Please use this identifier to cite or link to this item: https://www.arca.fiocruz.br/handle/icict/7499
Title: Schistosoma mansoni population structure and persistence after praziquantel treatment in two villages of Bahia, Brazil
Authors: Blanton, Ronald Edward
Blank, Walter A
Costa, Jackson Mauricio Lopes
Carmo, Theomira Mauadie de Azevedo
Reis, Eliana Almeida Gomes
Silva, Luciano Kalabric
Barbosa, Lúcio Macedo
Test, Matthew R.
Reis, Mitermayer Galvão dos
Affilliation: Case Western Reserve University. Centre for Global Health and Diseases. Cleveland, OH, USA
Case Western Reserve University. Centre for Global Health and Diseases. Cleveland, OH, USA
Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil
Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil
Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil
Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil
Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil
Case Western Reserve University. Centre for Global Health and Diseases. Cleveland, OH, USA
Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil
Abstract: Praziquantel has been used to treat schistosome infections since 1979 and currently is the only chemotherapeutic agent in production for this purpose, raising concerns about the potential for the emergence of drug resistance. In practice, 10–20% of infected patients will continue to excrete eggs after treatment. It is not understood to what degree this represents selection of a resistant population or incomplete elimination due to the presence of immature worms at the time of treatment. We used a population genetics approach to test whether or not persistent Schistosoma mansoni parasites were drawn from the same population as susceptible parasites. In this study, stool samples were collected from 96% of individuals in two small Brazilian communities (populations 482 and 367) and examined for S. mansoni eggs. The combined prevalence of S. mansoni infections in the villages was 41%. Total egg DNA was extracted from each sample and was genotyped at 15 microsatellite markers. Day-to-day variation of the infrapopulation from an individual human host was low (median differentiation using Jost’s D = 0.010), so that a single stool was representative of the genotypes present in stool eggs, at least in the short term. Average pairwise analysis of D among all pre-treatment infrapopulations suggested moderate differentiation (mean D = 0.082 and 0.122 for the two villages), whereas the pre-treatment component population differentiation between the two communities was 0.047. The differentiation of the component population remaining after treatment from the fully susceptible component population was low (mean D = 0.007 and 0.020 for the two villages), suggesting that the persistent parasites were not selected by praziquantel treatment. We will continue to follow these communities for evidence of selection or changes in population structure.
Keywords: Praziquantel
Resistance
Microsatellite
Population genetics
Sampling
Genetic differentiation
Selection
DeCS: Anti-Helmínticos/administração & dosagem
Resistência a Medicamentos
Praziquantel/administração & dosagem
Schistosoma mansoni/classificação
Schistosoma mansoni/efeitos de drogas
Esquistossomose mansoni/quimioterapia
Seleção Genética
Adolescente
Adulto
Idoso
Idoso de 80 anos ou mais
Animais
Brasil
Criança
Fezes/parasitologia
Pré-Escolar
Feminino
Genótipo
Humanos
Repetições de Microssatélites
Lactente
Masculino
Schistosoma mansoni/genética
Adulto-Jovem
Issue Date: 2011
Publisher: National Institute of Health
Citation: BLANTON, R. E. et al. Schistosoma mansoni population structure and persistence after praziquantel treatment in two villages of Bahia, Brazil. International Journal of Parasitology, v. 41, n. 10, p. 1093-1099, 2011.
DOI: 10.1016/j.ijpara.2011.06.002.
ISSN: 1879-0135
Copyright: open access
Appears in Collections:BA - IGM - Artigos de Periódicos

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