Mecanismo de interação magnética dos ovos de Schistosoma spp. e características biológicas da cepa Esteio, Rio Grande do Sul

• Ano de defesa: 2012
• Autor(a) principal: Maurer, Rafael Lucyk
• Orientador(a): Graeff-teixeira, Carlos
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Pontifícia Universidade Católica do Rio Grande do Sul
• Programa de Pós-Graduação: Programa de Pós-Graduação em Zoologia
• Departamento: Faculdade de Biociências
• País: BR
• Palavras-chave em Português: ZOOLOGIA; BIOLOGIA MOLECULAR; PARASITOLOGIA; TREMATÓDEOS; PARASITOS; GENÉTICA POPULACIONAL; ESQUISTOSSOMOSE
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::ZOOLOGIA
• Link de acesso: http://tede2.pucrs.br/tede2/handle/tede/233

The autochthonous transmission of schistosomiasis in Rio Grande do Sul was confirmed for the first time in 1998, establishing the southernmost focus in Americas. Although no morphological differences were detected in a previous study, the investigation of biological characteristics of the parasite in the current study showed some peculiarities that may be relevant for a better understanding of transmission dynamics in the Esteio focus and adequacy of control measures. The epidemiological study of this focus led to the development of a diagnostic method, Helmintex, more sensitive than the traditional methods for detecting small number of eggs shed in the patients feces. In this method eggs are isolated through magnetic interaction with paramagnetic beads and this mechanism could be related to the presence of iron in the eggshell. Schistosoma mansoni worms ingest large amounts of blood and requires specialized metabolic pathway for iron elimination. When analyzed by energy dispersive spectroscopy iron and small crystal structures probably magnetite were identified in the eggshell. The presence of structures with potentially magnetizing properties led to the magnetic characterization of Schistosoma eggs and demonstration of ferromagnetic and paramagnetic behavior. Eggs were also analyzed to see if other helminth eggs compositional differences were related to different taxonomic groups and habitat types. These findings stimulate further research on the metabolic pathway involving iron, development of new treatment modalities and diagnostic tools.