PHAGE TYPING OF LACTOCOCCUS-GARVIEAE (FORMERLY ENTEROCOCCUS-SERIOLICIDA) A PATHOGEN OF CULTURED YELLOWTAIL

Bacteriophages of Lactococcus garvieae, designated as PLgW and PLgS, w ere isolated from sea water and sediment samples by an enrichment meth od. Morphological and genomic features of these phages were in agreeme nt with those of the L. garvieae phage, designated as PLgY, belonging to the family Siphoviridae that was detected in an L. garvieae strain isolated from diseased yellowtail in the previous study. One hundred a nd eleven strains oft. garvieae examined were divided into 14 phage ty pes (A similar to N) by using the phage isolates which were differenti ated from each other in the infectivity, with a major phage type (type A) containing 73 strains. One phage type (type N) consisting of 9 bac terial strains was insensitive to any of the phages used. However, the re were no apparent correlations between the phage types and the geogr aphical sources of the bacterial strains or between phage types and th e antigenic forms (KG- and KG+).