Made available in DSpace on 2014-12-17T14:03:26Z (GMT). No. of bitstreams: 1 PatriciaBBMB.pdf: 749567 bytes, checksum: e355ba98f4fd47889fd16327a3ca1f09 (MD5) Previous issue date: 2005-07-11 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / American visceral leishmaniasis is a zoonosis caused by Leishmania infantum and transmitted by the bite of the sand flies Lutzomia longipalpis.The main domestic reservoir is the dog, while foxes and opposums are the known wild reservoirs. However, identification of natural infections with L. infantum in rodents appears for need of investigating the participation of these rodents how source of infection of the parasite. In the present work the Leishmania infantum infection was investigated in rodents captured in Rio Grande do Norte, aiming at to offer subsidies to the understanding of the epidemic chains of LVA in the State. Thirteen Galea spixii were distributed in four groups, being G1 the group control with four animals and the others, G2, G3 and G4, with three animals each. Those animals were intraperitoneally inoculated with 107 promastigotas of L. infantum and accompanied for, respectively, 30, 90 and 180 days. Weekly the animals were monitored as for the corporal weight and rectal temperature. At the end of each stipulated period the animals were killed. Blood were used for determination of the parameters biochemical and haematological, PCR, ELISA, microscopic examination and cultivation in NNN medium. Liver, spleen and lymph node were used in Giemsa-stained impression and cultivation in NNN medium. Liver and spleen fragments were still used in PCR and histopathological, respectively. At the same time 79 rodents of the species Rattus rattus, Bolomys lasiurus, Oligoryzomys nigripis, Oryzomys subflavus and Trichomys apereoides were captured in the Municipal districts of Brejinho, Campo Grande, Coronel Ezequiel, Passa e Fica and V?zea for identification of natural infection with L. infantum. Evidence of infection was checked by direct examination of Giemsa-stained impression of liver, spleen and blood and culture of these tissues in NNN medium. Antibodies were researched by ELISA. They were not found differences among the weigh corporal final, rectal temperature and biochemical and haematological parameters of the Galea spixii controls and infected. The rectal temperature of the animals varied from 36OC to 40OC. For the first time values of the haematocrit (33,6% to 42,8%), hemoglobin (10,2 to 14,5g/dl), erythrocyts number (4,67x106 to 6,90x106/mm3), total leukocytes (0,9x103 to 9,2x103/mm3), platelets (49x103 to 509x103/mm3) total proteins (1,56 to 6,06 g/dl), albumin (1,34 to 3,05 g/dl) and globulins (0,20 to 3,01 g/dl) of the Galea spixii were determined. The lymphocytes were the most abundant leucocytes. Infection for L. infantum was diagnosed in two animals euthanasied 180 days after the infection. In one of the animals was also identified antibodies anti-Leishmania. The parasite was not found in none of the five other species of rodents captured. Galea spixii are resistant to the infection for L. infantum and they are not good models for the study for visceral leishmaniose, although they can act as infection sources. More studies are necessary to determine the paper of the rodents in the epidemic chain of transmission of the visceral leishmaniose in the State of Rio Grande do Norte / A leishmaniose visceral americana ? uma zoonose causada pelo parasita Leishmania infantum e transmitida pela picada do fleb?tomo Lutzomya longipalpis. O c?o ? o principal reservat?rio dom?stico, enquanto que raposas e gamb?s s?o os reservat?rios silvestres conhecidos. No entanto, a identifica??o de infec??es naturais com L. infantum em roedores aponta para a necessidade de se investigar a participa??o destes animais como fonte de infec??o do parasita para os insetos vetores. No presente trabalho investigou-se a infec??o com parasita Leishmania infantum em roedores capturados no Rio Grande do Norte, objetivando oferecer subs?dios ? compreens?o das cadeias epidemiol?gicas da LVA no Estado. Treze pre?s da esp?cie Galea spixii foram distribu?dos em quatro grupos, sendo G1 o grupo controle com quatro animais e os demais, G2, G3 e G4, com tr?s animais cada. Esses animais foram inoculados por via intraperitonial com 107 promastigotas de L. infantum e acompanhados por, respectivamente, 30, 90 e 180 dias. Semanalmente os animais foram monitorados quanto ao peso corporal e temperatura retal. Ao final de cada per?odo estipulado os animais foram eutanasiados. O sangue colhido foi utilizado na determina??o dos par?metros bioqu?micos e hematol?gicos, PCR, ELISA, confec??o de esfrega?o sangu?neo e cultivo em meio NNN. Fragmentos de f?gado, ba?o e linfonodos foram utilizados para confec??o de l?minas por aposi??o e cultivo em meio NNN. Fragmentos de f?gado e ba?o foram ainda utilizados para realiza??o de PCR e histopatol?gico, respectivamente. Concomitantemente 79 roedores das esp?cies Rattus rattus,Bolomys lasiurus, Oligoryzomys nigripis, Oryzomys subflavus e Trichomys apereoides foram capturados nos Munic?pios de Brejinho, Campo Grande, Coronel Ezequiel, Passa e Fica e V?rzea para identifica??o de infec??o natural por L. infantum. O diagn?stico da infec??o nos animais foi realizado pelo exame direto das impress?es coradas com Giemsa e cultura em meio NNN de f?gado, ba?o e sangue. N?o foram encontradas diferen?as no o ganho de peso total, temperatura retal e par?metros bioqu?micos e hematol?gicos dos pre?s controles e infectados. A temperatura retal variou entre 36OC e 40OC. Pela primeira vez foram determinados os valores do hemat?crito (33,6% a 42,8%), hemoglobina (10,2 a 14,5g/dl), n?mero de eritr?citos (4,67x106 a 6,90x106/mm3), leuc?citos totais (0,9x103 a 9,2x103/mm3), plaquetas (49x103 a 509x103/mm3), prote?nas totais (1,56 a 6,06 g/dl), albumina (1,34 a 3,05 g/dl) e globulinas (0,20 a 3,01 g/dl) nesta esp?cie. Os linf?citos foram os leuc?citos mais abundantes. Infec??o por L. infantum foi diagnosticada em dois animais eutanasiados aos 180 dias, sendo que em um desses tamb?m foram identificados anticorpos contra o parasita. N?o foi observada positividade em nenhuma das cinco outras esp?cies de roedores capturadas. A esp?cie Galea spixii ? resistente ? infec??o por L. infantum e, portanto, n?o ? bom modelo para o estudo da leishmaniose visceral, embora possam atuar como fontes de infec??o. Mais estudos s?o necess?rios para que se possa determinar o papel dos roedores na cadeia epidemiol?gica da leishmaniose visceral no Estado do Rio Grande do Norte