Efficacy of a Commercial Vaccine against Lactococcus garvieae Serotype I in Chub Mackerel Scomber japonicus

Abstract

This study evaluated the protective efficacy of two vaccines against lactococcosis in chub mackerel Scomber japonicus: a commercial vaccine for Lactococcus garvieae serotype I approved for use in yellowtail Seriola quinqueradiata, and an inactivated vaccine prepared from L. garvieae serotype I strain L17-2, isolated from S. japonicus. Following experimental infection via intraperitoneal inoculation with strain L17-2, the relative percentage of survival for both vaccines was 55.6%. The serum agglutination antibody titers against L. garvieae were significantly higher in vaccinated fish than in the negative control, with no significant differences between the two vaccines. These results indicate that the commercial vaccine against L. garvieae serotype I is effective in chub mackerel.