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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.
11

Caracterização do microtranscriptoma de macrófagos infectados por cepas saprófita, atenuada ou virulenta de Leptospira spp. /

Garcia, Leandro Encarnação January 2018 (has links)
Orientador: Flavia Lombardi Lopes / Coorientador: Marcia Marinho / Banca: Juliana Regina Peiro / Banca: Jaqueline Carvalho de Oliveira / Banca: kathlenn Liezbeth de Oliveira da Silva / Resumo: Leptospirose é considerada uma zoonose de importância global causada pela bactéria Leptospira spp. A incidência da doença chega a um milhão de casos severos no mundo, atingindo uma mortalidade de 60.000 óbitos/ano. Apesar de considerados avanços na pesquisa sobre a doença, há muito ainda a se descobrir sobre sua patogenicidade. A influência de mecanismos epigenéticos em processos patológicos, particularmente da regulação pós-transcricional mediada por RNAs não-codificadores, é fundamental. Uma gama de estudos vem relatando a influência desses mecanismos na resposta imune do hospedeiro em uma variedade de infecções bacterianas. O objetivo desse estudo foi identificar e caracterizar, pela primeira vez, a influência de miRNAs na regulação da resposta de macrófagos frente a infecção por Leptospira. Foi realizado um microtranscriptoma, através da técnica de microarranjo, em macrófafgos murinos J774A.1 desafiados por cepa virulenta, atenuada e saprófita de Leptospira após 8h de infecção. Após análise dos dados, identificamos 29 miRNAs modulados pela infecção comparados ao controle, com fold change ± 1.5 e p-valor<0,01. Na análise de enriquecimento funcional, encontramos um grande número de alvos para os miRNAs modulados participando em processos-chave da resposta imune. Podemos sugerir que a regulação pós-transcricional por miRNAs possui papel na resposta do hospedeiro em infecção por Leptospirose, e que essa resposta é dependente da espécie, bem como da virulência da bactéria. / Abstract: Leptospirosis is a bacterial zoonosis of global importance, caused by Leptospira. The incidence of disease leading to one million severe cases and 60,000 deaths per year. Despite considerable advances in research, much is yet to be discovered about disease pathogenicity. The influence of epigenetic mechanisms, particularly RNA-mediated post-transcriptional regulation of host immune response has been proven vital following a variety of bacterial infections. The aim of this study was to identify and characterize, for the first time, the influence of miRNAs on the regulation of the immune response to Leptospira infection. We examined the microtranscriptome, trough microarray technique, of macrophages J774A.1 following an 8h infection with virulent, attenuated and saprophyte strains of Leptospira. Microarray analysis revealed that 29 miRNAs were de-regulated by the Leptospira strains compared to control with fold change ±1.5 and p-value <0.01. Enrichment analyses of the targets of these differentially expressed miRNAs suggest that several processes involved in immune response are directly regulated by miRNAs. We suggest that posttranscriptional regulation by miRNAs may play a role in host response to infection in leptospirosis, and that this response is dependent on species and bacterial virulence. / Doutor
12

The detection of Burkholderia spp. and pathogenic Leptospira spp. in South Africa

Saif, Adrienne N. 18 March 2013 (has links)
Leptospirosis is a zoonosis of ubiquitous distribution and causes a wide spectrum of disease. Burkholderia species are important plant and human pathogens. Little or no investigation has been performed on any clinically-relevant Burkholderia or Leptospira species in Johannesburg. Environmental samples were taken from different sites in Johannesburg along the Jukskei River. These were subjected to culturing for Burkholderia spp. and polymerase chain reaction (PCR) for Burkholderia and Leptospira spp. Human serum, animal serum and kidney samples were also subjected to PCR for both organisms. A Leptospira IgM ELISA was also performed on human serum samples. More Burkholderia spp. were isolated by culture from soil samples than water samples. The PCR yielded a significantly higher PCR positive from soil samples (p = 0.015). There was a high prevalence of pathogenic Leptospira spp. in soil samples. The ELISA yielded only 7.8% (26/332) positive samples. There were no human or animal positive PCR results for either organism. There is an environmental presence of both leptospires and Burkholderia in the area sampled. More studies are needed to establish how both organisms might affect patients with compromised immune systems, and how often both infections are incorrectly or under-diagnosed.
13

Estudo da infecção da leptospirose humana em coabitantes de casos ocorridos no Vale do Rio Aricanduva, município de São Paulo, 1983 / Study of human leptospirosis infection in cohabitants of cases occurring in the Aricanduva River Valley, São Paulo municipality, 1983

Souza, Doralice de 03 March 1986 (has links)
Realizamos uma investigação epidemiológica em uma zona que fora inundada pela rio Aricanduva e seus afluentes, a leste do município de São Paulo, em 61 coabitantes de casos confirmados laboratorialmente de leptospirose humana ocorridos em 1983, residentes nessa área, com o objetivo de conhecer o nível de infecção por leptospiras nesse grupo de pessoas. Para pesquisa de anticorpos anti-leptospiras realizamos o teste de soroaglutinação microscópica nas 61 amostras de soro colhidas, tendo sido considerado soro reagente aquele que apresentou um título mínimo igual ou superior a 1:100. Para diferenciarmos se a infecção encontrada era recente ou passada, além de outros dados epidemiológicos investigamos a presença de anticorpos da classe IgM nesses soros por meio da prova de hemaglutinação passiva, considerando significante o título igual ou maior que 1:128. Os resultados nos mostraram que 18 pessoas, ou seja 29,6 por cento dos coabitantes eram de prendas domésticas, enquanto que 18,2 por cento eram menores e 6,6 por cento eram aposentados; 6,6 por cento eram operários não qualificados, ficando outras ocupações com 3,3 por cento ou 1,6 por cento . Em relação ao meio ambiente, as unidades residenciais investigadas eram diferentes daquelas descritas na literatura no tocante a casos de leptospirose humana. Estas apresentavam codições de urbanismo, ou seja, eram servidas por transporte coletivo nas proximidades em 95,8 por cento , tinham iluminação pública em 79,2 por cento , apresentavam ruas pavimentadas em 75 por cento , além de serem servidas por rede de esgoto em 70,8 por cento e por rede pública de abastecimento de água em 100. por cento . Quanto ao tipo de construção, 100 por cento era de alvenaria. Em relação a fatores que poderiam favorecer a infecção humana por leptospiras verificamos que quase 90 por cento das unidades residenciais estudadas tinham terrenos baldios a menos de 100 m de distincia, 58,4 por cento apresentavam ratos ou nas próprias dependências ou nas suas proximidades e 79,1 por cento das casas estavam localizadas até 200 m de correntes fluviais. Dos 61 coabitantes estudados, 42 (67,8 por cento ) tiveram um ou mais contato com enchentes, a maioria das quais ocorreram nos meses de janeiro e fevereiro de 1983, época aproximada em que 127 (63,5 por cento ) dos 200 doentes desse ano também o fizeram. Quanto ao nível de infecção, encontramos 6(9,8 por cento ) amostras de soro, reagentes para os sorotipos panama (2), copenhageni (1), javanica (2) e patoc (1). Todos esses dados sugeriram influência do binômio enchente-população murina sobre esse nível de infecção. As 61 amostras de soro examinadas foram negativas para pesquisa de IgM fazendo-nos considerar os soros reagentes como relativos a uma infecção passada, presumivelmente relacionados à época de infecção do caso. / It was investigated actual leptospirosis prevalence, using epidemiological methodology, in a zone that was flood in 1983 by Aricanduva river and their tributaries situated at the east side of São Paulo country. On that time, this zone was affected by human leptospirosis, diagnosticated through laboratory. The population selected for the present survey was a group of 61 human beings who dwelled together with subjects affected by leptospirosis, in order to establish the actual level of infection by leptospira remaining on such a population. In 61 serum samples it was determined the antileptospira anti-body activity following microscopic agglutination test, considering as a reagent serum that having a lower tittle equal or higher than 1:100. In order to differentiate if the infection was either recent or anciently adquired, it was investigated, together with epidemiological data, the presence of antibodies concerning to IgM class using passive hemagglutination test, considering as significant a tittle equalor higher than 1:128. The population distribution according to the occupational activities showed that 29,6 per cent (18subjects) belonged to home task category, 18,2 per cent were children, 6,6 per cent were retired by social security laws, 6,6 per cent non-qualified manual workers. The rest of surveyed population belonged to indetermined or to different labor activities. In relation to living environment, the residential units were different to those previously descrived in cases of human leptospirosis. Houses showed characteristics of an urban environment, having 95,8 per cent a public transport system, 79,2 per cent had public lighting, 75 per cent had streets with pavement, 70,8 per cent showed drainage system and 100 per cent drinking water service. Masonry was detected in 100 per cent of buildings. Those factors which could favor human infection development by leptospira were also studied. It was verified that 90 per cent of residential units showed uncultivated yards in a radio lower to 100 m around the house, 58,4 per cent of cases studied had rats in or near the house and 79,1 per cent of houses were localized near the river (less than 200m). 67,8 per cent (42 subjects) had the chance to contact with flood water once or many times, ocurred most of them, during the months of january or february 1983. At that time, also 127 from 200 patients affected by leptospirosis (63,5 per cent ) had a similar chance of contact with flood water in 1983. It was found that 9,8 per cent (6 cases) of serum samples showed reagents for serovars panama (2), copenhageni (1), javanica (2) and patoc (1). All the data obtained from this research suggest the influence of flood-rat population binomial on the level of infection detected. Looking for IgM, 61 serum samples were found negative, which could be interpreted as the serum reagents were compatible with an past infection, may be related to the time of infection of the cases considered as leptospirosis in 1983.
14

Identificación de los serogrupos de Leptospira spp. en alpacas del IVITA Maranganí

Better Baca, Yaquelyn January 2016 (has links)
Identifica los serogrupos de Leptospira spp. presentes en las alpacas del IVITA Maranganí. La muestra es de 126 alpacas mayores a 1 año de edad en la Raya - Cusco. Los sueros obtenidos son evaluados mediante la Prueba de Microaglutinación (MAT) en la Sección Bacteriología y Micología del Laboratorio de Microbiología y Parasitología de la Facultad de Medicina Veterinaria de la Universidad Nacional Mayor de San Marcos, donde se utilizan serovares de referencia internacional de 21 serogrupos patógenos de Leptospira spp. El estudio concluye en la identificación de 5 serogrupos no reportados en alpacas: Ballum, Djasiman, Hurtsbridge, Panama y Ranarum. / Tesis
15

Frecuencia de infección por Leptospira sp. en ardillas nuca blanca (Sciurus stramineus) silvestres en el Patronato del Parque de las Leyendas "Felipe Benavides Barreda"

Montes Aliaga, Daniel January 2009 (has links)
El objeto del presente estudio fue detectar la frecuencia de anticuerpos contra Leptospira sp. en la población de ardillas nuca blanca (Sciurus stramineus) silvestres capturadas en el zoológico Parque de Las Leyendas. Para tal fin se colectaron 35 muestras de suero de ardillas nuca blanca de ambos sexos, diferentes edades y zonas de captura en el zoológico, para la detección de anticuerpos contra Leptospira sp. mediante la prueba de microaglutinación (MAT). El 82.3% (29/35) de animales tuvieron anticuerpos contra Leptospira sp. del cual el 60% correspondió a los serovares icterohemorraghiae, seguidos por georgia con 31,42%, canícola con 5.71%, y australis con 2.85%. No hubo diferencia estadística entre la presencia de anticuerpos contra Leptospira sp y las variables sexo, edad y área de procedencia de las ardillas nuca blanca en el zoológico. Los resultados obtenidos indican que la infección leptospiral está presente en las ardillas nuca blanca pudiendo constituir un riesgo para los animales de la colección faunística y las personas que laboran en el zoológico. / The purpose of this study was to detect frequency of antibodies against Leptospira sp. in the neck white squirrels population (Sciurus stramineus) wild caught in the Parque de las Leyendas Zoo. To this end were collected 35 samples of serum from neck white squirrels (Sciurus stramineus) of both sexs and various ages caught in the zoo, which were analyzed for antibodies against Leptospira sp. through micro agglutination test (MAT). The 82.3% (29/35) of animals had antibodies against Leptospira sp. of which 60% corresponded to serovars icterohemorraghiae, followed by georgia with 31.42%, canicola 5.71%, and australis with 2.85%. There was no statistical difference between the presence of antibodies against Leptospira sp and the variables sex, age and area of origin of the neck white squirrel (Sciurus stramineus) in the zoo. The results indicate that leptospiral infection is present in the neck white squirrels (Sciurus stramineus) pose a risk to animals and the collection faunal people who work at the zoo.
16

Seroprevalencia de leptospirosis en alpacas de la localidad de Quimsachata-Puno en época de lluvias

Santos Sánchez, Yvan Roger January 2006 (has links)
La leptospirosis es una enfermedad zoonótica, cuyo agente etiológico es la Leptospira interrogans, que afecta tanto a animales domésticos y silvestres, como al hombre. El objetivo del presente estudio fue estimar la seroprevalencia de leptospirosis en alpacas durante la época de lluvias. Con tal propósito se analizaron mediante la prueba de microaglutinación, sueros provenientes de 344 animales del C.I.P. Quimsachata perteneciente a la E. E. ILLPA - INIA - Puno, evaluando la asociación de las variables sexo y edad con la reacción a la prueba. Del total de sueros analizados el 44,77% (154/344) fueron positivos. Los serovares detectados fueron pomona, icterohaemorrhagiae, y canicola, no encontrándose ningún reactor a hardjo. Los serovares más frecuentes fueron pomona con 43,60% (150/344), icterohaemorrhagiae con 9,88% (34/344) y canicola con 1,45% (5/344). Al evaluar la variable edad, éste se analizó relacionado con el sexo; no habiendo ningún suero positivo en los tuis; mientras que para los adultos se encontró en hembras 60,98% y machos 74,36%. Al considerar la positividad de los sueros relacionados con la variable sexo, se observa ausencia de significación estadística (p > 0.05) indicando independencia de las variables analizadas; y considerando la variable edad se observa claramente la existencia de asociación (p menor a 0,05). Los altos títulos hallados para pomona e icterohaemorrhagiae en estos animales, sugieren una fuerte infección activa durante la época de lluvia. Palabras Claves: Leptospirosis, alpacas, seroprevalencia. / The Leptospirosis is a zoonotic infections disease, affecting wild and domestics animals and human beings, caused by the Leptospira interrogans. The objective of this study was to estimate the prevalence of leptospirosis in the alpacas during the period of rains. With such an intention were analyzed by means of microaglutination tests, serum of 344 animals of C.I.P. Quimsachata - E.E. ILLPA - INIA - Puno, evaluating the association of the sex and age with the reaction of the test. Of the serum samples analyzed, the 44,77% (154/344) was positive. The detected serovars were pomona, icterohaemorrhagiae, and canicola, not being antibodies against hardjo. Of the 4 studied serovars, pomona showed the highest prevalence 43,60% (150/344), followed by icterohaemorrhagiae with 9,88%(34/344) and canicola with 1,45%(5/344), not finding positive samples in the young animals, whereas for the adults was 60,98 % in males and 74,36 % in females. Relating the positive serum to the sex, there exists absence of statistical significance (p> 0.05) indicating independence, and considering the age, statistical association exists (p menor a 0,05). The high titles found for pomona and icterohaemorrhagiae in these animals, suggest a strong active infection during the period of rain. Key Words: leptospirosis, alpacas, seroprevalence.
17

Application of the polymerase chain reaction for the rapid diagnosis of leptospirosis /

Ellis, Geoffrey Richard. Unknown Date (has links)
Thesis (M.App.Sc.)--University of South Australia, 1995.
18

Identifying ecological factors affecting populations of reservoir hosts of leptospirosis : implications for management /

Rivera, Dario Fernando. January 2005 (has links) (PDF)
Thesis (M.Phil.) - University of Queensland, 2005. / Includes bibliography.
19

Estudo da infecção da leptospirose humana em coabitantes de casos ocorridos no Vale do Rio Aricanduva, município de São Paulo, 1983 / Study of human leptospirosis infection in cohabitants of cases occurring in the Aricanduva River Valley, São Paulo municipality, 1983

Doralice de Souza 03 March 1986 (has links)
Realizamos uma investigação epidemiológica em uma zona que fora inundada pela rio Aricanduva e seus afluentes, a leste do município de São Paulo, em 61 coabitantes de casos confirmados laboratorialmente de leptospirose humana ocorridos em 1983, residentes nessa área, com o objetivo de conhecer o nível de infecção por leptospiras nesse grupo de pessoas. Para pesquisa de anticorpos anti-leptospiras realizamos o teste de soroaglutinação microscópica nas 61 amostras de soro colhidas, tendo sido considerado soro reagente aquele que apresentou um título mínimo igual ou superior a 1:100. Para diferenciarmos se a infecção encontrada era recente ou passada, além de outros dados epidemiológicos investigamos a presença de anticorpos da classe IgM nesses soros por meio da prova de hemaglutinação passiva, considerando significante o título igual ou maior que 1:128. Os resultados nos mostraram que 18 pessoas, ou seja 29,6 por cento dos coabitantes eram de prendas domésticas, enquanto que 18,2 por cento eram menores e 6,6 por cento eram aposentados; 6,6 por cento eram operários não qualificados, ficando outras ocupações com 3,3 por cento ou 1,6 por cento . Em relação ao meio ambiente, as unidades residenciais investigadas eram diferentes daquelas descritas na literatura no tocante a casos de leptospirose humana. Estas apresentavam codições de urbanismo, ou seja, eram servidas por transporte coletivo nas proximidades em 95,8 por cento , tinham iluminação pública em 79,2 por cento , apresentavam ruas pavimentadas em 75 por cento , além de serem servidas por rede de esgoto em 70,8 por cento e por rede pública de abastecimento de água em 100. por cento . Quanto ao tipo de construção, 100 por cento era de alvenaria. Em relação a fatores que poderiam favorecer a infecção humana por leptospiras verificamos que quase 90 por cento das unidades residenciais estudadas tinham terrenos baldios a menos de 100 m de distincia, 58,4 por cento apresentavam ratos ou nas próprias dependências ou nas suas proximidades e 79,1 por cento das casas estavam localizadas até 200 m de correntes fluviais. Dos 61 coabitantes estudados, 42 (67,8 por cento ) tiveram um ou mais contato com enchentes, a maioria das quais ocorreram nos meses de janeiro e fevereiro de 1983, época aproximada em que 127 (63,5 por cento ) dos 200 doentes desse ano também o fizeram. Quanto ao nível de infecção, encontramos 6(9,8 por cento ) amostras de soro, reagentes para os sorotipos panama (2), copenhageni (1), javanica (2) e patoc (1). Todos esses dados sugeriram influência do binômio enchente-população murina sobre esse nível de infecção. As 61 amostras de soro examinadas foram negativas para pesquisa de IgM fazendo-nos considerar os soros reagentes como relativos a uma infecção passada, presumivelmente relacionados à época de infecção do caso. / It was investigated actual leptospirosis prevalence, using epidemiological methodology, in a zone that was flood in 1983 by Aricanduva river and their tributaries situated at the east side of São Paulo country. On that time, this zone was affected by human leptospirosis, diagnosticated through laboratory. The population selected for the present survey was a group of 61 human beings who dwelled together with subjects affected by leptospirosis, in order to establish the actual level of infection by leptospira remaining on such a population. In 61 serum samples it was determined the antileptospira anti-body activity following microscopic agglutination test, considering as a reagent serum that having a lower tittle equal or higher than 1:100. In order to differentiate if the infection was either recent or anciently adquired, it was investigated, together with epidemiological data, the presence of antibodies concerning to IgM class using passive hemagglutination test, considering as significant a tittle equalor higher than 1:128. The population distribution according to the occupational activities showed that 29,6 per cent (18subjects) belonged to home task category, 18,2 per cent were children, 6,6 per cent were retired by social security laws, 6,6 per cent non-qualified manual workers. The rest of surveyed population belonged to indetermined or to different labor activities. In relation to living environment, the residential units were different to those previously descrived in cases of human leptospirosis. Houses showed characteristics of an urban environment, having 95,8 per cent a public transport system, 79,2 per cent had public lighting, 75 per cent had streets with pavement, 70,8 per cent showed drainage system and 100 per cent drinking water service. Masonry was detected in 100 per cent of buildings. Those factors which could favor human infection development by leptospira were also studied. It was verified that 90 per cent of residential units showed uncultivated yards in a radio lower to 100 m around the house, 58,4 per cent of cases studied had rats in or near the house and 79,1 per cent of houses were localized near the river (less than 200m). 67,8 per cent (42 subjects) had the chance to contact with flood water once or many times, ocurred most of them, during the months of january or february 1983. At that time, also 127 from 200 patients affected by leptospirosis (63,5 per cent ) had a similar chance of contact with flood water in 1983. It was found that 9,8 per cent (6 cases) of serum samples showed reagents for serovars panama (2), copenhageni (1), javanica (2) and patoc (1). All the data obtained from this research suggest the influence of flood-rat population binomial on the level of infection detected. Looking for IgM, 61 serum samples were found negative, which could be interpreted as the serum reagents were compatible with an past infection, may be related to the time of infection of the cases considered as leptospirosis in 1983.
20

The Epidemiology of Canine Leptospirosis in the United States

Smith, Amanda Michelle 13 November 2020 (has links)
No description available.

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