Filogenia de parte da região codificadora de rRNAs de Neospora caninum isolado de conceptos provenientes de rebanhos bovino no Estado de Minas Gerais

Abstract

The neosporosis is currently a major cause of abortion in cattle worldwide. The literature mentions the occurrence of biological variation, pathogenic and genetic among different isolates of Neospora caninum, which information is scarce in Brasil. Thus, are necessary research about their genetic that would explain some aspects of host-parasite interrelationships. This study aimed to analyze phylogenetically part of the coding region of ribosomal RNA of N. caninum, specifically the region ITS-1 that represents a gene fragment polymorphism and subject to an evolutionary indicator of the parasite. Initially it was necessary to standardize a PCR product that had as a fragment of 588 pb and covering part of the gene region 5´ -18s rDNA - ITS 1 - 5.8s rDNA - 3´. The specificity of this fragment was determined by the BlastN program, demonstrating similarity above 90% with dozens of sequences N. caninum deposited in the Genome World Bank (GenBank). Three samples of conceptus positive for PCR were sequenced, edited and submitted to GenBank and fed into bioinformatics programs to generate a phylogenetic tree. The tree showed high conservation among the sequences of isolates of N. caninum in this study and those deposited in GenBank. Branches well defined and specific were generated to align sequences of another Apicomplexa belong to the subfamily Toxoplasmatinae. The results of PCR, histopathology and immunohistochemistry confirmed by diagnostic direct and effective the occurrence of neosporosis in cattle herds in Minas Gerais.