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1
Ye, Xiao-Ping. "Anti-egg immunity of Schistomsoma japonicum in humans." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389042.
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Davies, Charlotte Mary. "Snail-schistosome interactions and the evolution of virulence." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343421.
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Al-Samarai, Abdul-Ghani M. Ali Hasani. "Chemotherapy of parasitic infection by Herpesvirus hominis." Thesis, University of Sheffield, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318149.
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Mellor, C. M. "Immunomodulation and chemotherapy of parasitic infections." Thesis, University of Nottingham, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378990.
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Sulaiman, Azad A. "Immunoregulation in bovine parasitic infection : mechanisms and implications." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/31639/.
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One of the characteristic features of parasitic infections is the chronicity and persistence of the infection for long time. Their success is due to its ability to deviate the immune response of their host toward the immunoregulatory or immunosuppressive state. IL-10 is a multifunctional cytokine with both immunosuppressive and immunostimulatory effects during parasite infection, playing a crucial role in the regulation of the immunity by ameliorating the destructive immunopathology associated with excessive inflammation but often suppressing effective immune responses against pathogens and impairing parasite clearance. Several transcription factors have been characterised that act on the promoter region of human and mouse IL-10 and their role in the transcription of this cytokine has been experimentally verified. In our study, a 570 bp fragment of the 5' UTR region flanking the bovine il-10 gene was cloned and characterised by sequencing. Several SNPs relative to the reference sequence are described, the putative polymorphisms lie within the transcription factor binding sites Sp1, Cap, HSF, ADR1, MZF1, GATA1 and Hb. We have investigated the role of GATA1 in regulation of IL-10 expression from fluke naïve PBMCs in response to LFH and FhTLM and we demonstrate that both LFH and FhTLM treatment induced GATA1 expression from PBMCs. These molecules showed distinct effects on PBMC functions i.e. stimulation of IL-10 in response to FhTLM and inhibition when LFH is used. However, both factors inhibit PBMCs proliferation and IFN-γ expression. We have also found that FhTLM binds to bovine TGFβ-RIED and TGFβ-RIIED fusion proteins but with a higher avidity to TGFβ-RIIED. These results highlight the role of FhTLM as a potent immunomodulatory of the bovine immune system by binding to bovine cytokine receptors. Neospora caninum infection is the major cause of abortion in dairy cattle. Infection with this parasite leads to a polarized Th1 response with high IFN-γ and IL-12 which provide protection aginst N. caninum infection. We have determined the effects of IL-10 in the regulation of IFN-γ and its association with production parameters (milk yield, lactation numbers) by measuring the levels of these cytokines in serum of infected animals and relating these to the key production parameters. Our results have shown that 84 % of high seropositive dams gave birth to seropositive calves and IL-10 concentration was higher in seropositive animals compared to seronegative. However, no correlation was found between the IL-10 concentration of seropositive dams and their calves. Together these indicated that IL-10 is an important cytokine during neosporosis, which modulate the immune response and allow the transmission of the infection to the offspring. Finally, our results for association of the IL-10 with lifetime daily yield demonstrated that IL-10 has a negative association with milk production during infection with N. caninum. Results of our study demonstrate a key role for bovine IL-10 in the regulation of multiple facets of parasite infection and immunity.
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Franceschini, Lidiane [UNESP]. "Infecções parasitárias e microbianas na produção do pacu Piaractus mesopotamicus e do híbrido patinga procedentes da região noroeste do Estado de São Paulo." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/99444.
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O desenvolvimento das atividades relacionadas à aquicultura tem aumentado consideravelmente a relevância dos estudos sobre parasitas e outros patógenos de organismos aquáticos, principalmente, daqueles hospedeiros com potencial para o cultivo e comercialização. O objetivo deste estudo foi avaliar a ocorrência de infecções parasitárias e microbianas na produção de pacu Piaractus mesopotamicus e do híbrido patinga (P. mesopotamicus x Piaractus brachypomus) procedentes da região Noroeste do Estado de São Paulo, Brasil. Três pisciculturas foram amostradas bimestralmente, de fevereiro de 2010 a fevereiro de 2011: A - Reprodução e Larvicultura (pacu/patinga), B - Engorda (patinga) e C - Pesque-pague (pacu/patinga), das quais 35 peixes foram submetidos à análise parasitológica e 21 à análise microbiológica. Foram encontrados os parasitas: dactilogirídeos (Monogenea); Trichodina spp., Ichthyophthirius multifiliis, Chilodonella sp. (Protozoa); Myxobolus spp. e Henneguya spp. (Myxozoa); Rondonia rondoni e Contracaecum sp. (Nematoda); e Dolops carvalhoi (Crustacea). Dentre os peixes analisados, 62,9% de “A” e 100% de “B” e “C” estavam infectados/infestados por pelo menos uma espécie de parasita. Pacus (n=44) apresentaram maior suscetibilidade a infestações por Anacanthorus penilabiatus, e as patingas (n=61), por Mymarothecium viatorum (p<0,05). Na análise microbiológica, 23,8% dos peixes de “A” e “B” e 33,3% da propriedade “C” estavam infectados com pelo menos um gênero de bactéria. A sazonalidade influenciou as infestações por Trichodina spp., A. penilabiatus e infecções pela bactéria Enterobacter sp. em patingas (p<0,05). No antibiograma, cepas de Pseudomonas sp., Stenotrophomonas maltophilia e Aeromonas sp. apresentaram resistência a todos antibióticos...
The development of activities related to aquaculture has considerably increased the relevance of studies on parasites and other pathogens of aquatic organisms, especially those with potential for production and marketing. The aim of this study was to evaluate the occurrence of parasitic and microbial infections in the “pacu” Piaractus mesopotamicus and hybrid patinga (P. mesopotamicus x Piaractus brachypomus) from the Northwest of São Paulo State, Brazil. Fishes from three fish farms were evaluated every two months: A - Reproduction and larviculture (pacu / patinga), B - Growout (patinga) and C - Fee-fishing property (pacu / patinga). Fishes from each fish farm were collected from February 2010 to February 2011 for parasitological (n = 35 per property) and microbiological (n = 21 per property) analysis. The parasites found were: Dactylogyridae (Monogenea), Trichodina spp., Ichthyophthirius multifiliis, Chilodonella sp. (Protozoa), Myxobolus spp., Henneguya spp. (Myxozoa), Rondonia rondonia, third stage larvae of Contracaecum sp. (Nematoda), and Dolops carvalhoi (Crustacea). Among the fishes examined, 62.9% from A and 100% from B and C were infected / infested with at least one parasite species. Pacu (n = 44) showed higher susceptibility to infestations caused by Anacanthorus penilabiatus and patinga (n = 61) by Mymarothecium viatorum (p < 0.05). In the microbiological analysis, 23.8% of fishes from A and B properties and 33.3% of fish from the property C were infected with at least one bacteria species. Seasonality influenced Trichodina spp. and A. penilabiatus infestations and infection caused by Enterobacter sp. in patingas (p < 0.05). In antibiogram test, strains of Pseudomonas sp., Stenotrophomonas maltophilia and Aeromonas sp. were resistant to all beta-lactam antibiotics... (Complete abstract click electronic access below)
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Couper, Kevin Nisbet. "Immunological studies on the related apicomplexan parasites toxoplasma gondii and plasmodium chabaudi AS." Thesis, University of Strathclyde, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273907.
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Brunton, Catriona Lindsay. "Toxoplasma gondii infection of rat retinal vascular endothelial cells." Thesis, King's College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271755.
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Schweitzer, Andrea Nicola. "Genetic control of antibody responses to a surface-associated antigen of Schistosoma mansoni." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315949.
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Torlesse, Harriet. "Parasitic infection and anaemia during pregnancy in Sierra Leone." Thesis, University of Glasgow, 1999. http://theses.gla.ac.uk/7014/.
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The role of intestinal nematode infections in the aetiology of iron deficiency and anaemia in pregnant women was investigated in peri-urban and rural areas of Western Sierra Leone. A randomised placebo-controlled field trial was carried out to evaluate the efficacy of a single course of albendazole (400 mg) and daily iron-folate supplements (36 g iron and 5 mg folate), administered after the first trimester, as control interventions for intestinal nematode infections and anaemia during pregnancy. At baseline, in the first trimester of pregnancy, the prevalence (and geometric mean intensity) of intestinal nematodes was as follows: Ascaris lumbricoides 21.1% (267 eggs per gram); Necator americanus 66.5% (191 epg); and Trichuris trichiura 71.9% (93 epg). Chronic undernutrition (height < 150 cm) and chronic energy deficiency (body mass index < 18.5 kg/m2) was found in 5.4% and 8.2% of women respectively. Anaemia (Hb < 110 g/l) was diagnosed in 58.7% of women and associated with iron deficiency (serum ferritin < 20 μg/l) in 21.2% of women. Iron deficiency is likely to have a dietary basis in these women. The dietary iron intake was predominantly non-haem, and was estimated to supply less than 1 g of absorbable iron daily. High fertility and closely spaced pregnancies placed additional stress on iron stores. The findings of this study indicate that anthelminthic treatment should be included in strategies to control maternal anaemia in Western Sierra Leone. It is recommended that pregnant women routinely receive a single course of anthelminthics after the first trimester, alongside daily iron-folate supplements, to minimise the decline in maternal Hb concentration during pregnancy. These interventions could be implemented through the existing primary health care system, although the use of traditional birth attendants should be investigated as a means of improving compliance and coverage. The implications of these findings for public health policy in other antenatal populations will depend on the local epidemiology of intestinal nematode infections and on the extent of underlying maternal iron deficiency and anaemia.
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McKeand, Jacqueline B. "Aspects of the immumobiology of Dictyocaulus viviparus infection." Thesis, University of Glasgow, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314727.
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Devlin, Pauline. "The purification and characterisation of a nematode (Helligmosomoides polygyrus) derived immunomodulant." Thesis, University of Nottingham, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319621.
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Alfaiz, Faiz Abdulaziz. "Evaluation of the role of mast cells in parasitic infection." Thesis, University of Strathclyde, 2017. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=29560.
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Mast cells (MCs) are important for controlling both bacterial and parasitic infections, including those caused by helminths. However, their role in combatting these infections is unclear. MCs have been shown to be essential for the successful expulsion of Trichinella spiralis worms and play a role in mounting the immune response towards a T helper 2 type. Intestinal infection with parasitic worms is associated with mastocytosis and the activation and release of specific mediators and cytokines. In this case, MCs play an essential role in the successful expulsion of gastrointestinal worms via their release of mediators that serve the central function of protecting a host from these parasites. Specifically, the functions of MCs in the expulsion of T. spiralis were investigated using MC deficient c-kit mutant KitW/W-v(W/W-v) models. However, in addition to MC deficiency, these mice have a number of other abnormalities, including anaemia and a lack of interstitial cells of Cajal. Hence, there is a need to identify a model of MC deficiency that is not associated with other abnormalities that could affect the interpretation of results. The aim of the present study was to investigate the role of MCs in the immune response of mice to a parasitic infection of T. spiralis. Immune responses were explored in two recently developed strains of MC-deficient mice, the c-kit model C57BL/6-KitW-sh/W-sh (Wsh/Wsh) mice and an inducible mast cell-deficient model, Mas-TRECK, to determine the role of mast cells in protection against the parasite. These mice were infected with T. spiralis larvae, and the progression of the infection and the immune responses generated were examined via the enumeration of worms and the analysis of the associated intestinal pathology, cytokine production and antibody responses. The results obtained from mast cell deficient Wsh/Wsh mice with low-level infection resulted in a significant worm burden in these mice compared to wild-type mice that showed complete expulsion of the parasite. This suggests that the delay was potentially caused by dose dependent effect as a high dose did not show a significant delay in the expulsion of T. spiralis worms. In addition, the development of enteropathy and lengths of both villi and crypts were similar in both the lower and higher infection groups, in both wild-type and Wsh/Wsh mice. The immune responses were similar in wild-type and Wsh/Wsh mice as assessed by antigen-specific IgG1 levels, the total IgE levels and IL-4 levels. Moreover, Wsh/Wsh mice in both levels of infection were able to induce a significant marked mastocytosis, but they did not have significantly lower levels of mMCP-1 compared to wild-type mice. The results obtained from Mas-TRECK mice models showed no statistically significant differences between these mice and wild-type mice in the expulsion of T. spiralis worms. The enteropathy in Mas-TRECK mice following infection with T.spiralis was not significantly improved. In addition, the infection of Mas-TRECK mice did not induce a change in IgG2a levels compared with BALB/c mice, and no significant differences were observed in IgE levels or IL-4 levels in Mas-TRECK mice, compared with wild-type. In addition, Mas-TRECK were able to induce mastocytosis and did not have significantly lower levels of mMCP-1 following infection with T. spiralis, although they are considered to be MC-deficient, which suggests that MMCs may not be completely depleted in these mice. Mast cell activation was assessed using IgE-dependent MC activation to evaluate the ability of helminth antigens to activate mast cells through an immunoglobulin independent mechanism. An in vitro culture of bone marrow-derived mast cells(BMMCs) and peritoneal mast cells (PCMCs) used. Although cultured human MCs require stem cell factor (SCF) for growth, the expansion and growth of mouse MCs from bone marrow progenitors in the absence of SCF can be maintained with IL-3. It was found that stimulated PCMCs with Trichinella spiralis antigen (T. Ag) alone could activate mast cells to release IL-4 in all strains of mice. Moreover, the activation of PCMCs could be observed in the presence and absence of IgE, andC57BL/6 mice showed the greatest response to the stimulation and activation of PCMCs. BMMCs stimulated with helminth antigens led to similar secretions of mediators to those observed in wild-type mice, and all four strains of mice tended to secrete similar levels of mMCP-1. Overall, the present study concludes that MCs are crucial for protection against and expulsion of T. spiralis. However, it is evident that Wsh/Wsh and Mas-TRECK MC deficient mice are not entirely deficient in mucosal MC. Further studies are required to evaluate the benefits of different MC-deficient strains of mice and, particularly, to determine whether other abnormalities could have potentially affected the results of the present study.
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Nichol, Claire Patricia. "Host-parasite interactions of larval cestode infections." Thesis, University of Edinburgh, 1985. http://hdl.handle.net/1842/30579.
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Cabrera, Z. Y. "Characterisation of Onchocerca antigens and their application to diagnosis." Thesis, Brunel University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233303.
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Lynsdale, Carly L. "Evolutionary ecology of parasite infection in Asian elephants." Thesis, University of Sheffield, 2017. http://etheses.whiterose.ac.uk/19058/.
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Grimason, Anthony Martin. "The occurrence and removal of Cryptosporidium sp. oocysts and Giardia sp. cysts in surface, potable and waste-water." Thesis, University of Glasgow, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284104.
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Johnson, Maureen Jane. "Coproantigen capture ELISA for GI nematodes." Thesis, University of Nottingham, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240993.
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Kermanizadeh, Parviz. "The role of mast cells during experimental schistosomiasis mansoni in mice." Thesis, University of Glasgow, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363226.
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Franceschini, Lidiane. "Infecções parasitárias e microbianas na produção do pacu Piaractus mesopotamicus e do híbrido patinga procedentes da região noroeste do Estado de São Paulo /." Botucatu : [s.n.], 2012. http://hdl.handle.net/11449/99444.
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Orientador: Reinaldo José da SilvaCoorientador: Sérgio Henrique Canello Schalch
Banca: Eduardo Makoto Onaka
Banca: Maurício Laterça Martins
Resumo: O desenvolvimento das atividades relacionadas à aquicultura tem aumentado consideravelmente a relevância dos estudos sobre parasitas e outros patógenos de organismos aquáticos, principalmente, daqueles hospedeiros com potencial para o cultivo e comercialização. O objetivo deste estudo foi avaliar a ocorrência de infecções parasitárias e microbianas na produção de pacu Piaractus mesopotamicus e do híbrido "patinga" (P. mesopotamicus x Piaractus brachypomus) procedentes da região Noroeste do Estado de São Paulo, Brasil. Três pisciculturas foram amostradas bimestralmente, de fevereiro de 2010 a fevereiro de 2011: A - Reprodução e Larvicultura (pacu/patinga), B - Engorda (patinga) e C - Pesque-pague (pacu/patinga), das quais 35 peixes foram submetidos à análise parasitológica e 21 à análise microbiológica. Foram encontrados os parasitas: dactilogirídeos (Monogenea); Trichodina spp., Ichthyophthirius multifiliis, Chilodonella sp. (Protozoa); Myxobolus spp. e Henneguya spp. (Myxozoa); Rondonia rondoni e Contracaecum sp. (Nematoda); e Dolops carvalhoi (Crustacea). Dentre os peixes analisados, 62,9% de "A" e 100% de "B" e "C" estavam infectados/infestados por pelo menos uma espécie de parasita. Pacus (n=44) apresentaram maior suscetibilidade a infestações por Anacanthorus penilabiatus, e as patingas (n=61), por Mymarothecium viatorum (p<0,05). Na análise microbiológica, 23,8% dos peixes de "A" e "B" e 33,3% da propriedade "C" estavam infectados com pelo menos um gênero de bactéria. A sazonalidade influenciou as infestações por Trichodina spp., A. penilabiatus e infecções pela bactéria Enterobacter sp. em patingas (p<0,05). No antibiograma, cepas de Pseudomonas sp., Stenotrophomonas maltophilia e Aeromonas sp. apresentaram resistência a todos antibióticos... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The development of activities related to aquaculture has considerably increased the relevance of studies on parasites and other pathogens of aquatic organisms, especially those with potential for production and marketing. The aim of this study was to evaluate the occurrence of parasitic and microbial infections in the "pacu" Piaractus mesopotamicus and hybrid "patinga" (P. mesopotamicus x Piaractus brachypomus) from the Northwest of São Paulo State, Brazil. Fishes from three fish farms were evaluated every two months: A - Reproduction and larviculture (pacu / patinga), B - Growout (patinga) and C - Fee-fishing property (pacu / patinga). Fishes from each fish farm were collected from February 2010 to February 2011 for parasitological (n = 35 per property) and microbiological (n = 21 per property) analysis. The parasites found were: Dactylogyridae (Monogenea), Trichodina spp., Ichthyophthirius multifiliis, Chilodonella sp. (Protozoa), Myxobolus spp., Henneguya spp. (Myxozoa), Rondonia rondonia, third stage larvae of Contracaecum sp. (Nematoda), and Dolops carvalhoi (Crustacea). Among the fishes examined, 62.9% from "A" and 100% from "B" and "C" were infected / infested with at least one parasite species. Pacu (n = 44) showed higher susceptibility to infestations caused by Anacanthorus penilabiatus and patinga (n = 61) by Mymarothecium viatorum (p < 0.05). In the microbiological analysis, 23.8% of fishes from "A" and "B" properties and 33.3% of fish from the property "C" were infected with at least one bacteria species. Seasonality influenced Trichodina spp. and A. penilabiatus infestations and infection caused by Enterobacter sp. in patingas (p < 0.05). In antibiogram test, strains of Pseudomonas sp., Stenotrophomonas maltophilia and Aeromonas sp. were resistant to all beta-lactam antibiotics... (Complete abstract click electronic access below)
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Sturrock, Hugh. "Spatial epidemiology of parasitic infections and optimal survey design." Thesis, London School of Hygiene and Tropical Medicine (University of London), 2011. http://researchonline.lshtm.ac.uk/4609914/.
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Recent years have seen a shift towards integrated control of a number of tropical diseases. Such a strategy, however, relies on an understanding of the spatial distribution and overlap of different diseases. Using a combination of fieldwork, spatial and economic analyses and computerized simulations, optimal survey designs were explored for soil-transmitted helminths (STHs), Schistosoma mansoni and Plasmodium /alciparum in East Africa, and the potential of an integrated survey approach was evaluated. For STH, analysis indicated that hookworm clusters over larger scales than Ascaris lumbricoides and Trichuris trichiura, and that surveying small numbers of children, from four to five schools per district, provides a rapid and cost-effective approach to target treatment at district levels. For S. mansoni, Lot Quality Assurance Sampling (LQAS) was compared to a geostatistical survey design that allows spatial prediction at unsurveyed locations based on a subset of schools. Results showed that targeted treatment was more cost-effective than presumptive treatment and that, whilst LQAS correctly classified a higher proportion of schools requiring treatment, a geostatistical design proved more cost-effective. An investigation into the optimal spatial scale to conduct surveys for STH, S. mansoni and P. /alciparum in Kenya found that, over various cost scenarios, surveying fifty children from three randomly selected sites per sub-district provided a balance of performance and cost-effectiveness for all species. In sub-districts of low S. manson; and P.alciparum prevalence, LQAS should be used to target treatment. This thesis has shown that species-specific differences in spatial heterogeneity of infection and the costs of both mapping surveys and programme intervention have important implications for the optimal design of surveys. A two stage framework for integrated surveys is proposed allowing for a flexible approach to mapping. Similar studies in different settings are crucial and would help to assess whether changes in survey strategy are required as transmission drops due to control activities.
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White, Emily Claire. "Infection by the gastrointestinal parasite Trichuris muris : defining the microbiota of the parasite and the host." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/infection-by-the-gastrointestinal-parasite-trichuris-muris-defining-the-microbiota-of-the-parasite-and-the-host(e29ed75d-014d-4e36-87ed-a6db82845511).html.
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Intestinal dwelling parasites live in close association with the complex microbiota that inhabit our intestinal tracts. The intestinal helminth, Trichuris muris, depends on these bacteria for egg hatching and successful establishment of infection within the epithelium of the caecum and colon. Infection causes significant alterations to the host intestinal microbiota, including a decrease in bacterial diversity and shifts in proportions of certain bacterial groups. This is accompanied by a decrease in Foxp3+ regulatory T cells and changes to the metabolic potential of the host microbiota, consequently impacting host health. However, the factor(s) driving these changes and the existence and role of its own intestinal microbiota is unknown. Infection of C57BL/6 and immunodeficient SCID mice with a high dose (~ 200 embryonated eggs) and a low dose (~ 20 embryonated eggs) of T. muris was used to determine the impact of worm burden and the adaptive immune system on the host intestinal microbiota, in comparison to naïve controls. Microbiota analysis was performed by 16S rRNA gene denaturing gradient gel electrophoresis (DGGE) and Illumina sequencing. This revealed that infection-induced microbiota changes were dose dependent and high level infection caused an increase in the Bacteroidaceae and Enterobacteriaceae families, independently of the host adaptive immune system. Development of a surface sterilisation protocol enabled the internal T. muris microbiota to be analysed by 16S rRNA gene DGGE and fluorescence in situ hybridisation (FISH). The resulting data indicated that T. muris requires its own diverse intestinal microbiota that is derived from, but distinct to, that of its host. A core microbiota is selected and maintained by the parasite regardless of the surrounding host microbiota. The parasite microbiota is important for its fitness, shown in vitro using an antibiotic motility assay and in vivo using germ free (GF) mice. Furthermore, infection with T. muris causes a significant reduction in caecal butyrate concentrations and consequently a decrease in the expression of butyrate transporters in caecal tissue. Interestingly, the T. muris microbiota is able to produce the short-chain fatty acid (SCFA) butyrate, which the parasite is unable to make itself yet secretes into its local environment. Together these strategies promote the long term survival of T. muris within the intestinal niche, adding a new level of complexity to the interaction between the pathogen, the host and their respective microbiotas that underpins successful chronic nematode infection.
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Al-Rustamani, Laila Abdul Wahed Hassan. "Mixed Leishmania infection in vitro and in vivo." Thesis, London School of Hygiene and Tropical Medicine (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266278.
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Mtambo, Mkumbukwa Madundo Angelo. "Cryptosporidium infection in cats : epidemioloigy and cross transmission studies." Thesis, University of Glasgow, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384860.
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Betts, Catherine Jean. "RT-PCR analysis of cytokine expression in murine lymph node and lung tissue following exposure to the irradiated Schistosoma mansoni vaccine." Thesis, University of York, 1996. http://etheses.whiterose.ac.uk/10876/.
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Fulford, Anthony John Charles. "Analysis of the patterns of exposure to, and infection by, Schistosoma mansoni." Thesis, University of London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312466.
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Keir, Pamela Alexandra. "Early responses in the pulmonary phase of Nippostrongylus brasiliensis infection." Thesis, Edinburgh Napier University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270301.
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Johnson, Deborah Anne. "Coproantigen capture ELISA for the detection of intestinal nematode infections." Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310926.
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Wood, Bradbury Patrick. "The immune response of the grey mullet, Chelon labrosus (Risso, 1826), to Cryptocotyle lingua (Creplin, 1825), (Digenea)." Thesis, University of Plymouth, 1990. http://hdl.handle.net/10026.1/2237.
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The ability of thick-lipped grey mullet to mount both humoral and cellular immune responses to Cryptocotyle lingua has been demonstrated here for the first time. Of the 3 procedures for immunisation investigated, namely exposure to live cercariae, intraperitoneal (ip) injection of whole killed cercariae and ip injection of a cercarial sonicate, the former gave the highest primary antibody titres with a peak response at 4 weeks post infection. Peak titres occurred at 5 and 7 weeks after immunisation by ip injection of sonicated cercariae and whole killed cercariae respectively. An enhanced secondary antibody response was observed following challenge by ip injection of sonicated cercariae. Cercariacidal activity, apparently involving complement, was detected in normal serum and enhanced in immune serum. However, the mechanism for complement activation remains uncertain. Parasite antigens were identified following separation by SOS-PAGE and immunoblotting using mullet and rabbit antisera. Mullet failed to respond to certain parasite proteins recognised by rabbit antiserum and in situ immunogold-silver staining demonstrated that mullet. immunised by exposure to live cercariae, were unable to recognise the metacercarial cyst wall. Migration and polarisation of pronephric leucocytes in vitro was enhanced following immunisation but cellular adherence to encysted and unencysted parasites was not observed. In vitro studies further demonstrated a possible role for fish serum in stimulating metacercarial encystment. The intensity of melanisation of the host capsule in metacercarial infections was increased in fish held in total darkness and with increased temperature. The rate of development of the metacercarial tegument and cyst wall and the associated host response was similarly affected by temperature and initial development was inhibited by prior immunisation via ip injection of sonicated cercariae. There was however, no evidence of protection against cercarial infection following such immunisation. These results are discussed in relation to mechanisms of immunity, metacercarial survival strategies and control of metazoan infections in fish.
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Janssen, Christoph Stephan. "Biology of developmental activation of infective Trichinella spiralis." Thesis, University of Glasgow, 1998. http://theses.gla.ac.uk/39035/.
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The initiation of further development is fundamental to the infectious processes of parasitic nematodes. I have examined early developmental activation of Trichinella spiralis larvae during host invasion, with particular emphasis on gene regulation and the timing of events. Using a novel approach, changes in tissue specific transcriptional activity were observed in live larvae during the infectious process with the fluorescent nucleic acid dyes SYTO12 and acridine orange. Simultaneously, the metabolic switch from anaerobic metabolism, characteristic of the infective stage, to aerobic metabolism, as found in the enteral stages, was tracked by measuring activities of the key regulatory enzymes phosphoenolpyruvate carboxykinase and pyruvate kinase, as well as isocitrate dehydrogenase (NADP) activity, and used as a co-indicator for developmental activation. Both metabolic enzyme activities and transcription patterns were found to change in response to host death, liberation from the nurse cell, and exposure to components of the host stomach environment. The role of amphidial neurones in developmental regulation was examined using FITC based labelling, and at least part of the initial developmental processes were discovered to be under amphidial control. Changes to the surface properties of larvae during the process of infection were monitored using the fluorescent lipid probe PKH26, and gave evidence for temporal regulation of activation-related alterations of larval structure and/ or physiology. Further, RNA fingerprinting was carried out to identify specific genes associated with, or regulating, developmental activation. Some putatively differentially expressed transcripts were identified, but could not be completely characterised to date. The results give a clear indication that the activation processes of T. spiralis infective larvae occur at a much earlier time than previously thought, and are stimulated upon liberation of the larvae from the nurse cell inside the host stomach. Further, regulation of development appears to be under transcriptional control, and tissue specific transcription is initiated early during the infectious process, perhaps immediately after release from the nurse cell.
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Cooper, Jane. "The behavioural control of helminth infection by sheep." Thesis, University of Aberdeen, 1996. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU083310.
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Parasites have detrimental effects on an animal's fitness and could play a significant role in shaping the adaptive behaviour of animals. Natural selection may favour those behaviours utilised by animals that minimise the risk and intensity of infections. Animals use a range of behavioural strategies associated with grooming, social, mating, migratory and foraging behaviours to minimise their parasite burdens. Herbivores have two means available for reducing the effects of parasites while foraging. They may avoid parasites or consume plants with anti-parasitic properties. Sheep (Ovis aries) were shown to avoid foraging in areas of the sward contaminated with O. circumcincta infective larvae but could only do so when larvae were associated with faeces. The ability of sheep to avoid contaminated patches of the sward increased as the size of contaminated sward patches increased. This avoidance behaviour resulted in a reduction in the numbers of parasites ingested. Animals infected with O. circumcincta were more selective in their grazing behaviour than uninfected animals with respect to faeces avoidance. In order to determine which plants possess anti-parasitic properties Lotus pedunculatus, Pinus sylvestris, Tanacetum vulgare and Artemisia absinthium extracts were screened against Trichostrongylus colubriformis infections in the Mongolian gerbil (Meriones unguiculatus). Only A. absinthium merited further investigation as it appeared to suppress worm burdens when administered in a high single dose. A. absinthium extracts were subsequently administered to sheep infected with T. colubriformis.
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Feis, Marieke Eveline [Verfasser], Karl Mathias [Akademischer Betreuer] Wegner, and Hinrich [Gutachter] Schulenburg. "Host-parasite co-evolution and co-infection of invasive parasitic Mytilicola copepods in blue mussel hosts / Marieke Eveline Feis ; Gutachter: Hinrich Schulenburg ; Betreuer: Karl Mathias Wegner." Kiel : Universitätsbibliothek Kiel, 2018. http://nbn-resolving.de/urn:nbn:de:gbv:8-diss-237738.
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Bourke, Claire Deirdre. "Human cytokine responses during natural and experimental exposure to parasitic helminth infection." Thesis, University of Edinburgh, 2012. http://hdl.handle.net/1842/9434.
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Over one third of the human population is currently infected by one or more species of parasitic helminth, but the immune responses elicited by these infections remain poorly defined. Studies in helminth-exposed human populations and laboratory models suggest that helminth infection elicits a range of different effector cell types and that protective immunity and resistance to immune-mediated pathology depends on the balance between these responses. The aim of this thesis was to investigate how cytokines, the molecular mediators of the immune system, can be used to characterise human immune phenotype during natural and experimental helminth infection. Cytokines associated with innate inflammatory (TNFα, IL-6 and IL-9), Thl (IFNγ, IL-2 and IL-12p70), Th2 (IL-4, IL-5 and IL-13), Th17 (IL-17A, IL-21 and IL-23) and regulatory (IL-10 and TGFβ)immune phenotypes were analysed to provide the most comprehensive analysis of cytokine responses in human helminth infection conducted to-date. Using a multivariate statistical approach cytokines were analysed as combined immune profiles to reflect their complex interactions in vivo. In the first part of the study venous blood samples collected from a cross-sectional cohort of 284 Zimbabweans (age range: 3 -86 years) endemically-exposed to Schistosoma haematobium were cultured with antigens from different stages of the parasite's life-cycle(cercariae, adult worms and eggs) and the anti-schistosome vaccine candidate antigen glutathionine-S-transferase (GST). Cytokines responses were quantified in culture supernatants via enzyme-linked immunosorbent assay (ELISA). These assays were repeated 6 weeks after clearance of infection by anti-helminthic treatment. Parasitological and demographic characterisation of the cohort before, 6 weeks, 6 and 18 months after treatment allowed cytokine responses to be related to epidemiological patterns of infection before treatment and the risk of re-infection after treatment. The main findings of this study were:Cytokine responses to the antigens of S. haematobium cercariae are more proinflammatory than those elicited by adult worms and eggs prior to treatment, reflecting the distinct proteomes and exposure patterns of the 3 life-cycle stages Young children (5-10 years old) have a more regulatory and Th17-polarised cytokine response to S. haematobium antigens than older children and adults. These responses are significantly associated with schistosome infection intensity and may contribute to the development of resistance to schistosomiasis with age and exposure to infection Anti-helminthic treatment leads to a shift in S. haematobium cercariae, egg and GST specific cytokine responses towards a more pro-inflammatory phenotype The magnitude of change in S. haematobium-specific cytokine profiles after treatment is dependent on schistosome infection intensity at the time of treatment Individuals who remain un-infected up to 18 months after treatment to clear schistosome infection have a more pro-inflammatory and IL-21-polarised response to S. haematobium antigens 6 weeks after treatment than those who become re-infected, suggesting that post-treatment cytokine profiles promote resistance to re-infection. The second part of the study assayed systemic, parasite and allergen-specific cytokine responses in 45 adults with seasonally exacerbated allergy to grass pollen who were experimentally exposed to Trichuris suis. Cytokine responses in infected individuals were compared to those of 44 un-infected controls. This aspect of the study showed that: Exposure to T. suis promotes systemic and parasite-specific Th2 and regulatory cytokine responses, but does not alter cytokine responses to environmental allergens.
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Muthaukrishnan, L. "Effect of site of infection on host plant growth and metabolism." Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379917.
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Yichoy, Mayte. "Lipid uptake and metabolism in the parasitic protozoan giardia lamblia." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2009. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
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Curra, Chiara. "Protein trafficking and host cell remodeling in malaria parasite infection." Thesis, Montpellier 2, 2010. http://www.theses.fr/2010MON20219.
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Pour assurer ses besoins de croissance, multiplication, et survie, Plasmodium modifie sa cellule hôte, l'érythrocyte, après l'invasion. Le parasite met en place ainsi un système d'échanges (import/export) avec sa cellule hôte et le milieu extérieur. Nous avons identifié dans la base de données de Plasmodium berghei, le parasite de rongeurs, une famille de gènes, sep, correspondant à la famille etramp chez Plasmodium falciparum. Cette famille de gènes code pour des petites protéines exportées, et conservées dans tout le genre Plasmodium. Les protéines SEP (13?16 kDa) contiennent en N-terminal un peptide signal prédit, un domaine hydrophobe interne, et elles diffèrent au niveau des régions C-terminal et 3' UTR. Toutefois, les protéines SEP sont exprimées à différents moments du cycle de Plasmodium. Durant le cycle érythrocytaire, PbSEP1 et PbSEP3 sont exprimées à partir du stade trophozoïte, et la même quantité de protéine est détectée au stade schizonte et gamétocyte, pendant que PbSEP3 est hautement détectée dans les trophozoïtes mûrs et les gamétocytes. Chez le moustique, PbSEP1 et PbSEP3 sont détectées seulement chez les ookinètes, alors que PbSEP2 est très abondante dans les ookinètes, oocystes, et sporozoïtes des glandes salivaires. Les protéines SEP ont également des localisations différentes. Dans l'érythrocyte, PbSEP1 est localisée dans la membrane de la vacuole parasitophore, alors que PbSEP2 et PbSEP3 sont exportées au-delà de cette vacuole, et sont ainsi localisées dans la cellule hôte, en association avec des structures vésiculaires. Dans cette étude, nous avons identifié les signaux d'adressage des protéines SEP dans la vacuole parasitophore et dans la cellule hôte, chez Plasmodium berghei. L'autre partie du travail, effectuée à l'Université de Montpellier II, a consisté à étudier la localisation de deux protéines du squelette sous- membranaire de l'érythrocyte, la dématine, et l'adducine, durant le développement intra-érythrocytaire de Plasmodium falciparum. Le but de cette étude étant d'identifier un mécanisme potentiel d'internalisation des composants du squelette sous-membranaire de l'érythrocyte dans le parasite. Des études d'immuno-localisation ont montré que la dématine et l'adducine sont internalisées à partir du stade trophozoïte, et sont localisées probablement à la vacuole parasitophore (membrane et/ou lumière). Cette internalisation a été confirmée par des études de fractionnement cellulaire et d'accessibilité à la protéinase K, montrant que la dématine est totalement internalisée, alors l'adducine ne l'est que partiellement, suggérant une localisation de la protéine à la périphérie du parasitePlasmodium endurance depends on the ability of the parasite to reorganize the cytosol of the erythrocyte, a terminally differentiated cell, and remodel its skeleton membrane immediately after invasion. In this way the parasite can organize the import/export of the molecules necessary to its survival. The comprehension of cellular trafficking mechanisms which occur during Plasmodium infection is a very important step and fundamental contribute to understand the biology of the malaria parasite.We identified in database of the rodent malaria parasite Plasmodium berghei the gene family sep, corresponding to etramp in P. falciparum, encoding small exported proteins conserved in the genus Plasmodium. SEP proteins (13?16 kDa) contain a predicted signal peptide at the NH2-terminus, an internal hydrophobic region while they differ in their C-terminal region; the genes share the upstream regulative region while differ in the 3' UTR. Despite this, we showed that SEPs have a different timing of expression and a different localization: in the erythrocytic cycle PbSEP1 and PbSEP3 start to be expressed at trophozoite and the same amount of protein is detected also in schizonts and gametocytes, while PbSEP2 is highly detected in mature trophozoites and even more in gametocytes. In mosquitoes stages PbSEP1 and PbSEP3 are expressed only in ookinetes, while PbSEP2 is very abundant in ookinetes, oocysts and in sporozoites of the salivary glands. SEPs also have a different localization in the iRBC: PbSEP1 is targeted to the membrane of the parasitophorous vacuole, while PbSEP2 and 3 are exported beyond the parasite membrane and translocated to the host cell compartment in association with vesicle-like structures. In this study we identified the specific signals necessary for the correct timing of expression and to direct SEP proteins to the vacuolar membrane and to the host cell compartments.The second part of the work was carried out in Montpellier II University and aims to identify the localization of two RBC membrane skeleton components, dematin and adducin, during Plasmodium falciparum infection. Our purpose is to recognize a possible mechanism of internalization of host cytoskeleton components to the parasite compartments. In fact, IFA experiments carried on iRBCs showed that dematin and adducin start to be internalized at trophozoite stage and localize at the periphery of the parasite, most probably at the parasitophoruos vacuole (PV) membrane/lumen. Dematin and adducin internalization during Plasmodium infection is also demonstrated by subcellular fractionation and proteinase K assay: while dematin is fully internalized, adducin is partially protected and suggesting a localization of the protein at the periphery of the parasite where it can be exposed to PK degradation
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Arnold, Markus F. F. "Host-pathogen interactions in chronic infections." Thesis, University of Aberdeen, 2012. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=192267.
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The BacA protein plays a key role in the symbiosis of Sinorhizobium meliloti with the leguminous plant alfalfa (Medicago sativa) and is proposed to be the transmembrane subunit of an ATP‐binding cassette (ABC) transporter. BacA homologues are also present in Brucella species, enteric bacteria (known as SbmA) and Mycobacterium tuberculosis. The S. meliloti‐alfalfa symbiosis, although beneficial to both partners, can also be viewed as a chronic infection. The M. tuberculosis BacA protein is important for M. tuberculosis for the maintenance of a chronic infection. In order to study the M. tuberculosis BacA protein a codon optimised M. tuberculosis bacA gene was synthesised and cloned into vectors for expression in an S. meliloti ΔbacA mutant. Evidence is presented that M. tuberculosis BacA sensitises an S. meliloti ΔbacA mutant towards the glycopeptide bleomycin and the truncated proline rich peptide Bac71‐16, and further that a functional ATPase domain is essential to perform BacA mediated peptide transport. The M. tuberculosis BacA protein protected an S. meliloti ΔbacA mutant from being killed by host defensins. In addition, it was determined that M. tuberculosis BacA‐mediated protection of the legume symbiont S. meliloti against legume defensins as well as mouse alveolar lavages and human ‐defensin 2 is dependent on an ATPase domain which is present in the M. tuberculosis BacA protein. M. tuberculosis encounters ‐defensins during mammalian infections in the host’s lungs and my data show that BacA is likely to be important in conferring immunity to these peptides. The mechanism of persistent infection by M. tuberculosis is therefore very reminiscent of the Sinorhizobium ‐ legume interaction. Also Salmonella enterica is able to cause asymptomatic infections and about 5% of these develop a chronic carrier state and are able to spread the pathogen. In enteric bacterial species SbmA is in close proximity to the putative lipoprotein YaiW. In this study it was determined that YaiW is exposed on the cell surface and that it is involved in the protection of E. coli and potentially Salmonella spp. against a cysteine rich host peptide. YaiW is potentially involved in swarming motility. It was also determined that an alfalfa plant infection model can distinguish between Salmonella strains forming acute and chronic infections. Staphylococcus aureus is one of the major hospital acquired and opportunistic pathogens. Asymptomatic carriers, infected with multi‐drug resistant strains (MRSA) pose a threat to immunocompromised individuals. Here, novel compounds and ways from a variety of sources have been tested for their potential antimicrobial activity against a range of multi‐drug resistant clinical S. aureus isolates. This project significantly advanced the molecular understanding of asymptomatic bacteria‐host infections and helped to understand and establish novel ways to treat infections with multi‐drug resistant clinical pathogens.
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Sanchez-Silva, Martin Antonio. "Analysis of local T cell responses in experimental visceral leishmaniasis." Thesis, London School of Hygiene and Tropical Medicine (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326241.
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Beadell, Jon Sumner. "Emerging infectious disease host and parasite perspectives /." College Park, Md. : University of Maryland, 2007. http://hdl.handle.net/1903/6744.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2007.Thesis research directed by: Biology. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Stevenson, Lesley Margaret. "Studies on the role of the eosinophil leukocyte in ovine nematode infections." Thesis, Edinburgh Napier University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386225.
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Burton, Deborah. "The effects of parasitic nematode infection on body condition of New Forest ponies." Thesis, University of Southampton, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315095.
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Wyderko, Jennifer Anne. "Quantifying Metagonimoides oregonensis infection distribution and effects among stream salamander hosts." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/23208.
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Metagonimoides oregonensis is a digenetic trematode that infects raccoons as definitive hosts, the snail Elimia proxima as a first intermediate host and in the southern Appalachians, encysts in the muscle tissue of a variety of second intermediate salamander hosts. My first study examined 289 individual salamanders representing six species from 23 streams in North Carolina to determine which species of salamanders are naturally infected. I found that five of the six species examined had natural infections, but that there was variation in infection intensity and prevalence among the species. Of the six species, Desmognathus quadramaculatus may be most important in transmission, as they had the highest prevalence and intensity of infection. This may be due to their long larval period, which results in a longer trematode accrual period. My second study explored the role of host and parasite behavior in driving infection dynamics in this system. I examined both parasite response to host chemical cues and host response to parasite presence and chemical cues. I did not see a behavioral response by either the parasite or the host, indicating behavior is probably less important in determining variable infection among hosts in this system, than are environmental and ecological factors. My final study examined the effect of cercariae exposure (n=0, 20, 60) on locomotor performance of D. quadramaculatus, Eurycea wilderae and Hyla versicolor. I did not see any effect on locomotor performance for any of the species.Master of Science
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Laurenson, Yan Christian Stephen Mountfort. "Modelling nematode infections in sheep and parasite control strategies." Thesis, University of Edinburgh, 2012. http://hdl.handle.net/1842/8178.
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Gastrointestinal parasitism in grazing lambs adversely affects animal performance and welfare, causing significant production losses for the sheep industry. Control of gastrointestinal parasitism using chemotherapeutic treatment is under threat due to the emergence of anthelmintic resistance, thus stimulating research into alternative control strategies. Whilst investigating control strategies experimentally can be costly and time consuming, using a mathematical modelling approach can reduce such constraints. A previously developed model which describes the impact of host nutrition, genotype and gastrointestinal parasitism in a growing lamb, provided an appropriate starting point to explore control strategies and their impact on host-parasite interactions. Two contrasting mechanisms have previously been proposed to account for the occurrence of anorexia during parasitism. These were reductions in either intrinsic growth rate or relative food intake. Thus, the existing individual lamb model was modified to evaluate these mechanisms by exploring the relationship between anorexia and food composition (Chapter 2). For foods that did not constrain food intake, published data was found to be consistent with the predictions that arose from anorexia being modelled as a reduction in relative food intake. Reported genetic parameter estimates for resistance and performance traits appear to vary under differing production environments. In order to explore the impact of epidemiological effects and anthelmintic input on genetic parameter estimates the model was extended to simulate a population of lambs in a grazing scenario (Chapter 3). Whilst estimates of heritabilities and genetic correlations for drenched lambs remained constant, for lambs given no anthelmintic treatment, the heritability of empty body weight (EBW) reduced and the genetic correlation between faecal egg count (FEC) and EBW became increasingly negative with increasing exposure to infective larvae. Thus differences in anthelmintic input and pasture larval contamination (PC) may provide plausible causes for the variation in genetic parameter estimates previously reported. To investigate the interactions between host resistance and epidemiology (Chapter 4) a population of 10,000 lambs were simulated and FEC predictions used to assign the 1,000 lambs with the highest and lowest predicted FEC to ‘susceptible’ (S) and ‘resistant’ (R) groups, respectively. R and S groups were then simulated to graze separate pastures over 3 grazing seasons. The average FEC and PC predictions of these groups diverged during the first 2 grazing seasons and stabilised during the third, such that the difference in FEC predictions between R and S groups were double those predicted when grazed with the population. This was found to be consistent with experimental data. Further, anthelmintic treatment and grazing strategies were predicted to have no impact on the EBW of resistant lambs, suggesting that control strategies should be targeted towards susceptible animals. Targeted selective anthelmintic treatment (TST) has been proposed to reduce risks of anthelmintic resistance with minimal impacts on performance. To describe the short- and long-term impacts of TST and drenching frequency on sheep production and the emergence of anthelmintic resistance, the model was extended to include a description of anthelmintic resistance genotypes within the nematode population (Chapter 5). Reducing the proportion of treated animals was predicted to increase the duration of anthelmintic efficacy, whilst reducing the drenching frequency increased the long-term benefits of anthelmintic on sheep production. Various determinant criteria for use in TST regimes were compared (Chapter 5) including performance traits such as live weight and growth rate, and parasitological traits such as FEC. Using FEC as the TST criterion was predicted to allow the greatest reduction in the number of anthelmintic treatments administered whilst maintaining the highest average EBW, whilst live weight and growth rate were predicted to give little to no improvement in comparison to selecting animals at random for TST. Using estimated breeding values (EBVs) for FEC as the determinant criterion for TST regimes was compared to using measured FEC (Chapter 6). The EBV for true FEC across the entire growth period, akin to perfect genomic selection, was predicted to be a better criterion than measured time-specific FEC (including a sampling error) for a TST regime. EBVs calculated using measured time-specific FEC showed little benefit compared to measured FEC. The information gained from these simulation studies increases our understanding of control strategies and their impact on host-parasite interactions under various scenarios that may not have been possible using experimental methods. It is important to remember that the aim of alternative or complimentary control strategies is to maintain the sustainability of sheep production systems, and as such the production gain of any control strategy needs to be weighed against the financial, labour and time costs involved in implementation.
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Webster, K. A. "Ixodes ricinus, the sheep tick : Ecology and disease." Thesis, University of Glasgow, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379007.
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Mzembe, S. A. T. "Helminth/protozoal interaction and the host response thereto." Thesis, University of Cambridge, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383849.
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Whyte, Shona K. "Diplostomum spathaceum (digenea) in rainbow trout : experimental and immunological studies." Thesis, University of Aberdeen, 1989. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU016134.
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Diplostomiasis, or eyefluke is caused by the metacercarial stage of the digenean parasite Diplostomum spathaceum which selectively invades the lenses of freshwater fish and can cause partial and total blindness. This study investigates the host-parasite relationship of D. spathaceum infections in rainbow trout with particular reference to the diplostomule or post-penetration stage of the parasite. The point of cercarial penetration influenced the speed with which diplostomules reached the lens and the length of time they were exposed to the fish defence mechanisms. The further away the point of cercarial penetration from the eye, the longer diplostomules take to reach the lens and the fewer establish as metacercariae. Total body immersion using cercariae resulted in significantly more metacercariae establishing in the lens compared with entry via intramuscular, intraperitoneal or intracardial injection of either cercariae or diplostomules. Cercariae may be drawn in by the respiratory current and enter the fish via the gills and buccal cavity. The gills provide an immediate source of entry into the circulatory and lymphatic system of the fish. There did not appear to be any preferred route of migration. The optimum conditions for the in vitro collection of diplostomules were developed. The optimum conditions for in vitro transformation of D. spathaceum cercariae were established. The optimum conditions for the short-term in vitro maintenance of diplostomules were investigated. L-15 medium supplemented with 5% heat-inactivated foetal calf serum maintained approximately 80% survival for the first 24-48 h of culture. Rainbow trout were immunized with cercariae and diplostomules of D. spathaceum. Circulating antibody was detected by ELISA to both cercariae and diplostomules by 6-7 weeks post-immunization. Cross-reactivity occurred between anti-cercarial serum and diplostomule and metacercarial antigens, and anti-diplostomule serum cross-reacted with cercarial and metacercarial antigens in ELISA. Immunofluoresence studies indicated that the tail region of the cercriae was strongly antigenic; a differential fluorescence was observed for both anti-cercarial and anti-diplostomule sera with the cercarial tails fluorescing more strongly than the bodies. No cross-reactivity was observed in fluorescence between anti-cercarial or anti-diplostomule sera and metacercarial antigen although anti-cercariae serum cross-reacted with diplostomule antigen and vice versa. Normal trout serum and anti-diplostomule serum were cytotoxic to diplostomules of D. spathaceum in vitro. Immunized fish exhibited a significant degree of protection against further infection by D. spathaceum. However, there was no correlation between protection and the level of serum antibody. Isolated normal trout macrophages kill significant numbers of diplostomules in vitro at effector: parasite ratios of 150:1 or greater. In vitro killing was not increased using diplostomules opsonized with anti-serum or in vivo-activated macrophages individually, but when combined, increased killing occurred. Diplostomules were capable of eliciting respiratory burst activity from macrophages in vitro, suggesting that reactive oxygen species may have a role to play in the killing mechanism. Diplostomule antigen was capable of activating macrophages in vivo.
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Taylor, Pamela. "The effects of malaria infection on the blood feeding behaviour of anopheline mosquitoes." Thesis, Keele University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327701.
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Vivas, Livia V. "The immunobiology of parasite and host derived glycoconjugates in malarial infection." Thesis, Open University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363492.
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Hurd, H. "Hymenolepis diminuta : The pathophysiology of infection in the intermediate host, Tenebrio molitor." Thesis, Keele University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.354932.
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Tuohy, Maura B. "Genetic control and cytokine regulation of inflammatory responses to intestinal parasitic infections." Thesis, University of Nottingham, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334501.
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