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https://hdl.handle.net/20.500.12348/1576
Studies on Bacillus subtilis and Lactobacillus acidophilus, as potential probiotics, on the immune response and resistance of Tilapia nilotica (Oreochromis niloticus) to challenge infections
Abstract
- The probiotic activity of two bacteria (<i>Bacillus subtilis</i> and <i>Lactobacillus acidophilus</i>) was evaluated by its effect on the immune response of Nile tilapia (<i>Oreochromis niloticus</i>), beside its protective effect against challenge infections. Furthermore, their in-vitro inhibitory activity was evaluated. The in-vitro antimicrobial assay showed that <i>Bacillus subtilis</i> and <i>Lactobacillus acidophilus</i> inhibited the growth of <i>A. hydrophila</i>. The <i>B. subtilis</i> inhibited the development of <i>P. fluorescens</i> while <i>L. acidophilus</i> inhibited the growth of <i>Strept. iniae</i>. The <i>B. subtilis</i> and <i>L. acidophilus</i> proved harmless when injected in the <i>O. niloticus</i>. The feed, containing a mixture of <i>B. subtilis</i> and <i>L. acidophilus</i> or <i>B. subtilis</i> alone, showed significantly greater numbers of viable cells than feed containing <i>L. acidophilus</i> only after 1, 2, 3 and 4 weeks of storage at 4°C and 25°C. The survival rate and the body-weight gain were significantly increased in the fish given <i>B. subtilis</i> and <i>L. acidophilus</i> for one and two months after application. The hematocrit values showed a significant increase in the group that received the mixture of <i>B. subtilis</i> and <i>L. acidophilus</i> compared with the control group. The nitroblue tetrazolium (NBT) assay, neutrophil adherence and lysozyme activity, showed a significant increase in all the probiotic-treated groups after 1 and 2 months of feeding, when compared with the untreated control group. The serum bactericidal activity was high in the group that was given a mixture of the two bacteria. The relative level of protection (RLP) was significantly higher against <i>A. hydrophila</i>, in the bacterial mixture treated group and against <i>P. fluorescens</i> in the <i>L. acidophilus</i> treated group, after one month of the feeding trial. A significantly higher RLP, against <i>A. hydrophila</i> or ,<i>P. fluorescens</i>, was noticed after 2 months of the feeding trial in the group given a mixture of the two bacteria, and against <i>Strept. iniae</i> in the group fed a diet containing <i>L. acidophilus</i>.
- External link to download this item: https://doi.org/10.1016/j.fsi.2008.03.013
Collections
- Sustainable aquaculture [2503]
Date
- 2008
Author
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Mesalhy, S.
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Abdek-Galil Ahmed, Y.
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Abdel-Aziz Ghareeb, A.
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Mohamed, M.F.
AGROVOC Keywords
Type
- Journal Article
Publisher
- Academic Press Inc.