TY - JOUR
T1 - Complete genome analysis and molecular characterization of Usutu virus that emerged in Austria in 2001
T2 - Comparison with the South African Strain SAAR-1776 and other flaviviruses
AU - Bakonyi, Tamás
AU - Gould, Ernest A.
AU - Kolodziejek, Jolanta
AU - Weissenböck, Herbert
AU - Nowotny, Norbert
N1 - Funding Information:
This study was funded by a grant of the Austrian Federal Ministry for Health and Women's Issues.
PY - 2004/10/25
Y1 - 2004/10/25
N2 - Here we describe the complete genome sequences of two strains of Usutu virus (USUV), a mosquito-borne member of the genus Flavivirus in the Japanese encephalitis virus (JEV) serogroup. USUV was detected in Austria in 2001 causing a high mortality rate in blackbirds; the reference strain (SAAR-1776) was isolated in 1958 from mosquitoes in South Africa and has never been associated with avian mortality. The Austrian and South African isolates exhibited 97% nucleotide and 99% amino acid identity. Phylogenetic trees were constructed displaying the genetic relationships of USUV with other members of the genus Flavivirus. When comparing USUV with other JEV serogroup viruses, the closest lineage was Murray Valley encephalitis virus (nt: 73%, aa: 82%) followed by JEV (nt: 71%, aa: 81%) and West Nile virus (nt: 68%, aa: 75%). Comparison of the genomes showed that the conserved structural elements and putative enzyme motifs were homologous in the two USUV strains and the JEV serogroup. The factors that determine the severe clinical symptoms caused by the Austrian USUV strain in Eurasian blackbirds are discussed. We also offer a possible explanation for the origins and dispersal of USUV, JEV, and MVEV out of Africa.
AB - Here we describe the complete genome sequences of two strains of Usutu virus (USUV), a mosquito-borne member of the genus Flavivirus in the Japanese encephalitis virus (JEV) serogroup. USUV was detected in Austria in 2001 causing a high mortality rate in blackbirds; the reference strain (SAAR-1776) was isolated in 1958 from mosquitoes in South Africa and has never been associated with avian mortality. The Austrian and South African isolates exhibited 97% nucleotide and 99% amino acid identity. Phylogenetic trees were constructed displaying the genetic relationships of USUV with other members of the genus Flavivirus. When comparing USUV with other JEV serogroup viruses, the closest lineage was Murray Valley encephalitis virus (nt: 73%, aa: 82%) followed by JEV (nt: 71%, aa: 81%) and West Nile virus (nt: 68%, aa: 75%). Comparison of the genomes showed that the conserved structural elements and putative enzyme motifs were homologous in the two USUV strains and the JEV serogroup. The factors that determine the severe clinical symptoms caused by the Austrian USUV strain in Eurasian blackbirds are discussed. We also offer a possible explanation for the origins and dispersal of USUV, JEV, and MVEV out of Africa.
KW - Austria
KW - Blackbird mortality
KW - Complete nucleotide sequences
KW - Emerging mosquito-borne flavivirus
KW - Flaviviridae
KW - Genome analysis and comparison
KW - Phylogenetic analysis
KW - SAAR-1776
KW - USUV
KW - Usutu virus
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UR - http://www.scopus.com/inward/citedby.url?scp=5344252994&partnerID=8YFLogxK
U2 - 10.1016/j.virol.2004.08.005
DO - 10.1016/j.virol.2004.08.005
M3 - Article
C2 - 15464850
AN - SCOPUS:5344252994
SN - 0042-6822
VL - 328
SP - 301
EP - 310
JO - Virology
JF - Virology
IS - 2
ER -