First Investigation of the Optimal Timing of Vaccination of Nile Tilapia (Oreochromis niloticus) Larvae against Streptococcus agalactiae
Issued Date
2023-12-01
Resource Type
eISSN
2076393X
Scopus ID
2-s2.0-85180714675
Journal Title
Vaccines
Volume
11
Issue
12
Rights Holder(s)
SCOPUS
Bibliographic Citation
Vaccines Vol.11 No.12 (2023)
Suggested Citation
Kumwan B., Bunnoy A., Chatchaiphan S., Kayansamruaj P., Dong H.T., Senapin S., Srisapoome P. First Investigation of the Optimal Timing of Vaccination of Nile Tilapia (Oreochromis niloticus) Larvae against Streptococcus agalactiae. Vaccines Vol.11 No.12 (2023). doi:10.3390/vaccines11121753 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/95848
Title
First Investigation of the Optimal Timing of Vaccination of Nile Tilapia (Oreochromis niloticus) Larvae against Streptococcus agalactiae
Corresponding Author(s)
Other Contributor(s)
Abstract
To investigate early immune responses and explore the optimal vaccination periods, Nile tilapia at 1, 7, 14, 21, 28, 35, and 42 days after yolk sac collapse (DAYC) were immersed in formalin-killed Streptococcus agalactiae vaccine (FKV-SA). A specific IgM was first detected via ELISA in the 21 DAYC larvae (0.108 g) at 336 h after vaccination (hav), whereas in the 28–42 DAYC larvae (0.330–0.580 g), the specific IgM could be initially detected at 24 hav. qRT–PCR analysis of the TCRβ, CD4, MHCIIα, IgHM, IgHT, and IgHD genes in 21–42 DAYC larvae immunized with the FKV-SA immersion route for 24, 168, and 336 hav revealed that the levels of most immune-related genes were significantly higher in the vaccinated larvae at all DAYCs than in the control larvae (p < 0.05) at 336 hav. Immunohistochemistry demonstrated stronger IgM signals in the gills, head kidney, and intestine tissues at 21, 28, and 35 DAYC in all vaccinated larvae compared with the control. Interestingly, at all DAYCs, FKV-SA larvae exhibited significantly higher survival rates and an increased relative percent survival (RPS) than the control after challenge with viable S. agalactiae, particularly in larvae that were immunized with FKV-SA at 168 and 336 hav (p < 0.05).