles. Parasite prevalence did not differ significantly between study sites or years. Phylogenetic reconstructions based on Maximum Likelihood and Bayesian analyses produced three major clades, corresponding to the three haemosporidian genera. Bird host species were well mixed within the trees, indicating infective vectors fed on bird species opportunistically rather than selectively and also shows that the Haemosporidia are generalists, being able to infect a wide range of the sampled bird species.

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18

O'Grady, Richard Terence. "Phylogenetic systematics and the evolutionary history of some intestinal flatworm parasites (Trematoda : Digenea: Plagiorchioidea) of Anurans." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/27502.

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Historical structuralism is presented as a research program in evolutionary biology. It uses patterns of common ancestry as initial hypotheses in explaining evolutionary history. Such patterns, represented by phylogenetic trees, or cladograms, are postulates of persistent ancestral traits. These traits are evidence of historical constraints on evolutionary change. Patterns and processes consistent with a cladogram are considered to be consistent with an initial hypothesis of historical constraint. As an application of historical structuralism, a phylogenetic analysis is presented for members of the digenean plagiorchioid genera Glypthelmins Stafford, 1905 and Haplometrana Lucker, 1931. The eight species studied are intestinal parasites of frogs and toads in North, Central, and South America. In a Wagner parsimony analysis of 21 morphological characters with both the PAUP and PHYSYS computer programs, a single phylogenetic tree with a consistency index of 84.8% can be inferred. This suggests strong historical constraint in the evolution of the characters examined. It is postulated that the eight species form a monophyletic group (clade), consisting of two less inclusive clades. Glypthelmins hyloreus and G. pennsylvaniensis comprise one of these clades; G. robustus, G. shastai, H. intestinalis, G. californiensis, G. quieta, and G. facioi comprise the other. G. robustus, found in Bufo marinus in Colombia, is both the southernmost and the most plesiomorphic member of its clade. Glypthelmins californiensis, G. quieta, and G. facioi form a clade, and parasitize frogs in the Rana pipiens complex in Mexico, eastern North America, and Central America, respectively. Glypthelmins shastai and H. intestinalis, the latter of which is the only member of its genus, form a western North American clade, and parasitize Bufo boreas and Rana pretiosa, respectively. The phylogenetic analysis includes a redescription of G. shastai, the synonymy of the genus Haplometrana with Glypthelmins, the redescription of H. intestinali s as G. intestinalis, an emended diagnosis of the genus Glypthelmins, and the first account of the life cycle of G. californiensis. Three aspects of phylogenetic analysis are examined in detail. These are the coding of multistate character trees, the use of parasite data to infer host relationships, and the properties of the Consistency Index and the F-Ratio. It is proposed that the Consistency Index be calculated without non-homoplasious autapomorphic characters. For the present study, this modification gives a value of 76.9%. Using the phylogenetic tree as a general reference system of patterns of common ancestry, it is inferred from developmental studies that (1) there is no conflict between the phylogenetic relationships indicated by only larval or only adult characters, and that (2) the evolution of some of the characters involved certain types of heterochrony. Paedomorphic heterochrony is inferred to have occurred in the evolution of the uterus in G. shastai, H. intestinalis, G. californiensis, G. quieta, and G. facioi. Peramorphic heterochrony is inferred to have occurred in the evolution of the penetration glands in G. facioi, and of the hindbody in H. intestinalis. The relatively longer hindbody of H. intestinalis was experimentally induced to show paedomorphic development by raising specimens of H. intestinalis in Bufo boreas, which is the host of G. shastai, its sister-species. By one year after infection, the relative length of the hindbody is shorter, and is equal to that of the primitive state found in G. shastai. The phylogenetic relationships among the anuran hosts are re-analyzed. There is 80% congruence between them and the postulated phylogenetic tree for their parasites, suggesting strong historical association between the parasite and host groups. This inference of coevolution is further supported by the concordance of the present geographical distributions of the parasites and their hosts with the historical geology of the areas in which they occur. This implies an historical association between the areas and the organisms.
Science, Faculty of
Zoology, Department of
Graduate
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19

Shirakashi, Sho, and University of Lethbridge Faculty of Arts and Science. "Behaviour of fathead minnows infected with a brain-encysting parasite." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 1999, 1999. http://hdl.handle.net/10133/140.

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A wide variety of parasites are known to cause changes in host behaviour. The altered behaviours range from simple changes in features such as activity and phototaxis, to the creation of behaviours that are new, and often bizarre. In this study, I investigated the effect of a trematode parasite, Ornithodiplostomum ptychocheilus (Strigeidae; Diplostomidae), on the behaviour of its intermediate host, the fathead minnow (Pimephales promelas). The larval stage (metacercaria) of this parasite resides within the central nervous system, specifically the optic lobes. In fish, one of the main functions of the optic lobes is to receive visual stimuli from the retina and then coordinate the optomotor response (OMR). This response is an innate component of rheotaxis that plays an important role in motion detection, navigation and orientation. In an initial experiment, 16 wk-old metacercariae reduced minnow OMR by 42% compared to uninfected controls. However, in a follow-up experiment, it was 2- and 4- wk old metacercariae that caused the greater (39 and 41% respectively) decrease in OMR. Because 2- and 4-wk old metacercariae are not infective to birds (the next host in the life-cylce), alterations in minnow OMR at this time are unlikely to be a parasite adaptive. During this period, reduced OMR is more likely a result of pathology caused by developing larvae within the optic lobes. However, negative effects of infection on OMR performance persisted to 16 wk post-infection indicating the parasite-induced reduction in host performance could be an adaptive strategy to increase parasite transmission. Surprisingly, the magnitude of reduction in minnow OMR was only loosely linked to metacercarieae intensity. Although both low (<5 parasites/fish), and high intensities (>100) led to large decreases in OMR, intermediate intensities had only a small effect. Such non-linearity between intensity and the magnitude of host behavioural changes suggest that the mechanisms leading to altered host behaviours are varied, and complex.
vii, 79 leaves : ill. ; 29 cm.
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20

Rollins, Amanda Ann. "Genetic Evidence for the Prehistoric Expansion of Enterobius vermicularis Parasites and Their Human Hosts in the Greater American Southwest." Thesis, Indiana University, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10828433.

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The human pinworm, Enterobius vermicularis, is an intestinal parasite that is transmitted through close interpersonal contact. Because this parasite is human-specific, pinworm DNA can be used in population genetics studies as a proxy to track the migration patterns of human hosts. At least three genetic haplogroups of the mitochondrial cox1 gene have been identified in E. vermicularis pinworms extracted from modern fecal samples.

This parasite has also been identified morphologically and genetically in preserved fecal material, or coprolites, from numerous archaeological sites. Analyses of Ancestral Pueblo coprolites indicate that the inhabitants of the prehistoric American Southwest experienced particularly high levels of pinworm infection. The Ancestral Pueblo archaeological tradition represents ethnically distinct groups that shared certain cultural features. Prehistoric architecture, material culture, and skeletal remains, in addition to modern genetics and linguistics data, have been used to explore the level of direct contact between Ancestral Pueblo sites and surrounding areas. A comparison of pinworm genetic haplotypes from coprolites provides an additional means of assessing the migratory histories of the Greater American Southwest.

In this study, genetic fragments of the E. vermicularis mitochondrial cox1 gene were isolated from 14 of 43 Ancestral Pueblo coprolites sampled from Antelope House and Antelope Cave in Arizona, from Salmon Ruin in New Mexico, and from Turkey Pen Ruin in Utah. Attempts to amplify pinworm DNA from La Cueva de los Muertos Chiquitos in Durango, Mexico were unsuccessful. Five coprolites from Antelope House generated sufficient genetic coverage of a 268 nucleotide fragment of the cox1 gene for phylogenetic analyses. Comparison to modern genetic haplogroups indicates the presence of a unique haplotype of pinworm mitochondrial cox1 gene in the prehistoric New World, haplogroup D.

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21

Bowen, Simon Andrew. "Aspects of the population biology of the cyst nematode parasites of oilseed rape." Thesis, University of Bedfordshire, 1988. http://hdl.handle.net/10547/596742.

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Investigation of the host-parasite relationship between oilseed rape, Heterodera cruciferae and H. schachtii has shown that the rate of hatching, development and reproduction is strongly influenced by temperature, two possible generations occurring on an autumn-sown crop. H.schachtii preferred warmer temperatures, hatched and reproduced more than H. cruciferae. Comparisons between newly-formed eggs in cysts and egg sacs showed that their different hatching responses were related to their physiology; cyst-bound eggs hatched poorly whereas juveniles hatched readily from egg sacs and facilitated the early establishment of a second generation. Multiplication of both species varied greatly between cultivars and differences in hatching and multiplication were attributed to the effects of plant growth and intrinsic differences between cultivars. Plant age influenced the hatching activity of root diffusates and nematode development. Multiplication rates of single and mixed species populations declined with increaSing initial population density indicating that intraspecific competition and root damage limited population growth. Nematodes multiplied synergistically in concomitant infestations suggesting that interspecific competition was less important. In a damage assessment test, root and shoot growth of nematodeinfested plants was reduced and the increased accumulation of calcium in their shoots indicated that they used water less efficiently than uninfested plants. These effects were density-dependent and H.schachtii was more damaging than H.cruciferae. Tolerance to nematode attack was attributed to good root establishment. The rate of decline of H.cruciferae populations varied with time, soil depth and between populations; low soil moisture and temperature favouring nematode survival. The role of weeds as ~maintainer hosts' of H.cruciferae was assessed but considered negligible. Nematode population dynamics were simulated using a computer model. Population densities fluctuated considerably under typical crop rotations but large populations had generally declined to less damaging levels before a host was cropped again. It was indicated that a long run of non-hosts or nematicide use would achieve better control of H.schachtii than H.cruciferae.
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22

Sandland, Gregory J., and University of Lethbridge Faculty of Arts and Science. "Interactions between a brain-encysting trematode and its intermediate host, the fathead minnow." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 1999, 1999. http://hdl.handle.net/10133/112.

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Determining the extent to which parasites influence natural populaions of hosts is a major focus of studies in parasitology. Addressing this issue requires host-parasite systems that can be monitored under natural conditions and can be manipulated in the laboratory. I study a model system involving the larval trematode Ornithodiplostomum ptychocheilus that encysts in the brains of its intermediate host, the fathead minnow (Pimephales promelas). This parasite was the most common and abundant of 13 other parasites found in minnows in four boreal lakes in Alberta, Canada. In two of these lakes, prevalence of infection reached 100% in most years and mean intensity ranged from 4 to 40 parasites/host. Field and laboratory experiments showed that the size, the rate of parasite development, and time to encystment were intensity-dependent. However, parasite intensity had no effect on host or parasite survival after a simulated winter in the laboratory. One effect of infection was that infected fish and significantly greater cranial heights and widths than controls. The expression of this parasite-induced alteration in host phenotype was dependent on the size of the fish at infection and on parasite intensity. The cranial distortion led to significantly higher mortality of fish maintained on poor diets and altered the host's phototactic response.
ix, 131 leaves : ill. (some col.), map ; 29 cm.
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23

Pelle, Karell Guemmegne. "Diversity of Antigenic Secretion in Apicomplexa Parasites and Its Role in Plasmodium Falciparum Malaria." Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:11000.

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Apicomplexan parasites are responsible for some of the most devastating human and veterinarian diseases and are parasites of great economic importance. Apicomplexa include Plasmodium, Toxoplasma and Babesia species. The pathogenic mechanisms developed by Apicomplexa parasites, in particular those that reside in a parasitophorous vacuole, involve considerable changes to the host cell, including the expression of variable surface proteins required for immune evasion. In Plasmodium falciparum infections, host cell remodeling is responsible for disease symptomology and severity in the human host. This work represents a multi-faceted study of antigenic secretion and the role of secreted antigens in pathogenesis. We study in detail the mechanisms of antigen secretion in Apicomplexa parasites. By use of comparative genomics, we find Plasmodium Export Element (PEXEL)-like motifs in a subset of Cryptosporidium and Babesia secreted proteins. However, in Babesia the motif functions as a spherical body targeting sequence, suggesting that secretory mechanisms in Apicomplexa are adapted to the parasite's intracellular lifestyle. To elucidate the relationship and function of exported antigens, we first focused on P. falciparum to determine gene co-expression modules. We found that in vivo, export modules are composed of constitutively or variably expressed genes, the latter group associated with patient clinical phenotypes. We then focused on a novel gene family called "phist" and show, using transcriptional expression profiling, its role in P. falciparum cytoadherence. In total, we demonstrate that antigen secretion is an evolutionary mechanism in Apicomplexa parasites and that variant expression of the genes encoding these antigens may allow parasites to adapt to environmental stresses.
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24

Prowse, Rhoda 1975. "The molecular basis for the resistance of Fasciola hepatica to cellular cytotoxicity." Monash University, Dept. of Biochemistry and Molecular Biology, 2003. http://arrow.monash.edu.au/hdl/1959.1/7714.

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25

Brooker, Adam Jonathan. "Aspects of the biology and behaviour of Lernaeocera branchialis (Linnaeus, 1767) (Copepoda: Pennellidae)." Thesis, University of Stirling, 2007. http://hdl.handle.net/1893/343.

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Lernaeocera branchialis (L., 1767) is a parasitic copepod that parasitises a range of gadoids by anchoring in the proximity of the branchial chamber of its host, deriving nutrition from the blood of its host and causing serious pathogenic effects. This study investigates the taxonomy of the juvenile free-swimming stages and host location behaviour in the pre-metamorphosed adult female. The large size and distinctive appearance of the metamorphosed adult female stage, coupled with the wide exploitation and commercial importance of one of its principle final gadoid hosts, the cod (Gadus morhua L.), means that this species has long been recognised in the scientific literature, and here the extensive literature concerning this potentially important and damaging pathogen is re-examined to provide an up to date overview, which includes both aquaculture and wild fisheries perspectives. Due to disagreements between several descriptions of the L. branchialis juvenile stages, and because the majority of the descriptions are over 60 years old, the juvenile free-swimming stages are re-described, using current terminology and a combination of both light and confocal microscopy. The time of hatching and moults in these stages is also examined. Techniques for the automated creation of taxonomic drawings from confocal images using computer software are investigated and the possibilities and implications of this technique are discussed. The method of host location in L. branchialis is unknown but is likely to involve a variety of mechanisms, possibly including chemo-reception, mechano-reception and the use of physical phenomena in the water column, such as haloclines and thermoclines, to search for fish hosts. In this study the role of host-associated chemical cues in host location by adult female L. branchialis is investigated by analysing the parasites behavioural responses to a range of host-derived cues, in both a choice chamber and a 3D tracking arena. To analyse the data from the experiments, specialised computer software (“Paratrack”) was developed to digitise the paths of the parasites’ movements, and calculate a variety of behavioural parameters, allowing behaviour patterns to be identified and compared. The results show that L. branchialis responds to host-associated chemical cues in a similar way to many copepods in the presence of chemical cues. Of the different cues tested, gadoid conditioned water appears to be most attractive to the parasites, although the wide variation in behavioural responses may indicate that other mechanisms are also required for host location. The different behavioural responses of parasites to whiting (Merlangius merlangus L.) and cod (Gadus morhua) conditioned water, which are both definitive hosts, provide some evidence for sub-speciation in L. branchialis. The role of chemical cues in host location of L. branchialis, and the relative importance of chemical and physical cues in host location are discussed. As well as demonstrating several techniques, which show potential for further development, this work has improved our knowledge of the biology and life-cycle of L. branchialis. Further study of this, and other areas of L. branchialis biology and its host-parasite interactions, should assist the development of contingency plans for the effective management and control of this widespread and potentially devastating pathogen.
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26

Anderson, Barry Clayton. "The Response of Mice to Infection by the Parasitic Nematode Trichinella: A Comparison of Trichinella Spiralis and Trichinella Pseudospiralis." PDXScholar, 2002. https://pdxscholar.library.pdx.edu/open_access_etds/1658.

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The intracellular parasite Trichinella is a genus in phylum Nematoda that contains six named species including Trichinella spiralis and Trichinella pseudospiralis. These parasites infect a large variety of wild and domestic animals, human beings and a few species of birds. The parasitic strategies and the pathological effects on the host between trichinella spiralis and Trichinella pseudospiralis are quite different. The purpose of this study is to gain an understanding of the physiological, immunological and pathological differences between these two species of Trichinella using infections in the mouse as a model. In the course of this research I have attempted to answer the following questions: A) Is cortisol a factor in the differences of the host response to Trichinella spiralis or Trichinella pseudospiralis? B) Are there differences in leukocyte response in the peripheral blood of Trichinella infected mice? C) Are there differences in the up-regulation or down-regulation of cell surface molecules on leukocytes in the spleens of Trichinella infected mice? D) Is there a difference in the degree of muscle damage (as measured by creatine phosphokinase) when infections by the two species of Trichinella are compared? E) Are there differences in angiogenesis and collagen deposition in Trichinella infected mice and are these differences related to cortisol? F) Is nitric oxide a component in parasite killing and are there differences in nitric oxide production in host mice when the two species of Trichinella are compared? My research has shown that there are significant differences in the parasitic strategies and pathological consequences in mice infected with one or the other of the two species of Trichinella. The two species appear to generate different immune and inflammatory responses from the host. Trichinella pseudospiralis is much less damaging to the host, generates a very different peripheral blood response, stimulates the production of substantially greater levels of serum cortisol, generates a significantly different profile in cytokine production presents a very different cell surface antigen profile and does not produce a collagen nurse cell or generate an angiogenic response when compared to T spiralis. In addition, I have shown a role for nitric oxide in parasite killing and a role for serum cortisol in larval survival. I have also shown that cortisol has no role in either collagen deposition or the angiogenic response in Balb/c mice under the experimental conditions detailed here.
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27

Adams, John Peter. "Parasites of feral cats and native fauna from Western Australia the application of molecular techniques for the study of parasitic infections in Australian wildlife /." Connect to this title online, 2003. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20040730.142034.

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28

Noble, Stewart J. "Factors influencing the pinworm community (Oxyurida : Nematoda) parasitic in the hindgut of the American cockroach, Periplaneta americana." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30171.

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Large cockroaches, such as Periplaneta Americana, typically harbour in their hindgut two or more species of parasitic pinworm (Nematoda: Oxyurida). Our laboratory colony was infected with three, possibly four species. The mechanism(s) permitting the sympatry of these potentially competing species were investigated by: i) repeatedly sampling over time hosts of various size to determine the structure, if any, in the pinworm guild and ii) infecting uninfected hosts with known doses of infective eggs and monitoring population changes via daily host dissections. Results indicate that chemically-mediated intraspecific interference competition maintains pinworm populations at densities well below the apparent carrying capacity of the majority of hosts. The concomitant reduction of interspecific pressures thus permits the cohabitation of multiple pinworm species in what is essentially a single niche. This intraspecific population limitation is likely a response to pressures produced by the large size of the parasite in relation the hindgut of early instar hosts.
Science, Faculty of
Zoology, Department of
Graduate
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29

Carvalho, Juliana Barboza 1986. "Avaliação de uma nova técnica (TF-Test Modified) destinada ao diagnóstico de parasitoses intestinais em amostras fecais." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317466.

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Orientadores: Jancarlo Ferreira Gomes, Alexandre Xavier Falcão
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-23T15:19:46Z (GMT). No. of bitstreams: 1 Carvalho_JulianaBarboza_M.pdf: 1818938 bytes, checksum: d44ab358d0482575e52d1f77a3f4c07b (MD5) Previous issue date: 2013
Resumo: As parasitoses intestinais são altamente prevalentes no mundo, estando entre as maiores causadoras de doenças e óbitos em seres humanos. Atualmente, o diagnóstico laboratorial destas parasitoses é realizado por meio de procedimentos técnicos manuais, desenvolvidos na sua grande maioria há décadas, o que justifica a aplicabilidade de técnicas mais sensíveis e práticas para esta finalidade, visando obter resultados eficientes, especialmente em programas governamentais direcionados à Saúde Pública. Sendo assim, o objetivo do projeto foi de avaliar e validar uma nova técnica parasitológica, denominada TF-Test Modified, em comparação com três técnicas parasitológicas convencionais consagradas pela literatura: TF-Test Conventional; Rugai, Mattos e Brisola; e Kato-Katz/Helm-Test. As etapas do trabalho consistiram em realizar coleta de material fecal de 457 indivíduos localizados em regiões endêmicas para parasitoses no município de Campinas, SP; no processamento laboratorial de 1.828 exames; no diagnóstico de 14 espécies parasitárias; e na análise estatística qualitativa de resultados de maneira abrangente. Dentre as espécies parasitárias encontradas, helmintos e protozoários intestinais foram detectados em 42,23% de indivíduos pela técnica de TF-Test Modified, ante 36,76% por TF-Test Conventional, 5,03% por Kato-Katz/Helm-Test, e 4,16% por Rugai, Mattos e Brisola. Destes casos, 54,40% de infecção simples dos indivíduos demonstrou serem portadores de monoparasitismo. A nova técnica parasitológica de TF-Test Modified, quando comparada com as demais técnicas, apresentou alto valor de infecção, como exemplo para dupla, tripla e múltipla, de maneira a perfazer um total de 98,37% de infecções. Ademais, a nova técnica apresentou índice Kappa com grau de concordância Quase Perfeito em todos os parâmetros avaliados com estimativa de 95% (P<0,05), permitiu encontrar com alta eficiência diagnóstica todas as espécies parasitárias estudadas, mostrou um notável diagnóstico verdadeiro, especialmente quando analisada comparativamente com as outras três técnicas convencionais. O atual estudo permitiu concluir que a técnica de TF-Test Modified pode ser utilizada de forma abrangente no diagnóstico qualitativo de protozoários e helmintos intestinais de humanos. O ganho de sensibilidade diagnóstica proporcionada por esta nova técnica deverá ser de estimável contribuição para o diagnóstico individual laboratorial, inquéritos populacionais e controle das parasitoses intestinais, de modo a repercutir em contribuição social
Abstract: Intestinal parasites are highly prevalent worldwide and is among the largest cause of illness and death in humans. Currently, the laboratory diagnosis of these parasites is accomplished through technical procedures manuals, developed mostly for decades, justifying the applicability of more sensitive techniques and practices for this purpose, to obtain effective results, especially in government programs aimed at Public Health. Thus, the objective of the project was to evaluate and validate a new technique parasite, called TF-Test Modified, compared with three conventional parasitological techniques enshrined in literature: TF-Test Conventional; Rugai, Mattos and Brisola, and Kato-Katz / Helm-Test. The steps of the work consisted of conducting a collection of fecal samples from 457 individuals located in regions endemic for parasitic infections in Campinas, SP, in laboratory processing of 1,828 examinations, the diagnosis of 14 parasitic species, and the qualitative statistical analysis of results so comprehensive. Among the species found parasitic, helminths and intestinal protozoa were detected in 42,23% of subjects using the technique of TF-Test Modified, against 36,76% by TF-Test Conventional, 5,03% by Kato-Katz/Helm-Test, and 4,16% Rugai, Mattos and Brisola. Of these cases, 54,40% of single infections of individuals were shown to be carriers of monoparasitism. The new technique parasitological TF-Test Modified compared to other techniques of infection showed a high value, for example double, triple and multiple so as to make a total of 98,37% infections . Moreover, the new technique presented Kappa index level of agreement with Almost Perfect in all parameters with estimated 95% (P <0.05), allowed to meet with high diagnostic efficiency all parasitic species studied showed remarkable true diagnosis, especially when viewed in comparison with other three conventional techniques. The current study showed that the technique TF-Test Modified can be used comprehensively in qualitative diagnosis of intestinal protozoa and helminths of humans. The gain in diagnostic sensitivity afforded by this new technique should be estimable contribution to the individual diagnostic laboratory, population surveys and control of intestinal parasites, in order to reflect on social contribution
Mestrado
Parasitologia
Mestra em Parasitologia
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30

com, dbearham@hotmail, and Douglas Bearham. "Identification and characterisation of two haplosporidian parasites of oysters in north Western Australia." Murdoch University, 2008. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20081114.120135.

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A cryptic haplosporidian parasite was detected infecting rock oysters from the Montebello Islands in north-western Australia using a PCR targeting the parasite’s small ribosomal subunit gene. The PCR products were cloned and sequenced along with the remaining sections of the parasite’s SSU rRNA gene. Phylogenetic analysis of the sequence generated indicated a Minchinia species (Haplosporidia). The SSU sequence generated was used to develop two in situ hybridisation assays to visualise the parasite in H/E sections as well as a PCR assay to detect the parasite. The molecular assays were assessed for specificity and sensitivity and were then used to compare the parasite to previous haplosporidian parasite infections of pearl oysters. Both assays produced positive results from the infected pearl oysters but not from other closely related haplosporidian species. An SEM and TEM electron microscopy analysis was performed on spores from both parasite species. The spores of the pearl oyster parasite had two spore wall filaments wound around the spore originating for a posterior thickening while the spores of the rock oyster parasite were covered in microtubule-like structures. These data suggests pearl oysters where co-infected with both the Haplosporidium sp. and the Minchinia sp. detected in rock oysters. No evidence of a posterior thickening could be found on the spores of the rock oyster parasite. Attempts to detect the parasite at the previous geographic sites of its detection in pearl oysters resulted in detection of the Minchinia species in tropical oysters in the Kimberley region of Western Australia by in-situ hybridisation.
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31

Jossart, Quentin. "Ecologie moléculaire d'une relation hôte-parasite en contexte insulaire marin: crabes parasites des oursins spatangues en Mer des Caraïbes." Doctoral thesis, Universite Libre de Bruxelles, 2014. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209237.

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Comparer les structures génétiques des populations d’un couple hôte-parasite permet d’évaluer les facteurs qui façonnent la dispersion ainsi que la potentialité d’adaptation locale de ces espèces. Le modèle étudié est le crabe ectoparasite Dissodactylus primitivus et son oursin-hôte Meoma ventricosa, endémiques des Caraïbes et des côtes américaines voisines.

En étudiant des populations le long de l’arc antillais et de la côte panaméenne, ce travail a mis en évidence que la structure génétique des populations du parasite D. primitivus diffère fortement de celle de son hôte M. ventricosa (microsatellites et cytochrome oxydase I). En effet, alors que les populations du parasite présentent une différenciation au sein de cette région, celles de l’hôte sont génétiquement homogènes. Ce contraste peut être expliqué par des caractères biologiques et écologiques (fécondité, habilité à la nage, disponibilité de l’habitat) et suggère des potentialités d’adaptation locale distinctes. La distance géographique semble être importante dans la structuration des populations du crabe mais la courantologie ou encore des évènements passés (glaciations) jouent également un rôle. A l’échelle d’une même île, les crabes ne présentent pas de différenciation entre des sites distincts. En outre, nous avons pu montrer que des crabes issus d’hôtes d’espèces différentes ne sont pas différenciés génétiquement ce qui pourrait être liée à la mobilité des crabes adultes. Par des analyses de paternité, nous avons souligné cette mobilité, démontrant que le mode de reproduction du crabe est de la polygamie mais aussi que des accouplements pouvaient avoir lieu entre crabes d’espèces hôtes distinctes.


Doctorat en Sciences
info:eu-repo/semantics/nonPublished

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32

Salman, Ahmed Mahmoud Ahmed A. "Assessment of novel liver-stage vaccines using transgenic rodent malaria parasites." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:8c0e9338-3f33-4c83-b673-c17906ca1e38.

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33

Flaherty, Siobhan Marie. "Efficacy and Resistance Potential of JPC-3210 in Plasmodium falciparum." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5832.

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Combating drug resistant malaria has been historically challenging, and remains so today. Recent reports from Southeast Asia show that Plasmodium falciparum is developing resistance to even our best defenses; artemisinin-based therapies. This development threatens to become a significant challenge in controlling malaria infections worldwide, making research into developing and characterizing new antimalarial drugs increasingly important. The purpose of this study was to characterize the resistance potential of novel antimalarial compound JPC-3210 in vitro using P. falciparum clones. JPC-3210 is a new long acting drug with potential to be used in combination with fast-acting drugs like artemisinins to cure drug resistant malaria. In this study several methods were used to characterize the efficacy and resistance potential of JPC-3210. To determine the frequency of resistance generation in P. falciparum clones, parasites were kept under continuous drug pressure for thirty days, at which point drug pressure was removed and cultures were observed for signs of recrudescence. P. falciparum clones also were exposed to increasing levels of intermittent drug pressure that involved 3-4 days of drug exposure followed by a recovery period. The step-wise experiment was conducted over three months with drug pressure being increased step-wise until a maximal concentration of 700 ng/ml of JPC-3210; resistance was measured phenotypically in drug susceptibility assays at multiple time points. Additionally, the ability of JPC-3210 to induce dormant stage parasites, and its effect on dihydroartemisinin (DHA)-induced dormant stages was assessed in both a chloroquine resistant parasite (W2) and in an artemisinin resistant clone (4G). Results showed that the frequency of resistance against JPC-3210 in W2 clones was less when compared to that of atovaquone. The step-wise pulse exposure of JPC-3210 induced resistance in W2 clones, however, resistance proved unstable. Dormant stage parasites were not induced by JPC-3210, even at high concentrations in W2 or 4G clones, furthermore, the effect of JPC-3210 on dormant-induced parasites was found to be dose dependent, yet the drug did not kill DHA-induced dormant rings. JPC-3210 appears to be a good drug to use in combination with other antimalarial compounds for treatment of P. falciparum, but further research is needed. Future studies to assess the field performance of new antimalarial compounds by investigating resistance and dormancy profiles in vitro, and thereby maximizing out understanding of such drugs and their optimal implementation, are of the utmost importance.
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34

Araujo, Ana Julia Urias dos Santos. "Utilização do método de concentração em formol-acetato de etila na quantificação de ovos de helmintos e avaliação de sua aplicabilidade em inquéritos epidemiológicos." Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/9/9136/tde-05022015-081024/.

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O método de diagnóstico coproparasitológico de concentração em formolacetato de etila foi empregado para a quantificação de ovos de helmintos. O método quantitativo proposto foi padronizado utilizando-se o Sistema Comercial Coprotest® e amostras fecais contendo diferentes cargas de ovos de Ascaris lumbricoides. O \"Coprotest quantitativo\" foi aplicado em estudo populacional numa área de baixa endemicidade para parasitas diagnosticáveis através das fezes, e os resultados analisados comparativamente ao método de Kato-Katz. A metodologia proposta foi ainda comparada a outros métodos quantitativos, utilizando-se amostras fecais, preparadas em laboratório, com cargas decrescentes de ovos de A. lumbricoides, Trichuris trichiura e Schistosoma mansoni. Discutem-se as vantagens de se empregar um método capaz de detectar o maior número de espécies, tanto de helmintos quanto de protozoários, . e que permita, concomitantemente, estimar a intensidade das infecções por geohelmintos e S. mansoni nas populações. O \"Coprotest quantitativo\" mostrou ser de aplicação viável em trabalhos de campo, fornecendo resultados comparáveis aos outros métodos quantitativos já descritos na literatura.
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35

Krause, Luís Eduardo Barcellos. "Prevalência e fatores associados aos enteroparasitos em pacientes HIV positivos atendidos no Serviço de Assistência Especializada de Pelotas - RS, Brasil." Universidade Federal de Pelotas, 2009. http://repositorio.ufpel.edu.br/handle/ri/2344.

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Enteric parasitic infections are worldly known and reach mainly the poorest countries. This problem becomes more serious when it is associated with the Human Immunodeficiency Virus (HIV) infection. The objective of the study was to understand the prevalence and the risk factors associated with the enteric parasites among AIDS patients and HIV-positive healthy carriers. Cross-sectional study was carried out at the single assistance health service specialized in HIV/AIDS on Pelotas, a city in southern Brazil. Out of 273 patients who were interviewed in this study, 19,8% had pathogenic enteric parasites, and the most frequent pathogens were Trichuris trichiura, Giardia lamblia and Ascaris lumbricoides. The prevalence of pathogenic enteric parasites was significantly higher (31,4%) among who were not undergoing antiretroviral therapy (HAART) than among who were undergoing HAART (13,0%). The frequency of opportunistic enteric parasites (Cryptosporidium spp., Cystoisospora belli and Strongyloides stercoralis) was low; and it was 1,9% and 2,4%, respectively, among who were and were not undergoing HAART. This difference was not statistically significant. People with lower socioeconomic status, who had domestic animals and were not undergoing antiretroviral therapy (HAART), would have more chance to suffer from enteric parasitic infection when contrasted with the compared groups. The study has shown that it is necessary to adopt and carry out preventive and diagnosis actions among HIV-positive patients.
As parasitoses intestinais são conhecidas globalmente, atingindo especialmente países mais pobres. Este problema se torna ainda mais grave quando associado à infecção pelo vírus da imunodeficiência humana (HIV). O objetivo do estudo foi estimar a prevalência e os fatores associados aos enteroparasitos em pacientes HIV positivos. Foi realizado estudo transversal no único serviço de assistência especializada em HIV/AIDS de Pelotas, RS. Do total de 273 entrevistados, 19,8% estavam infectados por enteroparasitos patogênicos, sendo que os mais frequentes foram Trichuris trichiura, Giardia lamblia e Ascaris lumbricoides. A prevalência de parasitos patogênicos foi significativamente superior (31,4%) entre pacientes que não estavam usando a terapia antirretroviral altamente potente e efetiva (HAART) em relação aos que estavam usando HAART (13,0%). As prevalências foram baixas para os parasitos intestinais oportunistas Cryptosporidium spp., Cystoisospora belli e Strongyloides stercoralis, sendo de 2,4% em pacientes que não faziam uso de HAART e de 1,9% em pacientes tratados com HAART, não havendo diferença estatística. Os pacientes com níveis socioeconômicos mais baixos, que referiam ter animais domésticos e que não faziam uso de terapia com HAART tiveram mais chance de desenvolver enteroparasitos patogênicos. O estudo demonstra que é necessária a adoção e implementação de medidas preventivas e de investigação diagnóstica nos pacientes HIV positivos.
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36

Pérez, García David. "A journey to the deeps of the sea: parasite communities of the Alepocephalidae and the Macrouridae in the Balearic Sea (NW Mediterranean)." Doctoral thesis, Universitat Autònoma de Barcelona, 2017. http://hdl.handle.net/10803/402267.

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Tot i el gran nombre d’estudis del mar Mediterrani, el seu mar profund segueix sent en gran part desconegut, especialment en relació a la seva fauna parasitària. Els paràsits són components importants dels ecosistemes. Al trobar-se al llarg de la xarxa tròfica, aquests poden aportar informació sobre el seu hoste. També és d’esperar que l’hoste respongui als efectes perjudicials dels paràsits a diferents nivells. A més a més, les alteracions cito-histològiques i/o les variacions de certs marcadors bioquímics poden ser relacionades amb la presència de paràsits i ser útils per avaluar la salut dels peixos. Com la majoria dels peixos del Mediterrani profund són encara en gran part desconeguts, els seus paràsits poden ser valuoses fonts d’informació. Alepocephalus rostratus i els Macrouridae són components importants de les comunitats íctiques del talús profund del mar Balear. Per aquest motiu, l’objectiu de la present tesi és caracteritzar per primer cop les comunitats de paràsits d’Alepocephalus rostratus i dels macrúrids Coelorinchus caelorhincus, Coelorinchus mediterraneus, Coryphaenoides guentheri i Coryphaenoides mediterraneus, i estudiar la seva variabilitat natural i el seu efecte sobre la salut dels peixos en el mar Balear. A més a més, es discutiran la relacions entre el perfil tròfic dels hostes i les comunitats parasítiques. Les comunitats de paràsits de A. rostratus estaven constituïdes per un baix nombre d’espècies (set espècies de metazous i un coccidi). Una baixa riquesa conjuntament amb una alta proporció de formes larvàries dels paràsits és normalment característic de peixos meso- i batipelàgics. Això és deu probablement a la dieta especialitzada d’A. Rostratus en organismes planctònics. Les espècies predominants van ser les larves de Tetraphyllidea i de nematodes cucullànids. L’activitat de acetilcolinesterassa estava positivament relacionada amb l’abundància de Tetraphyllidea fam. gen. sp., Anisakis physeteris i H. aduncum i negativament amb la de Cucullaninae gen. sp. L’activitat de lactat deshidrogenassa va mostrar una relació positiva amb l’abundància dels paràsits Paracyclocotyla cherbonnieri i Tetraphyllidea fam. gen. sp. Es van detectar coccidis als cecs pilòrics amb una prevalença del 90% a Barcelona. Un total de 11 taxons van ser trobats als quatre macrúrids estudiats, sent el copèpode Hamaticolax resupinus l’únic paràsit comú entre tots ells. Coelorinchus mediterraneus, C. guentheri i Cor. mediterraneus van exhibir unes comunitats de paràsits bastant homogènies, especialment en els últims dos peixos, segurament per la seva similar dieta. Coelorinchus mediterraneus va tenir la major riquesa de taxons paràsits (vuit espècies), mentre que C. guentheri i Cor. mediterraneus en van tenir cinc i sis, respectivament, i C. caelorhincus tres. Gran part dels paràsits van ocórrer en baixa prevalença (<10%), mentre que només tres espècies van ser excepcionalment prevalents i abundants: les larves de Cucullanidae fam. gen. sp. en C. caelorhincus; Lepidapedon desclersae en Coe. mediterraneus i Hysterothylacium aduncum en ambdues espècies de Coryphaenoides. Pocs efectes en la salut dels peixos van quedar reflectits a nivell enzimàtic i histopatològic, probablement per la poca càrrega parasitària en els hostes. Hamaticolax resupinus n. sp. és descrit per primer cop en Coe. mediterraneus i Cor. mediterraneus. És la segona espècie d’Hamaticolax que es troba en macrúrids i és el Bomolochidae trobat a major profunditat a nivell mundial. Hamaticolax resupinus n. sp. és molt similar a H. maleus Oldewage, 1994, però es diferencia d’aquest, entre d’altres, per tenir una mida del cos més petita. Raphidascaris (R.) macrouri n. sp. és descrit per primer cop en els macrúrids del mediterrani profund Nezumia aequalis i Trachyrincus scabrus. Aquesta espècie es diferencia de la resta del subgènere pel seu gran nombre de papil·les caudals i espícules curtes.
Despite the great number of studies on the Mediterranean, its deep sea remains largely unknown, especially in relation to its parasite fauna. Parasites are important components of ecosystems. Being ubiquitous throughout all food webs, they can provide significant information of their hosts. In addition, it is expected that host respond to the harmful effects of parasites at different levels. Moreover, histo-cytological alterations and/or variations on the levels of certain biochemical markers can be related to the presence of parasites and are means to evaluate fish health. Since most of the important deep Mediterranean fishes are still largely unknown, their parasites can prove to be valuable sources of information. Alepocephalus rostratus and Macrouridae are important components of the fish community along the deep slope of the Balearic Sea. For this reason, the objectives of the present thesis are to characterize for the first time the parasite communities of Alepocephalus rostratus, and the macrourids Coelorinchus caelorhincus, Coelorinchus mediterraneus, Coryphaenoides guentheri and Coryphaenoides mediterraneus, their natural variability and their effects on fish health in the Balearic Sea. In addition, the relationship between the trophic profile of hosts and parasite communities will be discussed. The parasite communities of A. rostratus were constituted by little number of species (seven metazoan species and one coccidian). Low richness together with the high proportion of parasite larval forms are usually characteristic of meso- and bathypelagic fish species. This is probably due to the specialized diet of A. rostratus on planktonic organisms. The larval tetraphyllideans and cucullanid nematodes were the predominant species. A positive relationship was found between acetylcholinesterase activity and Tetraphyllidea fam. gen. sp., Anisakis physeteris and H. aduncum abundance and a negative one with the abundance of Cucullaninae gen. sp. Lactate dehydrogenase showed a positive relationship with the abundance of the parasites Paracyclocotyla cherbonnieri and Tetraphyllidea fam. gen. sp. Coccidians were detected in the pyloric caeca with a prevalence of 90% in Barcelona. A total of 11 parasite taxa were found among the four macrourids studied, being the copepod Hamaticolax resupinus the only parasite shared by all of them. Coelorinchus mediterraneus, C. guentheri and Cor. mediterraneus exhibited rather homogeneous parasite communities, especially in the case of the latter two, probably due to their similar diet composition. Coelorinchus mediterraneus showed the highest richness of parasite taxa (eight species), whereas C. guentheri and Cor. mediterraneus harboured up to five and six, respectively, and C. caelorhincus up to three. Several of the encountered parasites occurred at very low prevalence (<10%), while only three species were exceptionally prevalent and abundant: Cucullanidae fam. gen. sp. larvae in C. caelorhincus; Lepidapedon desclersae in Coe. mediterraneus and Hysterothylacium aduncum in both Coryphaenoides spp. Few parasite effects on fish health were reflected at enzymatic and histological level, probably due to the low parasite burden in their hosts. Hamaticolax resupinus n. sp. is described for the first time from Coe. mediterraneus and Cor. mediterraneus. It is the second Hamaticolax species that parasitizes a macrourid species and it is the deepest bomolochid encountered worldwide. Hamaticolax resupinus is smaller than its closely related species H. maleus, females have wider genital double-somite markedly wider than free abdominal somites and with convex lateral margins. Raphidascaris (R.) macrouri n. sp. is described for the first time from the deep Mediterranean macrourids Nezumia aequalis and Trachyrincus scabrus. This species differentiates from the rest of the subgenus by having high number of caudal papillae and short spicules.
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37

Flammer, Patrik Guido. "Molecular archaeoparasitology as a novel tool for the study of trading and migration networks through history." Thesis, University of Oxford, 2014. https://ora.ox.ac.uk/objects/uuid:642b62a8-431f-47b9-91ae-05339324cfd4.

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This project represents the first comprehensive study applying molecular and genetic methods to study historical contexts such as migration and trade based on human parasites. Using specially developed techniques, the study focused on parasites with minor symptoms which allowed the infected person to go about their daily business. The combination of state of the art techniques in archaeology, molecular methods and phylogenetic analysis enabled us to develop a novel powerful tool to study historic events. Diseases have a considerable impact on societies. Various publications indicate that human intestinal parasites are commonly found in a variety of archaeological contexts, including latrines, graves and mummies. These parasites can be detected by microscopy which focuses the work on samples which do close association to humans; widespread prevalence and the possibility for reliable microscopic diagnostics suggest that these parasites are an attractive study system for human activities. Infectious diseases have a much short generation time which offers greater opportunity to track historical events at higher resolution. Looking at a range of human parasites, their different life-cycles allowed insight into various aspects of human culture, comparing different origins of the samples allows an estimation of the epidemiological burden of ancient populations. Application of a parallel sequencing approach (MiSeq) enabled building a comprehensive database of sequences from various archaeological sites dating as far back as 3630 BCE. Indepth phylogenetic analysis reveals patterns in the genetic signatures of both coding and non-coding genetic regions, taking various levels of selective pressure into account. This project has produced the oldest pathogen sequence and the most comprehensive database of ancient pathogen sequences.
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38

Richardson, Merrie Renee. "Efficacy of an Electronic Scarecrow on 4 Mammalian Crop-Raiders in Limpopo Province, South Africa." TopSCHOLAR®, 2014. http://digitalcommons.wku.edu/theses/1400.

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In South Africa, 2 primate species, Chacma baboons (Papio ursinus) and vervet monkeys (Chlorocebus pygerythrus), and 2 nocturnal mammals, Cape porcupine (Hystrix africaeaustralis) and bushbuck (Tragelaphus scriptus), are among many species of crop raiders. Currently, cost-effective, non-lethal solutions are lacking. From June through December 2012, I installed novel electronic scarecrows on two commercial citrus orchards and a private reserve and used video-recording remote cameras to assess cropraiders’ reactions to them in Limpopo Province, South Africa. I used focal animal sampling data from treatment and control group animals to examine differences in activity budgets and behaviors of interest between groups. Compared to animals at sites with an inactive or no scarecrow, I hypothesized that animals in the treatment group would have altered activity budgets and rates of behaviors; that they would forage or feed less, run more (as a result of being frightened), be more vigilant and thus scan their surroundings more often, and display a visible startle in response to stimuli from scarecrows. Bushbuck at treatment sites spent a larger proportion of their activity budget running, and were more often startled. However, foraging was never observed, and bushbuck in the control group scanned their surroundings more often. Porcupines at treatment sites spent a larger portion of their activity budget running, though foraging was only observed in 1 control group animal and looking was never observed. For primates, treatment (control, scarecrow) was meaningful in explaining differences in focal animal activity budgets of baboons (F = 5.49, P = 0.001) and vervet monkeys (F = 7.09, P = 0.001) as indicated by a permutational MANOVA in R. In baboons, treatment was positively correlated with running; ratios of baboons that ran to baboons that did not run differed between treatment groups (G = 15.78, P < 0.001). Treatment was negatively correlated with feeding; ratios of baboons that fed or foraged to baboons that did not feed or forage differed (G = 5.39, P = 0.02). Significant differences between groups of vervet monkeys were not found with G-tests for the same behaviors of interest. Electronic scarecrows are promising tools for human-wildlife conflict mitigation, particularly for nocturnal antelopes. For primates, further innovation in design of scarecrows to incorporate a visual stimulus is recommended.
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39

Duranton, Christelle. "Comparaison de l'infestation par Oestrus ovis (Linné, 1761) chez la chevre et le mouton." Toulouse 3, 1997. http://www.theses.fr/1997TOU30171.

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Strus ovis (linnaeus, 1761) est un parasite frequent chez le mouton et la chevre de nombreux pays mediterraneens et tropicaux, responsable d'une maladie (l'strose) due a la presence et au developpement de larves dans les cavites nasales de l'hote. Une etude bibliographique et une enquete epidemiologique menee a l'abattoir de pezenas ont montre que la prevalence et l'intensite de l'infestation sont plus importantes chez le mouton que chez la chevre naturellement infestes par strus ovis. Nous avons infeste experimentalement des chevreaux et des agneaux par des larves de premier stade d'strus ovis et compare le nombre de larves recoltees a l'abattage. Les resultats ont confirme que la chevre etait moins receptive a l'infestation par strus ovis. La nature des populations cellulaires recrutees, mastocytes et eosinophiles, au niveau de la muqueuse nasale du septum de chevreaux infestes experimentalement a permis de suspecter la participation d'un phenomene d'hypersensibilite dans la pathogenie de l'strose, confirmant des travaux precedents realises chez l'agneaux. Cependant, apres infestation unique, nous avons montre que le recrutement des eosinophiles et des mastocytes est beaucoup plus important chez les agneaux que chez les chevreaux ou les valeurs restent semblables a celles des temoins. Apres infestations repetitives ; le nombre d'eosinophiles trouves au niveau de la muqueuse nasale des chevreaux est 2,5 fois plus faible que celui obtenu pour les agneaux ; les mastocytes de chevreaux sont tres peu recrutes. Le phenomene d'hypersensibilite developpe par les chevreaux n'est donc pas aussi important que celui des agneaux. La reactivite de certains facteurs de l'immunite peut etre impliquee dans cette difference de reponse cellulaire. Nous avons comparee in vitro, l'emission de monoxyde d'azote par les macrophages de chevreaux et d'agneaux pour determiner si l'infestation par strus ovis en modifiant la production. La toxicite de ce radical oxydatif vis a vis des larves de premiers stades a ete testee et prouvee in vitro. Pour les deux especes hotes, la stimulation in vitro des macrophages par l'extrait antigenique l1 diminue la production de monoxyde d'azote tandis que l'extrait antigenique l2 l'augmente significativement. Compte-tenu des donnees epidemiologiques, nous avons etudie par les marqueurs genomiques (rapd), la diversite genetique des populations d'strus ovis de moutons et de chevres. Ce travail constitue une premiere analyse genetique realisee chez cette espece. Nos resultats ont montre d'une part, une forte diversite intra-population et d'autre part, une importante divergence genetique entre les populations d'stres de moutons et de chevres.
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40

Katagiri, Satie [UNESP]. "Avaliação de duas técnicas coproparasitológicas convencionais e de um kit comercial na investigação da epidemiologia de parasitas gastrintestinais de cães no Estado de São Paulo." Universidade Estadual Paulista (UNESP), 2006. http://hdl.handle.net/11449/89304.

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Universidade Estadual Paulista (UNESP)
As técnicas coproparasitológicas de concentração por sedimentação e por flutuação e o kit TF-Test® foram utilizadas na investigação da epidemiologia dos parasitas gastrintestinais de cães no Estado de São Paulo. Amostras de fezes de 129 cães errantes e de 125 domiciliados foram colhidas de outubro de 2004 a setembro de 2005 e processadas de acordo com os protocolos do kit TF Test® e dos métodos de centrífugo-sedimentação e centrífugo-flutuação. Os seguintes parasitas e suas respectivas freqüências foram detectados: Ancylostoma spp. (38,2%), Giardia sp. (16,9%), Toxocara canis (8,7%), Tnchuns vulpis (7,1%), Isospora spp. (3,5%), Sarcocystís spp. (2,7%) e Dipy!idium caninum (2,4%). Dos 132 animais parasitados, 79 apresentaram parasitismo único e 53 estavam parasitados por dois ou mais gêneros e/ou espécies. Em cães errantes a prevalência de Ancylostoma spp., T. canis e Giardia sp. e a ocorrência de poliparasitismo foi maior (P < 0,01) que em animais domiciliados. Não houve diferença na freqüência de parasitas intestinais relacionada ao sexo, raça ou ao tratamento anti-helmíntico dos animais (P > 0,05), no entanto a freqüência de T. canis foi maior (P < 0,05) em cães jovens. Com relação à sazonalidade, a detecção de cistos de Giardia sp. foi mais freqüente nos meses de outubro a março. A sensibilidade diagnóstica do método de centrífugo-flutuação foi maior para todos os parasitas intestinais diagnosticados, porém somente no caso de Ancylostoma spp. essa diferença (P <0,05) se expressou em termos de uma maior freqüência de detecção de cães infectados. O elenco de parasitas diagnosticados na região estudada faz com que a técnica de centrifugo-flutuação com sulfato de zinco seja a mais apropriada tanto para os estudos epidemiológicos como para o diagnóstico individual, especialmente nas infecções subclínicas.
The sedimentation and flotation procedures for concentration of fecal specimens and the commercial device TF were used, in an epidemiological investigation of gastrointestinal parasites of dogs in São Paulo state. Fecal samples from 129 stray dogs and 125 dogs with an owner were collected from October 2004 to September 2005. AlI samples were concentrated by the sedimentation and flotation methods and by TF-Test® device. The following parasites, and their respective frequency were diagnosed in fecal samples : Ancylostoma spp. (38,2%), Giardia sp. (16,9%), Toxocara canis (8,7%), Tnchuris vulpis (7,1%), Isospora spp. (3,5%), Sarcocystis spp. (2,7%) and Dipylidium caninum (2,4%). Fifty-three out of 132 infected animais had mixed infection with two or more parasite genera. The prevalence of Ancy!ostoma spp., 1 canis and Giardia sp. as well as the occurrence of mixed infections were significantly higher in stray dogs (P <0,01) than in dogs with an owner. No effect of gender, breed and anti-helminthic treatment (P> 0,05) on the parasite frequency was observed, but the frequency of T. canis was higher (P < 0,05) in young animais. Giardia sp. cysts were more frequently detected from October to March. The centrifugation-flotation method was generally more accurate in the diagnosis of ali intestinal parasites of dogs, but only for Ancylostoma spp. this difference was observed in terms of prevalence. The species of parasites found in the studied region make the zinc sulfate flotation the most appropriate method not only to epidemiological studies, but also to individual diagnosis, speciaily in subciinical infections.
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41

Júnior, Mauro Cardoso. "Taxonomia das linhagens de Acanthobothrium van Beneden, 1850 (Eucestoda: Tetraphyllidea) parasitas de Potamotrygonidae (Chondrichthyes: Myliobatiformes)." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/41/41133/tde-07122010-175601/.

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Membros de Acanthobothrium (Cestoda: Tetraphyllidea: Onchobothriidae) são primariamente parasitas elasmobrânquios em todos os oceanos. No entanto, algumas linhagens são encontradas em arraias de água doce da família Potamotrygonidae da região Neotropical. O reconhecimento das entidades taxonômicas que participam de um sistema parasita/hospedeiro é essencial para que estudos comparativos que visam elucidar os padrões e processos responsáveis pela diversificação destes systemas. Atualmente, 175 espécies são reconhecidas para o gênero, das quais apenas seis parasitam exclusivamente potamotrigonídeos (A. terezae, A. quinonesi, A. amazonensis, A. regoi, A. ramiroi e A. peruviense). Historicamente, a maioria das espécies de Acanthobothrium, em particular as espécies parasitas de potamotrigonídeos, foi descrita baseandose em um número restrito de exemplares provindos de localidades muito distantes umas das outras e coletados em poucas espécies de potamotrigonídeos. Esta prática tem conduzido pesquisadores a denominar novos táxons sob a premissa de que estas linhagens exibem pouca variação morfológica. Neste trabalho, foram examinados 649 espécimes de hospedeiros, representando 10 espécies e 14 morfo-espécies de potamotrigonídeos, provenientes de 10 sub-bacias hidrográficas. Somente cinco espécies de Acanthobothrium são reconhecidas neste trabalho para o sistema de água doce, A. terezae (sinônimo A. ramiroi), A. quinonesi (sinônimos A. regoie A. peruviense), A. amazonensis e duas novas espécies A. sp. n.1 e A. sp. n. 2. Verificouse que estas cinco espécies de Acanthobothrium parasitam 27 espécies de potamotrigonídeos em quase todas as sub-bacias hidrográficas da América do Sul, demonstrando um padrão de especificidade distinto de seus congêneres marinhos. As diferenças observadas nos padrões de especificidade entre estes dois ambientes pode decorrer da inexistência de amostras representativas de grupos monofiléticos de hospedeiros marinhos e/ou a despreocupação em obter amostragens adequadas de espécimens seja de hospedeiros ou parasitas. Novas fontes de dados (e.g., molecular) são necessárias para entender melhor os limites do atual status taxonômico das espécies de água doce de Acanthobothrium. Outra recomendação para acessar a variabilidade morfológica de tetrafilídeos, em geral, é o aumento do tamanho amostral considerando diferentes áreas e hospedeiros. A representatividade biogeográfica é fundamental para a compreensão da biodiversidade. Sistematas que trabalham com a taxonomia de tetrafilídeos devem ter cautela no uso de dados morfométricos e merísticos na diagnose de espécies que são descritas com base um material biológico reduzido.
Members of Acanthobothrium (Eucestoda: Tetraphyllidea: Onchobothriidae) are mainly parasites marine elasmobranchs throughout the oceans. However, few lineages are found in freshwater stingrays of the family Potamotrygonidae, which members are restricted to the Neotropic. The recognition of taxonomic units involved in a host/parasite system is essential for comparative studies so that the diversification process resulting from historic associations can be accurately elucidated. Currently, 175 species are recognized for the genus, but only six parasite potamotrygonids (A. terezae, A. quinonesi, A. amazonensis, A. regoi, A. ramiroi e A. peruviense). Historically, most species of Acanthobothrium, including freshwater ones, has been described based on a restricted number of specimens from distant localities and few potamotrygonid species. This practice has led researchers to describe new species based on the premises that those lineages present low morphological variation. In this study, 649 host specimens were examined, representing 10 species and 14 morphotypes of potamotrygonids from 10 river sub basins of South America. Only five Acanthobothrium species were recognized as valid for the freshwater system, Acanthobothrium terezae (synonym A. ramiroi), A. quinonesi (synonyms A. regoi and A. peruviense), A. amazonensis and two new species A. sp. n.1 and A. sp. n. 2. These five species of Acanthobothrium parasite 27 species of potamotrygonids in almost all river basins of South America, presenting a distinct host specificity pattern from their marine counterparts. The differences in the diversity patterns observed for marine and freshwater lineages could be due to inadequate sampling of monophyletic marine groups and/or to the lack of concern with obtaining a representative number of specimens attributed to one species (host or parasite). New sources of data (e.g., molecular) are necessary to better understand the limits of the present taxonomic status of freshwaters species of Acanthobothrium. Another recommendation to access morphological variability of tetraphyllideans is to increase the sample size to different areas and hosts. Meaningful biogeographical representation is fundamental to the comprehension of biodiversity. Systematists working on the taxonomy of tetraphyllideans should also be cautious when using morphometric and meristic characters to distinguish species, which are described based on reduced biological material.
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42

Almeida, Fabiana Alves de [UNESP]. "Caracterização da resistência a anti-helmíntico de isolados de Haemonchus contortus e trichostrongylus colubriformis orieundo de ovinos." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/87795.

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O estudo teve por objetivo determinar o grau de eficácia da levamisol, albendazol, ivermectina, moxidectina, closantel e triclorfon em isolados de Haemonchus contortus e Trichostrongylus colubriformis. Quarenta e dois cordeiros da raça Santa Inês, com três meses de idade, foram infectados artificialmente com 4000 larvas infectantes (L3) de H. contortus e 4000 L3 de T. colubriformis. Os animais foram separados em sete grupos, com seis animais cada, os quais receberam os seguintes tratamentos: Grupo 1 – controle, sem tratamento; Grupo 2 - moxidectina injetável (0,2 mg/kg de peso vivo (PV), Cydectin®, Fort Dodge), Grupo 3 - closantel via oral (10 mg/kg de PV, Zuletel®, Laboratório Microsules) Grupo 4 – triclorfon via oral (100 mg/kg de PV, Neguvon®, Bayer); Grupo 5 – fosfato de levamisol injetável (4,7 mg/kg de PV, Ripercol®, Fort Dodge), Grupo 6 - albendazol via oral (5,0 mg/kg de PV, Valbazen®, Pfizer) e o Grupo 7- tratado com ivermectina injetável (0,2 mg/kg de PV, Ivomec® , Merial). A via de administração e a dosagem empregada foram realizadas de acordo com as instruções do fabricante. Amostras de fezes foram coletadas no dia do tratamento, três, sete, 10 e 14 dias após, para a realização de contagem de ovos por grama de fezes (OPG) e cultura de fezes para obtenção e posterior identificação das L3. Os animais foram sacrificados 14 dias após o tratamento para obtenção e quantificação dos vermes presentes no abomaso e no intestino delgado. A eficácia dos tratamentos foi calculada a partir da média aritmética do OPG ou número total de vermes encontrados nos grupos tratados em comparação com os valores do grupo controle. As reduções percentuais das cargas parasitárias de H. contortus foram de 17% para o albendazol, 10% para o levamisol, 45% para moxidectina, 20% para ivermectina, 23% para o closantel e 73% para o triclorfon...
The objective of this study was to determine the efficacy of levamisole, albendazole, ivermectin, moxidectin, closantel and trichlorfon, against Haemonchus contortus and Trichostrongylus colubriformis isolates. Forty-two lambs of the Santa Ines breed, at three months of age, were simultaneously artificially infected with 4000 infective H. contortus larvae (L3) and 4000 T. colubriformis L3. The animals were divided into seven groups with six animals each that received one of the following treatments: Group 1 - control, no treatment; Group 2 - moxidectin (0.2 mg/kg body weight (BW), Cydectin®, Fort Dodge); Group 3 - closantel (10 mg/kg BW, 10% Zuletel®, Microsules Laboratories); Group 4 - trichlorfon (100 mg/kg BW, Neguvon®, Bayer); Group 5 – levamisole phosphate (4.7 mg/kg BW, Ripercol®, Fort Dodge); Group 6 - albendazole (5.0 mg/kg BW, Valbazen®, Pfizer); and Group 7 - treated with ivermectin (0.2 mg/kg BW, Ivomec®, Merial). Fecal samples were collected 3, 7, 10 and 14 days after treatment and processed for nematode fecal egg counts (FEC) and fecal cultures for the production and subsequent identification of L3. The animals were sacrificed 14 days after treatment for collection and quantification of the worms in the abomasum and small intestine. The efficacy of the treatments was calculated from the arithmetic mean of the FEC or worm burden of the treated groups, compared with the values of the control group. The percentage reductions in H. contortus worm burdens were 17% for albendazole, 10% for levamisole, 45% for moxidectin, 20% for ivermectina, 23% for closantel and 73% for trichlorfon. Reductions for T. colubriformis were 19% for albendazole, 28% for ivermectin, 82% for moxidectin and 0% for levamisole, closantel and trichlorfon. The fecal examination was not effective for the detection of resistance to T. colubriformis, since T. colubriformis L3 were not detected... (Complete abstract click electronic access below)
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43

Nunes, Victor Hugo Borba. "Parasitos encontrados em hospedeiros extintos." reponame:Repositório Institucional da FIOCRUZ, 2015. https://www.arca.fiocruz.br/handle/icict/13471.

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Os estudos paleoparasitológicos se caracterizam pela busca de parasitos em material arqueológico e paleontológico. Em geral, a maioria das pesquisas gira em torno de material de épocas mais recentes, principalmente relacionados a grupos humanos, que não chegam a datações de um milhão de anos. A busca por explicações mais antigas em relação ao surgimento das parasitoses nos leva aos animais extintos, que revelam nos vestígios deixados por eles, os parasitos que circulavam antes do surgimento dos seres humanos. Esse trabalho objetivou identificar parasitos que por ventura fossem encontrados em vestígios de animais extintos de diferentes idades geológicas. Então, 32coprólitos de 6 hospedeiros diferentes (caprino, hiena, duas espécies de peixes, cinodonte e dicinodonte), foram analisados nessa pesquisa, com datações que compreendem do Quaternário ao Triássico (10 mil a 240 milhões de anos antes do presente). Várias técnicas de recuperação de material mineralizado e dessecado foram utilizadas, de acordo com que cada coprólito foi preservado. Se mineralizado, técnicas com ácido e aparelho de ultrassom possibilitaram a análise, já para os coprólitos dessecados, foi feita apenas a reidratação com fosfato trissódico. Amostras de 4 hospedeiros foram positivas para parasitos. Cisto de protozoário em caprino, dois ovos de helmintos em coprólitos de hiena, um nematoda em dicinodonte, foram encontrados. Além de um ascarídeo e um oxyurídeo em coprólito de cinodonte, um réptil mamaliforme pertencente a um clado que originou os mamíferos, que apresentaram dois parasitos comumente achados em mamíferos modernos. Portanto, esses achados permitem que respostas sejam respondidas para compreender melhor a relação parasito hospedeiro-ambiente em diferentes épocas da história da vida.
Paleoparasitological studies are characterized by the search for parasites in archaeological and paleontological material. In general, most research centers around more recent material, mainly related to human groups, which doesn‟t reach the dating ofa million years. The search for older explanations in relation to the emergence of parasites leads us to extinct animals, which reveal on the traces left by them, the parasites that circulates before the appearance of humans. This study aimed to identifyparasites that were found in traces of extinct animals of different geological ages.Thereby, 32 coprolites 6 different hosts (goat, hyena, two species of fish, cynodont anddicynodonte) were analyzed in this study, with dating comprising from Quaternary toTriassic (10 thousands to 240 million years before present). Several techniques forrecovery of mineralized and dried material were used in accordance with the way eachcoprolite was preserved. If mineralized, techniques with acid and ultrasound deviceenabled the analysis, and for the disiccated coprolites, it was only made rehydrationwith trisodium phosphate. Samples of 4 hosts were positive for parasites. Protozoan cystin goats, two eggs of helminths in coprolites of hyena and nematode in dicynodonte, were found. In addition, an ascarid and an oxyurid egg in a coprolites of cynodont, amamaliforme reptile that belongs to a monophiletic clade that originated mammals,which showed two parasites commonly found in modern mammals. Therefore, thesefindings allow to fill gaps to understand the host-parasite-environment relationship better at different times in the history of life. (AU)^ien
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44

Newman, Christopher. "The demography and parasitology of the Wytham Woods' badger population." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343438.

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45

Katagiri, Satie. "Avaliação de duas técnicas coproparasitológicas convencionais e de um kit comercial na investigação da epidemiologia de parasitas gastrintestinais de cães no Estado de São Paulo /." Botucatu : [s.n.], 2006. http://hdl.handle.net/11449/89304.

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Orientador : Teresa Cristina G. Oliveira-Sequeira
Banca: Lucia Helena O'Dwyer de Oliveira
Banca: Mara Regina Stip Balarin
Resumo: As técnicas coproparasitológicas de concentração por sedimentação e por flutuação e o kit TF-Test® foram utilizadas na investigação da epidemiologia dos parasitas gastrintestinais de cães no Estado de São Paulo. Amostras de fezes de 129 cães errantes e de 125 domiciliados foram colhidas de outubro de 2004 a setembro de 2005 e processadas de acordo com os protocolos do kit TF Test® e dos métodos de centrífugo-sedimentação e centrífugo-flutuação. Os seguintes parasitas e suas respectivas freqüências foram detectados: Ancylostoma spp. (38,2%), Giardia sp. (16,9%), Toxocara canis (8,7%), Tnchuns vulpis (7,1%), Isospora spp. (3,5%), Sarcocystís spp. (2,7%) e Dipy!idium caninum (2,4%). Dos 132 animais parasitados, 79 apresentaram parasitismo único e 53 estavam parasitados por dois ou mais gêneros e/ou espécies. Em cães errantes a prevalência de Ancylostoma spp., T. canis e Giardia sp. e a ocorrência de poliparasitismo foi maior (P < 0,01) que em animais domiciliados. Não houve diferença na freqüência de parasitas intestinais relacionada ao sexo, raça ou ao tratamento anti-helmíntico dos animais (P > 0,05), no entanto a freqüência de T. canis foi maior (P < 0,05) em cães jovens. Com relação à sazonalidade, a detecção de cistos de Giardia sp. foi mais freqüente nos meses de outubro a março. A sensibilidade diagnóstica do método de centrífugo-flutuação foi maior para todos os parasitas intestinais diagnosticados, porém somente no caso de Ancylostoma spp. essa diferença (P <0,05) se expressou em termos de uma maior freqüência de detecção de cães infectados. O elenco de parasitas diagnosticados na região estudada faz com que a técnica de centrifugo-flutuação com sulfato de zinco seja a mais apropriada tanto para os estudos epidemiológicos como para o diagnóstico individual, especialmente nas infecções subclínicas.
Abstract: The sedimentation and flotation procedures for concentration of fecal specimens and the commercial device TF were used, in an epidemiological investigation of gastrointestinal parasites of dogs in São Paulo state. Fecal samples from 129 stray dogs and 125 dogs with an owner were collected from October 2004 to September 2005. AlI samples were concentrated by the sedimentation and flotation methods and by TF-Test® device. The following parasites, and their respective frequency were diagnosed in fecal samples : Ancylostoma spp. (38,2%), Giardia sp. (16,9%), Toxocara canis (8,7%), Tnchuris vulpis (7,1%), Isospora spp. (3,5%), Sarcocystis spp. (2,7%) and Dipylidium caninum (2,4%). Fifty-three out of 132 infected animais had mixed infection with two or more parasite genera. The prevalence of Ancy!ostoma spp., 1 canis and Giardia sp. as well as the occurrence of mixed infections were significantly higher in stray dogs (P <0,01) than in dogs with an owner. No effect of gender, breed and anti-helminthic treatment (P> 0,05) on the parasite frequency was observed, but the frequency of T. canis was higher (P < 0,05) in young animais. Giardia sp. cysts were more frequently detected from October to March. The centrifugation-flotation method was generally more accurate in the diagnosis of ali intestinal parasites of dogs, but only for Ancylostoma spp. this difference was observed in terms of prevalence. The species of parasites found in the studied region make the zinc sulfate flotation the most appropriate method not only to epidemiological studies, but also to individual diagnosis, speciaily in subciinical infections.
Mestre
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46

Cruz, Leonardo Dominici [UNESP]. "Padrões ecológicos da relação de parasitismo entre ácaros mesostigmata e alguns roedores neotropicais." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/106546.

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Ácaros mesostigmatídeos e seus roedores hospedeiros compreendem um dos mais ricos e diversos sistemas parasito-hospedeiro da região Neotropical. A maior parte do conhecimento disponível sobre este sistema refere-se a listas de ocorrências, descrições de espécies parasitas e relações de especificidade hospedeira em escalas locais. Estudos ecológicos com o objetivo de procurar padrões de estruturas de comunidades de espécies parasitas, bem como investigar os possíveis processos subjacentes à organização destas comunidades são escassos. Dessa forma, o presente estudo tenta contribuir para o conhecimento ecológico deste sistema parasito-hospedeiro. No Capítulo 1, investigou-se a existência de padrões organizacionais nas infracomunidades de mesostigmatídeos em duas populações do hospedeiro roedor Oligoryzomys nigripes, bem como possíveis fatores subjacentes aos padrões observados. Demonstrou-se que as infracomunidades de mesostigmatídeos podem apresentar variações na sua organização, indo desde infracomunidades completamente aleatórias, a infracomunidades estruturadas. Fatores relacionados à história de vida dos hospedeiros podem ser responsáveis pela estruturação das infracomunidades de mesostigmatídeos; todavia, a proposição de padrões gerais não foi possível, principalmente devido a grande diversidade de espécies parasitas e hospedeiras envolvidas na região Neotropical. No Capítulo 2, investigou-se a existência de padrões de similaridades entre as comunidades de mesostigmatídeos em duas escalas observacionais: comunidade componente e comunidade composta. Os resultados obtidos demonstraram que as similaridades entre as comunidades componentes e entre as comunidades compostas geralmente são baixas, não sendo influenciadas pela distância geográfica e pela dissimilaridade ambiental entre as localidades...
Mites and their rodent hosts mesostigmatídeos comprise one of the richest and most diverse host-parasite systems of the Neotropical region. Most of the knowledge available about this system refers to occurrence lists, parasite species descriptions and host specificity relationships at local scales. Ecological studies with the aim looking for structure patterns of parasite communities, as well as investigate the possible processes underlying the organization of these communities are scarce. Thus, this study attempts to contribute to the ecological knowledge of this host-parasite system. In Chapter 1, we investigated the existence of organizational patterns in infracommunities of Mesostigmata mites of the two populations of the rodent host Oligoryzomys nigripes as well as possible factors underlying the observed patterns. It was demonstrated that the infracommunities of Mesostigmata mites may vary in their organization, ranging from completely random infracommunities to structured infracommunities. Factors related to the hosts life histories may be responsible for structuring Mesostigmata mites infracommunities. However, the proposition of general patterns was not possible, mainly due to the great diversity of parasites and host species involved in Neotropical region. In Chapter 2, we investigated the existence of similarity patterns among Mesostigmata mites communities in two levels: component community and compound community. The results showed that the similarities among the component communities and among the compound communities generally are low, not being influenced by geographical distance and environmental dissimilarity among the localities. However, the similarities of Mesostigmata mites among the compound communities were positively related to the host faunas similarities among the localities... (Complete abstract click electronic access below)
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47

Cruz, Leonardo Dominici. "Padrões ecológicos da relação de parasitismo entre ácaros mesostigmata e alguns roedores neotropicais /." Rio Claro : [s.n.], 2012. http://hdl.handle.net/11449/106546.

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Orientador: Claudio José Von Zuben
Banca: Aricio Xavier Linhares
Banca: Gilberto Salles Gazêta
Banca: Fabio Akashi Hernandes
Banca: Karim Christina Scopinho Furquim
Resumo: Ácaros mesostigmatídeos e seus roedores hospedeiros compreendem um dos mais ricos e diversos sistemas parasito-hospedeiro da região Neotropical. A maior parte do conhecimento disponível sobre este sistema refere-se a listas de ocorrências, descrições de espécies parasitas e relações de especificidade hospedeira em escalas locais. Estudos ecológicos com o objetivo de procurar padrões de estruturas de comunidades de espécies parasitas, bem como investigar os possíveis processos subjacentes à organização destas comunidades são escassos. Dessa forma, o presente estudo tenta contribuir para o conhecimento ecológico deste sistema parasito-hospedeiro. No Capítulo 1, investigou-se a existência de padrões organizacionais nas infracomunidades de mesostigmatídeos em duas populações do hospedeiro roedor Oligoryzomys nigripes, bem como possíveis fatores subjacentes aos padrões observados. Demonstrou-se que as infracomunidades de mesostigmatídeos podem apresentar variações na sua organização, indo desde infracomunidades completamente aleatórias, a infracomunidades estruturadas. Fatores relacionados à história de vida dos hospedeiros podem ser responsáveis pela estruturação das infracomunidades de mesostigmatídeos; todavia, a proposição de padrões gerais não foi possível, principalmente devido a grande diversidade de espécies parasitas e hospedeiras envolvidas na região Neotropical. No Capítulo 2, investigou-se a existência de padrões de similaridades entre as comunidades de mesostigmatídeos em duas escalas observacionais: comunidade componente e comunidade composta. Os resultados obtidos demonstraram que as similaridades entre as comunidades componentes e entre as comunidades compostas geralmente são baixas, não sendo influenciadas pela distância geográfica e pela dissimilaridade ambiental entre as localidades... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Mites and their rodent hosts mesostigmatídeos comprise one of the richest and most diverse host-parasite systems of the Neotropical region. Most of the knowledge available about this system refers to occurrence lists, parasite species descriptions and host specificity relationships at local scales. Ecological studies with the aim looking for structure patterns of parasite communities, as well as investigate the possible processes underlying the organization of these communities are scarce. Thus, this study attempts to contribute to the ecological knowledge of this host-parasite system. In Chapter 1, we investigated the existence of organizational patterns in infracommunities of Mesostigmata mites of the two populations of the rodent host Oligoryzomys nigripes as well as possible factors underlying the observed patterns. It was demonstrated that the infracommunities of Mesostigmata mites may vary in their organization, ranging from completely random infracommunities to structured infracommunities. Factors related to the hosts life histories may be responsible for structuring Mesostigmata mites infracommunities. However, the proposition of general patterns was not possible, mainly due to the great diversity of parasites and host species involved in Neotropical region. In Chapter 2, we investigated the existence of similarity patterns among Mesostigmata mites communities in two levels: component community and compound community. The results showed that the similarities among the component communities and among the compound communities generally are low, not being influenced by geographical distance and environmental dissimilarity among the localities. However, the similarities of Mesostigmata mites among the compound communities were positively related to the host faunas similarities among the localities... (Complete abstract click electronic access below)
Doutor
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48

Almeida, Fabiana Alves de. "Caracterização da resistência a anti-helmíntico de isolados de Haemonchus contortus e trichostrongylus colubriformis orieundo de ovinos /." Botucatu, 2009. http://hdl.handle.net/11449/87795.

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Orientador: Alessandro Francisco Talamini do Amarante
Banca: Maria Conceição Zocoller Seno
Banca: Raquel A. da Rocha de Oliveira
Resumo: O estudo teve por objetivo determinar o grau de eficácia da levamisol, albendazol, ivermectina, moxidectina, closantel e triclorfon em isolados de Haemonchus contortus e Trichostrongylus colubriformis. Quarenta e dois cordeiros da raça Santa Inês, com três meses de idade, foram infectados artificialmente com 4000 larvas infectantes (L3) de H. contortus e 4000 L3 de T. colubriformis. Os animais foram separados em sete grupos, com seis animais cada, os quais receberam os seguintes tratamentos: Grupo 1 - controle, sem tratamento; Grupo 2 - moxidectina injetável (0,2 mg/kg de peso vivo (PV), Cydectin®, Fort Dodge), Grupo 3 - closantel via oral (10 mg/kg de PV, Zuletel®, Laboratório Microsules) Grupo 4 - triclorfon via oral (100 mg/kg de PV, Neguvon®, Bayer); Grupo 5 - fosfato de levamisol injetável (4,7 mg/kg de PV, Ripercol®, Fort Dodge), Grupo 6 - albendazol via oral (5,0 mg/kg de PV, Valbazen®, Pfizer) e o Grupo 7- tratado com ivermectina injetável (0,2 mg/kg de PV, Ivomec® , Merial). A via de administração e a dosagem empregada foram realizadas de acordo com as instruções do fabricante. Amostras de fezes foram coletadas no dia do tratamento, três, sete, 10 e 14 dias após, para a realização de contagem de ovos por grama de fezes (OPG) e cultura de fezes para obtenção e posterior identificação das L3. Os animais foram sacrificados 14 dias após o tratamento para obtenção e quantificação dos vermes presentes no abomaso e no intestino delgado. A eficácia dos tratamentos foi calculada a partir da média aritmética do OPG ou número total de vermes encontrados nos grupos tratados em comparação com os valores do grupo controle. As reduções percentuais das cargas parasitárias de H. contortus foram de 17% para o albendazol, 10% para o levamisol, 45% para moxidectina, 20% para ivermectina, 23% para o closantel e 73% para o triclorfon... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The objective of this study was to determine the efficacy of levamisole, albendazole, ivermectin, moxidectin, closantel and trichlorfon, against Haemonchus contortus and Trichostrongylus colubriformis isolates. Forty-two lambs of the Santa Ines breed, at three months of age, were simultaneously artificially infected with 4000 infective H. contortus larvae (L3) and 4000 T. colubriformis L3. The animals were divided into seven groups with six animals each that received one of the following treatments: Group 1 - control, no treatment; Group 2 - moxidectin (0.2 mg/kg body weight (BW), Cydectin®, Fort Dodge); Group 3 - closantel (10 mg/kg BW, 10% Zuletel®, Microsules Laboratories); Group 4 - trichlorfon (100 mg/kg BW, Neguvon®, Bayer); Group 5 - levamisole phosphate (4.7 mg/kg BW, Ripercol®, Fort Dodge); Group 6 - albendazole (5.0 mg/kg BW, Valbazen®, Pfizer); and Group 7 - treated with ivermectin (0.2 mg/kg BW, Ivomec®, Merial). Fecal samples were collected 3, 7, 10 and 14 days after treatment and processed for nematode fecal egg counts (FEC) and fecal cultures for the production and subsequent identification of L3. The animals were sacrificed 14 days after treatment for collection and quantification of the worms in the abomasum and small intestine. The efficacy of the treatments was calculated from the arithmetic mean of the FEC or worm burden of the treated groups, compared with the values of the control group. The percentage reductions in H. contortus worm burdens were 17% for albendazole, 10% for levamisole, 45% for moxidectin, 20% for ivermectina, 23% for closantel and 73% for trichlorfon. Reductions for T. colubriformis were 19% for albendazole, 28% for ivermectin, 82% for moxidectin and 0% for levamisole, closantel and trichlorfon. The fecal examination was not effective for the detection of resistance to T. colubriformis, since T. colubriformis L3 were not detected... (Complete abstract click electronic access below)
Mestre
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49

Yilma, Jobre Makonnen. "Contribution à l'étude de l'épidémiologie, du diagnostic immunologique et de la physiopathologie de l'oestrose ovine (oestrus ovis linne 1761)." Toulouse, INPT, 1992. http://www.theses.fr/1992INPT036A.

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Une etude epidemiologique effectuee dans le sud-ouest a revele une prevalence elevee de l'infestation par oestrus ovis. L'evolution larvaire qui est fonction de la temperature exterieure et du niveau de precipitations, comprend une courte phase estivale de developpement actif et une phase prolongee d'inhibition hivernale. Des essais d'infestations experimentales ont confirme l'influence des facteurs climatiques sur la dipause. Dans une etude de simulation de l'strose par des transplantations larvaires repetees, des resultats ante mortem et post mortem significativement differents ont ete observes entre les animaux infestes et les temoins. La faiblesse du taux de recolte larvaire est du principalement a la grande mortalite des larves resultant de la reaction de l'hote. Un test de depistage par elisa a ete mis au point, les reactions optimales, hautement reproductibles et specifiques ont ete obtenues avec l'ag 20% de 2eme stade a 2 microgrammes de proteines par millilitre, avec des dilutions de serum et de peroxydase de 1/200 et 1/1000. F. Hepatica et h. Contortus n'ont presente aucune reaction croisee avec oestrus ovis. Des le septieme jour apres l'infestation unique, une augmentation du taux d'anticorps circulants a ete notee. Lors de l'infestation repetee, une chute initiale a ete suivie cinq semaines apres, par une augmentation spectaculaire. Des differences significatives de taux ont ete observees entre des groupes de moutons d'ages varies soumis a des infestations naturelles. Une cinetique bimodale de la population d'eosinophiles est la caracteristique de l'infestation unique. Une sensibilisation par des antigenes larvaires a declenche une reaction fugace, mais identique qu'avec des larves vivantes. L'effet mediateur des eosinophiles, par degranulation au contact de la larve semble etre le mecanisme principal de la reaction de l'hote. La reaction d'hypersensibilite immediate associee a cette infestation serait modulee par les produits des granules des eosinophiles
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50

Almeida, Isis Almeida de. "Prevalência de enteroparasitos em crianças hospitalizadas em Pelotas, Rio Grande do Sul, Brasil." Universidade Federal de Pelotas, 2013. http://repositorio.ufpel.edu.br/handle/ri/2324.

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Intestinal parasite infections are diseases caused by protozoa and helminth groups. They are common in developing countries and are the most frequent diseases especially among children. Although it is known that hospitalized children may be more susceptible to intestinal parasites, because they are usually neglected, few studies describe the prevalence. This study aimed to investigate the prevalence of enteric parasite infections among patients admitted to the University Hospitals Pediatric Units in the municipality of Pelotas, state of Rio Grande do Sul, Brazil, from April to December, 2012. Along with the delivery of the material for collecting feces sample, a structured questionnaire was administered to parents or guardians in order to obtain information about socioeconomic conditions of the family and how much they know about parasitic diseases. They were also given an educational material addressing the major parasitic diseases in the region. Feces samples were processed according to the techniques developed by Faust (centrifugal-flotation), Ritchie (centrifugal-sedimentation), and Baermann-Moraes. Of the 106 patients investigated, 32.1% were positive for one or more intestinal parasites. Trichuris trichiura (38.24%) and Ascaris lumbricoides (35.29%) were prevalent among helminthes. Giardia lamblia (14.7%) stood out among protozoa. Analysis of the questionnaires revealed alarming results regarding to people knowledge about parasitic diseases and the lack of parasite examination among children surveyed in this municipality. The index of parasitic diseases found in this study is a clear reflection of the lack of information behind parasitic diseases, and points to the need for implementing public policies that aim at inclusion of projects in education, including in elementary school curriculum hygiene and environmental sanitation issues, as well as fecal parasite testing in hospital routine.
Parasitoses intestinais são doenças causadas por protozoários ou helmintos, mais frequentes em países subdesenvolvidos e em desenvolvimento, acometendo principalmente as crianças. Embora se saiba que crianças hospitalizadas podem apresentar maior suscetibilidade às parasitoses intestinais, por serem geralmente negligenciadas, poucos trabalhos descrevem essa prevalência. Esse estudo teve como objetivo investigar a prevalência de enteroparasitoses em pacientes internados em unidades pediátricas de Hospitais Universitários em Pelotas, Rio Grande do Sul, Brasil, no período de abril a dezembro de 2012. Após a entrega de material para coleta de amostras de fezes, foi aplicado um questionário estruturado aos pais ou responsáveis com intuito de obter informações sobre as condições socioeconômicas da família e o conhecimento sobre parasitoses, sendo também distribuído material educativo, abordando as principais parasitoses da região. As amostras de fezes foram processadas através das técnicas de Faust (centrífugo-flutuação), Ritchie (centrífugo-sedimentação) e Baermann-Moraes. Dos 106 pacientes avaliados, 32,1% foram positivos para uma ou mais espécies de enteroparasito. Entre os helmintos, os prevalentes foram Trichuris trichiura (38,24%) e Ascaris lumbricoides (35,29%). Dentre os protozoários, destacou-se Giardia lamblia (14,7%). A análise dos questionários revelou resultados alarmantes no que diz respeito ao conhecimento da população sobre parasitoses e a ausência da realização de exames parasitológicos das crianças estudadas nesse município. O índice de parasitoses observado é um reflexo claro da falta de informação da população e atenta para a necessidade de implementação de políticas públicas que visem à inclusão de projetos na área educacional, introduzindo no currículo conteúdos que trabalhem propostas de higiene e saneamento ambiental, bem como a adoção de exames parasitológicos de fezes na rotina hospitalar.
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