First Isolation of a Herpesvirus (Family Alloherpesviridae) from Great Lakes Lake Sturgeon (Acipenser fulvescens)

Authors: JOHNSTON, AMBER - Michigan State University; SHAVALIER, MEGAN - Michigan State University; SCRIBNER, K T - Michigan State University; SOTO, E - University Of California, Davis; GRIFFIN, MATT - Mississippi State University; Waldbieser, Geoffrey - Geoff; Richardson, Brad; WINTERS, ANDREW - Wayne State University; YUN, SUSAN - University Of California, Davis; BAKER, EDWARD - Michigan Department Of Natural Resources; LARSON, DOUGLAS - Michigan Department Of Natural Resources; KIUPEL, MATTI - Michigan State University; LOCH, THOMAS - Michigan State University

Submitted to: Animals
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/16/2022
Publication Date: 11/28/2022
Citation: Johnston, A.E., Shavalier, M.A., Scribner, K., Soto, E., Griffin, M.J., Waldbieser, G.C., Richardson, B.M., Winters, A.D., Yun, S., Baker, E.A., Larson, D.L., Kiupel, M., Loch, T.A. 2022. First Isolation of a Herpesvirus (Family Alloherpesviridae) from Great Lakes Lake Sturgeon (Acipenser fulvescens). Animals. https://doi.org/10.3390/ani12233230.
DOI: https://doi.org/10.3390/ani12233230

Interpretive Summary: The lake sturgeon (Acipenser fulvescens) is the only sturgeon species native to the Great Lakes, where it’s the largest and longest living fish therein. However, current populations of Great Lakes lake sturgeon are estimated to be <1% of historical abundances. One possible contributing factor, for which little remains known, is the impact of infectious diseases. Thus a two-year disease surveillance study was undertaken, resulting in the detection and recovery of a herpesvirus from lesions observed on wild adult lake sturgeon in the watersheds of Lake Erie and Lake Huron. Genomic analyses revealed the recovered virus was distinct but similar to a herpesvirus recently recovered from lake sturgeon in the Lake Michigan watershed (Wisconsin, USA). The recovered virus also demonstrated the ability to induce disease and mortality in juvenile (<1 year old) lake sturgeon. Overall, the results generated throughout this project highlight the potential threat this newly recovered virus poses to Great Lakes lake sturgeon conservation.

Technical Abstract: The Lake sturgeon (Acipenser fulvescens; LST) is the only native sturgeon in the Great Lakes (GL), but due to multiple factors, their populations are estimated to be <1% of historical abundances. Little remains known about infectious diseases affecting adult and juvenile GL-LST in hatchery and wild settings. Therefore, a two-year disease surveillance study was undertaken, resulting in the detection and first in vitro isolation of a herpesvirus from wild adult LST with grossly apparent cutaneous lesions inhabiting two GL watersheds (e.g., Huron and Erie). Histological and ultrastructural examination of lesions revealed proliferative epidermitis associated with herpesvirus-like virions. A virus with identical ultrastructure was recovered from lesions in vitro. Partial DNA polymerase gene sequencing placed the virus within the Family Alloherpesviridae, with high similarity to a molecularly detected lake sturgeon herpesvirus (LSHV) from Wisconsin, USA. Genomic comparisons revealed ~84% ANI between Wisconsin and Michigan strains, leading to the proposed classification of LSHV-1 and -2 for the two taxa. When naïve juvenile LST were immersion-exposed to LSHV-2, severe disease and ~33% mortality followed, with virus re-isolated from representative skin lesions. Results collectively show LSHV-2 is associated with skin damage in wild adult LST, disease and mortality in juvenile laboratory exposed LST, and highlight this virus as a potential threat to GL LST conservation.