Cercarial Chaetotaxy and Sex Differentiation of Schistosoma mansoni Deriving from Humans and Nectomys squamipes (Muridae: Sigmondontinae) in Brazil

A comparative study was made between sympatric isolates of Schistosoma mansoni   : one from a wild rodent (R) Nectomys squamipes and another one from humans (H) isolated from a low endemic schistosomiasis transmission area in Brazil. Our purpose was to detect differences between them concerning chaetotaxy (number and pattern of distribution of the argentophilic papillae) of the cercariae by means of silver impregnation. No significant difference (x > 0.05) between isolates was noted. Nevertheless, a significant difference (x < 0.05) was observed in the cercarial index (ratio of the distance between the first and the second preacetabular papillae and the distance between the first and the second dorsal preacetabular papillae) of male and female cercariae in both isolates. Males presented a greater cercarial index than females. By means of multivariate analysis, male cercariae were distinguished from female cercariae through the following characteristics: average number of dorsal papillae on the right quadrant, average number of ventral middle papillae on the right quadrant (H isolate) and average number of dorsal middle papillae on the left quadrant (R isolate). The results suggest that R and H isolates belong to the same population that could complete its life cycle in rodent-snail-rodent fashion

A comparative parasitologic study on Biomphalaria glabrata snail and C3H/He mice infected with human and murine isolates of Schistosoma mansoni derived from Sumidouro, Rio de Janeiro, Brazil

Experiments were carried out to analyze the biological characteristics of two sympatric isolates of Schistosoma mansoni derived from humans and murines in a low endemic transmission area (Sumidouro county, state of Rio de Janeiro, Brazil). Sympatric reared-laboratory Biomphalaria glabrata and C3H/He mice were used as experimental hosts. Parameters assessed comprised: precercarial period, infectivity and mortality (snails), prepatent period, infectivity (percentage of cercariae maturation into adult worm) and intestinal egg count (mice). The murine isolate showed a shorter precercarial period and higher infectivity than human isolate (p < 0.05). This biological heterogenicity did not correspond to the vertebrate data because any biological parameter presented significant difference (p > 0.05). These data suggest that both isolates are local sub-populations, providing support for the hypotheses that in a same biotope mixed populations or sub-populations circulate among their main host (human beings) and/or rodent as an anfixenous infection

Natural infection of wild rodents by Schistosoma mansoni parasitological aspects

Submitted by Gentil Jeorgina ([email protected]) on 2012-01-04T15:40:27Z No. of bitstreams: 1 Natural infection of wild rodents by Schistosoma mansoni parasitological aspects.pdf: 308130 bytes, checksum: bcb9acbae612b21d4f9e8d4a2e9946cf (MD5)Made available in DSpace on 2012-01-04T15:40:27Z (GMT). No. of bitstreams: 1 Natural infection of wild rodents by Schistosoma mansoni parasitological aspects.pdf: 308130 bytes, checksum: bcb9acbae612b21d4f9e8d4a2e9946cf (MD5) Previous issue date: 1992Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Biologia. Rio de Janeiro, RJ, BrasilUniversidade do Estado do Rio de Janeiro. Departamento de Patologia e Laboratórios. Rio de Janeiro, RJ, BrasilUniversidade do Estado do Rio de Janeiro. Departamento de Patologia e Laboratórios. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Patologia. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Biologia. Rio de Janeiro, RJ, Brasilhe evaluation of the role of rodents as natural hosts of Schistosoma mansoni was studied at the Pamparrão Valley, Sumidouro, RJ, with monthly captures and examination of the animals. Twenty-three Nectomys squamipes and 9 Akodom arviculoides with a shistosomal infection rate of 56.5% and 22.2% respectively eliminated a great majority of viable eggs. With a strain isolated from one of the naturally infected N. squamipes, we infected 75% of simpatric Biomphalaria glabrata and 100% of albino Mus musculus mice. The adult worms, isolated from N. squamipes after perfusion were located mainly in the liver (91.5%) and the mesenteric veins (8.5%). The male/female proportion was 2:1. The eggs were distributed on small intestine segments (proximal, medial and distal portions) and the large intestine without any significant differences in egg concentration of these segments. In A. arviculoides, the few eggs eliminated by the stools were viable and there was litlle egg retention on intestinal segments. Considering the ease to complete S. mansoni biological cycle in the Nectomys/Biomphalaria/Nectomys system under laboratory conditions, probably the same is likely to occur in natural conditions. In support to this hypotesis there are also the facts that human mansonic shistosomiasis has a very low prevalence in Sumidouro and endemicity among the rodents has not changed even after repetead treatments of the local patients. Based on our experiments, we conclude that N. squamipes has become a natural host of S. mansoni and possibly may participate in keeping the cycle of schistosomiasis transmission at Pamparrão Valley

Cravo, canela, bala e favela Clove and cinnamon, guns and slums

A partir da discussão sobre o lugar do corpo feminino subalterno, palco de conflitos onde se desdobram as tensões resultantes das relações desiguais de gênero, raça e classe no Brasil, este artigo se propõe a realizar uma leitura de textos ficcionais recentes - nomeadamente os romances As mulheres de Tijucopapo, de Marilene Felinto, e Ponciá Vicêncio, de Conceição Evaristo, e o filme O céu de Suely, de Karim Aïnouz -, inserindo-os no debate de um projeto de tradução da agenda pós-colonial para o português. Decorrentes dessa abordagem, temas como a viagem, o deslocamento e o exílio farão parte da experiência subjetiva ficcionalizada que se irá enfocar, e serão, portanto, também objeto de interpretação<br>Based on the discussion about the subaltern woman's body as a stage of conflicts where the tensions resulting from Brazil's unequal gender, class and race relations unfold, this article intends to analyze recent fictional works - specifically the novels: Marilene Felinto's As mulheres de Tijucopapapo and Conceição Evaristo's Ponciá Vicêncio, as well as the film O céu de Suely, by Karim Aïnouz - in order to place them within the debate of translation of the post-colonial agenda into Portuguese. Focusing the subjective experience represented in these fictional narratives, themes like travel, dislocation and exile will also be analyze