Serological characterization of Edwardsiella ictaluri strains isolated from wild ayu Plecoglossus altivelis

Abstract

The serological relationships among 13 strains of Edwardsiella ictaluri isolated from wild ayu Plecoglossus altivelis in Japan were studied, using other E. ictaluri strains isolated from catfish as references. Slide agglutination with rabbit antisera revealed that all E. ictaluri strains from ayu were antigenically homogeneous and closely related to two Vietnamese strains and three Indonesian strains from striped catfish Pangasius hypophthalmus. The type strain of E. ictaluri (JCM1680 = ATCC33202) isolated from channel catfish Ictalurus punctatus and one Indonesian strain from striped catfish belonged to a different serogroup. These results were corroborated by serum absorption tests with the homologous and heterologous antigens. © 2010 The Japanese Society of Fish Pathology.