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Stimulation of gut immune system by early administration of probiotic strains in dicentrarchus labrax and sparus aurata

Wed, 31 Dec 2008 23:00:00 GMT

Title: Stimulation of gut immune system by early administration of probiotic strains in dicentrarchus labrax and sparus aurata Authors: Abelli, Luigi; Randelli, Elisa; Picchietti, Simona; Carnevali, Oliana Abstract: Early feeding (started during gut metamorphosis and establishment of the hypothalamic–pituitary–interrenal axis) with probiotic-supplemented diets, besides modifying the intestinal microflora, evoked profound effects on the physiology of fish larvae. Using rotifers and Artemia as living vectors, the autochthonous bacterium Lactobacillus delbrueckii delbrueckii or a multispecies probiotic formulation (autochthonous Lactobacillus fructivorans + Lactobacillus plantarum from human feces) were orally administered to sea bass and gilthead sea bream larvae, respectively. The treatments enhanced larval rearing (significantly increased body weight, decreased cortisol levels, and improved stress response compared with controls) and the immune system. In sea bass, the probiotic raised intestinal T cells, in keeping with increased total body TcR-β transcripts, and increased acidophilic granulocytes concomitant to lower transcription of pro-inflammatory genes (IL-1-β, TGF-β, IL-10, Cox-2). In sea bream, the multispecies probiotic formulation raised intestinal immunoglobulin (Ig+) cells and acidophilic granulocytesmainly belonging to theMAbG7+ phagocytic population. These results point to stimulatory actions of probiotics on the gut immune system that are devoid of harmful effects and that correlate with improvement of fry survival. Description: L'articolo è disponibile sul sito dell'editore http://onlinelibrary.wiley.com/

Microbial manipulations to improve fish health and production – a Mediterranean perspective

Fri, 31 Dec 2010 23:00:00 GMT

Title: Microbial manipulations to improve fish health and production – a Mediterranean perspective Authors: Dimitroglou, Arkadios; Merrifield, Daniel L.; Carnevali, Oliana; Picchietti, Simona; Avella, Matteo; Daniels, Carly; Güroy, Derya; Davies, Simon J. Abstract: The interactions between the endogenous gut microbiota and the fish host are integral in mediating the development, maintenance and effective functionality of the intestinal mucosa and gut associated lymphoid tissues (GALTs). These microbial populations also provide a level of protection against pathogenic visitors to the gastrointestinal (GI) tract and aid host digestive function via the production of exogenous digestive enzymes and vitamins. Manipulation of these endogenous populations may provide an alternative method to antibiotics to control disease and promote health management. Applications of probiotics for Mediterranean teleosts can stimulate immune responses, enhance growth performance, feed utilisation, digestive enzyme activities, antioxidant enzyme activities, gene expression, disease resistance, larval survival, gut morphology, modulate GI microbiota and mediate stress responses. Although considerably less information is available regarding prebiotic applications for Mediterranean teleosts, prebiotics also offer benefits with regards to improving immune status and fish production. Despite the promising potential benefits demonstrated in current literature, obtaining consistent and reliable results is often difficult due to our incomplete understanding of indigenous fish GI microbiota and their subsequent host interactions which mediate and drive both localised and systemic host immunological responses. Additionally, the probiotic and prebiotic (biotics) mechanisms which mediate host benefits at the mucosal interface are poorly understood. Future studies focused on these interactions. utilising gnotobiotic techniques should provide a better understanding of how to extract the full potential of biotic applications to promote immune function of Mediterranean teleosts. 2010 Published by Elsevier Ltd. Description: L'articolo è disponibile sul sito dell'editore http://www.sciencedirect.com/

Effect of dietary alginic acid on juvenile tilapia (Oreochromis niloticus) intestinal microbial balance, intestinal histology and growth performance

Fri, 31 Dec 2010 23:00:00 GMT

Title: Effect of dietary alginic acid on juvenile tilapia (Oreochromis niloticus) intestinal microbial balance, intestinal histology and growth performance Authors: Merrifield, Daniel L.; Harper, Glenn M.; Mustafa, Sanaa; Carnevali, Oliana Abstract: The aim of the present study was to assess the effect of a commercial alginic acid source (Ergosan) on tilapia Oreochromis niloticus intestinal microbial balance, intestinal morphology, and growth parameters. Fish were fed a basal control diet or the basal diet plus a source of alginic acid (5 gkg-1 Ergosan; Schering-Plough Aquaculture, UK) for 9 weeks. At the end of the trial, light and electron microscopy demonstrated that the morphology of the intestinal tract at the gross and ultra-structural level was not affected by dietary alginic acid inclusion. Both groups of fish displayed healthy, normal morphology with no signs of disease, cell or tissue damage. Intestinal epithelial leucocyte infiltration was not affected by dietary alginic acid. Molecular bacterial profiles derived from PCR-DGGE illustrated highly similar microbial communities (both within the lumen and associated with the intestinal mucosa) in the respective treatment groups. Microbial ecological parameters (e.g. species diversity and richness) also remained unaffected. Although not significant, trends towards elevated survival and body protein content were observed in the alginic acid-fed fish. These results are suggestive that alginic acid does not adversely impact the indigenous gastrointestinal microbial balance and subsequently does not impact upon the epithelial brush border integrity. Validation of non-detrimental impacts of immunostimulatory products on gastric microbiota and epithelial integrity should be pursued in future studies as maintaining microbial balance and epithelial integrity is essential for proper gut functionality. Description: L'articolo è disponibile sul sito dell'editore HTTP://www.springerlink.com

Early treatment with Lactobacillus delbrueckii strain induces rise in intestinal T cells and granulocytes and modulates immune related genes of larval Dicentrarchus labrax (L.)

Wed, 31 Dec 2008 23:00:00 GMT

Title: Early treatment with Lactobacillus delbrueckii strain induces rise in intestinal T cells and granulocytes and modulates immune related genes of larval Dicentrarchus labrax (L.) Authors: Picchietti, Simona; Fausto, Anna Maria; Randelli, Elisa; Carnevali, Oliana; Taddei, Anna Rita; Buonocore, Francesco; Scapigliati, Giuseppe; Abelli, Luigi Abstract: Lactobacillus delbrueckii ssp. delbrueckii (AS13B), isolated from the gut of adult Dicentrarchus labrax, was administered live to developing sea bass using rotifers and Artemia as live carriers. Immune-related gene transcripts were quantified in post-larvae at day 70 post-hatch (ph) and histology, electron microscopy and immunocytochemistry of the intestinal tissue were performed at day 74 ph. Since the probiotic was orally administered the studies were focused on intestinal immunity. In treated fish gut integrity was unaffected, while the density of T-cells and acidophilic granulocytes in the intestinal mucosa was significantly higher than in controls. Probiotic-induced increases in intestinal T-cells and total body TcR-beta transcripts are first reported in fish. Significantly lower IL-1beta transcripts and a trend towards lower IL-10, Cox-2 and TGF-beta transcription were found in the treated group. Evidence is provided that early feeding with probiotic-supplemented diet stimulated the larval gut immune system and lowered transcription of key pro-inflammatory genes. Description: L'articolo è disponibile sul sito dell'editore http://www.sciencedirect.com/

Effects of administration of probiotic strains on GALT of larval gilthead seabream: immunohistochemical and ultrastructural studies

Sun, 31 Dec 2006 23:00:00 GMT

Title: Effects of administration of probiotic strains on GALT of larval gilthead seabream: immunohistochemical and ultrastructural studies Authors: Picchietti, Simona; Mazzini, Massimo; Taddei, Anna Rita; Renna, Raffaella; Fausto, Anna Maria; Mulero, Victoriano; Carnevali, Oliana; Cresci, Alberto; Abelli, Luigi Abstract: Two bacterial strains Lactobacillus fructivorans (AS17B), isolated from adult seabream (Sparus aurata L.) gut, and Lactobacillus plantarum (906), isolated from human faeces, were administered contemporaneously during seabream development using Brachionus plicatilis and/or Artemia salina and dry feed as vectors. Experimental group A received the probiotic strains already via rotifers from day 5 post-hatch (ph), whereas treatment of group B began with Artemia feeding from day 27 ph. Fish were sampled at day 28 ph (group A and control) and day 99 ph (groups A, B and control) for electron microscopy, histology and immunohistochemistry with the polyclonal antiserum ORa against homologous serum Ig and the mAb G7 specific for seabream acidophilic granulocytes. In all groups, timing and pattern of differentiation of the digestive tract did not differ. Furthermore, neither tissue damage nor manifest inflammation was provoked by probiotic administration. At day 28 ph, the developing GALTalready housed mucosal leucocytes, including Igþ cells but no acidophilic granulocytes. No differences were seen between experimental groups. At day 99 ph, the density of Igþ cells (þ51%) and acidophilic granulocytes (þ284%) was significantly higher (p < 0.05) in group A than in controls. Also group B had a higher density of Igþ cells (þ17%) and acidophilic granulocytes (þ130%) compared with controls, although less pronounced. Light and electron microscopy observations detailed the occurrence of heterogeneous populations of lymphocytes and granulocytes in the developing intestinal mucosa, and highlighted the net expansion of G7þ acidophilic granulocytes (A þ536%, B þ292% vs. control) due to probiotic administration. Description: L'articolo è disponibile sul sito dell'editore http://www.sciencedirect.com/