Virulence factors in vibrios and aeromonads isolated from seafood

Thirty-one isolates from seafood, identified as Aeromonas hydrophila (7), A eromonas caviae (11), Vibrio parahaemolyticus (3), Vibrio fluvialis (5), Vi brio alginolyticus (3), Vibrio metschnikovii (1) and Vibrio damsela (1), we re tested for possible virulence factors including extracellular hydrolytic enzymes, haemolysins, cytotoxins (VERO and HEp-2 cells) and adherence abil ity (HEp-2 cells). All the A. hydrophila strains were beta -haemolytic and produced cytotoxins as well as one strain of V. fluvialis. A. hydrophila an d A. caviae strains, frequently adhesive, showed both aggregative and diffu sive patterns, while five Vibrio strains only (three V. fluvialis, one V. p arahaemolyticus and one V. alginolyticus) were adhesive with an aggregative pattern.