• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 36
  • 2
  • 1
  • 1
  • Tagged with
  • 40
  • 40
  • 8
  • 8
  • 8
  • 8
  • 7
  • 7
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Investiga??es preliminares sobre a sesibilidade parasit?ria de duas ra?as de coelhos a Rhipicephalus sanguineus (Latreille, 1806) (Acari:Ixodidae) / Preliminary Investigations on Parasitic Sensitivity of Two Breeds of Rabbits to Rhipicephalus sanguineus (Latreille,1806) (Acari: Ixodidae).

Pinto, Fl?via Santos 28 February 2000 (has links)
Made available in DSpace on 2016-04-28T20:15:28Z (GMT). No. of bitstreams: 1 2000- Flavia Santos Pinto.pdf: 229877 bytes, checksum: 5ac9dc34947f0f90f514886c5e4e15e0 (MD5) Previous issue date: 2000-02-28 / The natural sensitivity of two breeds of rabbit, White New Zealand (WNZ) e California (CA), and their crossbreeds (CB) to Rhipicephalus sanguineus were compared under experimental conditions. Three rabbits of each breed, without previously tick exposure, were infested once with 2300 larvae, 100 nymphs and 40 adults (20 males + 20 females). The experiment with the parasitic phase was conducted in the environment while the free-living phase was conducted under 27 ? 1? C, 80 ? 10 % relative humidity and scotophase. The dynamic of the sensitivity had in the larvae phase a variation statistically significant (p<0.05) in the pr?ecdise period, with the best performance in the CB group. However, the percentage of recovery was greater in the treatment of WNZ. In the adult phase, females of the WNZ group presented a greater mean weight (p<0.0) e did not differ from the Nutritional Efficiency Index(NEI) from CB, which had the best performance. For larvae of the females in the three treatments the only statistic variation (p<0.05) was with the period hatching, where the CA group presented the smallest period, the CB group presented the greatest and the WNZ group did not change statistically in the both. The life cycle in all three groups was very close, without great differences according to the treatment received. / A sensibilidade natural a Rhipicephalus sanguineus de duas ra?as de coelhos, Nova Zel?ndia e Calif?rnia, e seus mesti?os foi comparada em condi??es experimentais. Tr?s coelhos de cada ra?a, sem contato pr?vio com carrapatos, foram infestados uma ?nica vez com 2300 larvas, 100 ninfas e 40 adultos (20 machos + 20 f?meas). O experimento com a fase parasit?ria foi conduzido no meio ambiente enquanto que o da fase de vida livre foi conduzido a 27 ? 1? C, 80 ? 10 % de umidade relativa e escotofase. A din?mica da sensibilidade obteve na fase larval uma varia??o estatisticamente significativa ( p< 0,05) no per?odo de pr?-ecdise com melhor desempenho no grupo Mesti?o, por?m o percentual de recupera??o foi maior no tratamento Nova Zel?ndia. N?o houve diferen?a estatisticamente significativa (p> 0,05) na fase de ninfas, onde o grupo de melhor desempenho foi o Calif?rnia. Na fase adulta , as f?meas do grupo Nova Zel?ndia apresentaram maior peso m?dio(p<0,05) e n?o diferiram para o ?ndice de Efici?ncia Nutricional do tratamento Mesti?o, o qual teve melhor desempenho. Para larvas oriundas das f?meas que passaram pelos tr?s tratamentos a ?nica varia??o estat?stica (p<0,05) foi com o per?odo de eclos?o, onde o grupo Calif?rnia apresentou menor per?odo, o grupo Mesti?o o maior e Nova Zel?ndia n?o variou estatisticamente destes dois. O ciclo biol?gico nos tr?s grupos foi muito pr?ximo, sem grandes diferen?as de acordo com o tratamento recebido.
32

Estudo da variabilidade genot?pica de Rhipicephalus sanguineus (Latreille, 1806) (Acari, Ixodidae) de diferentes regi?es geogr?ficas do Brasil / Genotipic variability study of Rhipicephalus sanguineus (Latreille, 1806) (Acari, Ixodidae) from different geografic regions of Brazil.

Soares, Leonardo Burlini 28 February 2008 (has links)
Made available in DSpace on 2016-04-28T20:15:28Z (GMT). No. of bitstreams: 1 2008- Leonardo Burlini Soares.pdf: 1364725 bytes, checksum: a5a09ed4e869fe7e3a75342f6f3f7d8a (MD5) Previous issue date: 2008-02-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The taxonomic status of ticks of the Rhipicephalus sanguineus group is difficult to be determined by phenotypic methods and has been object of frequent revisions and ongoing debate. The differentiation of species within this group has clinical importance, especially in veterinary medicine due to transmission of different pathogens. The objective of this study was to evaluate de genetic variability of Rhipicephalus sanguineus from different geografic regions of Brazil and fill in some gaps in the species study. This work was conducted in the laboratories of: Ixodology of the W. O. Neitz station for parasitologic research, Molecular Biology and Acarology, of the Departamento de Parasitologia Animal, Instituto de Veterin?ria, da Universidade Federal Rural do Rio de Janeiro; and in the laboratories of: Genetic and Biochemistry, and Genome of EMBRAPA Agrobiologia (RJ). Mitochondrial DNA (mt-DNA) fragments of R sanguineus from Esp?rito Santo (ES), Goi?s (GO), Par? (PA), Rond?nia (RO), Mato Grosso do Sul (MS), Rio de Janeiro (RJ) e Rio Grande do Norte (RN) were compared. The results showed that fasting larvae, preserved in ethanol, from the different localities presented genotipic variability considering the 12S and 16S mt-rDNA genes. To 12S, the Esp?rito Santo strain presented the highest genetic diversity in comparison with the other brazilian strains; to 16S, the distinction can be given to the Rio de Janeiro strain, which presented the highest divergence values in regarding the other strains. The intraspecific variability detected between the isolates ranged from 0 to 6.6% regarding the 12S gene and from 0 to 2.7% regarding the 16S. On the other hand, a strong genetic relationship was detected between brazilian isolates and asian R. sanguineus (0-5.8% of variability for 12S, and 0-1.3% for 16S) and between the brazilian strains and african Rhipicephalus turanicus (2.2-7.6% of difference to 12S) while R. sanguineus populations from Argentina and Uruguai appeared to be related to French R. sanguineus (identic 12S sequences); considering 16S, R. sanguineus from Israel presented moderate distance from the brazilian isolates (3.6-5.8%). These results showed that the differences between these brazilian isolates are great and to a certain extent greater than should be expected between some of them, and that the systematic of R. sanguineus ticks from Latin America as much as of countries of other continents should be better and more studied. Wide variations, such as these might account for the reported worldwide differences in several biological parameters in this species. / O posicionamento taxon?mico de carrapatos do grupo Rhipicephalus sanguineus ? de dif?cil determina??o por m?todos fenot?picos e tem sido objeto de freq?entes revis?es e debates cont?nuos. A diferencia??o das esp?cies dentro desse grupo ? de import?ncia cl?nica, especialmente em medicina veterin?ria, devido a transmiss?o de diferentes pat?genos. O estudo teve como objetivo avaliar a variabilidade gen?tica de Rhipicephalus sanguineus provenientes de diferentes regi?es geogr?ficas do Brasil e preencher algumas lacunas no estudo da esp?cie. Este trabalho foi realizado nos laborat?rios de: Ixodologia da Esta??o para Pesquisas Parasitol?gicas W. O. Neitz, Biologia Molecular e Acarologia, pertencentes ao Departamento de Parasitologia Animal, Instituto de Veterin?ria, da Universidade Federal Rural do Rio de Janeiro; e nos laborat?rios de: Gen?tica e Bioqu?mica, e Genoma da EMBRAPA Agrobiologia (RJ). Foram comparados fragmentos de DNA mitocondrial (DNA-mt) de R sanguineus do Esp?rito Santo (ES), Goi?s (GO), Par? (PA), Rond?nia (RO), Mato Grosso do Sul (MS), Rio de Janeiro (RJ) e Rio Grande do Norte (RN). Os resultados mostram que larvas em jejum, preservadas em etanol, das diferentes localidades apresentaram variabilidade genot?pica considerando-se os genes 12S e 16S DNAr-mt. Para o gene 12S DNAr-mt, a amostra do Esp?rito Santo apresentou a maior diversidade gen?tica em compara??o ?s demais amostras brasileiras; j? para o gene 16S DNAr-mt, o destaque pode ser dado ? amostra do Rio de Janeiro, que apresentou os maiores valores de diverg?ncia em rela??o ?s demais seq??ncias. A variabilidade intraespec?fica detectada entre os isolados variou de 0 a 6,6% em rela??o ao gene 12S DNAr-mt e de 0 a 2,7% em rela??o ao 16S DNArmt. Por outro lado, uma forte rela??o gen?tica foi detectada entre os isolados brasileiros e R. sanguineus asi?ticos (0-5,8% de variabilidade para 12S, e 0-1,3% para 16S DNAr-mt) e entre as amostras brasileiras e Rhipicephalus turanicus africanos (2,2-7,6% de diferen?a para 12S) enquanto popula??es de R. sanguineus da Argentina e Uruguai se relacionaram com R. sanguineus da Fran?a (seq??ncias de 12S id?nticas); no tocante ao 16S, R. sanguineus de Israel apresentou moderada dist?ncia dos isolados brasileiros (3,6-5,8%). Esses resultados mostraram que as diferen?as entre esses isolados brasileiros s?o grandes e at? mesmo maiores do que poderia se esperar entre alguns deles, e que a sistem?tica de carrapatos R. sanguineus, tanto da Am?rica Latina quanto de pa?ses de outros continentes deve ser melhor e mais estudada. Amplas varia??es como estas podem justificar as diferen?as mundiais relatadas para diversos par?metros biol?gicos nessa esp?cie.
33

Carrapatos coletados em aves em uma ?rea de Cerrado, munic?pio de Tr?s Marias, Estado de Minas Gerais, Brasil / Ticks collected on birds in an area of Cerrado, Tr?s Marias, Minas Gerais, Brazil.

Luz, Hermes Ribeiro 09 February 2012 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-05-03T17:33:38Z No. of bitstreams: 1 2012 - Hermes Ribeiro Luz.pdf: 2629217 bytes, checksum: 8e75ef38df8d873d63a0480f410610a8 (MD5) / Made available in DSpace on 2017-05-03T17:33:38Z (GMT). No. of bitstreams: 1 2012 - Hermes Ribeiro Luz.pdf: 2629217 bytes, checksum: 8e75ef38df8d873d63a0480f410610a8 (MD5) Previous issue date: 2012-02-09 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / This study analyzes the prevalence and mean intensity of infestation of ticks on birds captured in ESEC-Pirapitinga (180 20?S e 450 17?WGr), in Tr?s Marias, Minas Gerais, Brazil. Of a total of 1.295 birds captured, distributed in nine orders, 28 families and 92 species, 165 (12.7%) individuals were parasitized by ticks. Of these 160 (97%) belonged to the order Passeriformes and only 5 (3%) belonged to the grouping of non-passerines. We identified five tick species: Amblyomma longirostre (n = 274) was the most common species followed by Amblyomma parvum (n = 43), Amblyomma nodosum (n = 39), Amblyomma ovale (n = 24) and Rhipicephalus sanguineus (n = 7). The average infestation was 2.7 ticks by bird. Only 16 (10%) birds were infected with more than 5 ticks, while 97 (58.8%), birds were infected with a single tick. Also present in this study, some new records of A. longirostre. A. parvum, A. nodosum, A. ovale and R. sanguineus parasitizing birdscn / No presente estudo analisamos a preval?ncia e intensidade m?dia de infesta??o de carrapatos em aves capturadas na ESEC-Pirapitinga (180 20?S e 450 17?WGr), no munic?pio de Tr?s Marias, Minas Gerais, Brasil. De um total de 1295 aves capturadas, distribu?das em 9 ordens, 28 fam?lias e 92 esp?cies, 165 (12,7%) indiv?duos estavam parasitados por carrapatos. Destes 160 (97%) pertencia a ordem Passeriformes e apenas 5 (3%) pertenciam ao grupamento dos n?o passeriformes. Foram identificadas 5 esp?cies de carrapatos: Amblyomma longirostre (n= 273) foi a esp?cie mais comum seguida por Amblyomma parvum (n=43), Amablyomma nodosum (n=39), Amblyomma ovale (n=24) e Rhipicephalus sanguineus (n=7). A infesta??o m?dia foi de 2,7 carrapatos por ave. Somente 16 (10%) aves estavam infestadas por mais que 5 carrapatos, enquanto que 97(58,8%), aves estavam infestadas por um ?nico carrapato. Tamb?m apresentamos, neste estudo, alguns registros novos de A. longirostre. A. parvum, A. nodosum, A. ovale e R. sanguineus parasitando diferentes esp?cies de aves
34

Aspectos da biologia de Amblyomma cajennense (Fabricius, 1787) e Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae), em condi??es experimentais. / Aspects of the biology of Amblyomma cajennense (Fabricius, 1787) and Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae), em condi??es experimentais.

Ribeiro, Armando de Lemos 16 December 1997 (has links)
Made available in DSpace on 2016-04-28T20:16:32Z (GMT). No. of bitstreams: 1 1997 - Armando de Lemos Ribeiro.pdf: 1637429 bytes, checksum: 67368e92ac3e601a127f511f61aef35b (MD5) Previous issue date: 1997-12-16 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The first experiment was set up to measure the drop-off rhythm of larvae and nymphs of Amblyomma cajennense feeding on the rabbits as experimental hosts. Infestations were carried out with unfed larvae and nymphs aging 15 and 45 days post eclosion and host larval moulting, respectively. Three rabbits were infested with approximately 825 larvae (50 mg of eggs) and 100 nymphs for each age totaling 12 rabbits. Each host were examined at 8, 12, 16 and 24 hours and the dropped larvae and nymphs collected. Regardless of age and instar higher drop-off rhythm were observed from 8 to 16 hours: 73,6 and 72,8% larvae with 15 and 45 days post eclosion and 69,6 and 57,5 nymphs with 15 and 45 days post larval moulting, respectively. The second experiment was set up to evaluate the effect of age on the attachment of larvae and nymphs of Amblyomma cajennense using the rabbit as experimental host. Infestations were carried out with unfed larvae aging from 0-4 to 150 days post-eclosion and unfed nymphs aging from 0-2 to 165 days post-larval moulting. A total of 11 and 12 infestations respectively for larvae and nymphs with 15 days interval were monitored. Three rabbits were infested with 825 larvae and 100 nymphs per rabbit at each interval. Larvae and nymphs with 0-2 day post-eclosion and post larval moulting were able to attach and feed at rates of 45 and 77%. Higher attachment rates for larva (> 70%) were observed from days 15 to 60 post eclosion. Then, start to decrease until 25% at 150 days post-eclosion. Higher attachment rates for nymphs were observed from days 15 to 90 post moulting (> 80%). Then, start to decrease until 36% at 165 days. The periods of attachment and ecdisis, and the percentage of ecdisis were similar for both stages regardless the age prior attachment. When the period of pre-ecdisis is analyzed one might note a shortening as the nymphs because older whereas it was similar for larvae in ali evaluated ages. This third experiment was conduct as an attempt to correlate the weight pre-ecdisis period and timing of drop-off of nymphs with the forecast of the sexes in adults of Rhipicephalus sanguineus. The mean weight of nymphs that moulted to males (n = 96) was 1,97 ? 0,97 and 2,52 ? 0,90 to females (n = 103) (P > 0,05) between the weight of nymphs can not be used to forecast the sexes due to overlapping of to weight ranges. The pre-ecdisis periods were 15,13 ? 0,94 and 14,60 ? 0,77 days for nymphs that moulted to males (n = 96) and females (n = 103) (P > 0,05) respectively. Nymphs (n = 50) that dropped-off on both third and fourth day (mode) post-infestation moulted to 29 females and 21 males whereas those (n = 50) that dropped-off on the fifth day post-infestation moulted to 30 females and 20 males (x2 > 0,05). Although there are numerical differences in ali evaluated parameters none can be used to forecast the sexes in R. sanguineus due to an extensive overlapping. / O primeiro experimento foi montado para avaliar o ritmo de queda de larvas e ninfas de Amblyomma cajennense alimentadas em coelhos. Infesta??es foram feitas com larvas e ninfas em jejum com idades de 15 e 45 dias ap?s eclos?o e ecdise larval respectivamente. Tr?s coelhos foram infestados com aproximadamente 825 larvas (50 mg de ovos) e 100 ninfas para cada idade totalizando 12 coelhos. Cada hospedeiro foi examinado nos hor?rios de 8, 12, 16 e 24 horas e as larvas e ninfas desprendidas foram coletadas. Independente da idade e do instar, o maior n?mero se desprendeu entre 8 e 16 horas: 73,6% e 72,8% para larvas com 15 e 45 dias ap?s eclos?o e 69,6% e 57,5% para ninfa. Com 15 e 45 dias ap?s ecdise larval, respectivamente. O segundo experimento teve como objetivo avaliar o efeito da idade sobre a fixa??o de larvas e ninfas de Amblyomma cajennense, usando o coelho como hospedeiro. Infesta??es foram feitas com larvas com per?odos de jejum de zero a 4 at? 150 dias ap?s eclos?o e ninfas em jejum variando de zero a 2 at? 165 dias ap?s ecdise larval. Um total de 11 e 12 infesta??es para larvas e ninfas respectivamente, com intervalos de 15 dias foram acompanhados. Tr?s coelhos foram infestados com 825 larvas e 100 ninfas por coelhos e para cada tratamento. Larvas e ninfas com zero a 4 dias ap?s eclos?o e zero a 2 dias ap?s ecdise larval se fixaram e se alimentaram, com taxas de recupera??o de 45 e 77% respectivamente. Taxas de recupera??o alta para larvas (> 70%) foi observado para 15 at? 60 dias ap?s eclos?o. Entretanto a partir da? come?ou a decrescer para 25% at? 150 dias p?s-eclos?o. As taxas de recupera??o foram altas para ninfas com 15 at? 90 dias p?s-ecdise (> 80%). Ent?o, come?ou a decrescer para 36% at? 165 dias. Os per?odos de pr?-ecdise, de ecdise e as percentagens de ecdise foram est?veis para todas as idades estudadas. Quando o per?odo de pr?-ecdise ? analisado nota-se um encurtamento conforme as ninfas se tornam mais velhas; ao contr?rio este per?odo foi similar para larvas de todas as idades. Esse terceiro experimento foi conduzido para se observar a correla??o entre o peso, o per?odo de pr?-ecdise e o per?odo de queda de ninfas ingurgitadas com a previs?o do sexo dos adultos de Rhipicephalus sanguineus. A m?dia do peso de ninfas que originaram machos (n = 96) foi de 1,97 ? 0,97 e 2,52 ? 0,90 para f?meas (n = 103) (P > 0,05). O peso das ninfas n?o pode ser usado para a previs?o dos sexos devido ? superposi??o dos pesos. O per?odo de pr?-ecdise foi de 15,13 ? 0,94 e 14,60 ? 0,77 dias par ninfas que originaram machos (n = 96) e f?meas (n = 103) (P > 0,05), respectivamente. Ninfas (n = 50), dos per?odos de queda, inicial (3? dia) e modal (4? dia), desprenderam-se 29 f?meas e 21 machos, em ambos per?odos. No per?odo final (5? dia) (n = 50) desprenderam-se 30 f?meas e 20 machos (x2 > 0,05). Embora exista diferen?as num?ricas em todos os par?metros avaliados, tais par?metros n?o podem ser utilizados para a previs?o dos sexos em R. sanguineus devido a amplitude da superposi??o.
35

Levantamento epidemiol?gico de carrapatos em c?es assistidos em duas unidades privadas de servi?o de sa?de animal na Zona Oeste da cidade do Rio de Janeiro / Epidemiological investigation of ixodid ticks on dogs assisted in two private animal health services in the West Zone of city Rio de Janeiro

Silva, Silvio Rodrigues 29 July 2016 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-10-19T10:50:10Z No. of bitstreams: 1 2016 - Silvio Rodrigues da Silva.pdf: 1225497 bytes, checksum: d2f9db78af36de26e8b7a7201b2e6407 (MD5) / Made available in DSpace on 2017-10-19T10:50:10Z (GMT). No. of bitstreams: 1 2016 - Silvio Rodrigues da Silva.pdf: 1225497 bytes, checksum: d2f9db78af36de26e8b7a7201b2e6407 (MD5) Previous issue date: 2016-07-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / It evaluated the prevalence and potential risk factors for the occurrence of ticks in dogs from January 2000 to December 2014 in two private veterinary clinics, located in the West Zone of Rio de Janeiro state, Brazil. Fifteen hundred records were systematically sampled from an unknown population. Fifteen hundred records were systematically sampled from an unknown population. Statistical analysis was performed considering the outcome variable, tick presence (group 1) and positive tick + negative tick / positive hemoparasite (group 2) and the explanatory variables, sex, age, race, size, neighborhood, and clinic. An exploratory analysis was made to verify the distribution of the prevalence of ticks and their range of 95% confidence, considering all the explanatory variables for the presence of ticks. Differences in the prevalence also were testing by reason proportions test. Bivariate and multivariate analysis by logistic regression models were using to verify the relationship of the outcome of interest and their potential risk factors through the prevalence ratio (PR). The adopted modeling strategy was based on the bivariate analysis. After then, variables were selected to be included in the multivariate model. Akaike Information Criterion (AIC) were estimated to indicated the most parsimonious multivariate model. All statistical analysis was performed in the statistical package R. Of all the 1,500 records of dogs in 264 (17.60% [95% CI: 15.67, 19.52]) had the infestation by ticks in group 1 and 372 (24.80% [95% CI: 22 61, 26.98]) in group 2. Sex and age were not considered risk factors. There were differences in parasitism between races within groups 1 and 2. Males Cocker Spaniel, medium-sized and Bangu were the variables with the highest prevalence in both groups. German Shepherd race does not configured risk factor for ticks, confirmed by the most parsimonious model (PR = 1.77 [95% CI: 0.44, 07.10]). The Cocker Spaniels as well as animals living in Bangu had 7.5 [95% CI: 3.01, 18.53] and 1.7 [95% CI: 1.20, 2.32] times, respectively, more chance to be parasitized by ticks. The prevalence of hemoparasite transmitted by ticks should be considered as supplementary data for ticks epidemiological studies in dogs. This is the first study to rank the dog breeds in relation to the prevalence of parasitism by ticks. / Foi avaliada a preval?ncia e os potenciais fatores de risco para a ocorr?ncia de carrapatos em c?es no per?odo de janeiro de 2000 ? dezembro de 2014 em duas cl?nicas veterin?rias particulares, localizadas na zona oeste do Rio de Janeiro, Brasil. Mil e quinhentos prontu?rios foram amostrados sistematicamente de uma popula??o desconhecida. A an?lise estat?stica foi realizada considerando as vari?veis desfecho, presen?a de carrapato (grupo 1) e carrapato positivo + carrapato negativo/ hemoparasito positivo (grupo 2) e as vari?veis explicativas, sexo, idade, ra?a, porte, bairro e cl?nica. Para verificar a exist?ncia de fatores de risco, foram utilizadas desde testes de infer?ncia de Qui-Quadrado (??) at? o ajuste de modelos de regress?o log?sticas. Dos 1500 prontu?rios em 264 (17,60% [IC95%: 15,67; 19,52]) haviam registro de infesta??o por carrapatos no grupo 1 e 372 (24,80% [IC95%: 22,61; 26,98]) no grupo 2. As vari?veis sexo e idade, em ambos os grupos n?o foram consideradas potenciais fatores de risco. Houve diferen?a no parasitismo entre as ra?as dentro dos grupos 1 e 2. Machos de Cocker Spaniel Ingl?s, porte m?dio e Bangu foram as vari?veis com maiores preval?ncias de registros em ambos os grupos. Pastor Alem?o foi a ?nica ra?a que n?o configurou como potencial fator de risco para a presen?a de carrapato. No modelo mais parcimonioso apenas a ra?a Pastor Alem?o (RP=1,77 [IC95%:0,44; 07,10]) n?o se apresentou como potencial fator de risco. A ra?a Cocker Spaniel assim como animais que residem no bairro Bangu apresentaram 7,5 [IC95%:3,01;18,53] e 1,7 [IC95%:1,20; 2,32] vezes, mais chances de serem parasitados por carrapatos respectivamente. A preval?ncia de hemoparasitoses transmitidas por carrapatos deve ser considerada como dados complementares para estudos epidemiol?gicos de carrapatos em c?es. Esse ? o primeiro estudo a ranquear ra?as de c?es quanto ? preval?ncia de parasitismo por carrapatos.
36

Modulação da resposta imune pela saliva de carrapatos Rhipicephalus sanguineus: estudo do envolvimento de células T regulatórias / Immunemodulation by Rhipicephalus sanguineus tick saliva: study of regulatory T cell involvment

Daniela Dantas Moré 22 May 2006 (has links)
Carrapatos são artrópodes hematófagos de distribuição cosmopolita que têm grande importância médica e veterinária devido ao efeito deletério direto causado por se fixarem e sugarem seus hospedeiros, como também por serem importantes vetores de doenças para o homem e para os animais domésticos. Sabendo que carrapatos permanecem fixos em seus hospedeiros por longos períodos de tempo sem serem rejeitados, é possível inferir que esses ácaros possuam um arsenal de mecanismos que atuem no controle da resposta imune do hospedeiro. De fato, diversos trabalhos têm demonstrado que carrapatos são capazes de modular a resposta imune de seus hospedeiros através de componentes presentes na saliva, que são inoculados durante o repasto sangüíneo. Assim, este trabalho procurou investigar se carrapatos exercem a modulação da resposta imune do hospedeiro através do recrutamento de células T regulatórias CD4+CD25+ (Tregs), com a intenção de conter uma resposta inflamatória / imune prejudicial à sua alimentação. Para isso, células isoladas de amostras de pele e linfonodos de camundongos BALB/c infestados com carrapatos Rhipicephalus sanguineus foram analisadas quanto à expressão das moléculas de superfície CD4, CD25, CTLA-4, CD45RB, GITR e CD103 (fenótipo de células Tregs), por citometria de fluxo. Adicionalmente, as células obtidas dos linfonodos foram avaliadas quanto à expressão de mensagem para o fator de transcrição Foxp3 (característico da função regulatória), por PCR quantitativo. Paralelamente, saliva de R. sanguineus foi inoculada na orelha de animais da mesma linhagem, a fim de se comparar o infiltrado celular com o obtido na pele dos camundongos infestados com carrapatos. Os resultados mostraram que as infestações não alteraram a percentagem de células T CD4+CD25+ nem a expressão de moléculas associadas ao fenótipo de células Tregs nas células infiltradas na lesão de fixação dos carrapatos ou nos linfonodos em comparação a camundongos controles. Também não se verificou aumento da expressão do gene para Foxp3 nos linfonodos em nenhum dos grupos analisados. Por outro lado, a inoculação de saliva na orelha de camundongos induziu um aumento significativo da população de células T CD4+, porém estas também não apresentavam fenótipo regulatório, sugerindo que o mecanismo de imunomodulação exercido pelos carrapatos sobre seus hospedeiros não é mediado por essas células. Resultados adicionais mostraram que a saliva de carrapatos reduziu significativamente a percentagem de células dendríticas nas orelhas dos camundongos, sugerindo que carrapatos podem estar modulando a resposta imune de seus hospedeiros por diminuírem o repovoamento da pele com células dendríticas, as quais são essenciais na vigilância imune dos tecidos periféricos. / Ticks are bloodsucking arthropods that feed on vertebrates and are responsible for serious global economic losses both through the effects of blood sucking and as vectors of pathogens. A tick?s bloodmeal lasts for several days, during which it remains fixed to the host and avoids rejection by local inflammatory and immunological reactions. This status is achieved by the escape mechanisms ticks have evolved. In fact, many studies have demonstrated that ticks modulate the host immune response through salivary compounds inoculated during their bloodmeals. This study investigated if during bloodfeeding ticks can recruit regulatory T cells in an attempt to modulate the host immune response and to control inflammatory responses that could be harmful to tick feeding. BALB/c mice were infested with Rhipicephalus sanguineus, the skin at feeding sites and the regional lymph nodes were collected, and the cells forming the local infiltrates were analyzed by flow cytometry for simultaneous expression of CD4, CD25, CTLA-4, CD45RB, GITR and CD103 molecules. Additionally, expression of mRNA for Foxp3 was measured in the lymph node cells. Tick saliva was also inoculated into the ears of BALB/c mice in order to compare the local cellular infiltrate with that elicited by artificial infestation. Control animals were sham infested. The results show that, relative to sham-infested tissues, tick infestations did not alter the percentage of CD4+CD25+ T cells present at the site of their attachment or in draining lymph nodes. Infestations also did not increase the expression of Foxp3 in skin and lymph nodes. On the other hand, saliva inoculated into the ear induced a significant increase in the number of CD4+ T lymphocytes recruited to the site of inoculation, although these cells did not express a regulatory phenotype. These results suggest that the modulation of the host immune response by ticks does not involve CD4+CD25+ T cells. Additional results showed that tick saliva reduced the percentage of dendritic cells in the skin of infested mice. This finding indicates that ticks may modulate the host immune response by diminishing the repopulation of skin with dendritic cells, which are essential for maintaining surveillance of peripheral tissues for incoming antigens.
37

Detec??o de Anaplasma platys em c?es e em carrapatos: padroniza??ode qPCR e an?lise epidemiol?gica no Estado do Rio de Janeiro, Brasil e na regi?o ocidental de Cuba / Detection of Anaplasma platys in dogs and ticks: standardization of qPCR and epidemiological analysis in the State of Rio de Janeiro, Brazil and in western Cuba

Silva, Claudia Bezerra da 11 March 2016 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-10-19T13:49:16Z No. of bitstreams: 1 2016 - Claudia Bezerra da Silva.pdf: 8032175 bytes, checksum: ef71dd2a0e7801e9000e116c822a3a00 (MD5) / Made available in DSpace on 2017-10-19T13:49:16Z (GMT). No. of bitstreams: 1 2016 - Claudia Bezerra da Silva.pdf: 8032175 bytes, checksum: ef71dd2a0e7801e9000e116c822a3a00 (MD5) Previous issue date: 2016-03-11 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / and investigate the circulation of this agent in dogs in the Itaguai microregion, Rio de Janeiro, Brazil, and dogs and ticks in two provinces of the island of Cuba, analyzing epidemiological aspects associated with infections caused by this bacterium in dogs. A new real-time polymerase chain reaction method (qPCR) was patterned to target the citrate synthase gene (gltA) for the identification of A. platys in naturally infected dogs. The primers and probe were designed to amplify a fragment of 84 base pairs based on gltA gene sequences of A. platys available in GenBank. 186 blood samples of dogs from Itaguai microregion, Rio de Janeiro, Brazil, were tested by qPCR. The same samples were tested by cytology and nested polymerase chain reaction (nPCR, 16S rDNA) to determine the performance of qPCR front of these techniques. 17.20% of the samples tested positive by qPCR were significantly more than that detected by nPCR (13.98%). The qPCR technique was more specific than cytology, due to false-positive results obtained by optical microscopy. The prevalence of A. platys in dogs from Itaguai microregion was 14.4%. Dogs less than six months, infested by ticks, that spend the most of the time restrict to domestic environment and without shelter are factors associated with infection by this hemoparasite in dogs in the study area. During research, A. platys held in Cuba, 100 blood samples were collected from residents dogs in four cities located in the provinces of Havana and Mayabeque. When inspecting the animals, found ticks were collected, identified and carefully grouped, forming a total of 49 pools. DNA extracted from blood samples from dogs and ticks were subjected nPCR (16S rDNA). Positive samples in nPCR were also subjected to conventional PCR (gltA gene), and the products were sequenced. Only the species Rhipicephalus sanguineus sensu lato was found in Cuban dogs and 10.2% (n=5/49) of these ticks added to 16.0% (n=16/100) dogs were considered positive for A. platys. All sequences analyzed of the gltA and 16S rDNA genes, respectively, showed a 99-100% identity with sequences from A. platys reported in other countries. Phylogenetic analysis showed two clusters defined for the 16S rDNA gene and three clusters defined for the gltA gene. Based on the gltA gene, the deduced amino acid sequence showed two points of non-synonymous mutations at positions 88 and 168 compared to the reference sequence DQ525687. A preliminary study on the epidemiological aspects associated with infection with A. platys showed no statistical association with the variables studied (p> 0.05). This study also to report the first evidence of A. platys in both dogs and ticks in Cuba also presents for the first time the development of a new qPCR method that contributes to the advancement of research involving A. platys. The epidemiological study in Brazil allowed us to identify significant factors in the occurrence of canine anaplasmosis, while in Cuba, it can be concluded that more research is needed to assess what the deciding factors in the transmission and spread of A. platys in that country. / platys, e investigar a circula??o deste agente em c?es na microrregi?o de Itagua?, Rio de Janeiro, Brasil, e c?es e carrapatos em duas prov?ncias da ilha de Cuba, analisando aspectos epidemiol?gicos associados ? infec??o causada por esta bact?ria em c?es. Um novo m?todo de rea??o em cadeia da polimerase em tempo real (qPCR) foi padronizado com alvo no gene citrato sintase (gltA) para a identifica??o de A. platys em c?es naturalmente infectados. Os oligoiniciadores e a sonda foram desenhados para amplificar um fragmento de 84 pares de base baseado em sequ?ncias do gene gltA de A. platys dispon?veis no GenBank. 186 amostras de sangue de c?es da microrregi?o de Itagua?, Rio de Janeiro, Brasil, foram testados pela qPCR. As mesmas amostras foram testadas pela citologia e rea??o em cadeia da polimerase nested (nPCR, 16S rDNA) para determinar o desempenho da qPCR frente ? essas t?cnicas. 17,20% das amostras testadas pela qPCR foram positivas, significativamente mais do que detectado pela nPCR (13,98%). A t?cnica de qPCR foi mais espec?fica que a citologia, em virtude dos resultados falsopositivos obtidos pela microscopia ?ptica. A preval?ncia de A. platys em c?es da microrregi?o de Itagua? foi de 14,4%. C?es com menos de seis meses, infestados por carrapatos, que possam maior tempo restrito ao ambiente dom?stico e sem abrigo s?o fatores associados a infec??o por este hemoparasito em c?es na regi?o do estudo. Durante investiga??o de A. platys realizada em Cuba, 100 amostras de sangue foram coletadas de c?es residentes em quatro cidades localizadas nas prov?ncias de Habana e Mayabeque. Ao inspecionar os animais, carrapatos encontrados foram coletados, identificados e criteriosamente agrupados, formando um total de 49 pools. Amostras de DNA extra?das do sangue dos c?es e de carrapatos foram submetidas a nPCR (16S rDNA). Amostras positivas na nPCR foram tamb?m submetidas a PCR convencional (gene gltA), e os produtos foram sequenciados. Somente a esp?cie Rhipicephalus sanguineus sensu lato foi encontrada em c?es cubanos, e 10,2% (n=5/49) desses carrapatos somado aos 16,0% (n=16/100) de c?es foram considerados positivos para A. platys. Todas as sequ?ncias analisadas dos genes gltA e 16S rDNA, respectivamente, mostraram uma identidade de 99-100% com sequ?ncias de A. platys reportadas em outros pa?ses. A an?lise filogen?tica mostrou dois clusters definidos para o gene 16S rDNA e tr?s clusters definidos para o gene gltA. Com base no gene gltA, a sequ?ncia de amino?cidos deduzidos demonstrou dois pontos de muta??es n?o-sin?nimas nas posi??es 88 e 168 comparados com sequ?ncia de refer?ncia DQ525687. Um estudo preliminar sobre os aspectos epidemiol?gicos associados com a infec??o por A. platys demonstrou nenhuma associa??o estat?stica com as vari?veis avaliadas (p > 0,05). O presente estudo al?m de relatar a primeira evid?ncia de A. platys em ambos c?es e carrapatos em Cuba, tamb?m apresenta pela primeira vez o desenvolvimento de um novo m?todo de qPCR que contribui para o avan?o da pesquisa envolvendo A. platys. O estudo epidemiol?gico realizado no Brasil permitiu identificar fatores importantes na ocorr?ncia da anaplasmose canina, enquanto em Cuba, pode-se concluir que mais investiga??es s?o necess?rias para avaliar quais os fatores decisivos na transmiss?o e dispers?o de A. platys nesse pa?s.
38

Modulação da resposta imune pela saliva de carrapatos Rhipicephalus sanguineus: estudo do envolvimento de células T regulatórias / Immunemodulation by Rhipicephalus sanguineus tick saliva: study of regulatory T cell involvment

Moré, Daniela Dantas 22 May 2006 (has links)
Carrapatos são artrópodes hematófagos de distribuição cosmopolita que têm grande importância médica e veterinária devido ao efeito deletério direto causado por se fixarem e sugarem seus hospedeiros, como também por serem importantes vetores de doenças para o homem e para os animais domésticos. Sabendo que carrapatos permanecem fixos em seus hospedeiros por longos períodos de tempo sem serem rejeitados, é possível inferir que esses ácaros possuam um arsenal de mecanismos que atuem no controle da resposta imune do hospedeiro. De fato, diversos trabalhos têm demonstrado que carrapatos são capazes de modular a resposta imune de seus hospedeiros através de componentes presentes na saliva, que são inoculados durante o repasto sangüíneo. Assim, este trabalho procurou investigar se carrapatos exercem a modulação da resposta imune do hospedeiro através do recrutamento de células T regulatórias CD4+CD25+ (Tregs), com a intenção de conter uma resposta inflamatória / imune prejudicial à sua alimentação. Para isso, células isoladas de amostras de pele e linfonodos de camundongos BALB/c infestados com carrapatos Rhipicephalus sanguineus foram analisadas quanto à expressão das moléculas de superfície CD4, CD25, CTLA-4, CD45RB, GITR e CD103 (fenótipo de células Tregs), por citometria de fluxo. Adicionalmente, as células obtidas dos linfonodos foram avaliadas quanto à expressão de mensagem para o fator de transcrição Foxp3 (característico da função regulatória), por PCR quantitativo. Paralelamente, saliva de R. sanguineus foi inoculada na orelha de animais da mesma linhagem, a fim de se comparar o infiltrado celular com o obtido na pele dos camundongos infestados com carrapatos. Os resultados mostraram que as infestações não alteraram a percentagem de células T CD4+CD25+ nem a expressão de moléculas associadas ao fenótipo de células Tregs nas células infiltradas na lesão de fixação dos carrapatos ou nos linfonodos em comparação a camundongos controles. Também não se verificou aumento da expressão do gene para Foxp3 nos linfonodos em nenhum dos grupos analisados. Por outro lado, a inoculação de saliva na orelha de camundongos induziu um aumento significativo da população de células T CD4+, porém estas também não apresentavam fenótipo regulatório, sugerindo que o mecanismo de imunomodulação exercido pelos carrapatos sobre seus hospedeiros não é mediado por essas células. Resultados adicionais mostraram que a saliva de carrapatos reduziu significativamente a percentagem de células dendríticas nas orelhas dos camundongos, sugerindo que carrapatos podem estar modulando a resposta imune de seus hospedeiros por diminuírem o repovoamento da pele com células dendríticas, as quais são essenciais na vigilância imune dos tecidos periféricos. / Ticks are bloodsucking arthropods that feed on vertebrates and are responsible for serious global economic losses both through the effects of blood sucking and as vectors of pathogens. A tick?s bloodmeal lasts for several days, during which it remains fixed to the host and avoids rejection by local inflammatory and immunological reactions. This status is achieved by the escape mechanisms ticks have evolved. In fact, many studies have demonstrated that ticks modulate the host immune response through salivary compounds inoculated during their bloodmeals. This study investigated if during bloodfeeding ticks can recruit regulatory T cells in an attempt to modulate the host immune response and to control inflammatory responses that could be harmful to tick feeding. BALB/c mice were infested with Rhipicephalus sanguineus, the skin at feeding sites and the regional lymph nodes were collected, and the cells forming the local infiltrates were analyzed by flow cytometry for simultaneous expression of CD4, CD25, CTLA-4, CD45RB, GITR and CD103 molecules. Additionally, expression of mRNA for Foxp3 was measured in the lymph node cells. Tick saliva was also inoculated into the ears of BALB/c mice in order to compare the local cellular infiltrate with that elicited by artificial infestation. Control animals were sham infested. The results show that, relative to sham-infested tissues, tick infestations did not alter the percentage of CD4+CD25+ T cells present at the site of their attachment or in draining lymph nodes. Infestations also did not increase the expression of Foxp3 in skin and lymph nodes. On the other hand, saliva inoculated into the ear induced a significant increase in the number of CD4+ T lymphocytes recruited to the site of inoculation, although these cells did not express a regulatory phenotype. These results suggest that the modulation of the host immune response by ticks does not involve CD4+CD25+ T cells. Additional results showed that tick saliva reduced the percentage of dendritic cells in the skin of infested mice. This finding indicates that ticks may modulate the host immune response by diminishing the repopulation of skin with dendritic cells, which are essential for maintaining surveillance of peripheral tissues for incoming antigens.
39

Avaliação da atividade de acaricidas químicos sintéticos, extrato botânico sobre Rhipicephalus sanguineus e ação dos óleos essenciais sobre Amblyomma cajennens. / Evaluation of activity of synthetic chemical acaricides, botanical extract on Rhipicephalus sanguineus and action of essential oils on Amblyomma cajennense.

D`ALESSANDRO, Walmirton Bezerra 22 October 2008 (has links)
Made available in DSpace on 2014-07-29T15:30:42Z (GMT). No. of bitstreams: 1 Dissertacao WalmirtonBezerra.pdf: 3515322 bytes, checksum: 262c3d8c28e9609dbeee4234b3332f81 (MD5) Previous issue date: 2008-10-22 / Amblyomma cajennense (Fabricius, 1787) (Acari, Ixodidae) known as tick-star , is a ixodid heteroxenous tree-host found too often in horses. Have little specific parasite, particularly in periods of larvae and nymph, is considered the most important in ixodid transmission of spotted fever to humans in Brazil. Rhipicephalus sanguineus, tick ectoparasite mainly from domestic dogs in urban areas, but also parasite other mammals, birds and reptiles, is responsible for the transmission of pathogens to their hosts. By developing in synanthropic environments, with their immature stages occasionally infecting man, this ixodídeo could cause increased incidence of erliquiosis, babesiosis and spotted fever in humans. The difficulties in controlling these ixodids, including the development of resistance to some acaricides chemicals synthetic main products used in their control, studies to encourage development of alternative measures, more efficient and less environmental impact. The objective of this work was monitoring the susceptibility and/or resistance of R. sanguineus to 14 insecticide products/acaricides, among the most acaricide sold in Goiás for control of ectoparasites of medical and veterinary importance, and verify the potential of substances extracted from plants, Carapa guianensis AUBLET (Meliaceae), Piper hispidinervum C.DC. (Piperaceae) and Magonia pubescens St. Hil. (Sapindaceae) in botanical exploration of acaricides for control of A. cajennense and R. saguineus. Engorged female of R. sanguineus were collected in environments naturally infested frequented by dogs in different districts and municipalities of Goiânia. Engorged female of A. cajennense were collected on horses from rural farms of different neighborhoods and surrounding municipalities of Goiânia. In the laboratory they were washed with distilled water, dried with paper towel and put in incubators B.O.D., to conduct the oviposition. Envelopes were used to filter paper impregnated with different concentrations of synthetic chemical acaricides, of essential oils from the leaves and branches side of P. hispidinervum, essential oil coming seeds of C. guianensis and stem bark of M. pubescens. In the control group used up only distilled water and solvent. Bioassays were made in quadruplicate. In the first study, Lethal Concentrations, CL50 and CL99, after 24 h and 48 h of exposure were calculated for the products that caused a framework for possible resistance or resistance to larvicidal R. sanguineus, according to WHO criteria. There was a framework of resistance to the basic products of Cypermethrin, Cypermethrin + Piperonyl Butoxide (PBO), Deltamethrin, Permethrin and Amitraz in 24 h presenting mortalities of 58.36%, 71.36%, 48.7%, 64.5% and 77.8%, respectively. In 48 h of exposure to Amitraz the mortality rate was 88%, presenting a framework for possible resistance accounting for 0.07% of the products tested. The lethal concentrations CL50 and CL99 were: Cypermethrin (0.06% and 7.04%), Cypermethrin + PBO (0.06% and 2.1%), Deltamethrin (0.06% and 1.57%); Permethrin (0.06% and 0.3%), Amitraz 24 h (0025% and 0.73%) and Amitraz 48 h (0.06% and 0.31%). The products Deltamethrin, Cypermethrin, Permethrin, Cypermethrin + PBO and Amitraz (24 and 48 h of exposure) were 35.2, 21, 7.85, 3, 3.65, 1.55 times, respectively, higher than the dosages recommended by manufacturers. In the second study noted that the essential oil of C. guianensis on the larvae of A. cajennense resulted in 24 h, mortality not exceeding 10% for 35% concentration in 48 h of exposure received at the CL50 of 7.38% and 45.45% of CL99, the essential oil of P. hispidinervum shown in 24 h of exposure CL50 of 0.42% and CL99 of 0.88%, in 48 h of exposure CL50 of 0.45% and CL99 of 1.06%. There was Knock down the effect on the larvae of A. cajennense the essential oil of P. hispidinervum, significantly influencing mortality average. In the third study there was the lethal action of ethanol crude extract of stem of bark M. pubescens on R. sanguineus, in the reading of 48 h LC50 and CL99 was 0.15% and 0.99%, respectively.The plants showed larvicidal effect on A. cajennense and R. sanguineus. The essential oils and extracts studied demonstrated greatest potential for the exploration of acaricides plants, with less environmental impact, to be used as a strategy for control of R. sanguineus and A. cajennense. / Amblyomma cajennense (Fabricius, 1787) (Acari, Ixodidae) conhecido como carrapato-estrela , é um ixodídeo heteroxeno encontrado com muita freqüência em eqüídeos. Têm pouca especificidade parasitária, principalmente nos estágios de larva e ninfa, sendo considerado o ixodídeo mais importante na transmissão da febre maculosa para os humanos no Brasil. Rhipicephalus sanguineus, carrapato ectoparasita principalmente dos cães domésticos em áreas urbanizadas, mas que também parasita outros mamíferos, aves e répteis, é responsável pela transmissão de patógenos aos seus hospedeiros. Por se desenvolver em ambientes sinantrópicos, com seus estágios imaturos, parasitando ocasionalmente o homem, este ixodídeo poderá vir a causar aumento na incidência de erliquiose, babesiose e febre maculosa no homem. As dificuldades existentes no controle dos ixodídeos, incluindo o desenvolvimento de resistência a alguns acaricidas químicos sintéticos, principais produtos utilizados em seu controle, incitam estudos para desenvolvimento de medidas alternativas, mais eficientes e de menor impacto ambiental. O objetivo do presente trabalho foi monitorar a susceptibilidade e/ou resistência de R. sanguineus a 14 produtos inseticidas/acaricidas, dentre os mais comercializados em Goiás para controle de ectoparasitos de importância médica e veterinária, e verificar a potencialidade de substâncias extraídas das plantas Carapa guianensis AUBLET (Meliaceae), Piper hispidinervum C.DC. (Piperaceae) e Magonia pubescens St. Hil. (Sapindaceae), na prospecção de acaricidas botânicos para controle de A. cajennense e R. sanguineus. As teleóginas de R. sanguineus foram coletadas, em ambientes naturalmente infestados, freqüentados por cães, de diferentes bairros e municípios de Goiânia. Teleóginas de A. cajennense foram coletadas em cavalos oriundos de propriedades rurais de diferentes bairros e municípios circunvizinhos de Goiânia. No laboratório, as teleóginas foram lavadas com água destilada, secas em papel toalha e acondicionadas em incubadoras B.O.D., para realizarem a oviposição. Foram utilizados envelopes de papel filtro impregnados com diferentes concentrações dos acaricidas químicos sintéticos, óleo essencial provenientes das folhas e ramos secundários de P. hispidinervum, óleo essencial provindo das sementes de C. guianensis e o extrato bruto etanólico da casca do caule de M. pubescens. No grupo controle utilizou-se apenas água destilada e solvente. Os bioensaios foram realizados em quadruplicata. No primeiro estudo, Concentrações Letais, CL50 e CL99, após 24 h e 48 h de exposição foram calculadas para os produtos que proporcionaram um quadro de resistência ou possível resistência larvicida para R. sanguineus, segundo critérios da OMS. Observou-se resistência para as larvas de R. sanguineus produtos que apresentaram mortalidades a base de Cipermetrina (58,36%), Cipermetrina + Butóxido de Piperolina (PBO) (71,36%), Deltametrina (48,7%), Permetrina (64,5%) e Amitraz (77,8%) nas 24 h, correspondendo a 36% dos produtos testados. Em 48 h de exposição ao Amitraz a mortalidade foi de 88%, apresentando um quadro de possível resistência, correspondendo a 0,07% dos produtos testados. As concentrações letais CL50 e CL99 encontradas foram: Cipermetrina (0,06% e 7,04%), Cipermetrina + PBO (0,06% e 2,1%), Deltametrina (0,06% e 1,57%), Permetrina (0,06% e 0,3%), Amitraz 24 h (0,025% e 0,73%) e Amitraz 48 h (0,06% e 0,31%). Os produtos Deltametrina, Cipermetrina, Permetrina, Cipermetrina + PBO e Amitraz (24 e 48 h de exposição), foram 35,2; 21; 7,85; 3; 3,65; 1,55 vezes, respectivamente, maiores do que as dosagens recomendadas pelos fabricantes. No segundo estudo observou-se o efeito letal do óleo essencial de C. guianensis sobre as larvas de A. cajennense ocasionando nas 24 h, mortalidade não superior a 10% para concentração 35%, nas 48 h de exposição obtiveram-se as CL50 de 7,38% e CL99 de 45,45%. O óleo essencial de P. hispidinervum ocasionou nas 24 h de exposição CL50 de 0,42% e CL99 de 0,88%, nas 48 h de exposição CL50 de 0,45% e CL99 de 1,06%. Observou-se o efeito Knock down sobre as larvas de A. cajennense pelo óleo essencial de P. hispidinervum, influenciando significativamente na mortalidade média. No terceiro estudo observou-se a ação letal do extrato bruto etanólico da casca do caule de M. pubescens sobre R. sanguineus, em 48 h a CL50 e CL99 foi de 0,15% e 0,99%, respectivamente. Os óleos essenciais e extrato estudados demonstraram como método alternativo para a prospecção de acaricidas vegetais, de menor impacto ambiental, a serem utilizados como nova estratégia para controle de R. sanguineus e A. cajennense.
40

The occurrence of tick-borne pathogens, in dogs in welfare organisations and townships of Cape Town

Allan, Rosalind Elizabeth 02 1900 (has links)
In impoverished and resource limited communities such as townships, and welfare organizations, areas such as living and sleeping spaces are sometimes shared with animals, and occasionally humans. Dogs play an integral role in our lives and have become part of the family. Therefore, it is probable that ectoparasites, such as ticks, that feed on dogs also feed on other vertebrates, thereby, transmitting pathogens. The primary aim of this study was to screen for the presence of tick-borne pathogens in dogs from welfare organisations and townships in Cape Town, with special focus on Ehrlichia and Babesia spp. The reason for this choice of subject is due to the fact that very few tick-borne infection studies have focused on resource limited communities. Furthermore, welfare organisations have continuously attracted awareness due to the amount of unrestricted work performed by veterinarians in communities with limited resources. Consequently, the topic was borne. A total of 126 blood samples and 509 ticks (adults and nymphs) were collected directly from dogs from four welfare organisations and two townships in Cape Town. Samples were collected from April to July 2014. The four welfare organisations where samples were collected included the Animal Anti Cruelty League welfare organisations in Epping and Bellville, the Lucky Lucy Foundation in Joostenberg Vlakte and The Emma Animal Rescue Society (TEARS), located in the Sunnydale area. Samples were also collected from the Asanda village and Nomzamo, two townships located just outside the Cape Town suburb, the Strand. DNA was extracted from blood and ectoparasites and screened for the presence of Ehrlichia, Anaplasma, Theileria and Babesia species infections using touchdown PCR and RLB hybridization assays. Genus and species-specific probes were used during hybridization in order to identify specific parasite infections in the blood samples and the tick samples pooled according to geographical origin and species. Forty six (36.5%) of the blood samples tested positive for tick-borne pathogen DNA. Of the positive blood samples, 17 (13.5%) were infected with Ehrlichia canis; 16 (12.7%) with Babesia rossi and four (3.2%) samples were infected with Babesia vogeli. Incidental infections were also detected, these included Ehrlichia ruminantium (n=6, [4.7%]), Theileria taurotragi (n=2, [1.6%]) and Anaplasma sp. Omatjenne (n=1, [0.8%]) infections. DNA detected from 10 samples (7.94%) hybridized only to the Ehrlichia/Anaplasma genus-specific probes and four samples (3.17%) hybridized only to the Theileria/Babesia genus-specific probes. None of these 14 samples hybridized to any of the species-specific probes. Collected Rhipicephalus sanguineus (n=457) and Haemaphysalis elliptica (n=52) ticks were grouped into 15 pools, representing both tick species according to specific collection locations. Since only two H. elliptica from Asanda and one R. sanguineus from TEARS were collected, these ticks were mixed in pools of the dominant species as they were too few for DNA extraction. Ticks were collected from the Nomzamo Township (R. sanguineus n=400), Asanda village (H. elliptica n=2; R. sanguineus n=42), TEARS (H. elliptica n=21; R. sanguineus n=1), and the Animal Anti Cruelty League in both Epping (R. sanguineus n=14), and Bellville (H. elliptica n=29), in Cape Town. Analysis by the RLB assay showed that 11 (73.3%) of the 15 tick pools representing both tick species were positive for at least one parasite species. All positive samples hybridized with the Ehrlichia/Anaplasma genus-specific probe. Three (20%) tick pools containing both tick species tested positive for Ehrlichia canis infection, two (13.3%) tested positive for Babesia rossi and Babesia vogeli DNA was identified in one (6.6%) tick pool. The Theileria/Babesia genus-specific probe hybridised in three (20%) tick pools. These three pools were comprised of both R. sanguineus and H. elliptica tick species. These tick pools also tested positive for a specific Babesia tick-borne pathogen. Tick-borne pathogen DNA could not be detected in four (26.6%) tick pools. The fore-mentioned tick-borne pathogen DNA detected in the dog blood samples, and the ectoparasites collected from the same dogs during this study, suggests that dogs play a large role in the endemicity of these pathogens / Environmental Sciences / M. Sc. (Life Science)

Page generated in 0.0925 seconds