title: Interactions between candidate probiotics and the immune and antioxidative responses of European sea bass (Dicentrarchus labrax) larvae.
abstract: The use of lactic acid bacteria (LAB) as probiotics in aquaculture may improve the quality of seed production and limit the use of antibiotics in fish hatcheries. This study attempted to further characterize the candidate probiotic Lactobacillus casei X2, and the immune and physiological responses of the sea bass larvae. L. casei X2 was confirmed as a good candidate, due to its wide antibacterial spectrum against both Gram-positive and Gram-negative bacteria, and its free radical scavenging activity. In addition, if the strain did not seem able to form biofilm on abiotic surfaces, it adhered strongly to Hep-2 cells. However, these characteristics did not seem efficient in vivo. At 20 days post-hatch (dph), the expression level of CAT gene was significantly different between group fed without probiotic and the two groups treated with either Pediococcus acidilactici or L. casei. This gene was upregulated in the group treated with strain X2 and downregulated in the group with a commercial probiotic strain P. acidilactici, suggesting a better antioxidant activity with the later strain. At the same sampling date, the IL-1β gene was upregulated in the group treated with P. acidilactici, and the HSP70 gene was overexpressed at 41 dph. As the stimulation of these two last genes, such transcriptomic indicators must be cautiously interpreted.
authors.affiliation: Ifremer, UMR 6539 LEMAR, Laboratoire 'Adaptation, Reproduction, Nutrition' (ARN), Centre de Bretagne, Plouzané, France. lamari.faouzi@gmail.com.|Laboratory of Analysis, Treatment and Valorization of Environment Pollutants and Products, Faculty of Pharmacy, Monastir University, Monastir, Tunisia. lamari.faouzi@gmail.com.
authors.forename: F
authors.initials: F
authors.lastname: Lamari
authors.affiliation: Laboratory of Analysis, Treatment and Valorization of Environment Pollutants and Products, Faculty of Pharmacy, Monastir University, Monastir, Tunisia.
authors.forename: A
authors.initials: A
authors.lastname: Mahdhi
authors.affiliation: Laboratory of Analysis, Treatment and Valorization of Environment Pollutants and Products, Faculty of Pharmacy, Monastir University, Monastir, Tunisia.
authors.forename: I
authors.initials: I
authors.lastname: Chakroun
authors.affiliation: Fish Innate Immune System Group, Department of Cell Biology and Histology, Faculty of Biology, Campus Regional de Excelencia Internacional 'Campus Mare Nostrum', University of Murcia, Murcia, Spain.
authors.forename: M A
authors.initials: MA
authors.lastname: Esteban
authors.affiliation: Ifremer, UMR 6539 LEMAR, Laboratoire 'Adaptation, Reproduction, Nutrition' (ARN), Centre de Bretagne, Plouzané, France.
authors.forename: D
authors.initials: D
authors.lastname: Mazurais
authors.affiliation: Laboratory of Analysis, Treatment and Valorization of Environment Pollutants and Products, Faculty of Pharmacy, Monastir University, Monastir, Tunisia.
authors.forename: B
authors.initials: B
authors.lastname: Amina
authors.affiliation: Ifremer, UMR 6539 LEMAR, Laboratoire 'Adaptation, Reproduction, Nutrition' (ARN), Centre de Bretagne, Plouzané, France.|NUMEA, INRA, Université de Pau et des Pays de l'Adour, Saint Pée sur Nivelle, France.
authors.forename: F-J
authors.initials: FJ
authors.lastname: Gatesoupe
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001492:Bass / Q000276:immunology / Q000382:microbiology; D004269:DNA, Bacterial / Q000235:genetics; D004032:Diet / Q000662:veterinary; D029941:Fish Proteins / Q000235:genetics*; D015870:Gene Expression; D007113:Immunity, Innate; D007778:Lactobacillus / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D007934:Leuconostoc / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D010376:Pediococcus / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D019936:Probiotics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA / Q000662:veterinary
chemical_list: D000975:Antioxidants; D004269:DNA, Bacterial; D029941:Fish Proteins; D012336:RNA, Ribosomal, 16S
keywords: 
  Dicentrachus labrax
  ; adhesion; fish larvae; gene expression; lactic acid bacteria; probiotic