Abstract
The newly emerging pathogen Lactococcus garvieae serotype II, which appears to be morphologically and biochemically indistinguishable from L. garvieae serotype I, has been isolated from farmed Seriola quinqueradiata and S. dumerili. To distinguish the two serotypes, a primer set was designed to target the glxR-argS intergenic region. PCR with the primer set amplified different-sized fragments: 1,285 bp for serotype II and 285 bp for serotype I. Therefore, the primer set enables the PCR-mediated identification of serotype II strains isolated from marine fish species in Japan.