DAO 91:23-34 (2010)  -  DOI: https://doi.org/10.3354/dao02217

ABSTRACT: The present study compared the susceptibility of representative Laurentian Great Lakes fish species to the emerging viral hemorrhagic septicemia virus (VHSV) Genotype IVb. The median lethal dose of infection by intraperitoneal injection (IP-LD₅₀) was obtained from fish that were experimentally infected with the MI03 index strain of VHSV-IVb. Fish were injected at doses ranging from 7 × 10⁷ to 7 × 10^–2 plaque-forming units (pfu) and maintained at 12 ± 1°C. The infection trials identified species of high, medium, and low susceptibility based on the IP-LD₅₀ values. Pathogenicity of VHSV-IVb was highest in largemouth bass Micropterus salmoides, which resulted in an IP-LD₅₀ of 1.5 × 10² pfu, while also demonstrating the clinical diathesis of VHSV-infected fish. The virus was moderately pathogenic in yellow perch Perca flavescens (IP-LD₅₀ of 2.5 × 10⁵ pfu), but also showed the classical signs of VHSV infection. Salmonids were the least susceptible to VHSV-IVb with IP-LD₅₀ values of no less than 1.4 × 10⁶ pfu; however, in fish that succumbed to infection, characteristic VHSV lesions were observed. Histopathologic alterations were most profound in gill, skin, muscle, gonads, and liver of largemouth bass and yellow perch, while in salmonids, hemorrhages in the swimbladder and/or degenerative changes in the liver were the most common lesions noticed. VHSV was isolated from infected fish, and its identity was confirmed by the reverse transcriptase polymerase chain reaction. These results highlight the variations among fish species susceptibility to this emerging strain of VHSV and offer insights into the potential impact of VHSV-IVb on the Laurentian Great Lakes fish community.

KEY WORDS: Susceptibility · Viral hemorrhagic septicemia virus · Genotype IVb · Host range · Great Lakes · Experimental infection · Rhabdovirus

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Cite this article as: Kim R, Faisal M (2010) Comparative susceptibility of representative Great Lakes fish species to the North American viral hemorrhagic septicemia virus Sublineage IVb. Dis Aquat Org 91:23-34. https://doi.org/10.3354/dao02217 Export citation Share:    Facebook - - linkedIn