Surface properties of Streptococcus dysgalactiae strains isolated from marine fish

The cell surface related properties, such as the hemagglutination capacity and hydrophobicity, of the Streptococcus dysgalactiae isolates recovered from amberjack (Seriola dumerili)), yellowtail (S. quinqueradiata), and mullet species (Mugil cepalus) were examined. In addition, the relationship between these properties and the adhesion and the invasiveness of the isolates was investigated. The S. dysgalactiae isolates exhibited hydrophobic properties. Their hemagglutination activity was highest against amberjack and guinea pig erythrocytes followed by bovine, equine, and avian erythrocytes. The S. dysgalactiae isolates adhered to and invaded cells of a fish epithelial cell line Cultured in vitro. It was observed that fish isolates of S. dysgalactiae had similar adhesion and possibly invasion properties with that of previous studies on S. dysgalactiae of bovine mastitis when examined in an appropriate cell line.