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United States Department of Agriculture

Agricultural Research Service

Research Project: Integrated Aquatic Animal Health Strategies

Location: Aquatic Animal Health Research

Title: Development of a novobiocin-resistant Edwardsiella ictaluri as a novel vaccine in channel catfish (Ictalurus punctatus)

Authors
item Wei Pridgeon, Yuping
item Klesius, Phillip

Submitted to: Vaccine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 7, 2011
Publication Date: July 20, 2011
Repository URL: http://hdl.handle.net/10113/55583
Citation: Wei Pridgeon, Y., Klesius, P.H. 2011. Development of a novobiocin-resistant Edwardsiella ictaluri as a novel vaccine in channel catfish (Ictalurus punctatus). Vaccine. 29: 5631-5637.

Interpretive Summary: The efficacy of a novel attenuated Edwardsiella ictaluri vaccine was determined in channel catfish (Ictalurus punctatus) by bath immersion and intraperitoneal (IP) injection. The vaccine was developed from a virulent strain of Edwardsiella ictaluri through selection for novobiocin resistance. When channel catfish were IP injected with the novel attenuated E. ictaluri vaccine strain, no fish died. However, when the same age and same size group of the catfish were IP injected with lesser amount of modified live RE-33 vaccine or the AL93-58 virulent strain of E. ictaluri, 65% and 95% fish died, respectively. At 15-, 30-, and 60- days post vaccination with this novel vaccine through bath immersion, the relative percent of survival values of vaccinated fish compared to non-vaccinated fish were all greater than 90% when channel catfish were challenged with the virulent strain AL93-58. At 15-, 30-, and 60- days post vaccination with this novel vaccine through intraperitoneal injection, when catfish were challenged with virulent strain AL93-58, the relative percent of survival values of vaccinated fish were 100, 93, and 100%, respectively. Taken together, our results suggest that this novel vaccine could be used as a novel safe and efficacious vaccine against ESC in channel catfish.

Technical Abstract: The efficacy of a novel attenuated Edwardsiella ictaluri vaccine (B-50348) was determined in channel catfish (Ictalurus punctatus) by bath immersion and intraperitoneal (IP) injection. The vaccine was developed from a virulent strain of Edwardsiella ictaluri (AL93-58) through selection for novobiocin resistance. When channel catfish (average weight 10g) were IP injected with 4.2 × 1,000,000 colony-forming units (CFU) of the novel attenuated E. ictaluri vaccine strain, no fish died. However, when the same age and same size group of the catfish were IP injected with lesser amount (2.4 × 1,000,000 CFU/fish) of modified live RE-33 vaccine or the AL93-58 virulent strain (2.5 x 1,000,000 CFU/fish) of E. ictaluri, 65% and 95% fish died, respectively. At 15-, 30-, and 60- days post vaccination with B-50348 through bath immersion, the relative percent of survival values of vaccinated fish compared to non-vaccinated fish were all greater than 90% when channel catfish were challenged with AL93-58. At 15-, 30-, and 60- days post vaccination with B-50348 through intraperitoneal injection, when catfish were challenged with AL93-58, the relative percent of survival values of vaccinated fish compared to non-vaccinated fish were 100, 93, and 100%, respectively. Taken together, our results suggest that B-50348 could be used as a novel safe and efficacious vaccine against ESC in channel catfish.

Last Modified: 8/27/2014
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