Vaccination with whole-cell vaccine and bacterial protein extract protects tilapia against Streptococcus difficile meningoencephalitis.
Formalin-killed Streptococcus difficile strains used as vaccines delivered intraperitoneally were able to protect tilapia against a challenge of 100 LD50. The protection obtained was not strain specific. A vaccine based on an S. difficile extract containing 50% protein conjugated to alum also protected tilapia challenged with a virulent S. difficile strain. Protection in tilapia was correlated with the development of specific agglutinins. Western blot analysis supported the hypothesis that only a few proteins act as protective antigens in both the whole-cell vaccine and the streptococcal extract. The high efficacy of these vaccines make them good candidates for the control of streptococcal fish meningoencephalitis.
D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D001428:Bacterial Vaccines / Q000276:immunology* / Q000627:therapeutic use; D005393:Fish Diseases / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D008590:Meningoencephalitis / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D013290:Streptococcal Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D017210:Tilapia / Q000276:immunology*
D000942:Antigens, Bacterial; D001428:Bacterial Vaccines