Resumen

GONZALEZ, María  C; HERRERA, Flor; CORREIA, Heriberto  y  RUIZ, Johanny. Phylogenetic Analysis of Venezuelan Strains of the Eastern Equine Encephalitis Virus. Rev. Fac. Cienc. Vet. [online]. 2012, vol.53, n.1, pp.49-60. ISSN 0258-6576.

A molecular study of five strains of the eastern equine encephalitis virus (EEEV) was conducted by sequencing of products generated using the reverse transcriptase assay, coupled to the polymerase chain reaction (RT-PCR). Sequences of approximately 500 pair of bases from the non-translated 3’ region of the genome were compared with homologous sequences of the South American (SA) and North American (NA) variants of the EEEV complex. The EE VE02 EL PAO strain, used to develop an inactivated oil vaccine had most resemblance with the EE VE76 EL DELIRIO strain, followed by the EE VE75 CATATUMBO, the EE VE96 MLLANO and the EE VE84 TUCACAS strains, respectively. The alignment of sequences among typical strains revealed differences of 2.82 and 8.48%, respectively, while the EE VE02 EL PAO strain differed in 8.86% from the Perú strain (EE PE-0.0155, from lineage III) and in 38.08% from the NA strain (EE-PE-6, from lineage I, used in commercial vaccines). The results of the present investigation indicate that the autochthonous strains have more similarly with the SA strain than with the NA strain. Four major lineages (I-IV) in the EEEV complex have been identified. The phylogenetic tree evidenced two clades, one which groups lineages I-III and another, lineage IV. Most of the sequences are contained in the first clade, which at the same time, separates into two groups containing sequences of lineage I and lineages II-III; and, due to the high bootstrap value (99%) the groups are considered completely different. However, this was not the case of the group which enclosed the lineages II and III; because these only separate 53% of the time, but it is assumed that the Venezuelan strains belong to linage III, which diverges into two subclades: IIIA and IIIB

Palabras clave : Equine encephalomyelitis virus; phylogeny; PCR; reverse transcriptase; biological differences.

        · resumen en Español     · texto en Español     · Español ( pdf )