Orientador: Antonio Carlos Paes / Resumo: A Ehrlichiose Monocítica Canina (EMC), causada por Ehrlichia canis, destaca-se dentre as hemoparasitoses de cães. A EMC causa doença multissistêmica e pode ser classificada em fase aguda, subclínica ou crônica. A fase crônica caracteriza-se por hipoplasia/aplasia medular e muitos cães vêm a óbito por falência medular, embora as causas da supressão medular ainda sejam indefinidas. Neste estudo, foi investigado se a fase crônica resulta de alterações medulares iniciadas na fase aguda. Em particular, verificar se, durante a fase aguda, células precursoras podem ser parasitadas por E. canis e se processos imunomediados podem ser responsáveis por alterações hematológicas durante o curso da doença. Dezoito cães com EMC na fase aguda foram submetidos a exames hematológicos (hemograma, bioquímica sérica e mielograma) e sorológicos. A presença de E. canis foi confirmada mediante PCR e cultivo celular. A citologia de medula óssea revelou alterações principalmente na série eritróide que comumente estão associadas a doenças imunomediadas, inclusive em animais não anêmicos. Também confirmou-se a presença de E. canis na medula óssea de 11/18 cães e certa tendência entre a positividade das amostras medulares e a série eritróide, embora sem significância estatística. Os títulos sorológicos de 2560 em 9/18 e 10240 nos demais confirmou a resposta humoral exacerbada descrita pela literatura, contudo também sem relação significativa com a presença de E. canis na medula e algumas variáveis medula... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre

Made available in DSpace on 2014-06-11T19:27:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-08-22Bitstream added on 2014-06-13T20:27:43Z : No. of bitstreams: 1 demoner_lc_me_botfmvz.pdf: 668999 bytes, checksum: f0837d7e0a185cd0a8385b4105355512 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Hepatozoon canis é um hemoparasita transmitido por carrapatos que afeta cães em diversas regiões do mundo. Rhipicephalus sanguineus é considerado seu vetor biológico, entretanto, é possível que existam outros vetores. No Brasil, H. canis é descrito principalmente em áreas rurais, onde cães podem ser infestados por outras espécies, incluindo Amblyomma spp. O objetivo do presente trabalho foi infectar experimentalmente diferentes espécies de carrapatos com H. canis, a partir de cães naturalmente infectados. Para isso, foram utilizadas ninfas de A. cajennense e R. sanguineus e adultos de A. cajennense e A. ovale. Após o ingurgitamento dos espécimes em animal infectado, foi realizada pesquisa de formas evolutivas do protozoário na hemolinfa, intestino e hemocele dos ixodídeos, por técnicas citológicas e histológicas. Alguns carrapatos foram submetidos ao diagnóstico molecular pela técnica de PCR. Somente em duas fêmeas de A. cajennense foram observadas estruturas morfologicamente semelhantes a Hepatozoon spp. e uma fêmea de A. ovale apresentou oocistos na hemocele. Além disso, duas fêmeas de A. ovale e uma de A. cajennense foram positivas na PCR. Entretanto, não é possível caracterizar essas espécies como vetores de H. canis, pois foram usados muitos exemplares nas infecções experimentais e poucos foram capazes de se infectar com o parasita. É provável que R. sanguineus tenha pouca importância epidemiológica na transmissão de H. canis no Brasil, pois este estudo, assim como pesquisas anteriores, demonstraram que a espécie foi incapaz de se infectar experimentalmente com o protozoário / Hepatozoon canis is a hemoparasite that afflicts dogs in several regions of the world. Rhipicephalus sanguineus is considered to be the biologic vector of this agent, although other species may act as possible vectors. In Brazil, H. canis is described mainly in rural areas, where dogs are infested by other species, such as Amblyomma spp. The aim of this study was to transmit experimentally H. canis to different species of ticks, using naturally infected dogs. For this purpose A. cajennense and R. sanguineus nymphs and A. cajennense and A. ovale adults were used. After the repletion of specimens fed on a naturally infected animal, we searched for development forms of the protozoa in hemolymph, gut and hemocoel of the ticks by cytological and histopathologic examinations. Some ticks were also examined by molecular detection (PCR). Only two female ticks of the species A. cajennense contained structures morphologically similar to Hepatozoon spp. and oocysts were recovered from the hemocoel of an A. ovale female. In addition, two females of A. ovale and one female of A. ovale were positive through PCR. However, our results are not enough to characterize these species as vectors of H. canis mainly because many ticks were used in experimental infections and few were infected with the parasite. It is likely that R. sanguineus has little epidemiological importance in the transmission of H. canis in Brazil, since this research and previous researchers demonstrated that R. sanguineus was unable to experimentally get infected with the protozoan

Orientador: Lucia Helena O'Dwyer / Banca: Elizabeth Moreira dos Santos Schmidt / Banca: Gervásio Henrique Bechara / Resumo: Hepatozoon canis é um hemoparasita transmitido por carrapatos que afeta cães em diversas regiões do mundo. Rhipicephalus sanguineus é considerado seu vetor biológico, entretanto, é possível que existam outros vetores. No Brasil, H. canis é descrito principalmente em áreas rurais, onde cães podem ser infestados por outras espécies, incluindo Amblyomma spp. O objetivo do presente trabalho foi infectar experimentalmente diferentes espécies de carrapatos com H. canis, a partir de cães naturalmente infectados. Para isso, foram utilizadas ninfas de A. cajennense e R. sanguineus e adultos de A. cajennense e A. ovale. Após o ingurgitamento dos espécimes em animal infectado, foi realizada pesquisa de formas evolutivas do protozoário na hemolinfa, intestino e hemocele dos ixodídeos, por técnicas citológicas e histológicas. Alguns carrapatos foram submetidos ao diagnóstico molecular pela técnica de PCR. Somente em duas fêmeas de A. cajennense foram observadas estruturas morfologicamente semelhantes a Hepatozoon spp. e uma fêmea de A. ovale apresentou oocistos na hemocele. Além disso, duas fêmeas de A. ovale e uma de A. cajennense foram positivas na PCR. Entretanto, não é possível caracterizar essas espécies como vetores de H. canis, pois foram usados muitos exemplares nas infecções experimentais e poucos foram capazes de se infectar com o parasita. É provável que R. sanguineus tenha pouca importância epidemiológica na transmissão de H. canis no Brasil, pois este estudo, assim como pesquisas anteriores, demonstraram que a espécie foi incapaz de se infectar experimentalmente com o protozoário / Abstract: Hepatozoon canis is a hemoparasite that afflicts dogs in several regions of the world. Rhipicephalus sanguineus is considered to be the biologic vector of this agent, although other species may act as possible vectors. In Brazil, H. canis is described mainly in rural areas, where dogs are infested by other species, such as Amblyomma spp. The aim of this study was to transmit experimentally H. canis to different species of ticks, using naturally infected dogs. For this purpose A. cajennense and R. sanguineus nymphs and A. cajennense and A. ovale adults were used. After the repletion of specimens fed on a naturally infected animal, we searched for development forms of the protozoa in hemolymph, gut and hemocoel of the ticks by cytological and histopathologic examinations. Some ticks were also examined by molecular detection (PCR). Only two female ticks of the species A. cajennense contained structures morphologically similar to Hepatozoon spp. and oocysts were recovered from the hemocoel of an A. ovale female. In addition, two females of A. ovale and one female of A. ovale were positive through PCR. However, our results are not enough to characterize these species as vectors of H. canis mainly because many ticks were used in experimental infections and few were infected with the parasite. It is likely that R. sanguineus has little epidemiological importance in the transmission of H. canis in Brazil, since this research and previous researchers demonstrated that R. sanguineus was unable to experimentally get infected with the protozoan / Mestre

Made available in DSpace on 2014-07-29T15:07:33Z (GMT). No. of bitstreams: 1 Dissertacao Herika Xavier da Costa.pdf: 698865 bytes, checksum: 5690033d276bcffe9deb9d5e0535394d (MD5) Previous issue date: 2011-02-25 / The most important hemoparasites in dogs clinic are often associated with the manifestation of thrombocytopenia, being characterized by a lowering in platelet numbers. The aim of the current study was to verify the involvement of hemoparasites in finding thrombocytopenia in dogs from the city of Goiânia treated at the Veterinary Hospital of Federal University of Goiás (HV/EV/UFG). For this study, 300 animals were selected and divided into two groups:one group with 150 animals with thrombocytopenia (< 200.000 platelets/mm3)and another one with 150 non-thrombocytopenic animals (&#8805; 200.000 platelets/mm3). Blood samples with EDTA were collected in the two groups for total DNA extraction. All DNA eluates were tested by PCR for specific detection of Ehrlichia canis, Anaplasma canis,Hepatozoon canis, Mycoplasma haemocanis, Babesia canis vogeli, Babesia gibsoni and Theileria equi. The frequency of positive samples within the group of thrombocytopenic animals was 71.3% (107/150) to E. canis, 8.7% (13/150) for A. platys, 9.3% for B. c. vogeli (14/150), 2.0% (3/150) for H. canis and 3.3% (5/150)for M. haemocanis.In the group of non-thrombocytopenic animals the frequency of positives was 14% (21/150) for E. canis, 3.3% (5/150) for A. platys, 0.7% (1/150) for B. c. Vogeli, 4.0% (6/150) for H. canis and 1.3% (2/150) for M.haemocanis. Babesia gibsoni and Theileria equi were not detected using PCR assays.Statisti cally significant associations between thrombocytopenia and infections by hemoparasites were only observed for E. canis (P <0.05) and B. c.vogeli (P <0.05). The most frequently hemoparasitosis was Canine Monocitic Erliquiosis, which occurred in 71,33% (107/150) within thrombocytopenic dogs group and in 14% (21/150) within non-thrombocytopenic dogs group. There was a relationship between the thrombocytopenia degree observed and the infection by E. canis. Values of severe thrombocytopenia (<50.000 platelets/mm3 blood) can be considered an indicator for infection of E. canis. / Os principais hemoparasitos de importância na clínica de cães estão, frequentemente, relacionados com a manifes tação de trombocitopenia, a qual é caracterizada por uma diminuição no número de plaquetas. Objetivou-se com este trabalho verificar o envolvimento de hemoparasitos nos achados de trombocitopenia em cães atendidos no Hospital Veterinário da Universidade Federal de Goiás. Para o estudo foram selecionados 300 animais, divididos em dois grupos de 150, sendo um grupo de animais trombocitopênicos (<200.000 plaquetas/mm3) e outro grupo representado por animais não-trombocitopênicos (&#8805;200.000 plaquetas/mm3). Foram coletadas amostras de sangue com EDTA dos dois grupos para a extração de DNA total. Os eluatos de DNA foram, todos, submetidos a testes de PCR para a detecção específica de Ehrlichia canis, Anaplasma canis, Hepatozoon canis, Mycoplasma haemocanis, Babesia canis vogeli, Babesia gibsoni e Theileria equi. A frequência de amostras positivas entre o grupo de animais trombocitopênicos foi de 71,3% (107/150) para E. canis, 8,7% (13/150) para A. platys, 9,3% para B. c. vogeli (14/150), 2,0% (3/150) para H. canis e 3,3% (5/150) para M. haemocanis. No grupo de não-trombocitopênicos a frequência de positivos foram de 14% (21/150) para E. canis, 3,3% (5/150) para A. platys, 0,7% (1/150) para B. c. vogeli, 4,0% (6/150) para H. canis e 1,3% (2/150) para M. haemocanis. Babesia gibsoni e Theileria equi não foram detectadas usando ensaios de PCR. Associações estatisticamente significativas entre casos de trombocitopenia e infecções por hemoparasitos foram observadas apenas para E. canis (P<0,05) e B. c. vogeli (P<0,05). A hemoparasitose de maior frequência foi a Erliquiose Monocitica Canina, ocorrendo em 71,33% (107/150) no grupo de cães trombocitopênicos e em 14% (21/150) do grupo de cães não trombocitopênicos. Verificou-se uma relação entre o grau de trombocitopenia e a infecção por E. canis. Valores de trombocitopenia severa (<50.000 plaquetas/mm3 de sangue) demonstrou ser um indicador de infecção por E. canis.

Please read the abstract in the section 00front of this document / Canine babesiosis, caused by the tick-borne protozoan Babesia canis rossi, is an economically important and potentially fatal disease of dogs in South Africa. The host's response to many infectious diseases is mediated (at least in part) by intercellular messengers called cytokines. One of the most important cytokines released is tumour necrosis factor (TNF). A study was designed to measure serum concentrations of TNF in dogs naturally infected with canine babesiosis and to relate TNF concentrations to clinical severity, mortality, rectal temperature and parasitaemia. There was a statistically significant difference in TNF concentrations between groups of differing disease severity, with a general trend of increasing mean 10g(TNF) with increasing severity of disease. A noteworthy finding was that dogs with hypoglycaemia had very high TNF (mean 15.03 nglml compared to a mean of 2.32 nglml for other sick dogs without hypoglycaemia). When TNF values were compared between survival and non-survival groups, there was no significant difference. The rectal temperature of the dogs in this study did not show any statistically significant association with TNF concentrations. When parasitaemia and TNF were examined within groups of infected dogs, there was no significant relationship. However, when the sample size was increased by pooling all infected dogs and treating them as a single group, there was a highly significant positive correlation (p = 0.003) between parasitaemia and serum TNF concentrations. The results ofthis study were encouraging and indicate that canine babesiosis may share a similar pathophysiology with human malaria in terms ofTNF being associated with disease severity. One ofthe most significant findings in this study was the presence ofvery high TNF values in two ofthree dogs with hypoglycaemia. Hypoglycaemia has not been previously recorded in dogs with babesiosis and is a potentially important finding particularly in view ofthe hypoglycaemia associated with malaria in humans. Malarial hypoglycaemia is correlated with a higher mortality in humans, especially in pregnant women and children. If the findings ofthis study can be Vl confinned and expanded, they may lend further support to the use of canine babesiosis as a model for some ofthe problems encountered in human malaria research. / Dissertation (MMed Vet (Med))--University of Pretoria, 2001. / Companion Animal Clinical Studies / unrestricted

A hypercoagulable state has been demonstrated in human falciparum malaria in mild and complicated forms of the disease. Disseminated intravascular coagulation (DIC) was implicated by some authors, but deemed a rare occurrence by others. The possibility of coagulopathy in Babesia canis rossi infections in the canine patient has also been suggested in the literature, but minimal work has been done to evaluate the clinicopathological nature of it in further detail. In the canine babesiosis (CB) pathogenesis thought-process, DIC has been implicated. A DIC-like syndrome, as evidenced by intravascular fibrin deposition and haemorrhage into muscles and tissues was found at post mortem in one study. On the basis of these findings, it was postulated that DIC might be a serious complication of severe Babesia infection in the dog. Clinical DIC (haemorrhagic diathesis) is however seldom seen. It was also hypothesised in the literature that the multiple organ dysfunction syndrome (MODS) demonstrated in the complicated form of Babesia was caused, in addition to tissue damage due to local hypoxia, by microthrombi as a result of a coagulopathy. This needs to be further investigated. Pulmonary thromboembolism (PTE) has not been implicated in CB, however thromboemboli in the lungs were found in dogs with immune-mediated haemolytic anaemia (IMHA) for which a similar mechanism of venous stasis, hypercoagulability and endothelial damage (as found in CB) is proposed. In humans, PTE is believed to be a major underdiagnosed contributor to mortality in 5 to 15% of hospitalised adults. If early diagnosis of PTE can be achieved, the mortality rate can certainly be decreased. A similar situation with resultant serious implications in complicated CB cases may exist. Clinically, PTE is suspected if a patient with a known prothrombotic condition develops sudden dyspnoea and tachypnoea. These clinical symptoms are frequently seen in complicated CB patients and may, in addition to being a compensatory mechanism for the metabolic acidosis and anaemia, be attributed to thrombus-induced mechanical changes in lung function. Pulmonary scintigraphy provides a sensitive means of diagnosing PTE. It was (and some authors still do) believed that a ventilation scintigraphic scan should be done in association with a perfusion scan to increase the specificity and accuracy of diagnoses. However, authors of the recent PISA-PED study in humans proposed that the sensitivity and specificity of a perfusion scan, without a ventilation scan, in patients with suspected PTE was sufficient. The incidence of PTE or the use of pulmonary perfusion scintigraphy in CB dogs has never been studied. The objective of this study was to prospectively evaluate the scintigraphic pulmonary perfusion pattern in hospitalised Babesia dogs in an attempt to ascertain whether a scintigraphic pattern consistent with PTE does indeed occur in these patients. The study consisted of a normal control group of nine mature healthy Beagle dogs aged 36 – 43 months and weighing 9.9 – 15kg and a Babesia group with 14 dogs of a variety of breeds that were naturally infected with Babesia, aged 6 – 103 months and weighing 6.3 – 25.5kg. Pulmonary perfusion scintigraphy was performed after making thoracic radiographs and performing a blood gas analysis in both groups. The scintigraphic images were visually inspected for changes suggestive of PTE. Surprisingly, not a single dog in the Babesia group had segmental or wedge-shaped perfusion defects which would have resulted in a high probability for PTE. The scintigraphic pulmonary perfusion pattern demonstrated was not significantly different between the two groups (p = 1.00). Many dogs in both groups had a mottled appearance on the right and left dorsal oblique images, which was not believed to be consistent with clinically relevant PTE. This study provides baseline data that may be used to further investigate the pulmonary perfusion pattern in Babesia dogs. / Dissertation (MMedVet (Diagnostic Imaging))--University of Pretoria, 2007. / Companion Animal Clinical Studies / unrestricted

No description available.

No description available.

Cystoisospora canis is an Apicomplexan parasite of the small intestine of dogs. C. canis produces monozoic tissue cysts (MZT) that are similar to the polyzoic tissue cysts (PZT) of Toxoplasma gondii, a parasite of medical and veterinary importance, which can reactivate and cause toxoplasmic encephalitis. We hypothesized that C. canis is similar biologically and genetically enough to T. gondii to be a novel model for studying tissue cyst biology. We examined the pathogenesis of C. canis in beagles and quantified the oocysts shed. We found this isolate had similar infection patterns to other C. canis isolates studied. We were able to superinfect beagles that came with natural infections of Cystoisospora ohioensis-like oocysts indicating that little protection against C. canis infection occurred in these beagles. The C. canis oocysts collected were purified and used for future studies. We demonstrated in vitro that C. canis could infect 8 mammalian cell lines and produce MZT. The MZT were able to persist in cell culture for at least 60 days. We were able to induce reactivation of MZT treated with bile-trypsin solution. In molecular studies, we characterized C. canis genetically using ITS1 and CO1 to build phylogenetic trees and found C. canis was most similar to C. ohioensis-like with ITS1 and more similar to T. gondii than any other coccidia using ITS1 and CO1. We identified genes and proteins involved with virulence, cyst wall structure, and immune evasion of T. gondii and examined the DNA of C. canis for orthologs. C. canis had orthologs with 8 of 20 T. gondii genes examined. Monoclonal and polyclonal antibody and lectin studies demonstrated similar tissue cyst wall proteins on C. canis MZT and T. gondii PZT. Our findings in vitro and using genetic characterization of C. canis indicated the presence of similar genes and proteins, and its close phylogenetic location with T. gondii demonstrate that C. canis may serve as a model to examine tissue cyst biology. The system we described provides a simple model to produce tissue cysts and to study host factors that cause reactivation of tissue cysts. / Ph. D.

L’étude des faunes du Quaternaire s’inscrit dans une dynamique de connaissance des paléoenvironnements et est de ce fait nécessaire pour mieux cerner les contraintes environnementales qui ont rythmé la dispersion des hominidés sur l’ensemble des continents. Le genre Canis, autour duquel nous avons axé ce travail de recherche, présente la particularité d’être resté constamment présent en Europe occidentale depuis son apparition, il y a plus de trois millions d’années, jusqu’à aujourd’hui. Cette constance fait de lui, malgré son caractère ubiquiste, un excellent témoin de l’évolution des paléoenvironnements.A travers l’analyse de la variabilité des populations actuelles et l’étude de dix séries fossiles du Sud de la France couvrant le Pléistocène, de nouveaux éléments de discussion sont avancés sur l’évolution des représentants du genre. Nos résultats, couplés à l’analyse critique des données bibliographiques nous ont dès lors permis de proposer une nouvelle phylogénie. Cette dernière permet non seulement de mieux cerner les phases d’apparition et de dispersion des différentes espèces du genre Canis, mais également de démontrer son potentiel biochronologique. Ainsi, trois grandes phases dans l’évolution du genre ont pu être mises en évidence. La transition de ces espèces est corrélée à de grands événements de l’histoire des faunes quaternaires (bioevent) et autorise de ce fait l’utilisation de cette phylogénie à des fins biochronologiques ainsi qu’une discussion autour des relations entre ces espèces et les paléocommunautés animales et humaines. / Quaternary mammals form an important part of the material available for researchers focusing on paleoenvironmental reconstructions. Their study is thus often used to infer the environmental constraints that set the pace of human dispersal through the world. The genus Canis, main subject of this thesis, is present in Western Europe since its origin three million years ago. This continuous presence makes it a good candidate as a paleoenvironmental proxy, even when considering its ecological plasticity.The study of ten fossil sequences from Southern France spanning the Pleistocene, coupled with the analysis of the variability of modern populations, bring new insights on the evolution of the members of this lineage. Our results, once confronted to previous studies, allowed us to propose a new phylogeny. This new framework permits a better understanding of the apparition and disappearance of the different species, but also demonstrates the biochronological potential of the Canis genus. Three major phases have been identified in its evolutionary history. The transition between the different Canids is correlated with major events in the history of quaternary mammals (bioevent). Thus, its phylogeny can be used for biochronological purposes and has to be considered in the bigger debates that focus on the interactions between animal communities and human groups.