RESUMEN
Nucleotide sequences of two regions of the genomes of 11 yellow fever virus (YFV) samples isolated from monkeys or humans with symptomatic yellow fever (YF) in Brazil in 2000, 2004, and 2008 were determined with the objective of establishing the genotypes and studying the genetic variation. Results of the Bayesian phylogenetic analysis showed that sequences generated from strains from 2004 and 2008 formed a new subclade within the clade 1 of the South American genotype I. The new subgroup is here designated as 1E. Sequences of YFV strains recovered in 2000 belong to the subclade 1D, which comprises previously characterized YFV strains from Brazil. Molecular dating analyses suggested that the new subclade 1E started diversifying from 1D about 1975 and that the most recent 2004-2008 isolates arose about 1985.
Asunto(s)
Variación Genética , Enfermedades de los Monos/epidemiología , Filogenia , Fiebre Amarilla/epidemiología , Virus de la Fiebre Amarilla , Regiones no Traducidas 3'/genética , Animales , Teorema de Bayes , Brasil/epidemiología , Evolución Molecular , Genotipo , Humanos , Datos de Secuencia Molecular , Enfermedades de los Monos/virología , Análisis de Secuencia de ADN , América del Sur , Proteínas del Envoltorio Viral , Fiebre Amarilla/veterinaria , Fiebre Amarilla/virología , Virus de la Fiebre Amarilla/clasificación , Virus de la Fiebre Amarilla/genética , Virus de la Fiebre Amarilla/aislamiento & purificaciónRESUMEN
Dengue Fever and Dengue Hemorrhagic Fever are diseases affecting approximately 100 million people/year and are a major concern in developing countries. In the present study, the phylogenetic relationship of six strains of the first autochthonous cases of DENV-4 infection occurred in Sao Paulo State, Parana State and Rio Grande do Sul State, Brazil, 2011 were studied. Nucleotide sequences of the envelope gene were determined and compared with sequences representative of the genotypes I, II, III and Sylvatic for DEN4 retrieved from GenBank. We employed a Bayesian phylogenetic approach to reconstruct the phylogenetic relationships of Brazilian DENV-4 and we estimated evolutionary rates and dates of divergence for DENV-4 found in Brazil in 2011. All samples sequenced in this study were located in Genotype II. The studied strains are monophyletic and our data suggest that they have been evolving separately for at least 4 to 6 years. Our data suggest that the virus might have been present in the region for some time, without being noticed by Health Surveillance Services due to a low level of circulation and a higher prevalence of DENV-1 and DENV- 2.