CHARACTERIZATION OF VIBRIO-ANGUILLARUM STRAINS ISOLATED FROM DISEASEDFISH IN FINLAND

Characterization of V. anguillarum strains (n=109) isolated from disea sed salmonids was performed. Eight O serovars were found among the str ains. Serovar O1 was predominant (90 %), while serovars O2, O3, O5, O8 , O9, and a new serovar Va NT2, were represented by 1 or 2 strains. Tw o strains remained non-typeable. One of these was crossreactive with s everal antisera, but had a LPS profile identical to that of serovar O8 . All serovars showed specific LPS profiles. All but 1 of the O1 strai ns had a plasmid comparable in size to the pJM1 virulence plasmid, whi le plasmids of different sizes were found in O2, Va NT2 and the non-ty peable strains. Apart from a single strain resistant to tetracycline, all the strains were sensitive to oxolinic acid, tetracycline, and tri methoprim-sulfonamides. By their biochemical and antigenic properties strains causing vibriosis among salmonids in Finland closely resemble Scandinavian strains. Predominance of the serovars O1 and O2 suggests that commercial vaccines containing these serovars should afford suffi cient protection against vibriosis in Finland.