Picchietti Simona, Mazzini Massimo, Taddei Anna Rita, Renna Raffaella, Fausto Anna Maria, Mulero Victoriano, Carnevali Oliana, Cresci Alberto, Abelli Luigi
Dipartimento Scienze Ambientali, Università della Tuscia, 01100 Viterbo, Italy.
Fish Shellfish Immunol. 2007 Jan-Feb;22(1-2):57-67. doi: 10.1016/j.fsi.2006.03.009. Epub 2006 Mar 28.
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 GALT already housed mucosal leucocytes, including Ig(+) cells but no acidophilic granulocytes. No differences were seen between experimental groups. At day 99 ph, the density of Ig(+) cells (+51%) and acidophilic granulocytes (+284%) was significantly higher (p<0.05) in group A than in controls. Also group B had a higher density of Ig(+) cells (+17%) and acidophilic granulocytes (+130%) 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 G7(+) acidophilic granulocytes (A +536%, B +292% vs. control) due to probiotic administration. Evidence is provided that early feeding with probiotic-supplemented diet increased the number of Ig(+) cells and acidophilic granulocytes in seabream gut and that the effects were more pronounced when administration started during gut metamorphosis. These results point to a stimulatory effect of probiotics on the gut immune system that correlates with improvement of fry survival.
从成年海鲷（Sparus aurata L.）肠道分离出的两株细菌——果糖乳杆菌（AS17B）和从人类粪便中分离出的植物乳杆菌（906），在海鲷发育期间，以褶皱臂尾轮虫和/或卤虫无节幼体以及干饲料作为载体同时进行投喂。实验组A从孵化后第5天（ph）开始通过轮虫投喂益生菌菌株，而B组从孵化后第27天开始用卤虫无节幼体投喂。在孵化后第28天（A组和对照组）以及第99天（A组、B组和对照组）对鱼进行采样，用于电子显微镜检查、组织学检查以及免疫组织化学分析，使用针对同源血清Ig的多克隆抗血清ORa和对海鲷嗜酸性粒细胞特异的单克隆抗体G7。在所有组中，消化道的分化时间和模式没有差异。此外，投喂益生菌并未引发组织损伤或明显的炎症。在孵化后第28天，发育中的肠道相关淋巴组织（GALT）已经含有黏膜白细胞，包括Ig(+)细胞，但没有嗜酸性粒细胞。实验组之间没有观察到差异。在孵化后第99天，A组中Ig(+)细胞的密度（增加51%）和嗜酸性粒细胞的密度（增加284%）显著高于对照组（p<0.05）。与对照组相比，B组中Ig(+)细胞的密度（增加17%）和嗜酸性粒细胞的密度（增加130%）也更高，尽管程度较轻。光镜和电镜观察详细描述了发育中的肠道黏膜中淋巴细胞和粒细胞的异质群体的出现，并突出了由于投喂益生菌导致G7(+)嗜酸性粒细胞的净增加（A组增加536%，B组增加292%，对照组无变化）。有证据表明，早期投喂添加益生菌的饲料会增加海鲷肠道中Ig(+)细胞和嗜酸性粒细胞的数量，并且当在肠道变态期间开始投喂时效果更明显。这些结果表明益生菌对肠道免疫系统有刺激作用，这与鱼苗存活率的提高相关。
