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Molecular characterization of Sarcocystis spp. isolates from marsupials of the genus Didelphis spp. through the analysis of mitocondrial and apicoplast genes, internal transcribed spacers (ITS-1) and surface antigen genes

Grant number: 11/11226-4
Support Opportunities:Regular Research Grants
Duration: October 01, 2011 - September 30, 2013
Field of knowledge:Agronomical Sciences - Veterinary Medicine - Preventive Veterinary Medicine
Principal Investigator:Rodrigo Martins Soares
Grantee:Rodrigo Martins Soares
Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil


Sarcocystis neurona and Sarcocystis falcatula are very similar species that use marsupials of the gender Didelphis as definitive hosts. These mammals can participate as definitive hosts not only for these two parasites, but for other Sarcocystis such as Sarcocystis speeri and Sarcocystis lindsayi. Sarcocystis shed by opossums (except for S. neurona) can cause disease in a great variety of birds, being commonly associated with acute pulmonary sarcocistosis in zoos. Sarcocystis neurona is the most commonly associated parasite with the Equine Protozoal Myeloencephalitis in horses. In a previous work (unpublished results), we assessed the variability of Sarcocystis spp. isolated from opossums of the state of Rio Grande do Sul by sequencing the surface antigens genes. Unexpected results were found, possibly indicating two different lineages among the Sarcocystis isolates (genetically related to S. falcatula) that might exchange genes in possible sexual recombination processes. Also, a third Sarcocystis lineage, similar but not identical to S. neurona was detected. This last lineage does not share alleles with the former two. Our proposal is to study the genetic variation of the Sarocystis isolates from opossums captured in São Paulo, and those isolated from opossums of the state of Rio Grande do Sul by assessing other molecular markers in addition to the surface antigens genes. For that matter, we will analyze DNA Barcode markers. This marker allows the identification of a species by knowing one or more segments of standard gene sequences. The DNABarcode is known as a universal marker present in most of the eukaryote organisms (for example the Apicomplexa phylum), making them a very powerful marker for phylogenetic studies. In this project, loci genes of the mitochondrial and apicoplast genome will be evaluated as well the internal transcribed spacer of the ribosomal locus. In summary, our hypothesis is: If there are two lineages Sarcocystis that exchange genes with each other, it implies that both lineages belong to a mono-specific group with high genotypic and antigenic variability. These results may have a great impact in our knowledge of the different Sarcocystis species that infect opossums in our environment and also in the epidemiology of the infections caused by these protozoans. (AU)

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Scientific publications
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
VALADAS, SAMANTHA Y. O. B.; DA SILVA, JULIANA I. G.; LOPES, ESTELA GALLUCCI; KEID, LARA B.; ZWARG, TICIANA; DE OLIVEIRA, ALICE S.; SANCHES, THAIS C.; JOPPERT, ADRIANA M.; PENA, HILDA F. J.; OLIVEIRA, TRICIA M. F. S.; et al. Diversity of Sarcocystis spp shed by opossums in Brazil inferred with phylogenetic analysis of DNA coding ITS1, cytochrome B, and surface antigens. Experimental Parasitology, v. 164, p. 71-78, . (11/11226-4, 11/10550-2)
CESAR, MARINA O.; MATUSHIMA, ELIANA R.; ZWARG, TICIANA; DE OLIVEIRA, ALICE S.; SANCHES, THAIS C.; JOPPERT, ADRIANA M.; KEID, LARA B.; OLIVEIRA, TRICIA MARIA F. S.; FERREIRA, HELENA L.; BEDOYA LLANO, HORWALD ALEXANDER; et al. Multilocus characterization of Sarcocystis falcatula-related organisms isolated in Brazil supports genetic admixture of high diverse SAG alleles among the isolates. Experimental Parasitology, v. 188, p. 42-49, . (11/11226-4)

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