Aquaculture America 2024

February 18 - 21, 2024

San Antonio, Texas

DEVELOPMENT OF RIFAMPICIN AND NOVOBIOCIN RESISTANT Aeromonas SALMONICIDA STRAINS AND THEIR POTENTIAL AS LIVE ATTENUATED VACCINE CANDIDATES

????Development of rifampicin and novobiocin resistant  Aeromonas salmonicida strains and their potential as live attenuated vaccine candidates

Jie Ma*1 , Veronica Myrsell1 ,  Joseph Dietrich2, and Kenneth Cain1,3*

 1 Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, ID 83844

 2 Environmental & Fisheries Science Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Newport Research Station, Newport, OR 97365

 3 Environmental & Fisheries Science Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Manchester Research Station, Port Orchard, WA 98366

 



Abstract:

 Aeromonas salmonicida , the causative agent of furunculosis,  poses a significant threat to a diverse range of hosts  in both fresh and marine fish. Currently, there are no commercial vaccines available to treat furunculosis in non-salmonid fish. Limited vaccine options exist to prevent furunculosis in sablefish specifically. This problem is evident as sablefish aquaculture has intensified in the Pacific Northwest, furunculosis continues to cause high mortality rates during production.  The primary objective of this study is to develop a live-attenuated vaccine suitable for immersion administration, aiming to effectively treat furunculosis  in sablefish for commercial aquaculture production.  Attenuated strains of A. salmonicida were generated using rifampicin and novobiocin through successive passages on TSA with escalating concentrations of the antibiotics, reaching up to 400 mg/ml for both rifampicin and novobiocin . Attenuation of  A. salmonicida strains was confirmed through in vivo challenges in sablefish and rainbow trout. Overall, the proposed live-attenuated vaccine to prevent furunculosis in sablefish and rainbow trout could become an asset to sustainable aquaculture management if proven effective.