Submitted to: International Veterinary Vaccines and Diagnostics Conference
Publication Type: Other
Publication Acceptance Date: 5/1/2000
Publication Date: 7/23/2000
Citation: EVANS, J.J., KLESIUS, P.H., SHOEMAKER, C.A. EFFICACY OF STREPTOCOCCUS INIAE VACCINE ADMINISTRATED BY INTRAPERITONEAL AND INTRAMUSCULAR ROUTES IN TILAPIA. 2nd INTERNATIONAL VETERINARY VACCINES AND DIAGNOSTICS CONFERENCE. POSTER. 2000. Interpretive Summary:
Technical Abstract: We evaluated the effectiveness of Streptococcus iniae vaccines 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 1 H 108 colony-forming units of S. iniae after 30 days post immunization. Tilapia IP immunized with ARS-10 vaccine and challenged with the homologous isolate ARS-10 had a relative percent survival (RPS) of 43.4%. Tilapia IP immunized with ARS-10 vaccine and challenged with the heterologous isolate (ARS-60) had a RPS of 89.5%. In contrast, we found that the RPS was17.7% in tilapia IM immunized with the ARS-10 vaccine and challenged with the same isolate. Heterologous isolate ARS-60 challenge resulted in RPS of 59.5%. However, tilapia IM immunized with a vaccine combining the ARS-10 +ARS-60 isolates provided an RPS of 61.8% against ARS-10 isolate and RPS of 86.6% against ARS-60 isolate. These results suggest that efficacious vaccines, administered by either IP or IM injection, are dependent on the antigenic composition of the S. iniae.