Exploring Genomic, Geographic and Virulence Interactions among Epidemic and Non- Epidemic St. Louis Encephalitis Virus (Flavivirus) Strains

LUIS ADRÍAN DIAZ; SANDRA GOÑI; JAVIER ISERTE; AGUSTÍN IE. QUAGLIA; AMBER SINGH; CHRISTOPHER H. LOGUE; ANN M. POWERS; MARTA SILVIA CONTIGIANI

PLOS ONE

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2015 vol. 10

1932-6203

St. Louis encephalitis virus (SLEV) is a re-emerging arbovirus in South America. In 2005, anencephalitis outbreak caused by SLEV was reported in Argentina. The reason for the out-break remains unknown, but may have been related to virological factors, changes in vec-tors populations, avian amplifying hosts, and/or environmental conditions. The main goal ofthis study was to characterize the complete genome of epidemic and non-epidemic SLEVstrains from Argentina. Seventeen amino acid changes were detected; ten were non-con-servative and located in proteins E, NS1, NS3 and NS5. Phylogenetic analysis showed twomajor clades based on geography: the North America and northern Central America(NAnCA) clade and the South America and southern Central America (SAsCA) clade. Inter-estingly, the presence of SAsCA genotype V SLEV strains in the NAnCA clade wasreported in California, Florida and Texas, overlapping with known bird migration flyways.This work represents the first step in understanding the molecular mechanisms underlyingvirulence and biological variation among SLEV strains.