Submitted to: USDA-ARS Technology Showcase
Publication Type: Other
Publication Acceptance Date: October 1, 2002
Publication Date: March 12, 2003
Citation: EVANS, J.J., KLESIUS, P.H., SHOEMAKER, C.A. EFFICACY OF STREPTOCOCCUS INIAE VACCINE ADMINISTERED BY INTRAPERITONEAL AND INTRAMUSCULAR ROUTES IN TILAPIA. (poster presentation). USDA-ARS Technology Showcase. 2003. Technical Abstract: We evaluated the effectiveness of Streptococcus iniae vaccine prepared from formalin-killed cells and concentrated extracellular products (greater than 2 kDa) of a single isolate of S. iniae (ARS-10) and a combination of ARS-10 + ARS-60 S. iniae isolates. Tilapia were vaccinated by IP or IM injection of the vaccine or tryptic soy broth (control) and challenged by IP injection with 1X 10 colony-forming units of S. iniae 30 days post immunization. Tilapia IP immunized with ARS-10 vaccine and challenged with homologous isolate (ARS-10) had a relative percent survival (RPS) of 43.4%. Tilapia IP immunized with ARS-10 vaccine and challenged with homologous isolate (ARS-60) had a (RPS) of 89.5%. In contrast, we found that the RPS was 17.7% in tilapia IM immunized with the ARS-10 vaccine and challenged with the same isolate, ARS-10. Heterologous (ARS-60) isolate challenge resulted in a RPS of 59.5%. However, IM administration of the vaccine combining the ARS-10 + ARS-60 isolates provided an RPS of 61.8 against ARS-10 isolate and RPS of 86.8% against ARS-60 isolate in comparison to RPS of 17.7 and 59.5 against ARS-10 and 60 isolates provided by the single isolate ARS-10 vaccine. These results suggest that efficacious vaccines, administered by either IP or IM injection, are dependent on the antigenic composition of the S. iniae.