Taxonomia e sistemática de helmintos de mamíferos silvestres do Parque Nacional Serra da Capivara, Piauí, Brasil

Abstract

CHAPTER I - The National Park Serra da Capivara, Piauí state, Brazil, presents an extraordinary scenario for improvement of the studies of helminth biodiversity. The Park has diversity mammals’ species among them marsupials and armadillos are frequently seen and occasionally found dead by running over on the road. Three specimens of opossum Didelphis albiventris and two of armadillo Dasypus novemcinctus were found dead in the Park and their viscera were donated by Fundação Museu do Homem Americano (FUMDHAM) to be studied in Instituto Oswaldo Cruz. Helminths collected in intestine were fixed in alcohol 70% or formal 4%. Parasites were clarified in glycerin for studies in microscopy of light. Some specimens were post-fixed in 1% OsO4 and potassium ferrocyanide 0.8%, dehydrated in alcoholic series, and conducted to critical point with CO2 coated with gold and visualized through scanning electron microscopy. Genomic DNA of the parasites was extracted using QIAmp DNA Mini Kit, and two set of primers were designed to polymerase chain reaction and amplicons sequenced. The species found were Aspidodera raillieti, and A. subulata from Didelphis albiventris and A. binansata, A. vazi and Hadrostrongylus speciosum from Dasypus novemcinctus from the Serra da Capivara National Park, Piauí State, Brazil were studied herein. New ultrastructural data of A. binansata and A. vazi were obtained. Sequences of cytochrome c-oxidase subunit 1 of mitochondrial DNA (mtDNA cox-1), partial mitochondrial 16S rDNA (rnnL), new sequence of partial 18S rDNA (SSU), internal transcriber spacers (ITS) 1, and 2 and 5.8S rDNA gene, and new sequence of partial 28S rDNA (LSU) gene of A. raillieti are presented. Genetic data includes the first sequence of SSU and LSU for A. raillieti and first LSU gene for Aspidoderidae. Additionally, first sequence of 16S rDNA of A. vazi was obtained. Phylogenetic analysis of maximum-likelihood using LSU gene showed Heterakoidea (represented by Aspidoderidae and Heterakidae) compose clade strongly supported (100%) and considered sister-group of Cosmocercoidea, represented by Rondonia rondonia and Orientatractis moraveci (Atractidae). Ramsonnematoidea, Rhigonematoidea and other Cosmocercoidea represented by Cosmocercoides pulcher and C. tonkinensis (Cosmocercidae) appear in a separeted clade with high statistical support. Cosmocercoidea is considered a paraphyletic group. New ultrastructural, genetic and of geographical distribution are presented and discussed. =========== CHAPTER II - The diagnosis of helminth eggs is routinely performed in the areas of human and veterinary parasitology as it provides a quick and low cost result for the treatment of parasitic diseases. In the Serra da Capivara National Park (PNSC), Piauí, Brazil, archaeological sites have revealed helminth eggs obtained in coprolites dating back thousands of years. Specific identification of eggs is difficult without the adult parasites being properly identified. The objective of this work was to study the biodiversity of helminth eggs of wild mammals from the PNSC, after identification of adult parasites. Seven species of wild mammals from a total of 16 specimens found dead were examined: deer, wild pig, agouti, ocelot, dog-eating fox, opossum and armadillo. The parasites collected from the gastrointestinal contents were identified by morphology and genetics. The eggs obtained from female adults were measured and photographed. A total of 12 species of helminth and their eggs were found, being 1 Acanthocephala and 11 Nematoda species. In the phylum Acanthocephala, Oncicola venezuelensis was found and among the Nematoda, four species of Aspidoderidae (Aspidodera raillieti, A. subulata, A. binansata and A. vazi), two Trichonstrongyloidea (Haemonchus sp. and Trichostrongylus colubriformis), two Molineidae (Molineus sp. and Hadrostrongylus speciosum), a Toxocaridae (Toxocara canis) and two Nematoda gen. sp. unidentified were reported. Our data compared with the eggs obtained from fresh faeces corroborate the presence of Aspidoderidae and Trichostrongyloidea members in wild mammals in the park area. When compared to eggs obtained in coprolites, the genera Toxocara and Oncicola appear in the ancestral and current fauna of carnivores, and is likely that species within this genus may be keeping their lifecycles for millennia in the park. In addition, an identification key to the species found in this study was designed to serve as an aid in the diagnosis of species. These data become important because they can serve as a comparative basis for the studies of current and ancestral fauna of helminths occurring in the park.