title: Phylogenetic analysis of antimicrobial lactic acid bacteria from farmed seabass  Dicentrarchus labrax.
abstract: The use of lactic acid bacteria (LAB) in the prevention or reduction of fish diseases is receiving increasing attention. In the present study, 47 LAB strains were isolated from farmed seabass ( Dicentrarchus labrax ) and were phenotypically and phylogenetically analysed by 16S rDNA and randomly amplified polymorphic DNA - polymerase chain reaction (RAPD-PCR). Their antimicrobial effect was tested in vitro against a wide variety of pathogenic and spoilage bacteria. Most of the strains isolated were enterococci belonging to the following species: Enterococcus faecium (59%), Enterococcus faecalis (21%), Enterococcus sanguinicola (4 strains), Enterococcus mundtii (1 strain), Enterococcus pseudoavium (1 strain), and Lactococcus lactis (1 strain). An Aerococcus viridans strain was also isolated. The survey of their antimicrobial susceptibility showed that all isolates were sensitive to vancomycin and exhibited resistance to between 4 and 10 other antibiotics relevant for therapy in human and animal medicine. Different patterns of resistance were noted for skin and intestines isolates. More than 69% (32 strains) of the isolates inhibited the growth of the majority of pathogenic and spoilage bacteria tested, including Listeria monocytogenes, Staphylococcus aureus, Aeromonas hydrophila, Aeromonas salmonicida, Vibrio anguillarum, and Carnobacterium sp. To our knowledge, this is the first report of bioactive enterococcal species isolated from seabass that could potentially inhibit the undesirable bacteria found in food systems.
authors.affiliation: Institut national des sciences et technologies de la mer, rue 2 Mars 1934, 2025 Salammbô, Tunis, Tunisia.
authors.forename: Ouissal Chahad
authors.initials: OC
authors.lastname: Bourouni
authors.forename: Monia
authors.initials: M
authors.lastname: El Bour
authors.forename: Pilar
authors.initials: P
authors.lastname: Calo-Mata
authors.forename: Radhia
authors.initials: R
authors.lastname: Mraouna
authors.forename: Boudabous
authors.initials: B
authors.lastname: Abedellatif
authors.forename: Jorge
authors.initials: J
authors.lastname: Barros-Velàzquez
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D017756:Aquaculture; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D001483:Base Sequence; D001492:Bass / Q000382:microbiology*; D016983:Enterococcus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D019105:Random Amplified Polymorphic DNA Technique; D017747:Seafood / Q000382:microbiology; D014640:Vancomycin / Q000494:pharmacology; D020713:Vancomycin Resistance / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D019344:Lactic Acid; D014640:Vancomycin