Cross-protective potential of a live, attenuated Edwardsiella ictaluri, vaccine against Edwardsiella piscicida in channel (Ictalurus punctatus) and channel x blue (Ictalurus furcatus) hybrid catfish

Authors: GRIFFIN, MATT - Mississippi State University; GREENWAY, TERRENCE - Mississippi State University; BYARS, TODD - Mississippi State University; WARE, CYNTHIA - Mississippi State University; AARATTUTHODIYIL, SUJA - Mississippi State University; KUMAR, GANESH - Mississippi State University; WISE, DAVID - Mississippi State University; Waldbieser, Geoffrey

Submitted to: Journal of the World Aquaculture Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/25/2020
Publication Date: 5/19/2020
Citation: Griffin, M.J., Greenway, T.E., Byars, T.S., Ware, C., Aarattuthodiyil, S., Kumar, G., Wise, D.J., Waldbieser, G.C. 2020. Cross-protective potential of a live, attenuated Edwardsiella ictaluri, vaccine against Edwardsiella piscicida in channel (Ictalurus punctatus) and channel x blue (Ictalurus furcatus) hybrid catfish. Journal of the World Aquaculture Society. 51(3)740-749. https://doi.org/10.1111/jwas.12696.
DOI: https://doi.org/10.1111/jwas.12696

Interpretive Summary: This study demonstrates that a live-attenuated E. ictaluri vaccine provides cross-protection against E. piscicida, a pathogen of growing concern in hybrid catfish aquaculture. Immunization through both oral and immersion methods was effective in enhancing survival rates against different doses of E. piscicida and E. ictaluri, suggesting that E. ictaluri vaccines have the additional benefit of also providing protection against the closely related E. piscicida and could be a valuable tool in managing bacterial diseases in catfish farming, especially in hybrid catfish production system

Technical Abstract: Edwardsiella piscicida has emerged as an important pathogen of channel × blue catfish hybrids cultured in the southeastern United States. With increasing popularity of hybrid catfish and growing concern over E. piscicida, the cross-protective potential of a live-attenuated E. ictaluri vaccine was evaluated. An immunization bath of E. piscicida (3'×'10e7 CFU/ml) protected channel catfish against immersion challenge of wild-type E. ictaluri (1'×'10e7 CFU/ml) across multiple temperatures and feeding regimens (relative percent survival [RPS]: 89–100%). Channel catfish immunized orally with a live-attenuated E. ictaluri vaccine/feed admix (3'×'107 CFU/g of feed) were protected against intracoelomic injections of both high (HD) (7.4x10e5 CFU/fish; RPS = 85%) and low doses (LD) (1.5'×'10e5 CFU/fish; RPS = 88%) of E. piscicida. Because of limited feed consumption during vaccination, oral immunization of hybrids was followed by a 30-min immersion bath with cultured vaccine (5'×'10e6 CFU/ml). Combinatory oral/bath vaccination was ineffective against HD E. piscicida but was protective against LD E. piscicida (48% RPS) and E. ictaluri (96% RPS). Finally, naïve catfish that survived LD E. piscicida injections were protected against E. ictaluri immersion challenge (2'×'10e7 CFU/ml; RPS: Hybrids 55%; Channels 75%). Results suggest a live-attenuated E. ictaluri vaccine can also protect channel and hybrid catfish against E. piscicida.