In vivoandin vitrophenotypic differences between Great Lakes VHSV genotype IVb isolates with sequence types vcG001 and vcG002.
Viral hemorrhagic septicemia virus (VHSV) is an aquatic rhabdovirus first recognized in farmed rainbow trout in Denmark. In the past decade, a new genotype of this virus, IVb was discovered in the Laurentian Great Lakes basin and has caused several massive die-offs in some of the 28 species of susceptible North American freshwater fishes. Since its colonization of the Great Lakes, several closely related sequence types within genotype IVb have been reported, the two most common of which are vcG001 and vcG002. These sequence types have different spatial distributions in the Great Lakes. The aim of this study was to determine whether the genotypic differences between representative vcG001 (isolate MI03) and vcG002 (isolate 2010-030 #91) isolates correspond to phenotypic differences in terms of virulence using both anin vitroandin vivoapproach.In vitroinfection of epithelioma papulosum cyprini (EPC), bluegill fry (BF-2), and Chinook salmon embryo (CHSE) cells demonstrated some differences in onset and rate of growth in EPC and BF-2 cells, without any difference in the quantity of RNA produced.In vivoinfection of round gobies (Neogobius melanostomus) via immersion exposure to different concentrations of vcG001 or vcG002 caused a significantly greater mortality in round gobies exposed to 102plaque forming units ml-1of vcG001. These experiments suggest that there are phenotypic differences between Great Lakes isolates of VHSV genotype IVb.
Aquatic Animal Health Program, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY.
Sierra M
SM
Imanse
Aquatic Animal Health Program, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY.
Emily R
ER
Cornwell
Aquatic Animal Health Program, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY.
Rodman G
RG
Getchell
Western Fisheries Research Center, U.S. Geological Survey, 6505 NE 65 Street, Seattle, WA.
Gael
G
Kurath
Aquatic Animal Health Program, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY.
Paul R
PR
Bowser
Neogobius melanostomus; genetic diversity; round goby; sequence type; viral hemorrhagic septicemia virus