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  • 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

Influence du paysage sur les communautés de micromammifères hôtes d'agents infectieux transmis par les tiques / Influence of the landscape on the small mammal communities as hosts of tick-borne infectious agents

Perez, Grégoire 31 May 2016 (has links)
Une recrudescence de l’émergence ou de la réémergence de maladies infectieuses touchant l’homme ou ses animaux domestiques a été constatée ces dernières décennies. La majorité de ces maladies sont zoonotiques, c’est à dire originaires de la faune sauvage, et impliquent souvent un vecteur dans leur cycle de transmission. Parallèlement, des changements d’utilisation du sol en lien avec une intensification agricole modifient les paysages. L’objectif de cette thèse était d’améliorer l’état des connaissances de l’influence du paysage sur les relations entre hôtes, vecteurs et pathogènes. En Europe, les micromammifères peuvent abonder dans la plupart des écosystèmes terrestres, ce qui en fait des hôtes de choix pour les tiques généralistes Ixodes ricinus. Ils sont aussi des réservoirs d’agents infectieux transmis par les tiques. Les résultats de la thèse sont basés sur deux ans d’échantillonnage, printemps et automne, des micromammifères et des tiques dans différents paysages. Nous avons aussi recherché trois agents infectieux qu’ils hébergent et transmettent : Borrelia burgdorferi sensu lato (maladie de Lyme), Anaplasma phagocytophylum (anaplasmose) et Theileria (Babesia) microti (piroplasmose), ce dernier n’ayant pu être exploité en raison de sa trop faible prévalence. Les 24 sites d’échantillonnage étaient pour moitié en cœur ou en lisière de forêt et pour moitié dans des paysages agricoles offrant un gradient d’occupation du sol et d’ouverture du paysage. Le meilleur facteur explicatif de l’abondance de nymphes est la présence de larves d’I. ricinus l’année précédente. Les résultats indiquent aussi une relation entre le nombre de larves portées par les mulots sylvestres (Apodemus sylvaticus ; 76,5% des captures) et l’abondance de nymphes l’année suivante. Les campagnols roussâtres (Myodes glareolus ; 22,3% des captures) portaient moins de larves au printemps, certainement du fait d’une résistance acquise aux tiques des individus hivernants. Bien que ces deux espèces réagissent différemment aux variables de composition et de configuration du paysage, les abondances de nymphes n’étaient pas expliquées par ces variables. D’autres hôtes, comme les chevreuils (Capreolus capreolus), et des facteurs microclimatiques et météorologiques influencent donc probablement aussi les abondances et la distribution des tiques dans le paysage. La richesse spécifique des hôtes et l’abondance des campagnols roussâtres, trois fois plus infectés que les mulots sylvestres, amplifieraient les prévalences d’A. phagocytophylum de ces deux espèces de rongeurs. A l’inverse, la fragmentation du paysage, via la réduction de la taille des populations d’hôtes, semble agir négativement sur ces prévalences. Aucun patron spatial évident n’a été observé pour B. burgdorferi s.l.. De même, aucun lien n’a pu être fait entre les prévalences des rongeurs et celles des nymphes d’I. ricinus. Ces résultats suggèrent un rôle probable d’espèces de tiques plus spécialistes, I. trianguliceps et I. acuminatus, dans la circulation des agents infectieux étudiés, soulignant l’intérêt qu’il pourrait y avoir à considérer l’ensemble de la communauté de vecteurs dans de futures études. L’ensemble des résultats soulignent aussi l’importance qu’il y aurait à considérer un maximum d’hôtes micromammifères réservoirs, même peu abondants, à l’échelle du paysage pour mieux comprendre la transmission de ces maladies infectieuses vectorielles. / An increase in the emergence or in the reemergence of infectious diseases of human and his domestic animals has been observed in the last decades. Most of these diseases are zoonotic, i.e. originated from wildlife, and imply often a vector for their transmission. At the same time, land use changes linked to agricultural intensification have modified the landscapes. The aim of the thesis was to enhance the state of knowledge on the influence of the landscape on the relationships between hosts, vectors and pathogens. In Europe, small mammals can be abundant in most of terrestrial ecosystems; they are thus preferred hosts for the generalist tick species Ixodes ricinus. They are also reservoirs of tick-borne infectious agents. The results of this thesis are based on two years of sampling, in spring and autumn, of small mammals and ticks in different landscapes. We analyzed them for three of the infectious agents they host and transmit: Borrelia burgdorferi sensu lato (Lyme disease), Anaplasma phagocytophylum (anaplasmosis) and Theileria (Babesia) microti (piroplasmosis), this last one could not be exploited because of too low prevalence. The 24 sampling sites were half in the core or the edge of a forest and half in agricultural landscapes with a gradient of land cover and of landscape openness. The best explanatory variable for nymph abundance was the presence of I. ricinus larvae the previous year. The results also indicate a relationship between the number of larvae attached on wood mice (Apodemus sylvaticus ; 76,5% of the catches) and the abundance of nymphs the following year. Bank voles (Myodes glareolus ; 22,3% of the catches) harbored less larvae in spring, certainly because of an acquired resistance to ticks in the overwintering individuals. Despite that these two species react differently to the composition and configuration features of the landscape, the abundances of nymphs were not related to these features. Other hosts, like roe deer (Capreolus capreolus), meteorological and microclimatic factors probably influence the abundances and the distribution of ticks in the landscape. The host specific richness and the abundance of bank voles, which were threefold more infected than wood mice, likely amplified the prevalence of A. phagocytophylum of these two rodent species. Conversely, landscape fragmentation, via the reduction of host population sizes, seems to act negatively on this prevalence. No clear spatial pattern was observed for B. burgdorferi s.l.. Likewise, no link could be established between the prevalence of the rodents and the prevalence of the nymphs. These results suggest a possible role of more specialist tick species, I. trianguliceps and I. acuminatus, in the circulation of the studied infectious agents, emphasizing the possible interest of considering the whole vector community in further studies. The results also emphasize the importance of considering a maximum of small mammal reservoir hosts, even at low abundances, at the landscape scale to better understand the transmission of these vector-borne infectious diseases.
32

Overwintering and Early Season Amplification of Eastern Equine Encephalitis Virus in the Southeastern United States

Bingham, Andrea 31 March 2014 (has links)
Eastern equine encephalitis virus (EEEV) is a highly pathogenic arbovirus that causes severe disease, with a mortality rate of approximately 30-35% in humans and 80-90% in horses. Studies dating back to the 1930's have identified many of the epidemiological and ecological aspects of the virus. However, there are several aspects of EEEV's transmission cycle that remain unclear. In the northeastern states, transmission is seasonal, peaking in the late summer months, while in Florida there is year-round transmission of EEEV. Recent phylogenetic studies have also suggested that Florida may serve as a reservoir for EEEV; the virus may periodically be introduced from Florida to the northeastern US where it locally amplifies, overwinters, and can remain stable for several years. How EEEV is able to migrate from Florida and how it persists during the winter in North America is not yet known, however several theories exist and are examined further by this research. The first part of this study investigates the hypothesis that snakes may serve as overwintering reservoir hosts for EEEV. Rates of exposure and infection of wild snakes were examined by testing serum samples from wild snakes at a focus of EEEV in Alabama. Two species of vipers, the cottonmouth and the copperhead, were found to be positive for EEEV RNA. The second part of the study attempts to identify the hosts and vectors of enzootic winter transmission of EEEV in Florida, with a focus on avian host preference. EEEV was detected in two mosquito species, Culiseta melanura and Anopheles quadrimaculatus, and were both from the month of February. In addition, the results also suggest that EEEV vectors preferentially feed upon wading birds during the winter months.
33

Endemic trichinellosis - experimental and epidemiological studies /

Oivanen, Leena. January 2005 (has links) (PDF)
Ph.d.-afhandling. University of Helsinki, 2005. / Også elektronisk adgang via Internetttet.
34

Native plants as repellents against malaria mosquitoes : ethnobotanical, behavioural & electrophysiological studies /

Waka, Maedot. January 2005 (has links)
Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.
35

The sweet potato butterfly Acraea acerata in Ethiopia : ecology and economic importance /

Azerefegne, Ferdu, January 1900 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 5 uppsatser.
36

Welcoming Online Communities : Social Sustainability of ESN Kalmar

Liekovuori, Reetta January 2018 (has links)
Erasmus Student Network (ESN) plays an important role in the integration process of international students who spend their study abroad period in a new country. ESN community in Kalmar in Sweden has Facebook groups for every semester which spread the hospitality through the local ESN members, also called as ‘hosts’, for the new members who can be called either ‘guests’, ‘tourists’, ‘exchange students’ or ‘freemovers’. The previous literature in tourism regarding social life online has emphasised the user-generated content on travel-related online communities on social media and ‘mobility turn’ that is an emerged topic in social sciences and has put social into travel and has thus forced researches to come up with new mobile methods to study online communities. Despite the fact that the word ‘social’ seems to be everywhere, social sustainability has been somewhat overlooked research area particularly in terms of online communities. This thesis project aims to fill this gap in the tourism literature and seeks to find out what social sustainability means in a context of online communities. Social sustainability forms the conceptual framework of the thesis and discusses the hosts and guests paradigm connecting it to online environments. The empirical material was collected by using qualitative methods including online survey distributed on ESN Kalmar Facebook groups and netnography concerning the ESN Kalmar online communities on Facebook. In addition to a theoretical contribution, the thesis project makes a methodological addition since netnography is still underutilised method among tourism scholars. These methods provided comprehensive data both from subjective and objective perspectives. The data was analysed by thematic analysis under the themes of social support, well-being and friendships, which were found to be connected to socially sustainable communities in the literature. The results found that online communities benefit from offline meetings that make the relationships between the community members stronger and thus create trust among the members. The role of the hosts and their local knowledge in the online community was proven vital in making guests to feel welcome, cared and supported during their study abroad period. However, the socially sustainable online community requires interaction and hospitality from both parties. Social sustainability of an online community can be disrupted if the community members are not cooperating and being open enough. Besides the local importance of the study in developing ESN Kalmar’s online community dynamics by emphasising the role of social sustainability, the results can be applied to discussions of internet behaviour in general. Also, the study provides help for communities where the roles between the hosts and guests are constantly “on move”.
37

Epidemiological factors impacting the development of Wheat streak mosaic virus outbreaks

Webb, Christian A. January 1900 (has links)
Master of Science / Department of Plant Pathology / Erick D. DeWolf / Wheat streak mosaic (WSM) is a devastating disease of winter wheat (Triticum aestivum L.) in Kansas. Although WSM can cause heavy crop losses, the severity of regional and statewide losses varies by year and location. Wheat streak mosaic is caused primarily by the Wheat streak mosaic virus (WSMV) and is spread by the wheat curl mite, Aceria tosichella Keifer. To infect fall planted wheat, both the virus and mite require a living, grass host to survive the summer months. The first research objective was to determine the risk of different grass species to serve as a source of WSM. Published experiments and surveys were reviewed to determine the suitability of each host based on a set of criteria. An analysis of the reports from the reviewed literature found 39 species to host both pests. Categorical analysis of these observations suggested that well-studied grass species could be placed in four risk groupings with ten species at high risk of carrying both pests. Furthermore, results from controlled experimentation generally agrees with results from field survey results for both pests. The second objective was to determine the weather and cropping factors that are associated with regional epidemics of WSM in Kansas. Historic disease observations, weather summaries, soil moisture indices, and cropping statistics were collected from Kansas crop reporting districts from 1995-2013. Binary response variables (non-epidemic case vs epidemic cases) were developed from different thresholds of district losses attributed to WSM. Variables associated with WSM epidemics were identified by a combination of non-parametric correlation, classification trees, and logistic regression. This analysis indicates that the total acres of wheat planted per season was associated with the low frequency of epidemics in Eastern Kansas. Temperature during September appears to influence the yield losses caused by WSM. Wheat planting generally begins during September and continues through October in the state. Temperature during the winter months (December-February) was also identified as important with warm conditions favoring outbreaks of disease. Dry soil conditions in February was also associated with epidemics of WSM. Models combining these variables correctly classified 60 to 74% of the cases considered in this analysis.
38

Investigação de fontes alimentares de culicídeos coletados em parques municipais de São Paulo pela técnica de Reação em Cadeia da Polimerase (PCR) / Investigation of blood meal sources of mosquitoes collected in Municipal Parks of São Paulo city, by Polymerase Chain Reaction (PCR) technique.

Gabriela Cristina de Carvalho 25 April 2013 (has links)
O estudo das fontes alimentares em culicídeos possui evidentes significados ecológicos e epidemiológicos, pois auxilia na identificação de animais possivelmente envolvidos na manutenção de surtos epidêmicos das doenças transmitidas por vetores, oferecendo informações para a indicação de potenciais reservatórios de patógenos. Entre os métodos utilizados para avaliar o possível grau de atração exercido por certas fontes de alimentação em relação às fêmeas de culicídeos, a técnica de Reação em Cadeia da Polimerase (PCR) se destaca como sendo uma das técnicas mais eficientes na detecção de repastos sanguíneos devido à alta sensibilidade e especifidade. O objetivo desse estudo foi descrever o perfil alimentar das fêmeas de culicídeos capturadas nos parques Alfredo Volpi, Anhanguera, Carmo, Chico Mendes, Ibirapuera, Santo Dias e Shangrilá, situados na cidade de São Paulo, investigando possíveis associações entre as espécies de mosquitos e suas respectivas fontes alimentares, analisando assim o comportamento no âmbito alimentar dessas espécies em diferentes localidades da cidade, durante os meses de Fevereiro de 2011 à Fevereiro de 2012. A identificação do repasto sanguíneo foi realizada por meio da técnica de PCR para os seguintes hospedeiros: aves, cães, gatos, humanos, primatas ( não humanos) e roedores em 510 fêmeas ingurgitadas distribuídas em 14 espécies capturadas pleas técnicas de aspiração, CDC copa, CDC solo e armadilha de Shannon. Dos vertebrados, apenas o hospedeiro gato não foi encontrado como sendo fonte de repasto, as demais têm sido utilizadas como fontes de alimentação para os culicídeos nos parques estudados. Baseando-se em testes estatísticos não se encontrou nenhuma tendência de associação entre as espécies de culicídeos capturadas ingurgitadas e as fontes utilizadas para repasto, evidenciando assim, padrões aleatórios por parte dos mosquitos em se alimentarem de fontes sanguíneas mais abundantes ou mais fáceis de serem abordadas, reforçando a característica oportunista das fêmeas de culicídeos em busca das suas fontes de alimentação sanguíneas. Sendo de fundamental importância tais informações em contexto epidemiológico, afim de, identificar novos possíveis hospedeiros e reservatórios de patógenos em cadeias de transmissão de doenças transmitidas por culicídeos / The study of the blood meal sources in culicids has evident ecological and epidemiologic meanings, because assists in the identification the possible animals involved in maintenance of epidemic outbreaks of the vector-borne diseases, offering information to indicate the potential pathogen reservoirs. Among the methods used to evaluate the possible degree of attraction exercised by certain source of meals relative to culicid females, the Polymerase Chain Reaction (PCR) stands out, because it is a more efficient technique in blood meals detected, due to the high sensitivity and specificity. The aim of this study was to describe the food profile of culicid females captured in the Alfredo Volpi, Anhanguera, Carmo, Chico Mendes, Ibirapuera, Santo Dias and Shangrilá parks, located in São Paulo city, investiganting possible associations between mosquito species and their blood meal sources, analyzing the feeding behavior of these species in different localities of city, during the months February 2011 and February 2012. The identification of blood meals was realized by PCR technique for the following vertebrate hosts: avian, dogs, cats, humans, primates (non-human) and rodents in 510 engorged females distributed in 14 species captured by aspirator technique, cup CDC, soil CDC and Shannon trap. Of vertebrates, only cats were not found as source of meal, while the others have been used as blood meals for mosquitoes in the parks. Based in statistical tests, there was no trend of association between culicid engorged species captured and sources of meals, thus evidencing random patterns of mosquitoes to feed on the blood meal sources more abundant or easiest to the addressed, reiforcing the opportuinistc characteristic of the mosquito females in searching blood meals. Being of fundamental importance such information in epidemiological context, in order to identify new hosts and pathogen reservoirs in the chains of transmission of vector borne diseases
39

Biologia e estrutura genética de populações do patógeno da brusone do trigo no centro-sul do Brasil / Biology and genetic structure of populations of the wheat blast pathogen in central-southern Brazil

Reges, Juliana Teodora de Assis [UNESP] 23 August 2016 (has links)
Submitted by JULIANA TEODORA DE ASSIS REGES null (juliana.teodora@bol.com.br) on 2016-10-21T00:48:25Z No. of bitstreams: 1 Reges-Tese-DR.pdf: 2852424 bytes, checksum: e86c4e7420b8cf40a8dcc1e723431082 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-10-27T16:48:41Z (GMT) No. of bitstreams: 1 reges_jta_dr_jabo.pdf: 2852424 bytes, checksum: e86c4e7420b8cf40a8dcc1e723431082 (MD5) / Made available in DSpace on 2016-10-27T16:48:41Z (GMT). No. of bitstreams: 1 reges_jta_dr_jabo.pdf: 2852424 bytes, checksum: e86c4e7420b8cf40a8dcc1e723431082 (MD5) Previous issue date: 2016-08-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Na primeira parte de nosso estudo descrevemos a associação de Pyricularia pennisetigena e P. zingibericola a gramíneas invasoras de áreas de trigo no centro-sul do Brasil. Desconhece-se, entretanto, qual o potencial de P. pennisetigena e P. zingibericola como patógenos de poáceas de interesse econômico para a agricultura brasileira. Dessa forma, objetivamos caracterizar o espectro de patogenicidade de P. pennisetigena e P. zingibericola a braquiária, cevada e trigo e compará-lo com P. grisea e com a espécie até recentemente descrita como P. oryzae patotipo Triticum, de ocorrência generalizada no agroecossistema brasileiro. Foram testados 20 isolados de Pyricularia spp. obtidos de amostras de folhas infectadas de plantas invasoras de campos de trigo. A classificação dos isolados em espécies distintas de Pyricularia foi efetuada usando-se filogenia molecular baseada nas sequencias parciais dos genes actina e calmodulina. Pyricularia pennisetigena e P. zingibericola inoculadas em folhas, foram patogênicas a braquiária, cevada e trigo, com diferenças na agressividade entre as espécies. Pyricularia zingibericola foi a espécie mais agressiva a braquiária e cevada, enquanto P. pennisetigena foi a espécie mais agressiva em plantas jovens de trigo. Por outro lado, P. grisea isolada de Digitaria sanguinalis ou de Urochloa spp. não infectou trigo. A análise filogenética das regiões ACT e CAL concatenadas reproduziu as relações filogenéticas e a magnitude das diferenças descritas entre Pyricularia zingibericola, P. pennisetigena, P. oryzae patotipo Triticum e P. grisea. Urochloa spp. provavelmente representam fonte permanente de inóculo inicial dos patógenos da brusone do trigo entre as épocas de cultivo. Na segunda parte desta pesquisa, foi estudado a estrutura genética de populações do patógeno da brusone do trigo, o fungo Ascomiceto Pyricularia graminis-tritici sp. nov., no centro-sul do Brasil. Os objetivos foram responder às seguintes perguntas: As populações geograficamente distintas de P. graminis-tritici do trigo eram geneticamente subdivididas? Como se distribuía a diversidade gênica e genotípica entre as populações regionais de P. graminis-tritici, cerca de 30 anos após as primeiras epidemias de brusone no Brasil? Qual o sistema reprodutivo predominante de P. graminis-tritici no país? Conclui-se que não houve subdivisão na maioria das populações geográficas contemporâneas de P. graminis-tritici do trigo, indicando mecanismo eficiente de fluxo gênico. A magnitude e a extensão do fluxo gênico entre populações geográficas de P. graminis-tritici do trigo, o sistema reprodutivo predominantemente sexual, aliados a alta diversidade genética do fungo, indicam um patógeno com alto potencial evolutivo no agroecossistema brasileiro. Outras espécies de poáceas hospedeiras com ampla distribuição geográfica no Brasil, como por exemplo, o capim-braquiária (Urochloa brizantha), podem ter importante papel no ciclo de vida e na biologia reprodutiva, na sobrevivência e na dispersão do inóculo de P. graministritici a curta e longa distâncias, mantendo as populações geográficas do patógeno conectadas. Os padrões de fluxo gênico e genotípico entre populações hospedeiro-distintas do patógeno reforçam a hipótese de que a brusone do trigo pode ter tido origem de novo a partir de populações endêmicas de P. graminis-tritici que infectam outras espécies de poáceas (nativas ou invasoras de áreas de trigo) no país. / In the first part of our study we described the association of Pyricularia pennisetigena and P. zingibericola with invasive grasses from wheat cropping areas in South-Central Brazil. However, the potential of P. pennisetigena and P. zingibericola as pathogens to poaceous plants of economic interest for Brazilian agriculture is still unknown. Therefore, this study aimed to characterize the pathogenicity spectrum of P. pennisetigena and P. zingibericola to signal grass, barley and wheat and compare with P. grisea and with the species until recently described as P. oryzae pathotype Triticum, of widespread occurrence in the Brazilian agroecosystem. Twenty isolates of Pyricularia spp. obtained from samples of infected leaves of weed species in wheat fields were tested. Classification of isolates into different species of Pyricularia was performed using molecular phylogeny based on the partial actin and calmodulin gene sequences. Pyricularia pennisetigena and P. zingibericola inoculated on leaves were pathogenic to signal grass, barley and wheat, with differences in aggressiveness between species. Pyricularia zingibericola was the most aggressive species to signal grass and barley, while P. pennisetigena was the most aggressive species to young plants of wheat. On the other hand, P. grisea isolated from Digitaria sanguinalis or Urochloa spp. did not infect wheat. Phylogenetic analysis of the concatenated regions ACT and CAL reproduced the phylogenetic relationships and the magnitude of the differences reported between Pyricularia zingibericola, P. pennisetigena, P. oryzae pathotype Triticum and P. grisea. Urochloa spp. probably represents a permanent source of initial inoculum of the wheat blast pathogens between growing seasons. In the second part of this research, we studied the genetic structure of populations of the wheat blast pathogen, the Ascomycete fungus Pyricularia graminis - tritici sp. nov., in the South-Central Brazil. The objectives were to answer the following questions: The geographically distinct populations of P. graminis-triticiwheat were genetically subdivided? How gene and genotypic diversity were distributed among regional populations of P. graminis-tritici about 30 years after the first outbreaks of wheat blast in Brazil? What is the predominant reproductive system of P. graminis-tritici in the country? We concluded that there was no subdivision among most of the contemporary geographical populations of Pyricularia graminis- tritici from wheat fields, indicating an efficient mechanism of gene flow. The magnitude and extent of gene flow among geographical populations of P. graminis-tritici, the predominantly sexual reproductive system, coupled with high genetic diversity of the fungus, indicated a pathogen with high evolutionary potential in the Brazilian agro-ecosystem. Other species of poaceous hosts with wide geographic distribution in Brazil, for example, signal grass (Urochloa brizantha) can play an important role in the life cycle and reproductive biology, survival and spread of inoculum of P. graminis- tritici at short and long distances, keeping the geographical populations of the pathogen connected. The patterns of gene and genotypic flow between host-distinct populations of the pathogen reinforce the hypothesis that the wheat blast may had a de novo origin from endemic populations of P. graminis-tritici infecting other poaceous species (native or invasive WRwheat areas) in the country.
40

Avaliação de roedores silvestres como fonte de infecção de Hepatozoon canis a cães

Demoner, Larissa de Castro January 2016 (has links)
Orientador: Lucia Helena O'Dwyer de Oliveira / Resumo: Espécies do gênero Hepatozoon incluem um grupo diverso de parasitas com mais de 340 espécies descritas em anfíbios, répteis, aves e mamíferos. A hepatozoonose canina é uma hemoparasitose transmitida por carrapatos relatada em diversas regiões do mundo e pode estar relacionada às espécies Hepatozoon canis e Hepatozoon americanum. Em nosso país, diferentes estudos demonstraram que H. canis é a espécie envolvida na infecção dos cães e os relatos são comuns, principalmente, em áreas rurais. Trabalhos previamente conduzidos mostram que o vetor de H. canis em áreas rurais do Brasil permanece desconhecido, o que pode sugerir a existência de outros mecanismos de transmissão, como a predação de hospedeiros paratênicos. Assim, este trabalho teve como objetivo investigar a presença de Hepatozoon spp. em pequenos roedores silvestres capturados em fragmentos florestais nos arredores de propriedades rurais do município de Botucatu, São Paulo, Brasil, onde o parasita foi também estudado em cães domésticos. Foram analisadas 158 amostras sanguíneas de cães, pela reação em cadeia da polimerase (PCR) e pela técnica de extensão de sangue periférico. Amostras de sangue e tecidos de 67 roedores foram coletadas para pesquisa do parasita pela técnica de extensão sanguínea, histopatologia e também por diagnóstico molecular. Os resultados do presente estudo mostraram uma prevalência elevada de H. canis em cães de áreas rurais do município de Botucatu (66,45%). Além disso, as espécies de roedores silve... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Hepatozoon spp. belong to a diverse group of parasites with more than 340 species described in amphibians, reptiles, birds and mammals. Canine hepatozoonosis is a tick-borne disease reported throughout the world and can be related to Hepatozoon canis and Hepatozoon americanum. In our country, previously studies have shown that H. canis is the species involved in the infection of dogs and reports are common, especially in rural areas. Hepatozoon canis vectors in rural areas of Brazil remain unknown, which might suggest the existence of other transmission mechanisms, such as predation of paratenic hosts. Thus, this study aimed to investigate the presence of Hepatozoon spp. in wild rodents trapped in forest fragments surrounding rural areas of Botucatu, São Paulo, Brazil, where the prevalence of the parasite was also studied in domestic dogs. In dogs, the study was conducted in 158 blood samples using polymerase chain reaction (PCR) and peripheral blood extension technique. Blood samples and tissues from 67 rodents were collected for parasite blood extension technique, histopathology and for molecular diagnosis. The results showed a high prevalence of H. canis in dogs from rural areas of Botucatu (66.45%). In addition, species of Brazilian wild rodents are infected with Hepatozoon spp., other than H. canis. Additionally, the finding of monozoics cysts in the examined rodents may indicate that, in addition to intermediate hosts, small wild rodents may also act as paratenic hosts ... (Complete abstract click electronic access below) / Doutor

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