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| Author(s): |
Renata Molina Monteiro
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. , ilustrações. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD) |
| Defense date: | 2006-11-29 |
| Examining board members: |
Rodrigo Martins Soares;
Solange Maria Gennari;
Aristeu Vieira da Silva
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| Advisor: | Rodrigo Martins Soares |
| Field of knowledge: | Agronomical Sciences - Veterinary Medicine |
| Indexed in: | Banco de Dados Bibliográficos da USP-DEDALUS; Biblioteca Digital de Teses e Dissertações - USP |
| Location: | Universidade de São Paulo. Biblioteca da Faculdade de Medicina Veterinária e Zootecnia; T.1757 FMVZ |
| Abstract | |
Hammondia hammondi, Toxoplasma gondii, Neospora huguesi, Neospora caninum and Hammondia heydorni are the known members of the sub-family Toxoplasmatinae. H. heydorni and N. caninum use canids as definitive hosts whereas felids are the definitive hosts from T. gondii and H. hammondi. The definitive host of N. hughesi is unknown. Here, the nucleotide diversity at internal transcribed spacer (ITS-1) and heat shock protein (HSP70 kDa) loci in the subfamily toxoplasmatinae were studied. The HSP70 coding genes are widely used for phylogenetic studies in a number of other organisms specially within the genus Cryptosporidium. In the present study, it was amplified by PCR and sequenced 951 bases pairs (bp) from HSP70 coding gene from oocysts T.gondii-like (from cat), from oocysts N. caninum-like (from dog) and tachyzoites of N. hughesi grown on cell cultures. The primers were designed based on consensus sequences within EST sequences of N. caninum sequences and RNAm sequences of T. gondii. ITS-1 sequences amplified from oocysts were also obtained in order to confirm the species of the parasites. The results showed that T. gondii and H. hammondi are monophyletic and genetically very close, but the monophyletic status of H. heydorni N. caninum was not demonstrated. In fact, the nucleotide diversity at the HSP70 locus has shown that the evolutionary distance between H. heydorni and N. caninum is as high as that observed between either H. heydorni or N. caninum and T. gondii., In addition, it was possible to identify two distinct groups among the H. heydorni oocysts. Concomitantly to the phylogenetic study it was also possible to standardize a diagnostic test capable of differentiate the oocysts Hammondia-like was development a diagnostic method that differ oocysts T. gondii-like and N. caninum-like. The sequences obtained from HSP70 coding gene were aligned and two new pair of PCR primers was designed. The first pair amplifies 771bp from T. gondii-like oocysts, whereas the second pair amplifies 400 bp from N. caninum-like oocysts. The restriction enzyme Hin6I used to cleave the 771 bp amplicons generated distinct profiles with samples from H. hammondi and T. gondii. The same occurred with the restriction of the fragments of 400bp cleaved by the enzyme MunI used in N. caninum e H. heydorni samples. The profiles can be differentiated by 2.5% agarose gel electrophoresis. (AU) | |