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| Author(s): |
Igor da Cunha Lima Acosta
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD) |
| Defense date: | 2017-08-23 |
| Examining board members: |
Solange Maria Gennari;
Marcelo Vasconcelos Meireles;
Sandra Mayumi Nishi;
Hilda Fátima de Jesus Pena;
Rodrigo Martins Soares
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| Advisor: | Solange Maria Gennari |
| Abstract | |
The genus Sarcocystis is composed of several species that are differentiated by the morphological, biological and molecular characteristics. More than 196 species found in mammals, birds and reptiles have been reported, and only 26 of these species have the complete known cycle. Toxoplasma gondii is an obligate intracellular parasite with cosmopolitan geographic distribution, capable of infecting a wide variety of mammals and birds, including man, characterizing its zoonotic potential. In recent decades, the number of penguins that have come from Argentine and Chilean Patagonia, the region of birth of these birds, to the Brazilian coast, where many of them are stranded and rescued, has increased significantly. Little is known about the diseases caused by protozoa in these birds. The present study had as objective to study epidemiological aspects of coccidia infection of the family Sarcocystidae in Magellanic Penguins (Spheniscus magellanicus), through molecular and serological analyzes. Two campaigns were carried out, one in 2014 and another in 2015, in order to obtain blood and tissue samples from penguins who died during rehabilitation at the Institute of Research and Rehabilitation of Marine Animals (IPRAM) in the municipality of Cariacica, Espírito Santo. Tissue samples (total = 514: muscle = 342, heart = 86, brain = 86) were collected from 310 birds. From the tissues of 54 penguins the mouse bioassay was performed for the isolation of T. gondii, but no isolates were obtained. Samples of 310 individuals had DNA extracted for coccidia from the Sarcocystidae family using the 18S rDNA, Transcribed internal spacer 1(ITS1), surface protein encoder (SAG)2, SAG3, SAG4, beta subunit of RNA polymerase (RPOB) and citocrome B (CytB) markers. Of these, 16 (3.0%) samples, of pectoral muscle, were positive and all were identical to Sarcocystis spp. when analyzed by the 18S marker. With ITS1, RPOB and CytB the Sarcocystis species were confirmed in 12 samples, all identical to S. falcatula-like. With the SAGs it was possible to observe that the sequences had no genetic variability. Of the 145 serum samples evaluated for the presence of anti-T. gondii antibodies by Modified Agglutination Test (MAT ≥20), 18 were positive with titers of: 20 (7 birds), 40 (9 birds) and 80 (2 birds). This is the first report of S. falcatula-like and the presence of antibodies to T. gondii in free-living magellanic penguins. (AU) | |
| FAPESP's process: | 13/25303-6 - Survey of Toxoplasma gondii in Magellanic penguins (Spheniscus magallanicus) in the State of Espírito Santo |
| Grantee: | Igor da Cunha Lima Acosta |
| Support Opportunities: | Scholarships in Brazil - Doctorate |