Phylogenetic analysis of Brazilian Flavivirus using nucleotide sequences of parts of NS5 gene and 3' non-coding regions.

Viruses of the genus Flavivirus, which are arboviruses, of the Flaviviridae family, are amongst the most important agents of infectious disease in Brazil, causing human infections with a high morbility and mortality. In this work, the phylogeny of 14 virus amplicon sequences that were obtained by RT-PCR with universal primers for mosquito-borne Flavivirus were studied. The amplicons included a region of the Flavivirus genome of 129 nucleotides at the 3' terminus of the NS5 gene and the 145 initial nucleotides of the 3' non-coding region (NS5-3'NCR). Based on phylogenetic trees, most Brazilian Flaviviruses were grouped into two main branches, including a yellow-fever branch and a second main branch divided into a dengue branch that in its turn is subdivided into serotype 1, 2 and 4 branches, and another (Japanese Encephalitis Virus Complex) branch including SLE and Ilhéus. Rocio and Cacipacoré viruses were included in the Japanese Encephalitis Virus Complex branch in one of the two phylogenetic trees. Iguape virus appears in phylogenetic trees as a separate distant branch.