INVESTIGADORES
PISANO Maria Belen
artículos
Título:
Genetic and evolutionary characterization of Venezuelan equine encephalitis virus isolates from Argentina
Autor/es:
PISANO MB; TORRES C; RE VE; FARÍAS A; SÁNCHEZ SECO MP; TENORIO A; CAMPOS R; CONTIGIANI MS
Revista:
Infection, Genetics and Evolution
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2014 vol. 26 p. 72 - 79
ISSN:
1567-1348
Resumen:
Venezuelan equine encephalitis viruses (VEEV) are emerging pathogens of medical and veterinary importance
circulating in America. Argentina is a country free from epizootic VEEV activity, with circulation of
enzootic strains belonging to Rio Negro virus (RNV; VEEV subtype VI) and Pixuna virus (PIXV, VEEV subtype
IV). In this work, we aim to report the sequencing and phylogenetic analyses of all Argentinean VEE
viruses, including 7 strains previously isolated from mosquitoes in 1980, 5 sequences obtained from
rodents in 1991 and 11 sequences amplified from mosquitoes between 2003 and 2005. Two genomic
regions, corresponding to the non-structural protein 4 (nsP4) and the protein E3/E2 (PE2) genes were
analyzed, but only 8 samples could be amplified in the last one (longer and more variable fragment of
702 bp). For both genomic fragments, phylogenetic trees showed the absence of lineages within RNV
group, and a close genetic relationship between Argentinean strains and the prototype strain BeAr35645
for PIXV clade. The analysis of nsP4 gene opens the possibility to propose a possible geographic clustering
of strains within PIXV group (Argentina and Brazil). Coalescent analysis performed on RNV sequences
suggested a common ancestor of 58.3 years (with a 95% highest posterior density [HPD] interval of
16.4?345.7) prior to 1991 and inferred a substitution rate of 9.8 105 substitutions/site/year, slightly
lower than other enzootic VEE viruses. These results provide, for the first time, information about genetic
features and variability of all VEEVs detected in Argentina, creating a database that will be useful for
future detections in our country. This is particularly important for RNV, which has indigenous circulation.