A leishmaniose visceral, na sua forma clinica ativa, caracteriza-se por febre de longa duração, hepatoesplenomegalia e caquexia. No Brasil, a letalidade é, em média, de 7% e as principais causas de morte são: hemorragia, comorbidade com doenças imunossupressoras e infecção bacteriana. O mecanismo de aumento de infecção bacteriana na LV não está claro e uma das hipóteses, é que pode haver translocação bacteriana da mucosa intestinal para o lúmen dos vasos sanguíneos e ocasionar uma maior severidade da resposta imuno-inflamatória e com consequente piora clínica. O objetivo deste trabalho foi avaliar a ocorrência de translocação microbiana em hamsteres infectados experimentalmente com Leishmania (L.) infantum e correlacionar com as alterações histopatológicas encontradas no intestino dos animais infectados. Hamsteres (Mesocricetus auratus) foram infectados intraperitonealmente com 2x107 amastigotas de L. (L.) infantum e eutanasiados após 48, 72 horas e 15, 45 e 90 dias de infecção. Como grupo controle foram utilizados hamsteres inoculados intraperitonealmente com meio de cultura RPMI. Foram coletados: sangue, fezes, baço, intestinos grosso e delgado. Para detecção de amastigotas na mucosa intestinal, foi utilizada a técnica de PCR em tempo real (qPCR), imunohistoquímica e análise histopatológica, sendo que nesta técnica também foram avaliadas alterações histológicas no tecido intestinal. O baço foi utilizado para determinar a carga parasitária através da técnica de Stauber. Para detecção da translocação microbiana ou produtos desde, foi realizada a quantificação de lipopolissacarídeo (LPS) em plasma. Para avaliar a possível mudança da flora bacteriana intestinal, foi realizado sequenciamento bacteriano de amostra de fezes de hamsteres controles e infectados nos vários tempos de infecção. Observamos aumento da carga parasitária em baço e em intestino com o decorrer da infecção, sendo a diferença significativa aos 90 dias de infecção. Paralelamente, observamos aumento de LPS circulante nos animais infectados em diferentes tempos, 48 horas, 72 horas, 45 dias e 90 dias, com diminuição no período intermediário de 15 dias, porém com diferença significante somente aos 90 dias após a infecção em relação ao grupo controle. Alterações histopatológicas foram observadas no intestino grosso e delgado, variando de infiltrado inflamatório leve a grave, enterite, histiocitose e ainda presença de amastigotas. As alterações observadas ocorreram a partir de 48 horas de infecção, diferenciando a população do infiltrado inflamatório entre neutrófilos, linfócitos, e ainda eosinófilos em intestino grosso de animais com 90 dias de infecção. O sequenciamento de DNA bacteriano das fezes mostra que houve alteração no microbioma dos animais, porém não há identidade significante, ou seja, acima de 95% na maioria das bactérias. Concluímos que as alterações de histologia da mucosa, a invasão de amastigotas neste tecido e o aumento do LPS, sugerem que a translocação microbiana é um evento ocorrente durante a infecção por L. (L.) infantum neste modelo experimental. / Visceral leishmaniasis, in its active clinical form, is characterized by long-lasting fever, hepatosplenomegaly and cachexia. In Brazil, the lethality is, on average, 7% and the main causes of death are hemorrhage, comorbidity with immunosuppressive diseases and bacterial infection. The mechanism of increased bacterial infection in LV is unclear and one of the hypotheses is that there may be bacterial translocation of the intestinal mucosa to the lumen of the blood vessels and cause a greater severity of the immune-inflammatory response and consequent clinical worsening. The objective of this work was evaluate the occurrence of microbial translocation in Leishmania (L.) infantum infected-hamsters and correlate with the histopathological changes found in the gut of infected animals. Hamsters (Mesocricetus auratus) were infected intraperitoneally with 2x107 amastigotes of L. (L.) infantum and euthanized after 48, 72 hours and 15, 45 and 90 days of infection. As a control group, hamsters were inoculated intraperitoneally with RPMI culture medium. Were collected: blood, feces, spleen, large and small intestines. To detection amastigotes in intestinal mucosa, real-time PCR (qPCR), immunohistochemistry and histopathological analysis were used, and histological alterations in intestinal tissue were also evaluated. Spleen was used to determine the parasitic load through the Stauber technique. To detection of microbial translocation or products related, was performed quantification of lipopolysaccharide (LPS) in plasma. In order to evaluate the possible change in intestinal bacterial flora, bacterial sequencing of sample faeces from control and infected hamsters was carried. We observed increased parasite load on spleen and intestine as the infection progressed, the difference being significant at 90 days of infection. At the same time, we observed increased circulating LPS in infected animals at different times, 48 hours, 72 hours, 45 days and 90 days, with decrease in the intermediate period of 15 days, howeversignificant difference was observed only at 90 days post-infection in relation to control group. Histopathological changes were observed in the large and small intestine, ranging from mild to severe inflammatory infiltrate, enteritis, histiocytosis, and amastigotes. The changes occurred from 48 hours of infection, differentiating the population of the inflammatory infiltrate between neutrophils, lymphocytes, and even eosinophils in the large intestine of animals with 90 days of infection. |Bacterial sequencing shows that there was a change in the microbiome of the animals, but there is no significant identity, ie, above 95% in most bacteria. We conclude that changes in mucosal histology, invasion of amastigotes in this tissue and increase in LPS, suggest that microbial translocation is an event occurring during L. (L.) infantum infection in this experimental model.

A leishmaniose visceral, na sua forma clinica ativa, caracteriza-se por febre de longa duração, hepatoesplenomegalia e caquexia. No Brasil, a letalidade é, em média, de 7% e as principais causas de morte são: hemorragia, comorbidade com doenças imunossupressoras e infecção bacteriana. O mecanismo de aumento de infecção bacteriana na LV não está claro e uma das hipóteses, é que pode haver translocação bacteriana da mucosa intestinal para o lúmen dos vasos sanguíneos e ocasionar uma maior severidade da resposta imuno-inflamatória e com consequente piora clínica. O objetivo deste trabalho foi avaliar a ocorrência de translocação microbiana em hamsteres infectados experimentalmente com Leishmania (L.) infantum e correlacionar com as alterações histopatológicas encontradas no intestino dos animais infectados. Hamsteres (Mesocricetus auratus) foram infectados intraperitonealmente com 2x107 amastigotas de L. (L.) infantum e eutanasiados após 48, 72 horas e 15, 45 e 90 dias de infecção. Como grupo controle foram utilizados hamsteres inoculados intraperitonealmente com meio de cultura RPMI. Foram coletados: sangue, fezes, baço, intestinos grosso e delgado. Para detecção de amastigotas na mucosa intestinal, foi utilizada a técnica de PCR em tempo real (qPCR), imunohistoquímica e análise histopatológica, sendo que nesta técnica também foram avaliadas alterações histológicas no tecido intestinal. O baço foi utilizado para determinar a carga parasitária através da técnica de Stauber. Para detecção da translocação microbiana ou produtos desde, foi realizada a quantificação de lipopolissacarídeo (LPS) em plasma. Para avaliar a possível mudança da flora bacteriana intestinal, foi realizado sequenciamento bacteriano de amostra de fezes de hamsteres controles e infectados nos vários tempos de infecção. Observamos aumento da carga parasitária em baço e em intestino com o decorrer da infecção, sendo a diferença significativa aos 90 dias de infecção. Paralelamente, observamos aumento de LPS circulante nos animais infectados em diferentes tempos, 48 horas, 72 horas, 45 dias e 90 dias, com diminuição no período intermediário de 15 dias, porém com diferença significante somente aos 90 dias após a infecção em relação ao grupo controle. Alterações histopatológicas foram observadas no intestino grosso e delgado, variando de infiltrado inflamatório leve a grave, enterite, histiocitose e ainda presença de amastigotas. As alterações observadas ocorreram a partir de 48 horas de infecção, diferenciando a população do infiltrado inflamatório entre neutrófilos, linfócitos, e ainda eosinófilos em intestino grosso de animais com 90 dias de infecção. O sequenciamento de DNA bacteriano das fezes mostra que houve alteração no microbioma dos animais, porém não há identidade significante, ou seja, acima de 95% na maioria das bactérias. Concluímos que as alterações de histologia da mucosa, a invasão de amastigotas neste tecido e o aumento do LPS, sugerem que a translocação microbiana é um evento ocorrente durante a infecção por L. (L.) infantum neste modelo experimental. / Visceral leishmaniasis, in its active clinical form, is characterized by long-lasting fever, hepatosplenomegaly and cachexia. In Brazil, the lethality is, on average, 7% and the main causes of death are hemorrhage, comorbidity with immunosuppressive diseases and bacterial infection. The mechanism of increased bacterial infection in LV is unclear and one of the hypotheses is that there may be bacterial translocation of the intestinal mucosa to the lumen of the blood vessels and cause a greater severity of the immune-inflammatory response and consequent clinical worsening. The objective of this work was evaluate the occurrence of microbial translocation in Leishmania (L.) infantum infected-hamsters and correlate with the histopathological changes found in the gut of infected animals. Hamsters (Mesocricetus auratus) were infected intraperitoneally with 2x107 amastigotes of L. (L.) infantum and euthanized after 48, 72 hours and 15, 45 and 90 days of infection. As a control group, hamsters were inoculated intraperitoneally with RPMI culture medium. Were collected: blood, feces, spleen, large and small intestines. To detection amastigotes in intestinal mucosa, real-time PCR (qPCR), immunohistochemistry and histopathological analysis were used, and histological alterations in intestinal tissue were also evaluated. Spleen was used to determine the parasitic load through the Stauber technique. To detection of microbial translocation or products related, was performed quantification of lipopolysaccharide (LPS) in plasma. In order to evaluate the possible change in intestinal bacterial flora, bacterial sequencing of sample faeces from control and infected hamsters was carried. We observed increased parasite load on spleen and intestine as the infection progressed, the difference being significant at 90 days of infection. At the same time, we observed increased circulating LPS in infected animals at different times, 48 hours, 72 hours, 45 days and 90 days, with decrease in the intermediate period of 15 days, howeversignificant difference was observed only at 90 days post-infection in relation to control group. Histopathological changes were observed in the large and small intestine, ranging from mild to severe inflammatory infiltrate, enteritis, histiocytosis, and amastigotes. The changes occurred from 48 hours of infection, differentiating the population of the inflammatory infiltrate between neutrophils, lymphocytes, and even eosinophils in the large intestine of animals with 90 days of infection. |Bacterial sequencing shows that there was a change in the microbiome of the animals, but there is no significant identity, ie, above 95% in most bacteria. We conclude that changes in mucosal histology, invasion of amastigotes in this tissue and increase in LPS, suggest that microbial translocation is an event occurring during L. (L.) infantum infection in this experimental model.

This research was performed to determine; (1) the prevalence of Toxoplasma antibodies among starlings in Northern California, (2) if such starlings can transmit the disease, and (3) if tissues from seropositive starlings contain encysted forms of T. gondii.

The purpose of this research was to examine the colonization process and relationship of physico-chemical parameters to diatom and protozoan communities colonizing polyurethane foam (PF) artificial substrates in lentic habitats. This was the first study to utilize multivariate techniques for comparison of protozoan and diatom communities The following hypotheses were examined in this study: 1. diatom and protozoan species accrual is similar because the organisms are approximately the same size and share similar ecological conditions, 2. protozoan assemblages are influenced by the physicochemical parameters of their environment, and 3. diatoms and photosynthetic protozoans are more closely related to the physico-chemical parameters of their environment than are the protozoans of all trophic groups. PF substrates were placed in the littoral zone of lentic habitats. Substrates were sampled through a time series and examined for their diatom and protozoan species' presence-absences. The first hypothesis was tested by using the MacArthur-Wilson equilibrium model and by fitting the data to the model by non·linear least squares regression. Protozoan species accrual fit the model in most cases, while diatom species accrual did not. The second part of the research dealt with five lentic habitats in northern lower Michigan which were sampled as described above and concurrent with organismal sampling several physico-chemical parameters were sampled. These environmental parameters included pH, alkalinity, conductivity, temperature, and concentrations of dissolved oxygen, chloride, silica, ammonia, and total and ortho-phosphate. Protozoan communities were examined using reciprocal averaging ordination. It was found that the bog and marsh had distinct communities, while the three lakes did not. Several physicochemical parameters and factors correlated significantly with axes generated by samples in species space. The final section tested the degree of relationship among diatoms, autotrophic protozoans, and protozoans to the physicochemical parameters and factors. pH had the highest correlations with the first axes for each group. Diatom communities had the greatest degree of relationship to the physico-chemical parameters, evidence for this is provided by the greatest number of correlations between ordination axes and the physico-chemical parameters and factors. / Ph. D. / incomplete_metadata

A prevalência de patógenos intestinais foi estudada entre os índios da etnia Tapirapé, da Amazônia mato-grossense, por meio de técnicas coproparasitológicas, imunológicas e moleculares. Do total de 1526 amostras, 83,35% apresentaram ao menos um parasito intestinal e 65% tinham mais de um parasito (poliparasitismo). Entamoeba coli foi o mais prevalente (827/1526 - 54,19%). Entamoeba histolytica/dispar (581/1526 - 38,07%), Giardia intestinalis (287/1526 - 18,81%), Blastocystis spp. (257/1526 - 16,84%) e Ancylostoma spp. (293/1526 - 19,20%) também foram freqüentes. Cistos de Giardia intestinalis foram seqüenciados utilizando os genes <font face=\"Symbol\">b-Giardina e gdh. Apenas os assemblages A e B foram encontrados, sendo que o assemblage A foi o mais prevalente. Análise molecular de Blastocystis spp. demonstrou que, por meio do gene SSU-rNA, o subtipo 1 foi o mais dominante entre os Tapirapé, seguido pelos subtipos 2 e 3. Com base nisso, G. intestinalis e Blastocystis spp. são potencialmente zoonóticos. Os resultados corroboram com outros estudos realizados na Amazônia brasileira. / The prevalence of intestinal pathogens was studied in indigenous of the Tapirapé ethnic from Amazon region of Mato Grosso State, using the coproparasitological, immunological and molecular. Of the total 1,526 fecal samples 83.35% had at least one intestinal parasite and 65% had more than one parasite (poliparasitism). The most prevalent parasite was Entamoeba coli (827/1526 - 54.19%). Entamoeba histolytica/dispar (581/1526 - 38, 07%), Giardia intestinalis (287/1526 - 18.81%), Blastocystis spp. (257/1526 - 16.84%) and Ancylostoma spp. (293/1526 -19.20%) were found too. Cysts of G. intestinalis were sequence by <font face=\"Symbol\">b-Giardina and GDH gene. Only assemblages A and B were found and assemblage A was the most prevalent. The molecular characterization of Blastocystis spp. by SSU-rRNA demonstrated that subtype 1 was dominant followed by subtypes 2 and 3. So, G. intestinalis and Blastocystis spp. are potentially zoonotic. The results are in agreement with previous studies conducted in the Brazilian Amazon.

A prevalência de patógenos intestinais foi estudada entre os índios da etnia Tapirapé, da Amazônia mato-grossense, por meio de técnicas coproparasitológicas, imunológicas e moleculares. Do total de 1526 amostras, 83,35% apresentaram ao menos um parasito intestinal e 65% tinham mais de um parasito (poliparasitismo). Entamoeba coli foi o mais prevalente (827/1526 - 54,19%). Entamoeba histolytica/dispar (581/1526 - 38,07%), Giardia intestinalis (287/1526 - 18,81%), Blastocystis spp. (257/1526 - 16,84%) e Ancylostoma spp. (293/1526 - 19,20%) também foram freqüentes. Cistos de Giardia intestinalis foram seqüenciados utilizando os genes <font face=\"Symbol\">b-Giardina e gdh. Apenas os assemblages A e B foram encontrados, sendo que o assemblage A foi o mais prevalente. Análise molecular de Blastocystis spp. demonstrou que, por meio do gene SSU-rNA, o subtipo 1 foi o mais dominante entre os Tapirapé, seguido pelos subtipos 2 e 3. Com base nisso, G. intestinalis e Blastocystis spp. são potencialmente zoonóticos. Os resultados corroboram com outros estudos realizados na Amazônia brasileira. / The prevalence of intestinal pathogens was studied in indigenous of the Tapirapé ethnic from Amazon region of Mato Grosso State, using the coproparasitological, immunological and molecular. Of the total 1,526 fecal samples 83.35% had at least one intestinal parasite and 65% had more than one parasite (poliparasitism). The most prevalent parasite was Entamoeba coli (827/1526 - 54.19%). Entamoeba histolytica/dispar (581/1526 - 38, 07%), Giardia intestinalis (287/1526 - 18.81%), Blastocystis spp. (257/1526 - 16.84%) and Ancylostoma spp. (293/1526 -19.20%) were found too. Cysts of G. intestinalis were sequence by <font face=\"Symbol\">b-Giardina and GDH gene. Only assemblages A and B were found and assemblage A was the most prevalent. The molecular characterization of Blastocystis spp. by SSU-rRNA demonstrated that subtype 1 was dominant followed by subtypes 2 and 3. So, G. intestinalis and Blastocystis spp. are potentially zoonotic. The results are in agreement with previous studies conducted in the Brazilian Amazon.

The aim of this thesis was to provide a picture of the trypanosomosis and drug resistance prevalence in Eastern Province of Zambia, to understand the underlying factors of drug resistance (drug use habits), to improve the diagnosis of trypanosomosis in livestock and finally, to improve the diagnosis of isometamidium resistance in T.congolense. After an introductory part where available trypanosomosis and trypanocide resistance diagnostic methods are described and discussed, the body of the thesis is divided in two main sections. In the first section are presented the results of a cross-sectional and a longitudinal epidemiological survey describing the geographical distribution of trypanosomosis cases, of resistant isolates and of cattle treated with isometamidium chloride. The results of the monitoring of unsupervised treatments of cattle with isometamidium by farmers and veterinary assistants with the Isometamidium-ELISA technique are also presented. The second section describes the development of two new diagnostic methods, the first one allowing the diagnosis of trypanosome infections with high sensitivity and specificity through semi-nested polymerase chain reaction and restriction fragment length polymorphism. This is the first report of a pan-trypanosome PCR test (a single PCR test for the diagnosis of all important pathogenic trypanosomes of cattle). The second new method that was developed allows the diagnosis of isometamidium resistant T.congolense strains by PCR-RFLP. This is the first report of a PCR based diagnostic test of trypanocide resistance in T. congolense.<p> / Doctorat en sciences, Spécialisation biologie moléculaire / info:eu-repo/semantics/nonPublished