Made available in DSpace on 2014-06-11T19:27:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-02-27Bitstream added on 2014-06-13T19:56:21Z : No. of bitstreams: 1 loureiro_cmb_me_jabo.pdf: 193126 bytes, checksum: 7871454a59e8dd164e24e73028d35ee6 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Avaliou-se o efeito do extrato de própolis na redução da verminose e sobre os parâmetros hematológicos e bioquímicos de 18 cordeiros Ile de France (nove machos não-castrados e nove fêmeas) dos 5 aos 15 kg de peso corporal, no desmame. Os animais foram distribuídos em três tratamentos, constituídos por dietas isoprotéicas e isoenergéticas, com adição ao concentrado de 0, 15 e 30 mg de extrato de própolis a 11%/kg de peso corporal . O delineamento experimental foi o inteiramente casualizado em esquema de parcela subdividida no tempo. Observou -se que a contagem de ovos por grama de fezes foi influenciada pelos diferentes tratament os. Nos cordeiros estudados, a ad ição de 30 mg de extrato de própolis foi mais efetiva em reduzir o número de ovos tipo Stron gylida por grama de fezes, do que a de 15 mg e a que não continha o extrato, indicando uma possível redução na ovoposição dos endoparasitos. As contagens globais de hemácias, neutrófilos bastonetes e monócitos, taxa de hemoglobina e o percentual de hematócrito apresentaram efeito para interação entre os tratamentos e as datas de observação. Não houve diferenças para as contagens de leucócitos, neutrófilos segmentados e linfócitos, já os eosinófilos variaram dentro do período de coleta. Em relação aos parâmetros bioquímicos analisados, o extrato de própolis não afetou as concentrações séricas de uréia, creatinina, albumina, bilirrubina direta e indireta, e plasmática de glicose. Já os níveis séricos d e colesterol, proteínas totais e bilirrubina total diferiram entre os tratamentos. Com base nos resultados, concluí-se que a adição de extrato de própolis às rações dos cordeiros não provocou alterações importantes nos parâmetros hematológicos e bioquímicos, que indicassem reações adversas à sua administração, além de ser uma possível alternativa no controle da verminose em cordeiros. / The effect of the propolis extract was evaluated in the reduction of the nematodes and on the hematological and bioch emical parameters of 18 lambs Ile of France (nine no-castrated males and nine females) of the 5 to the 15 kg of corporal weight, in it weans them. The animals were distributed in three treatments, constituted by protein and energy concentration diets, with addition to the concentrate of 0, 15 and 30 mg of propolis extract to 11%/kg of corporal weight. The experimental delineation was entirely occurred in portion outline subdivided in the time. It was observed that the counting of eggs for gram of feces was influenced by the different treatments. In the studied lambs, the addition of 30 mg of extract of propolis was more effective in reducing the number of eggs type Strongylida for gram of feces, than the one of 15 mg and the one that didn't contain the extra ct, indicating a possible reduction in the eggs of the endoparasites. The global countings of the red cells, neutrophiles and monocytes, hemoglobin tax and the percentile of hematocrits presented effect for interaction among the treatments and the dates fo r observation. There were not differences for the leucocytes countings, segmented neutrophiles and lymphocytes, whereas the eosinophiles varied inside of the collection period. In relation to the analyzed biochemical parameters, the extract of propolis did n't affect the serum urea, creatinine, albumin, direct and indirect, and plasmatic bilirubin concentration of glucose. The serum levels of cholesterol, total proteins and total bilirubin differed among the treatments. On base in the results, I was ended th at the addition of extract of propolis to the rations of the lambs didn't provoke important alterations in the hematological and biochemical parameters, that they indicated adverse reactions to his/her administration, besides being a possible alternative in the control of the nematodes in lambs.

Orientador: Alessandro Francisco Talamini do Amarante / Banca: Raimundo de Souza Lopes / Banca: Fernanda Rosalinski Moraes / Resumo: A epidemiologia das infecções por nematódeos gastrintestinais foi avaliada em ovinos criados em Botucatu - SP. A partir de abril de 2008 até março de 2011, dois cordeiros traçadores foram expostos à infecção natural por nematódeos gastrintestinais durante 28 dias consecutivos, ao pastejar junto com um rebanho de ovelhas. Haemonchus contortus apresentou as maiores intensidades de infecção com prevalência de 100%. Não houve influência significativa das estações do ano na intensidade de infecção por H. contortus. Trichostrongylus colubriformis também apresentou prevalência de 100% com a intensidade de infecção menor durante os meses de verão. No caso de T. colubriformis, houve correlação significativa entre as contagens de vermes x precipitação (r = -0,32; P < 0,05). Outras três espécies de nematódeos foram verificadas, no entanto, em pequenas quantidades, prevalências e intensidades de infecção: Oesophagostomum columbianum 28% (25,2), Cooperia curticei 7% (4,5) e Trichuris spp. 2 % (1). Contudo, as condições ambientais da área foram favoráveis durante todo o ano para a transmissão de H. contortus e T. colubriformis. Este fato explica parcialmente o fracasso de programas governamentais e privados realizados no intuito de promover a ovinocultura no Estado, devido a taxas elevadas de mortalidade e baixa produtividade causada pela verminose / Abstract: The epidemiology of gastrointestinal nematode infections was evaluated in sheep raised in Botucatu - SP. Every month, from April 2008 until March 2011, two tracer lambs were exposed to natural infection with gastrointestinal nematodes for 28 consecutive days, while grazing together with a sheep flock. Haemonchus contortus presented the highest infection intensities with 100% prevalence. There was no significant influence of the seasons in H. contortus infection intensity. Trichostrongylus colubriformis also presented 100% prevalence with the lowest infection intensity during the summer months. In the case of T. colubriformis, there was significant correlation coefficient between worm counts x precipitation (r = -0.32; P < 0.05). Other three nematodes species were found in tracer lambs, however, in small numbers. Their prevalence and mean intensity of infection (in parenthesis) were the following: Oesophagostomum columbianum 28% (25.2), Cooperia curticei 7% (4.5) and Trichuris spp. 2% (1). In conclusion, the environmental conditions of the area were very favourable for H. contortus and T. colubriformis transmission all year round. These explain in part the failure of private and governmental programs to promote the sheep breeding activity in São Paulo State due to high sheep mortality rates and low productivity caused by gastrointestinal nematode infections / Mestre

Les nématodes gastro-intestinaux (NGI) représentent un problème sanitaire majeur dans le monde entier en systèmes de production à l’herbe des élevages de moutons et de chèvres. La maîtrise de ces parasites est désormais compliquée par l'apparition de résistances aux anthelminthiques (AH) chez les nématodes. L'utilisation de plantes riches en tanins (PRT) comme AH non conventionnels est une des alternatives possibles au contrôle chimique de ces maladies parasitaires. Cependant, le mécanisme d'action de ces plantes sur les vers adultes demeure inconnu. Cet objectif a constitué le premier but de cette étude en particulier en essayant de déterminer quelle part jouent les effets directs et indirects dans l’action des PRT sur les populations de Nématodes adultes dans le tractus digestif des petits ruminants. Un effet direct correspond à une action de type pharmacologique sur la biologie, la structure et l’ultrastructure des nématodes liés à des composés biochimiques présents dans les PRT. L'hypothèse d’un effet indirect correspondrait une modification de la réponse cellulaire dans les muqueuses gastro-intestinales de l'hôte, affectant la biologie des NGI. Cette thèse est divisée en deux parties: 1) Deux expériences in vivo réalisées respectivement, au Mexique et en France, visant à déterminer les effets directs ou indirects sur la biologie des NGI liés à la consommation de PRT tel le tzalam (Lysiloma latisiliquum), une Légumineuse arbustive du Yucatan, le sainfoin (Onobrychis viciifolia) une Légumineuse fourragère tempérée, et ainsi que le quebracho(Schinopsis spp.), un extrait riche en tannins condensés Les agneaux ont été infestés par Haemonchus contortus (au Mexique) ou H. contortus et Trichostrongylus colubriformis (en France). La consommation de tzalam a provoqué une perturbation de croissance des vers ou de fertilité des femelles d’H. contortus. Selon la durée de consommation, le quebracho a réduit la population de H. contortus et T. colubriformis, et affecte également la fertilité de T. colubriformis. Le sainfoin a affecté la fécondité de H. contortus sans affecter celle de T. colubriformis. Le comptage de cellules effectrices dans les muqueuses pour évaluer l’implication d’un effet indirect n'a pas montré de différences significatives entre les lots recevant ou non des PRT. La seconde partie s’est fondée sur un test in vitro et deux essais in vivo chez des chèvres infestées par H. contortus pour mieux comprendre l'effet de la consommation de PRT (tzalam, au Mexique ou sainfoin, en France) sur la structure et l’ultrastructure d’H. contortus. Les principales altérations ont été trouvées dans la cuticule et la région céphalique des vers. Des agrégats de matériel végétal autour de la vulve n’ont été trouvé qu’in vitro. L’examen de l’ultrastructure des H. contortus a montré des signes de vacuolisation, surtout visible dans les tissus intestinaux et musculaires. Ces lésions suggèrent que des composés secondaires présents dans le feuillage des PRT peuvent être impliqués dans les fonctions vitales d’ H. contortus, telles que la mobilité, la nutrition et éventuellement la reproduction. / Gastrointestinal nematodes (GIN) represent a major health problem worldwide in grazing sheep and goat production systems. The control of these parasites has been complicated by the emergence of nematodes which are resistant to the commercially available anthelmintics (AHs). The use of tannin rich plants (TRP), as non-conventional Ahs, represents an alternative for the control of these parasites. However, the mechanism of action of such plants against adult populations of GIN has not been determined. The objective of the study was to determine the direct and indirect effect of TRP against adult populations of GIN in small ruminants. A direct effect is considered to be any action against the biology, structure and/or ultrastructure of the nematodes which is similar to a chemical AH. The indirect effect is a modification of the immune response of the host at the level of the gastrointestinal mucosa which affects the biology of the GIN. This study is divided into two stages: First stage) Two in vivo experiments conducted in Mexico and France respectively, determined the direct and indirect effects on the biology of GIN due to the consumption of the TRP forage of tzalam (Lysiloma latisiliquum), sainfoin (Onobrychis viciifolia) as well as a tannin-rich quebracho extract (Schinopsis spp). Lambs were artificially infected with Haemonchus contortus (Mexico) or H. contortus and Trichostrongylus colubriformis (France). The consumption of tzalam affected the length and fertility of H. contortus females. Meanwhile, the quebracho extract reduced the population of H. contortus and T. colubriformis also affecting the fecundity of T. colubriformis. The sainfoin affected the fecundity of H. contortus without affecting T. colubriformis. The indirect effect was not evident. Second stage) An in vitro assay and two in vivo experiments with goats infected with H. contortus allowed to identify the effect of the consumption of TRP (tzalam or sainfoin) on the structure and ultrastructure of H. contortus. Alterations in cuticle and cephalic region were found. The aggregates in the vulva were only found in vitro. The ultrastructure of H. contortus showed a vacuolization process in the intestinal and muscular tissues of these nematodes. The lesions suggest that the compounds contained in the foliage of TRP may be involved in vital functions of H. contortus such as mobility, nutrition and possibly reproduction. This study is a contribution towards the understanding the mechanisms of AH action of the TRP against GIN.

L'étude (i) identifie les usages thérapeutiques et les techniques traditionnelles de préparation de remèdes antihelminthiques par les utilisateurs de la phytothérapie vétérinaire, (ii) caractérise les groupes chimiques présents dans la poudre d‟écorce de racine de Vitex thomasii De Wild, (iii) évalue in vitro et in vivo leurs effets sur Haemonchus contortus chez la chèvre élevée sur pâturage. Des enquêtes menées auprès de 44 utilisateurs de plantes médicinales chez les chèvres d'élevage, ont montré que 9 plantes locales (dont Vitex thomasii la plus citée) sont utilisées pour combattre les pathologies qu'ils identifient comme parasitoses gastro-intestinales. Les recettes, généralement monospécifiques, sont administrées per os, suivant divers modes de préparation selon divers modes de préparation. Le criblage phytochimique réalisé sur les extraits de la poudre d'écorce de racine de Vitex thomasii De Wild a révélé la présence de terpènes, des flavonoïdes, de tanins, de saponines, de quinones et d'iridoïdes. L'activité antihelminthique des extraits aqueux et éthanoliques de Vitex thomasii a été évaluée in vitro sur les oeufs et les larves L3 d'Haemonchus contortus, en utilisant l'albendazole comme témoin positif (62,5 à 2000 μg/ml d'extraits et d'albendazole), l'eau distillée, le surnageant de la suspension d'oeufs et l'éthanol, respectivement comme placebo, témoin négatif et témoin éthanol. Les extraits éthanoliques et aqueux se sont révélés actifs sur les larves L3 d'Haemonchus contortus (CE50 = 56.44 μg/ml et 106.7 μg/ml respectivement) et ont inhibé l'éclosion des oeufs (CE50 = 53.09 μg/ml et 88.62 μg/ml respectivement). L'efficacité antiparasitaire de la poudre d'écorce de racine de Vitex thomasii a été testée sur les strongles gastro-intestinaux. 32 caprins ont été répartis en quatre lots de 8 animaux : témoin neutre, témoin positif traité avec l'albendazole à la dose 5 mg/kg de poids vif et deux lots ayant reçu 1g/kg et 2g/kg de poids vif de la poudre d'écorce de racine de Vitex thomasii. Le nombre d'oeufs par gramme de fèces et de leucocytes totaux ont baissé significativement dans les lots traités à l'albendazole (- 90 %; p < 0.05) et à la poudre d'écorce de racine de Vitex thomasii (- 85 % pour 1 g/kg et Ŕ 86 % pour 2 g/kg; p < 0.05). La créatinine, les transaminases ainsi que le poids sont restés stables dans les trois lots tandis que les protéines totales, l'albumine et l'hématocrite ont augmenté significativement. Les taux d'efficacité des deux posologies de Vitex thomasii De Wild restent comparables. Ces résultats sont un référentiel de base pour les recherches ultérieures à mener dans le but de contribuer au développement d'une approche thérapeutique chez les animaux d'élevage notamment en identifiant le groupe chimique actif et, plus loin, la molécule active.

Two studies were conducted to investigate anthelmintic resistance in goat parasites in New Zealand. In Study 1 parasites from goats on a farm with a long history of problems with anthelmintic efficacy were used to infect sheep for a controlled slaughter study. Nineteen lambs were acquired, effectively drenched and housed. Each was infected with a mixture of larvae comprising Haemonchus contortus, Teladorsagia circumcincta, Trichostrongylus colubriformis and Oesophagostomum venulosum. After 28 days lambs were restrictively randomised into 3 groups based on faecal egg counts. Group 1 was left untreated (n=6), Group 2 (n=6) was given a single dose of abamectin (0.2mg/kg) + levamisole HCL (8mg/kg) + oxfendazole (4.5mg/kg) (“Matrix Oral Drench for Sheep”®, Ancare, New Zealand) and Group 3 (n=7) was treated at twice the dose rate of Group 2. Fourteen days after treatment all animals were killed for total worm counts. The mean burdens of T. circumcincta in Group 1 was 337, in Group 2 was 68 (efficacy 80%) and in Group 3 was 10 (efficacy 97%). The mean burdens of T. colubriformis in Group 1 was 375, in Group 2 was 220 (efficacy 41%) and in Group 3 was 81 (efficacy 78%). Although the worm burdens in these lambs were low, all animals were infected with each of these two species except for T. circumcincta in Group 3 where only 3 lambs were infected. Efficacy against other species was 100%. These results clearly indicate that a single dose of a combination drench was ineffective against two species and even when a double dose was used the efficacy against T. colubriformis was only 78%. In Study 2 a survey of drench efficacy was conducted on 17 goat farms using the DrenchRite® larval development assay. Evidence of concurrent resistance to benzimidazoles, levamisole and ivermectin was detected in T. colubriformis and T. circumcincta on 11/17 and 3/14 respectively. Only 5 of 14 farms had previously undertaken some form of testing for drench resistance prior to this survey. Evidence from these two studies suggests that severe anthelmintic resistance is common on goat farms in New Zealand

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2016-10-06T12:24:38Z No. of bitstreams: 1 texto completo.pdf: 2332592 bytes, checksum: ea191ac1bd1c0ec54857a55aff6e21f9 (MD5) / Made available in DSpace on 2016-10-06T12:24:38Z (GMT). No. of bitstreams: 1 texto completo.pdf: 2332592 bytes, checksum: ea191ac1bd1c0ec54857a55aff6e21f9 (MD5) Previous issue date: 2016-05-23 / Fundação de Amparo à Pesquisa do Estado de Minas Gerais / Foram utilizados 5.796 registros de perfis parasitológico (ovos por grama de fezes - OPG) e histológico (contagem de eosinófilos sanguíneos – EOSI; e volume globular - VG), para obtenção da resposta à resistência ao parasitismo Haemonchus contortus ao longo do tempo, oriundos de 138 caprinos da raça Crioula com idades variando de 173 a 307 dias, pertencentes a empresa francesa INRA (Institut National de Recherche Agronomique) na Unité de Recherches Zootechniques (URZ) localizada em Guadalupe (Antilhas Francesa), coletados no período de 2009 a 2013. A primeira análise destes dados foi contrastar diferentes modelos estatísticos (repetibilidade - REP; e regressão aleatória - MRA) para uma avaliação genética relacionada à resistência de caprinos Crioulos infectados artificialmente com 10.000 larvas L3 de Haemonchus contortus, em 2 etapas (Desafio 1 - correspondente à imunização do animal ao parasita; e Desafio 2 - correspondente à resposta da imunização adquirida pelo animal após a primeira infecção artificial) e observados durante 56 dias. Para o MRA o ajuste ocorreu por meio de funções polinomiais de Legendre para a curva fixa (kf), efeito genético aditivo (ka) e de ambiente permanente (kp) considerando as ordens dois (função linear) e três (função quadrática) para descrever as estruturas de (co)variâncias em função do tempo. Por meio do software WOMBAT, os modelos (REP e MRA) foram comparados pelos critérios de informação de Akaike (AIC) e Bayesiano de Schwarz (BIC). Estes avaliadores de qualidade destacou no Desafio 1, os seguintes MRA com as ordens: 3,2,3 para OPG; 3,3,2 para EOSI e 2,2,3 para VG como sendo os mais plausíveis para descrever geneticamente a curva de resistência de caprinos Crioulos inoculados com Haemonchus contortus. Já para o Desafio 2, os MRA com as ordens: 3,2,3; 3,2,2 e 3,3, respectivamente para as características OPG, EOSI e VG foram ressaltado para a mesma finalidade. Na segunda análise destes dados para ambos os Desafios (1 e 2) foi realizada a identificação de genes associados aos mecanismos de resistência em caprinos Crioulos ao Haemonchus contortus, por meio um Estudo de Associação Genômica Ampla (Genome-Wide Association Study - GWAS) para contagem de ovos por grama de fezes (OPG). Todos os animais avaliados neste estudo foram genotipados utilizando o chip Illumina goat SNP50 BeadChip (Illumina Inc. San Diego, CA) contendo 53.347 SNPs (Single Nucleotide Polymorphism ou polimorfismo de nucleotídeos de base única). E após o controle de qualidade, os genótipos de todos os indivíduos passaram a ter 46.643 SNPs, onde foram incluídos no GWAS. As associações que mostraram significativas foram identificadas através de modelos lineares mistos e ajustados separadamente para cada Desafios (1 e 2) utilizando a função GWAS do pacote rrBLUP do software R. No Desafio 1 foram encontrados sete SNPs (no cromossomo 4, 6, 11 e 17) e no Desafio 2 foram reportados cinco SNPs (nos cromossomos 3, 8, 9 e 24). A anotação dos genes candidatos foi realizada nas posições destes marcadores significativos, onde o principal cromossomo em termos de número de genes anotados foi o seis (Desafio 1) e o oito (Desafio 2) para a característica de interesse OPG. Uma vez que a infecção de Haemonchus contortus provoca danos graves no intestino em animais infectados, resultando num processo de inflamação e também a perda de sangue (ou anemia), o uso destes genes anotados é grande importância, pois os mesmos podem ser analisados sob um ponto de vista para uma resposta imunológica integrada. / A total of 5.796 records of parasitological (fecal eggs count - FEC) and histological (counting blood eosinophils - EOSI, and packed cell volume - PCV) profiles were used to study the genetic resistance to Haemonchus contortus parasitism in Creole goats belonging to French company INRA (Institut National de Recherche Agronomique) in Unité de Recherches Zootechniques (URZ) located in Guadeloupe (French West Indies). The datasets were collected in the period between 2009 to 2013. The first analysis consisted in comparing statistical models (repeatability - REP, and random regression - MRA) for genetic evaluation related to the resistance of Creole goats artificially infected with 10.000 larvae L3 of Haemonchus contortus. The infection occurred in 2 steps (Challenge 1 - corresponding to the immunization of the animal to the parasite; and Challenge 2 - corresponding to the immunization response acquired by the animal after the first artificial infection). The MRA were fitted by Legendre polynomials assumed to the fixed curve (kf), additive genetic effect (ka) and permanent environmental (kp) considering the two orders (linear function) and three (quadratic function) to describe the structures of (co) variance as a function of time. The analyses were performed by using WOMBAT software, being the models compared through Akaike Information (AIC) and Bayesian Schwarz (BIC) Criteria. For Challenge 1, the following MRA with orders: 3,2,3 for FEC; 3,3,2 for EOSI e 2,2,3 for PCV were the most plausible to describe genetic variation in goats in relation to the resistance to Haemonchus contortus. For Challenge 2, the MRA with orders: 3,2,3; 3,2,2 e 3,3, respectively for the characteristics FEC, EOSI e PCV, presented the best fitting. The second analysis was performed to identify genes associated with resistance mechanisms in the Creole goats to Haemonchus contortus through Genome-Wide Association Study (GWAS) for fecal eggs count (FEC). All animals in this study were genotyped using the chip Illumina goat SNP50 BeadChip (Illumina Inc. San Diego, CA) containing 53,347 SNPs (Single Nucleotide Polymorphism). Significant associations were identified by linear mixed models fitted separately for each Challenges (1 and 2) using the function rrBLUP of R software. At Challenge 1 were found seven significant SNPs (on chromosome 4, 6, 11 and 17); and at Challenge 2 were reported five significant SNPs (on chromosomes 3, 8, 9 and 24). Candidate gene annotation study was performed in the positions of these significant markers. Chromosome 6 was the most relevant in terms of the number of annotated genes, since a total of six (Challenge 1) and eight (2 Challenge) genes were associated to FEC. These genes are related to inflammation process and loss of blood (or anemia), which are symptoms of Haemonchus contortus infection. These identified genes can be submitted to future studies aiming to elucidate the integrated immune response to this parasitism.

Made available in DSpace on 2016-06-02T20:21:35Z (GMT). No. of bitstreams: 1 6279.pdf: 1318446 bytes, checksum: 3ea93c315d61578a7b50605db41ae915 (MD5) Previous issue date: 2014-02-28 / Financiadora de Estudos e Projetos / Among the sheep parasites, Haemonchus contortus is the most prevalent and pathogenic nematode in tropical areas, causing huge economic losses. Alterations in the gene encoding the membrane P-glycoprotein (PgP) have been associated with multidrug resistance. The goal of this study was to identify single nucleotide polymorphisms (SNPs) on the PgP gene in H. contortus by comparing two isolates with different status of anthelmintic resistance. For this purpose, two ewes were experimentally infected, one with a susceptible H. contortus isolate (McMaster, Australia) and the other with a multidrug-resistant isolate (Embrapa2010, Brazil). Feces from infected animals were submitted to coproculture in order to obtain larvae and, after the slaughter of the ewes, adults H. contortus were collected from abomasum and individually submitted to DNA extraction. For the evaluation of potential molecular markers of geographic isolation, larvae originating from coprocultures of two other Brazilian isolates (Bahia and Pernambuco), with no determined resistance status, were also submitted to DNA extraction. After PCR amplification of DNA extracted from adults H. contortus, a fragment of the PgP gene was sequenced and six SNPs (position described in relation to the sequence of contig 004690 from the Wellcome Trust Sanger Institute) were identified : 508 (A> G in exon), 580 (G> A), 601 (G> C), 800 (G> A), 845 (G> T), and 878 (G> T), the last five in introns. The Fisher's exact test, applying the Bonferroni correction, revealed a significant association (P<0.01) between 508, 580, 601, 845 and 878 SNPs and the state of resistance to anthelmintics. Among these SNPs, 601 and 878 are in linkage disequilibrium and form the CC haplotype associated (P < 0.05) to resistance and the GG haplotype associated to susceptibility. Considering that there is considerable genetic differentiation between different continental areas in H. contortus, the frequencies of the SNPs were compared between the Brazilian isolates and the susceptible Australian one. It was found that the SNPs 580 and 845 may be associated with geographic isolation. We conclude that the 508, 601 and 878 SNPs in the P-glycoprotein gene can be molecular markers for multiple resistance to anthelmintics, and that the 580 and 845 SNPs can be candidate markers of geographical isolation in H. contortus. We developed software for Risk Analysis Development of Parasitic Resistance to Anthelmintics in Sheep (SARA) which will provide information that may guide the rational use of anthelmintics. / Among the sheep parasites, Haemonchus contortus is the most prevalent and pathogenic nematode in tropical areas, causing huge economic losses. Alterations in the gene encoding the membrane P-glycoprotein (PgP) have been associated with multidrug resistance. The goal of this study was to identify single nucleotide polymorphisms (SNPs) on the PgP gene in H. contortus by comparing two isolates with different status of anthelmintic resistance. For this purpose, two ewes were experimentally infected, one with a susceptible H. contortus isolate (McMaster, Australia) and the other with a multidrug-resistant isolate (Embrapa2010, Brazil). Feces from infected animals were submitted to coproculture in order to obtain larvae and, after the slaughter of the ewes, adults H. contortus were collected from abomasum and individually submitted to DNA extraction. For the evaluation of potential molecular markers of geographic isolation, larvae originating from coprocultures of two other Brazilian isolates (Bahia and Pernambuco), with no determined resistance status, were also submitted to DNA extraction. After PCR amplification of DNA extracted from adults H. contortus, a fragment of the PgP gene was sequenced and six SNPs (position described in relation to the sequence of contig 004690 from the Wellcome Trust Sanger Institute) were identified : 508 (A> G in exon), 580 (G> A), 601 (G> C), 800 (G> A), 845 (G> T), and 878 (G> T), the last five in introns. The Fisher's exact test, applying the Bonferroni correction, revealed a significant association (P<0.01) between 508, 580, 601, 845 and 878 SNPs and the state of resistance to anthelmintics. Among these SNPs, 601 and 878 are in linkage disequilibrium and form the CC haplotype associated (P < 0.05) to resistance and the GG haplotype associated to susceptibility. Considering that there is considerable genetic differentiation between different continental areas in H. contortus, the frequencies of the SNPs were compared between the Brazilian isolates and the susceptible Australian one. It was found that the SNPs 580 and 845 may be associated with geographic isolation. We conclude that the 508, 601 and 878 SNPs in the P-glycoprotein gene can be molecular markers for multiple resistance to anthelmintics, and that the 580 and 845 SNPs can be candidate markers of geographical isolation in H. contortus. We developed software for Risk Analysis Development of Parasitic Resistance to Anthelmintics in Sheep (SARA) which will provide information that may guide the rational use of anthelmintics. / Entre os parasitas de ovinos, Haemonchus contortus é o nematoide mais prevalente e patogênico em áreas tropicais, causando grandes perdas econômicas. As alterações no gene que codifica a glicoproteína-P de membrana (PgP) foram associadas com a resistência a múltiplas drogas. Assim, o objetivo deste estudo foi identificar polimorfismos de nucleotídeo único (SNPs) no gene PgP em H. contortus por comparação de dois isolados com diferentes status de resistência a anti-helmínticos. Para esse fim, uma ovelha foi infectada experimentalmente com o isolado suscetível (McMaster, Austrália) e outra ovelha com o isolado multirresistente (Embrapa2010, Brasil) de H. contortus. Fezes dos animais infectados foram submetidas à coprocultura para a obtenção de larvas e, após o abate das ovelhas, H. contortus adultos foram colhidos do abomaso e individualmente submetidos à extração de DNA. Para a avaliação de possíveis marcadores moleculares de isolamento geográfico, larvas oriundas de coprocultura de dois outros isolados brasileiros (Bahia e Pernambuco), com status de resistência não determinado, também foram submetidas à extração de DNA. Após amplificação por PCR do DNA extraído de H. contortus adultos, um fragmento do gene PgP foi sequenciado e foram identificados seis SNPs (posição descrita em relação à sequência do contig 004690 do Wellcome Trust Sanger Institute): 508 (A>G, em éxon), 580 (G>A), 601 (G>C), 800 (G>A), 845 (G>T) e 878 (G>T), os cinco últimos em íntrons. O teste exato de Fisher, por meio da correção de Bonferroni, revelou associação significativa (P<0,01) entre os SNPs 508, 580, 601, 845 e 878 e o estado de resistência a anti-helmínticos. Desses SNPs, o 601 e o 878 estão em desequilíbrio de ligação e formam os haplótipos CC, que está associado (P<0,05) à resistência, e GG, à suscetibilidade. Levando em consideração que em H. contortus há considerável diferenciação genética entre áreas continentais distintas, as frequências dos SNPs foram comparadas entre os isolados brasileiros e o isolado suscetível australiano e foi verificado que os SNPs 580 e 845 podem estar associados ao isolamento geográfico. Conclui-se que os SNPs 508, 601 e 878 no gene de glicoproteína-P podem ser marcadores moleculares para a resistência múltipla a anti-helmínticos, e os SNPs 580 e 845 candidatos a marcadores de isolamento geográfico em H. contortus. Nós desenvolvemos um software para Análise de Risco de Desenvolvimento de Resistência Parasitária a Anti- Helmínticos em Ovinos (SARA) que fornecerá informações que poderão orientar a utilização racional de anti-helmínticos. / Entre os parasitas de ovinos, Haemonchus contortus é o nematoide mais prevalente e patogênico em áreas tropicais, causando grandes perdas econômicas. As alterações no gene que codifica a glicoproteína-P de membrana (PgP) foram associadas com a resistência a múltiplas drogas. Assim, o objetivo deste estudo foi identificar polimorfismos de nucleotídeo único (SNPs) no gene PgP em H. contortus por comparação de dois isolados com diferentes status de resistência a anti-helmínticos. Para esse fim, uma ovelha foi infectada experimentalmente com o isolado suscetível (McMaster, Austrália) e outra ovelha com o isolado multirresistente (Embrapa2010, Brasil) de H. contortus. Fezes dos animais infectados foram submetidas à coprocultura para a obtenção de larvas e, após o abate das ovelhas, H. contortus adultos foram colhidos do abomaso e individualmente submetidos à extração de DNA. Para a avaliação de possíveis marcadores moleculares de isolamento geográfico, larvas oriundas de coprocultura de dois outros isolados brasileiros (Bahia e Pernambuco), com status de resistência não determinado, também foram submetidas à extração de DNA. Após amplificação por PCR do DNA extraído de H. contortus adultos, um fragmento do gene PgP foi sequenciado e foram identificados seis SNPs (posição descrita em relação à sequência do contig 004690 do Wellcome Trust Sanger Institute): 508 (A>G, em éxon), 580 (G>A), 601 (G>C), 800 (G>A), 845 (G>T) e 878 (G>T), os cinco últimos em íntrons. O teste exato de Fisher, por meio da correção de Bonferroni, revelou associação significativa (P<0,01) entre os SNPs 508, 580, 601, 845 e 878 e o estado de resistência a anti-helmínticos. Desses SNPs, o 601 e o 878 estão em desequilíbrio de ligação e formam os haplótipos CC, que está associado (P<0,05) à resistência, e GG, à suscetibilidade. Levando em consideração que em H. contortus há considerável diferenciação genética entre áreas continentais distintas, as frequências dos SNPs foram comparadas entre os isolados brasileiros e o isolado suscetível australiano e foi verificado que os SNPs 580 e 845 podem estar associados ao isolamento geográfico. Conclui-se que os SNPs 508, 601 e 878 no gene de glicoproteína-P podem ser marcadores moleculares para a resistência múltipla a anti-helmínticos, e os SNPs 580 e 845 candidatos a marcadores de isolamento geográfico em H. contortus. Nós desenvolvemos um software para Análise de Risco de Desenvolvimento de Resistência Parasitária a Anti- Helmínticos em Ovinos (SARA) que fornecerá informações que poderão orientar a utilização racional de anti-helmínticos.

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

Les lactones macrocycliques (LM) sont des anthelminthiques (AH) à effet paralysant très utilisés chez les animaux et les humains contre les nématodes parasites. Cependant, leur succès thérapeutique est compromis par la résistance croissante aux LM, qui pourrait être en partie dû aux ABC transporteurs P-glycoprotéines (Pgps) sélectionnés et surexprimés chez les nématodes résistants aux LM. Dans ce travail, nous avons étudié plus précisément la P-glycoprotéine 13 du parasite de petits ruminants, Haemonchus contortus. Son orthologue chez le modèle nématode C. elegans, Cel-Pgp-13, est exprimé dans les amphides, structures qui ont été associées à la sensibilité aux AH chez C. elegans et H. contortus. Pour prédire la capacité des Pgps de nematode à transporter des drogues, incluant des LM et autres AH, nous avons développé un modèle de docking in silico. Nous avons utilisé la structure cristallographique de C. elegans Pgp-1 (Cel-Pgp-1), et nous avons montré la liaison avec une forte affinité de plusieurs ligands décrits comme activateurs de sa fonction ATPasique. Nous avons aussi décrit une forte affinité des LM, et un site spécifique de liaison de ces composés à Cel-Pgp-1. Cette approche représente un outil important pour prédire les interactions entre AH, et pour concevoir rationnellement de nouveaux inhibiteurs compétitifs des Pgps de nématode, dans le but d'améliorer les stratégies thérapeutiques. Sur la base de cette approche, nous avons prédit la structure 3D de Hco-Pgp-13 à partir du cristal de Cel-Pgp-1 afin d'étudier son intéraction avec des substrats potentiels, en particulier les LM. Nous avons trouvé des affinités similaires pour différents composés précédemment testés sur Cel-Pgp-1. In vitro, la mesure de l'activité ATPasique montre que l'actinomycine D est un substrat de Hco-Pgp-13. Nos données démontrent la présence possible d'un domaine de reconnaissance multispécifique sur ce transporteur de parasite. La détermination par immunofluorescence de l'expression de Hco-Pgp-13 a montré une distribution tissulaire large indiquant que Hco-Pgp-13 pourrait jouer un role important dans le transport de substrats endogènes et/ou exogènes. En conclusion, ce travail permet de mieux comprendre le rôle des Pgps de nématodes dans le transport de médicaments AH, tant au niveau de l'organisme modèle C. elegans que du nématode parasite H. contortus. Cette étude suggère la conservation de la fonction de tranporteur ABC multidrogue dans ces espèces. La localisation de Hco-Pgp-13 sur les structures amphidiales, et son éventuelle implication dans la résistance aux médicaments et à la survie de H. contortus à l'exposition à des composés AH, restent à préciser. / Macrocyclic lactones (ML) are paralyzing anthelmintics used in animals and humans against parasite nematodes. However, their therapeutic success is compromised by the spread of ML resistance. This might be at least partly due to P-glycoproteins (Pgps) ABC transporters that are selected and overexpressed in ML-resistant nematodes. Deciphering the role of the 10 Pgps expressed in the parasite of small ruminants Haemonchus contortus is thus of major importance to guaranty anthelmintic (AH) efficacy of various drugs. Here we focused on Hco-Pgp-13 due to the expression in the amphids of its closest ortholog in the model nematode C. elegans. Indeed, the amphids represent a putative entry route of drugs to reach AH targets in the nervous system and have been linked to AH susceptibility in C. elegans and H. contortus. In order to predict the capacity of nematode Pgps to transport drugs, including ML and otherAH, we have developed an in silico drug docking model. We have used C. elegans Pgp-1 (Cel-Pgp-1) crystal structure and have showed a high affinity binding of several ligands that have been shown to be activators of its ATPase function. ML were also found to bind with high affinity to Cel-Pgp-1, on a specific binding site. This approach provides a valuable tool to predict drug-drug interactions and to rationally design new competitive inhibitors of nematode Pgps, in order to improve anthelmintic therapeutics. We then predicted a putative 3D structure of Hco-Pgp-13 based on the recently released crystal of Cel-Pgp-1, with which it presented a high homology. This allowed the study of the interaction of Hco-Pgp-13 with potential substrates, in particular ML. We found similar affinities for various drugs previously tested on Cel-Pgp-1, supporting the good homology of these two proteins. Together with in vitro ATPase assay experiments that confirmed the substrate status of actinomycin D, this indicates a possible multispecifc recognition capacity of this parasitic transporter. The determination of Hco-Pgp-13 localization using immunohistochemistry showed a wide tissue expression consistent with a critical role for Hco-Pgp-13 in endogenous and/or exogenous substrate transport. In conclusion, this work provides insights into the role of nematode Pgps in transporting AH drugs, both at the level of the model organism C. elegans and of the parasitic nematode H. contortus. This suggests a high homology of function conserved between ABC tranporters in these species. The localization of such protein on amphidial structures and its possible involvement in drug resistance and survival of H. contortus to exposure to AH compounds remain to be precised.