Emergence of viral hemorrhagic septicemia virus in the North American Great Lakes region is associated with low viral genetic diversity

Diseases of Aquatic Organisms
By: , and 

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Abstract

Viral hemorrhagic septicemia virus (VHSV) is a fish rhabdovirus that causes disease in a broad range of marine and freshwater hosts. The known geographic range includes the Northern Atlantic and Pacific Oceans, and recently it has invaded the Great Lakes region of North Ame­rica. The goal of this work was to characterize genetic diversity of Great Lakes VHSV isolates at the early stage of this viral emergence by comparing a partial glycoprotein (G) gene sequence (669 nt) of 108 isolates collected from 2003 to 2009 from 31 species and at 37 sites. Phylogenetic analysis showed that all isolates fell into sub-lineage IVb within the major VHSV genetic group IV. Among these 108 isolates, genetic diversity was low, with a maximum of 1.05% within the 669 nt region. There were 11 unique sequences, designated vcG001 to vcG011. Two dominant sequence types, vcG001 and vcG002, accounted for 90% (97 of 108) of the isolates. The vcG001 isolates were most widespread. We saw no apparent association of sequence type with host or year of isolation, but we did note a spatial pattern, in which vcG002 isolates were more prevalent in the easternmost sub-regions, including inland New York state and the St. Lawrence Seaway. Different sequence types were found among isolates from single disease outbreaks, and mixtures of types were evident within 2 isolates from ­individual fish. Overall, the genetic diversity of VHSV in the Great Lakes region was found to be extremely low, consistent with an introduction of a new virus into a geographic region with ­previously naïve host populations.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Emergence of viral hemorrhagic septicemia virus in the North American Great Lakes region is associated with low viral genetic diversity
Series title Diseases of Aquatic Organisms
DOI 10.3354/dao02362
Volume 96
Issue 1
Year Published 2011
Language English
Publisher Inter-Research
Contributing office(s) Western Fisheries Research Center
Description 15 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Diseases of Aquatic Organisms
First page 29
Last page 43