Occurrence and State of Cetacean Erysipelas in Okinawa Marine Research

Abstract

　At Okinawa Marine Research Center, Motobu-genkimura, we have experienced one case of cutaneous form erysipelas by Erysipelothrix rhusiopathiae in 2004. Because of this, we have decided use of inactivated vaccine to test effectiveness of vaccination. Next year, we have experienced two cases of cutaneous erysipelas in unvaccinated animals, But, vaccinated animals kept elevated levels of antibody against Erysipelothrix and did not affected with disease. The antibody titers were 1:64 and over for well over a year. Therefore vaccination was terminated. In September 2017, we have experienced one cutaneous and two case of acute septicemic form erysipelas. One of septicemic form was post-mortem diagnosis. In January 2018, four bottlenose dolphins elevated serum GOT and GPT. All of these dolphins had elevated levels of antibody to Erysipelothrix, confirmed by growth agglutination（GA）titer. That indicated possibility of infection with Erysipelothrix. Infection from food was suspected as the reason for the frequent occurrence of disease. We feed 7 different species of frozen fish to our cetacean collection and gene fragments specific to E. rhusiopathiae were detected from 2 out of 7 species of feed fish. Therefore these contaminated feeding fish were considered to be the source of infection.