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Approximately two billion people are infected with helminths worldwide. In order to develop a vaccine against these pathogens, more needs to be known about the immune response to helminths. Eosinophils are important for resistance to some helminth species and their recruitment to infected tissues, attachment to parasites and degranulation may all be critical processes for immunity. Complement may contribute to these processes via generation of chemotactic factors (C3a and C5a) or opsonisation of the parasite with C3b/iC3b. The importance of complement during helminth infection is unclear, though complement does promote leukocyte-mediated killing of several helminth species in vitro. The aim of the present study was to investigate the role of complement in immunity of mice to Nippostrongylus brasiliensis, with a focus on whether complement facilitates eosinophildependent resistance to this parasite. A new fluorescence-based method for quantifying in vitro complement deposition and leukocyte adherence on N. brasiliensis was developed. C3 from human serum was deposited on infective-stage L3 via the classical or lectin complement pathways. In contrast, the alternative complement pathway mediated binding of mouse C3 and eosinophil-rich mouse peritoneal leukocytes to L3. Interestingly, the ability of complement and leukocytes to bind to the parasite changed as it matured. Larvae recovered from the skin 30 min post-injection (p.i.) were coated with C3, however those harvested 150 min p.i. exhibited reduced C3 binding capacity. Binding of C3 and eosinophils to larvae recovered from the lungs 24-48 h p.i. (L4) was also diminished compared to that seen on L3. Adult intestinal worms bound C3 and leukocytes only when treated ex vivo with serum and cells. Mice lacking in classical (C1q-deficient), alternative (factor B-deficient) or all complement pathways (C3-deficient) were then employed to determine if complement was important for resistance of mice to N. brasiliensis. IL-5 Tg mice deficient in individual complement genes were generated to assess whether complement contributed to eosinophildependent resistance to the parasite. Factor B deficient mice exhibited impaired C3 deposition on larvae, eosinophil recruitment, eosinophil degranulation and larval aggregation in the skin 30 min p.i. Eosinophil recruitment was similarly abolished by treatment of mice with the C5aR inhibitor PMX53. However at 150 min p.i., larval aggregation, eosinophil and neutrophil recruitment, leukocyte adherence and eosinophil degranulation were largely complement-independent. Ablation of factor B or C3 caused minor but significant increases in lung-larval burden during primary, but not in secondary, infections. Critically, a lack of C3 or factor B in IL-5 Tg mice failed to greatly impair the strong innate anti-parasite resistance typical of these animals, suggesting that eosinophils can provide immunity to N. brasiliensis infection in the absence of complement. This was unexpected, given the evidence from this and previous studies which suggested that in vitro, complement is important for promoting eosinophil-dependent killing of N. brasiliensis and other helminth species. The mechanism(s) by which eosinophils kill N. brasiliensis remain unknown, but may involve the coordination of the complement system with complement-independent factors that act in the early stages of infection. Critically, the influence of complement is limited, because soon after entry into the host, the parasite develops the ability to resist complement activation. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1311182 / Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 2008

The aim of this research was to determine the influence of iron deficiency on both the efficacy and metabolic patterns of albendazole in mice infected with Heligmosomoides polygyrus. Anthelmintic efficacy was markedly decreased in iron-deficient mice; the deficiency was also associated with a decrease in body weight, altered hematological parameters and a decreased net egg output; worm establishment in the deficient group was not affected by the deficiency. Although anthelmintic efficacy was significantly decreased by the iron deficiency, plasma concentration profiles of the main metabolites, albendazole sulphoxide and albendazole sulphone, were not changed by the deficiency. Levels of intestinal cytochrome P-450, the main metabolizing enzyme of albendazole however, was significantly depressed in iron-deficient mice. These observations suggest that although pharmacokinetic parameters are not affected by iron deficiency, nutritional status has the potential to influence anthelmintic efficacy and thus warrants further study.

In the past 20 years, boron has been identified as an essential trace element for animals and humans but also as an increasingly important industrial pollutant. We examined first whether boron influenced survival of the gastrointestinal nematode Heligmosomoides bakeri. Female Balb/c mice were fed deficient (0.1 mug B/g), marginal (2.0 mug B/g) or control (12.0 mug B/g) diets, and infected with third-stage larvae. Although liver boron concentrations did not differ among diet groups, dietary boron deficiency impaired survival of the parasite and modulated a broad range of cytokines and chemokines. On the other hand, infection history altered liver mineral concentrations. Second, we examined whether elevated boron concentrations would exert toxic effects on H. bakeri in vitro. Boron toxicity was evidenced by reduced motility, fecundity, infectivity and survival. Feeding stages and free-living stages were more sensitive than non-feeding stages and parasitic stages respectively in a dose-dependent manner.

Thesis (Ph. D.)--University of Alabama at Birmingham, 2008. / Title from first page of PDF file (viewed Feb. 19, 2009). Includes bibliographical references.

As helmintoses gastrintestinais estão entre as principais enfermidades na criação de ovinos, sendo importante causa de mortalidade e de redução na produtividade dos animais. O controle das infecções por nematódeos é baseado no uso de drogas anti-helmínticas, porém com a descrição emergente de parasitos resistentes, a eficácia deste tratamento tem diminuído. Portanto, métodos alternativos de controle são necessários para a diminuição ou, até mesmo, a substituição do uso de drogas para o controle das verminoses em pequenos ruminantes. O uso dos taninos condensados (TC) no controle das helmintoses gastrintestinais de ovinos em todo o mundo tem se mostrado promissor. Este trabalho teve como objetivo avaliar o efeito anti-helmíntico dos TC sobre nematódeos gastrintestinais de ovinos. Durante o período de testes foram realizados quatro ensaios experimentais: ensaio A avaliação in vitro da ingestão por larvas de primeiro estágio (L1) de Haemonchus contortus, Trichostrongylus colubriformis e Teladorsagia circumcincta, para avaliar o efeito anti-helmíntico dos TC provenientes do extrato de acácia (Acacia mearnsii); ensaio B estudo sobre a infecção natural dos cordeiros a campo, animais infectados com H. contortus e T. colubriformis, sendo os mesmos divididos em dois grupos (tratados com extrato de acácia e não tratados); ensaios C e D realizados com infecção experimental dos animais por nematódeos gastrintestinais (H. contortus e T. colubriformis, respectivamente). Nos dois últimos ensaios, os animais foram divididos em cinco grupos, sendo: GI (controle infectado com nematódeo); GII (recebeu sorgo taninífero); GIII (recebeu extrato de acácia uma vez ao dia); GIV (recebeu extrato de acácia duas vezes ao dia) e GV (controle não infectado). Os resultados dos ensaios A (ingestão larval) e B (infecção natural) foram promissores e demonstraram o efeito direto dos TC sobre os nematódeos parasitas de ovinos, com diferença significativa (P < 0,05) entre os grupos. Observando-se os resultados do experimento com infecção experimental por H. contortus (ensaio C), não se detectou diferença estatística entre os grupos (P > 0,05), porém no experimento com infecção por T. colubriformis (ensaio D) foi evidenciada diferença (P < 0,01) nos valores de OPG entre os grupos tratados com sorgo (GI) e extrato de acácia por dois dias (GIV), quando comparados ao controle infectado (GI); sendo também evidenciada quando da comparação do número de fêmeas de helmintos do GI e GIV (P < 0,01). Redução na viabilidade dos ovos de helmintos (estágio de ovo até L1) e no número de larvas infectantes isoladas de coproculturas provenientes dos grupos tratados com TC foram evidentes nos ensaios C e D. Os resultados foram promissores demonstrando a ação direta dos TC sobre nematódeos gastrintestinais de ovinos e principalmente sobre a produção de larvas infectantes; porém mais estudos são necessários para a indicação de um controle de parasitos gastrintestinais baseado no uso de fontes de TC / Gastrointestinal nematodes are a major cause of economic loss in farm animals. Gastrointestinal parasite control programs based on chemotherapy are failing because of increased anthelmintic resistance; thus, alternative controls strategies are necessary to reduce the use of anthelmintic drug in animal production have been studied. Condensed tannins (CT) have shown potential for alternative control of gastrointestinal nematodes in sheep. The main objective of the present study was to investigate the anthelmintic effect of condensed tannin on sheep gastrointestinal nematodes. During the experimental period four experiments were carried out: Experiment A in vitro study of larval feed inhibition (first stage larvae-L1) of Haemonchus contortus, Trichostrongylus colubriformis and Teladorsagia circumcincta, to evaluate the anthelmintic effect of CT from acacia (Acacia mearnsii) condensed tannins extract (CTE); Experiment B study of the potential uses of CTE to control gastrointestinal parasites in sheep naturally infected with H. contortus e T. colubriformis, with animals divided into two groups (drenched and undrenched with CTE); Experiments C and D were carried out with sheep experimentally infected with gastrointestinal nematodes (H. contortus e T. colubriformis, respectively). In these experiments (C and D) the animals were divided into five groups GI (nematodes infect control); GII (supplemented with taniniferous sorghum); GIII (drenched with CTE once); GIV (drenched with CTE for two days) and GV (non-infect control). The results of experiment A (larval feed inhibition) and B (natural nematode infection) were promissory and showed the direct effect of CT on sheep gastrointestinal nematodes with significant difference (P < 0.05) between groups. The results of H. contortus experimental infections (experiment C) did not provide significant difference between groups (P > 0.05), however the T. colubriformis experimental infection results (experiment D) showed significant difference (P < 0.01) on EPG values of sheep supplemented with sorghum (GI) and drenched with CTE for two days (GIV), when compared with infect control (GI); Significant reduction of female worm burden was demonstrated between GI and GIV (P < 0.01) on experiment D. Reduction on nematode egg viability (from eggs to L1) and infective larvae (L3) from coprocultures made with faeces from CT treated groups were observed in experiments C and D. The results evidenced the direct action of CT on sheep gastrointestinal nematodes and mainly on L3 production; however more studies are necessary to indicate a strategic alternative parasite control based in CT sources

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-10-04T12:34:05Z No. of bitstreams: 1 izabelladeoliveirapinheiro.pdf: 2789735 bytes, checksum: 88fd51d57fe8e1982bbacbad4e1341dc (MD5) / Approved for entry into archive by Diamantino Mayra (mayra.diamantino@ufjf.edu.br) on 2016-10-04T12:39:56Z (GMT) No. of bitstreams: 1 izabelladeoliveirapinheiro.pdf: 2789735 bytes, checksum: 88fd51d57fe8e1982bbacbad4e1341dc (MD5) / Made available in DSpace on 2016-10-04T12:39:56Z (GMT). No. of bitstreams: 1 izabelladeoliveirapinheiro.pdf: 2789735 bytes, checksum: 88fd51d57fe8e1982bbacbad4e1341dc (MD5) Previous issue date: 2010-07-13 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / Doenças tropicais negligenciadas (DTNs), assim classificadas pela Organização Mundial de Saúde, constituem um grupo de infecções praticamente eliminadas no mundo desenvolvido, mas que persistem em áreas pobres de países de baixa renda. Dentre elas estão a ascaridíase, a tricuríase e a ancilostomíase, cujos agentes etiológicos têm parte de seu ciclo evolutivo passando pelo solo, e são, por isso, denominadas de geohelmintoses. Recentemente, a giardíase também foi incluída como DTN, uma vez que sua forma de transmissão pode ser associada com falta de saneamento. Este estudo transversal de base populacional visou à investigação da ocorrência dessas parasitoses em três municípios do sudeste de Minas Gerais. Para tanto, 2367 indivíduos foram selecionados aleatoriamente. Os dados foram obtidos por meio de um questionário estruturado acerca das condições socioeconômicas, ambientais e culturais da população amostral e do exame de uma única amostra fecal de cada participante, pelo método de sedimentação espontânea (HPJ). Para cada amostra fecal foram examinadas cinco lâminas, e concluiu-se que o exame de três lâminas por amostra expressou a melhor relação custo-benefício para o SUS. A análise dos resultados mostrou que 6,1% (n=145) da população amostral estava infectada com uma ou duas DTNs. Dentre os indivíduos infectados, as prevalências observadas para ancilostomídeos, G. lamblia, T. trichiura e A. lumbricoides foram 47,3%, 27,3%, 16,0% e 9,3%, respectivamente. Na análise bivariada dos dados (p<0,05; IC 95%), o teste do Qui-quadrado de Pearson foi usado para avaliar a força das possíveis associações entre as variáveis independentes e o desfecho. Na análise de regressão logística, quatro variáveis permaneceram estatisticamente significantes, sugerindo serem os possíveis fatores de risco para as DTNs nos municípios: o destino inadequado do esgoto (p<0,001), o hábito de beber água não potável (p<0,001), a falta de instalação sanitária adequada (p=0,015) e pertencer ao sexo masculino (p<0,001). Os resultados encontrados neste estudo nos permitem concluir que DTNs estão presentes mesmo em regiões mais desenvolvidas do Brasil. O número de pessoas parasitadas confirma a área como de baixa endemicidade para geohelmintoses e giardíase em relação a outras regiões do Estado, e justifica estudos que avancem no conhecimento do perfil epidemiológico da região e subsidiem o desenvolvimento de políticas públicas locais. / Neglected tropical diseases (NTDs), so classified by the World Health Organization, are a group of infections that have been eliminated in the developed world, but still persist in poor areas of low-income countries. Among them, ascariasis, trichuriasis, and hookworm infection are soil-transmitted helminthiasis. Recently, and despite its worldwide distribution, giardiasis was also included in the WHO list, due to its way of transmission, which can be associated with lack of sanitation. This population-based cross-sectional survey aimed at investigating the occurrence of such infections in three municipalities of southeastern Minas Gerais state. A total of 2,367 individuals randomly chosen provided one single fecal sample. The baseline data consisted of a questionnaire and parasitological coproscopy using the HPJ method. Five slides were examined from each fecal sample, allowing us to conclude that, regarding this method, the examination of three slides per sample presented a satisfactory sensitivity and the best cost-effectiveness for the SUS. The results showed that 6.1% (n=145) of the population sample was infected with either one or two NTDs, of which the prevalences observed for hookworms, G. lamblia, T. trichiura, and A. lumbricoides were 47.3%, 27.3%, 16.0% e 9.3%, respectively. In the bivariate analysis (p<0.05; CI 95%), Pearson Qui-square tests were used to assess the strength of the associations. Multivariate analysis was run with all significant variables. Four variables remained significant in the logistic regression, as the possible risk factors for the installation and spread of the infections in the municipalities: inadequate sewage discharge (p<0.001), the habit of drinking unsafe water (p<0.001), lack of adequate sanitary infrastructure in the household (p=0.015), and masculine sex of the individual (p<0.001). Our findings allow us to conclude that NTDs occur even in more developed areas of Brazil. Our numbers confirm the study area as low endemic for giardiasis and soil-transmitted helminthiasis, and justify surveys in order to get more information on the epidemiological profile of the Zona da Mata Mineira region, aiming at giving support to the development of local health policies.

Made available in DSpace on 2014-08-20T14:31:28Z (GMT). No. of bitstreams: 1 dissertacao_luis_augusto_xavier_cruz.pdf: 1391825 bytes, checksum: b731f2ece4a98ab80df6cebec7f6f26f (MD5) Previous issue date: 2012-03-02 / Human toxocariasis is a worldwide parasitic zoonosis, with underestimated prevalence and characterized by complex diagnosis, treatment, and control. These aspects justify the search for new supportive alternatives to control this tissue helminthiasis. In this sense, experimental models have shown the potential of probiotic agents in reducing the intensity of infections with Toxocara canis larvae. Therefore, studying the effect of probiotics in vertical transmission is also relevant, as this type of transmission is essential in definitive hosts and has been shown in humans. This study aims at assessing the effect of Saccharomyces boulardii probiotic on the vertical transmission of Toxocara canis larvae in female mice inoculated during the last third of pregnancy. Two groups of eight female Swiss mice were formed. Females in Group 1 (G1) were fed with ration supplemented with S. boulardii probiotic, and females in G2 (control) were fed with ration without probiotic. The supply of ration for both groups started 15 days before mating, continued during pregnancy and was maintained until the 21st day of lactation. Experimental infection of females was given on day 14 of pregnancy, when 300 T. canis eggs were intragastrically inoculated. Lactating females and infants were euthanized on the 21st day of lactation. After necropsy, organs and skeletal striated muscle (carcass) were submitted to tissue digestion with 1% pepsin and 1% hydrochloric acid. Next, detection and quantification of larvae were performed on the material. Frequency of vertical transmission to the G1 offspring (probiotic) was 21.6% lower than in the G2 (control). In addition, the number of T. canis larvae recovered from G1 female mice offspring (probiotic) was 42.1%, which is significantly lower (p=.026) than the number of larvae recovered from G2 female offspring (control). It can be concluded that there was a beneficial effect of S. boulardii on the studied conditions, resulting in a reduction in the rate of vertical transmission of T. canis and confirming its potential in contributing to the control of visceral toxocariasis. / A toxocaríase humana é uma zoonose parasitária com distribuição mundial, apresenta prevalência subestimada e é caracterizada pela complexidade na realização do diagnóstico, tratamento e controle. Estes aspectos justificam a busca por novas alternativas auxiliares no controle desta helmintíase tecidual. Neste sentido, já foi observado, em modelos experimentais, o potencial de agentes probióticos para a redução da intensidade da infecção por larvas de Toxocara canis. Desse modo, torna-se relevante estudar o efeito dos probióticos também na transmissão vertical, pois este tipo transmissão é fundamental nos hospedeiros definitivos e já foi demonstrada nos seres humanos. O objetivo deste estudo foi avaliar o efeito do probiótico Saccharomyces boulardii sobre a transmissão vertical de larvas de Toxocara canis em camundongos, fêmeas, inoculadas no terço final da gestação. Dois grupos de oito camundongos Swiss, fêmeas, foram formados. As fêmeas do Grupo 1 (G1) foram alimentadas com ração suplementada com probiótico S. boulardii e as fêmeas do G2 (controle) foram alimentadas com ração sem probiótico. O fornecimento de ração para os dois grupos iniciou 15 dias antes do acasalamento, continuou durante toda gestação e foi mantido até o 21° dia de lactação. A infecção experimental das fêmeas ocorreu no 14° dia de gestação, quando foram inoculados, pela via intragástrica, 300 ovos embrionados de T. canis. As fêmeas lactantes e os lactentes foram eutanasiados no 21º dia de lactação. Após a necropsia, órgãos e musculatura estriada esquelética (carcaça) foram submetidos à digestão tecidual com pepsina 1% e ácido clorídrico 1%. A seguir foi realizada a pesquisa e quantificação das larvas no material. A frequência da transmissão vertical para a prole no G1 (probiótico) foi 21,6% menor do que no G2 (controle). Além disso, o número de larvas de T. canis recuperadas, nos lactentes das fêmeas do G1 (probiótico) foi 42,1%, significativamente menor (p=0,026) do que o número de larvas recuperadas na prole das fêmeas do G2 (controle). Conclui-se que houve efeito benéfico do probiótico S. boulardii nas condições estudadas, com a redução na taxa de transmissão vertical de T. canis, confirmando o seu potencial em contribuir para o controle da toxocaríase visceral.

M.Tech. / Capra hircus (boer goats) are well known for their hardy adaptability to arid regions and their ability to survive and thrive in areas where grazing is low in nutrition. They are an irreplaceable source of protein for the lower income groups of arid regions in South Africa. Boer goats are prone to helminthiasis (infestation of intestinal parasitic worms), which can result in poor health (Kumba, 2002). This can have a significant effect on the long term productivity of the animal (Alexandre and Mandonnet, 2005), resulting in economic and nutritional strain in poor farming communities who depend on goats as a primary source of protein and income (Kumba, 2002). Conventional treatments worldwide show a trend of resistance of helminths to treatment and carry the risk of inducing side effects when administered (Kumba, 2002; Scarfe, 2004; Schnyder et al., 2005). Homoeopathic research has shown promising results in the treatment of helminthiasis in animals (Zacherias et al., 2008; Jeannes et al, 2001), but no research currently exists of homoeopathy on helminthiasis in Boer goats.

No description available.