Seewis virus: phylogeography of a shrew-borne hantavirus in Siberia, Russia.
BACKGROUND
Hantaviral antigens were originally reported more than 20 years ago in tissues of the Eurasian common shrew (Sorex araneus), captured in European and Siberian Russia. The recent discovery of Seewis virus (SWSV) in this soricid species in Switzerland provided an opportunity to investigate its genetic diversity and geographic distribution in Russia.


METHODS
Lung tissues from 45 Eurasian common shrews, 4 Laxmann's shrews (Sorex caecutiens), 3 Siberian large-toothed shrews (Sorex daphaenodon), 9 pygmy shrews (Sorex minutus), 28 tundra shrews (Sorex tundrensis), and 6 Siberian shrews (Crocidura sibirica), captured in 11 localities in Western and Eastern Siberia during June 2007 to September 2008, were analyzed for hantavirus RNA by reverse transcription-polymerase chain reaction.


RESULTS
Hantavirus L and S segment sequences, detected in 11 S. araneus, 2 S. tundrensis, and 2 S. daphaenodon, were closely related to SWSV, differing from the prototype mp70 strain by 16.3-20.2% at the nucleotide level and 1.4-1.7% at the amino acid level. Alignment and comparison of nucleotide and amino acid sequences showed an intrastrain difference of 0-11.0% and 0% for the L segment and 0.2-8.5% and 0% for the S segment, respectively. Phylogenetic analysis, using neighbor-joining, maximum-likelihood, and Bayesian methods, showed geographic-specific clustering of SWSV strains in Western and Eastern Siberia.


CONCLUSIONS
This is the first definitive report of shrew-borne hantaviruses in Siberia, and demonstrates the impressive distribution of SWSV among phylogenetically related Sorex species. Coevolution and local adaptation of SWSV genetic variants in specific chromosomal races of S. araneus may account for their geographic distribution.
Yashina
Liudmila N
LN
State Research Center of Virology and Biotechnology Vector, Koltsovo, Russia. yashina@vector.nsc.ru
Abramov
Sergey A
SA
Gutorov
Valery V
VV
Dupal
Tamara A
TA
Krivopalov
Anton V
AV
Panov
Victor V
VV
Danchinova
Galina A
GA
Vinogradov
Vladislav V
VV
Luchnikova
Ekaterina M
EM
Hay
John
J
Kang
Hae Ji
HJ
Yanagihara
Richard
R
D000818:Animals; D003710:Demography; D006476:Orthohantavirus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D010802:Phylogeny; D058974:Phylogeography; D012788:Shrews / Q000821:virology*; D012800:Siberia