http://http://dspace.unitus.it:80 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Fri, 24 May 2013 04:47:05 GMT 2013-05-24T04:47:05Z http://hdl.handle.net/2067/1554 Title: The effect of Pediococcus acidilactici on the gut microbiota and immune status of on-growing red tilapia (Oreochromis niloticus) Authors: Ferguson, R.M.W.; Merrifield, Daniel L.; Harper, Glenn M.; Rawling, Mark D.; Mustafa, Sanaa; Picchietti, Simona; Balcàzar, Josè Luis; Davies, Simon J. Abstract: Aim: To assess Pediococcus acidilactici as a dietary supplement for on-growing red tilapia (Oreochromis niloticus). Methods and Results: Tilapia were fed either a control diet or control diet supplemented with Ped. acidilactici at 107 CFU g)1 for 32 days. Ped. acidilactici colonized the intestinal tract and significantly affected the intestinal microbial communities. PCR-DGGE revealed direct antagonism of gastric Ped. acidilactici with an endogenous uncultured bacterium during a period of reverting to nonsupplemented feeding. Light microscopy revealed that gut integrity and leucocyte levels were unaffected by Ped. acidilactici; however, blood leucocyte levels and serum lysozyme activity were elevated after 14-days’ feeding. No significant improvements in growth performance were observed at the end of the trial (day 32), but survival was significantly higher in the probiotic group. Conclusions: The study demonstrates that oral supplementation of Ped. acidilactici modulates intestinal bacterial communities in on-growing red tilapia and also stimulates some aspects of the nonspecific immune response. Significance and Impact of the study: To our knowledge this is the first study assessing the effects of probiotics on the gut microbiota of tilapia using culture-independent methods. Such methods are crucial to understand the mechanisms which underpin and mediate host benefits. Description: L'articolo è disponibile sul sito dell'editore http://onlinelibrary.wiley.com/ Thu, 31 Dec 2009 23:00:00 GMT http://hdl.handle.net/2067/1554 2009-12-31T23:00:00Z