Location: Aquatic Animal Health ResearchTitle: Edwardsiellosis in ornamental fish Author
|Shelley, John - Johnny|
|Yanong, Roy P.e. - University Of Florida|
|Hawke, John - Louisana State University|
|Griffin, Matt - Mississippi State University|
Submitted to: Aquatic Fish Health International Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 7/12/2018
Publication Date: 9/1/2018
Citation: Shelley, J.P., Yanong, R., Hawke, J.P., Griffin, M. 2018. Edwardsiellosis in ornamental fish [abstract]. International Symposium on Aquatic Animal Health. p. 251.
Technical Abstract: Historically Edwardsiella ictaluri has been primarily associated with Channel Catfish, Ictalurus punctatus, aquaculture and the food fish industry. It is the causative agent of enteric septicemia of catfish (ESC) and in the United States is the most economically important infectious disease in farm-raised catfish. Once considered a host-specific pathogen of catfish species in the US, it has since been isolated from non-ictalurid species in natural or experimental infections from the US and internationally. Edwardsiella ictaluri appears to have a history within the ornamental fish industry as well, with sporadic reports in the 1980s. In 2013, Hawke et al. described a new strain of E. ictaluri as an emerging pathogen of zebrafish based on eight cases from five states that were submitted to the Zebrafish International Resource Center (ZIRC) and the Aquatic Disease Section of the Louisiana Animal Disease Diagnostic Laboratory (LADDL) between 2011 and 2012. The fish exhibited exophthalmia along with hemorrhage in the skin around the eyes, operculum, base of fins and the abdomen. Additionally, they had swollen abdomens due to ascites and they displayed neurologic swimming behaviors such as spinning, spiraling and lethargy. The zebrafish strain of E. ictaluri is believed to be unique compared to the catfish strain and the tilapia strain described by Soto et al. in 2013. Since 2011, the species that the zebrafish strain has been known to infect has expanded to include all the varieties of D. rerio, as well as the Blue Danio (Danio kerri), the Leopard Danio (Danio frankei) and the Giant Danio (Devario aequipinnatus). With the expansion of susceptible species, E. ictaluri is now recognized as an important pathogen of zebrafish and control methods are under investigation. Future works with the zebrafish strain of E. ictaluri will focus on comparing it against the channel catfish strain at the molecular level and the serological level for common and unique features related to virulence and infection. Additionally, the effectiveness of different disease management strategies will be investigated to help the ornamental fish industry combat the spread of the zebrafish strain of E. ictaluri.