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ARS Home » Southeast Area » Stoneville, Mississippi » Warmwater Aquaculture Research Unit » Research » Publications at this Location » Publication #423973
Research Project: Maximizing Profitability and Fish Health in Catfish Aquaculture

Location: Warmwater Aquaculture Research Unit

Title: Virulence and immunogenicity of blue catfish alloherpesvirus in channel, blue and blue × channel hybrid catfish

Author
item ARUN, VENUGOPALAN - Mississippi State University
item GRIFFIN, MATT - Mississippi State University
item WISE, DAVID - Mississippi State University
item WHITE, DANIELLE - Mississippi State University
item FORD, LORELEI - Mississippi State University
item LOPEZ-PORRAS, ADRIAN - Mississippi State University
item CAMUS, ALVIN - University Of Georgia
item HANSON, LARRY - Mississippi State University

Submitted to: Journal of Fish Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/25/2020
Publication Date: 5/19/2020
Citation: Arun, V., Griffin, M.J., Wise, D.J., White, D., Ford, L., Lopez-Porras, A., Camus, A.C., Hanson, L.A. 2020. Virulence and immunogenicity of blue catfish alloherpesvirus in channel, blue and blue × channel hybrid catfish. Journal of Fish Diseases. 51(3)740-749. https://doi.org/10.1111/jwas.12696.
DOI: https://doi.org/10.1111/jwas.12696

Interpretive Summary: This study highlights the discovery of blue catfish alloherpesvirus (BCAHV) and its potential implications for fish health management in catfish aquaculture. Blue catfish are essential for hybrid catfish production, and a virus that causes significant mortality in blue catfish could threaten hybrid supply and industry sustainability. While BCAHV does not affect channel or hybrid catfish and catfish exposed to the virus gain full protection against Ictalurid herpesvirus 1 (IcHV1), its impact on blue catfish populations raises concerns. These findings suggest BCAHV could serve as a vaccine candidate for IcHV1 while underscoring the need for monitoring and mitigation strategies to protect blue catfish stocks.

Technical Abstract: Blue catfish alloherpesvirus (BCAHV) is a novel virus isolated from the blue catfish (Ictalurus furcatus). To date, the ultrastructure, virulence and immunogenicity of BCAHV have not been reported. Given the importance of blue catfish in producing channel ' (I. punctatus) × ' blue (I. furcatus) catfish hybrids and the increasing demand for hybrid catfish in the US catfish industry, the susceptibility of blue, channel and hybrid catfish to BCAHV was assessed. Further, the cross-protective potential of BCAHV against Ictalurid herpesvirus 1 (IcHV1) was investigated in channel and hybrid catfish that survive BCAHV exposure. Neutralization assays revealed BCAHV is refractive (neutralization index [NI] = 0) to anti-IcHV1 monoclonal antibody Mab 95, compared to IcHV1 (NI = 1.8). Exposure of blue catfish fingerling to 1.3 × 10e5 TCID50/L BCAHV produced cumulative mortality of 51.67 ± 0.70% and pathologic changes similar to those of channel catfish virus disease. No mortality was observed in channel or hybrid catfish. Twenty-eight days post-challenge, surviving channel and hybrid catfish were exposed to 9.4 × 10e4 TCID50/L IcHV1 (LC50 dose), resulting in 100% relative per cent survival compared to naïve cohorts. These data provide baseline information for BCAHV and lay the groundwork for future studies. Data also identify BCAHV as a potential vaccine candidate against IcHV1. Based on host range and immunogenicity evaluations, in addition to genome sequence data from previous studies, BCAHV should be given consideration as a new species of Ictalurivirus.