Adhesion of lactic acid bacteria to mucus of farmed gilthead seabream, and interactions with fish pathogenic microorganisms

Seven lactic acid bacteria (LAB) from human and animal origin were evaluated for their adhesive capability to skin, gill and intestinal mucus of gilthead seabream (Sparus aurata), and their antagonistic effect against Vibrio anguillarum, Photobacterium damselae subsp. piscicida, V. alginolyticus and V. harveyi pathogenic microorganisms for this farmed fish. Four LAB showed high percentages of adhesion to fish mucus, whilst the pathogenic microorganisms assayed, except V. anguillarum, showed a lower adhesive ability to host-mucus. The results suggest that the adhesion to fish mucus was dependent on the LAB strain tested. All LAB strains tested showed antagonistic activity on all pathogenic microorganisms assayed. Four LAB were selected, according to their adhesive ability and antagonistic effect to study their adhesive interaction with V. anguillarum on skin, gill and intestinal gilthead seabream mucus. The results obtained show the ability of two LAB to displace V. anguillarum from gilthead seabream mucus under displacement, competition and exclusion conditions.