Development of Immersion and Oral Bivalent Nanovaccines for Streptococcosis and Columnaris Disease Prevention in Fry and Fingerling Asian Seabass (<i>Lates calcarifer</i>) Nursery Farms
Pakapon Meachasompop,
Anurak Bunnoy,
Wisawat Keaswejjareansuk,
Piroonrat Dechbumroong,
Katawut Namdee,
Prapansak Srisapoome
Affiliations
Pakapon Meachasompop
Laboratory of Aquatic Animal Health Management, Department of Aquaculture, Faculty of Fisheries, Kasetsart University, 50 Paholayothin Rd., Ladyao, Chatuchak, Bangkok 10900, Thailand
Anurak Bunnoy
Laboratory of Aquatic Animal Health Management, Department of Aquaculture, Faculty of Fisheries, Kasetsart University, 50 Paholayothin Rd., Ladyao, Chatuchak, Bangkok 10900, Thailand
Wisawat Keaswejjareansuk
National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Pathumthani 12120, Thailand
Piroonrat Dechbumroong
National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Pathumthani 12120, Thailand
Katawut Namdee
National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Pathumthani 12120, Thailand
Prapansak Srisapoome
Laboratory of Aquatic Animal Health Management, Department of Aquaculture, Faculty of Fisheries, Kasetsart University, 50 Paholayothin Rd., Ladyao, Chatuchak, Bangkok 10900, Thailand
In the present study, chitosan-based bivalent nanovaccines of S. iniae and F. covae were administered by immersion vaccination at 30 and 40 days after hatching (DAH), and the third vaccination was orally administered by feeding at 50 DAH. ELISA revealed that the levels of total IgM and specific IgM to S. iniae and F. covae were significantly elevated in all vaccinated groups at 10, 20, and 30 days after vaccination (DAV). A qRT-PCR analysis of immune-related genes revealed significantly higher IgT expression in the vaccinated groups compared to the control group, as revealed by 44–100-fold changes in the vaccinated groups compared to the control (p IgM, MHCIIα, and TCRα at significantly higher levels than the control group at 10 and/or 20 DAV (p S. iniae challenge tests, the survival of vaccinated groups ranged from 62.15 ± 2.11 to 75.70 ± 3.36%, which significantly differed from that of the control group (44.44 ± 1.92%). Similarly, all vaccinated groups showed higher survival rates of 68.89 ± 3.85 to 77.78 ± 5.09% during F. covae challenge than the control groups (50.00 ± 3.33%) (p < 0.05).
