Adhesive properties of Aeromonas hydrophila strains isolated from Tunisian aquatic biotopes

The ability of Aeromonas hydrophila strains isolated from aquatic environment and ornamental fishes to adhere to both biotic and abiotic surfaces was evaluated. The majority of strains were able to adhere to fish skin mucus, while the fish mucus preparation exhibited a high level of anti-bacterial effect. Adhesive properties were observed between 75 and 80% of the analyzed A. hydrophila to cells (Hep-2 and Caco-2). In addition, 40% of the tested strains were invasive on the two cell lines. On Congo Red Agar, only 65% of the strains produced slime, 65% of the strains were able to form biofilm on glass tube with Crystal violet and 85% with Safranin. Most A. hydrophila strains (95%) were adhesive to polystyrene with high optical density values. These proprieties may allow the persistence to Aeromonas strains in the aquatic biotope in a free-living planctonic state or attached to biotic and abiotic surfaces.