果寡糖对银鲫非特异性免疫功能的影响

为研究果寡糖（Fructooligosaccharides）对银鲫（Carassius auratus）非特异性免疫功能的影响,以50g左右的银鲫为实验对象,在其基础饲料中分别添加浓度为0．5g／kg（A。组）、1g／kg（A：组）、2g／kg（A,组）、4g／kg（A。组）的果寡糖,另设基础饲料为对照组（A。组）,分别于7d、14d、21d、28d、42d、56d检测银鲫血液中白细胞吞噬活性、血清溶菌酶活力、血清SOD酶活性和补体C3的含量。结果表明,A2组的白细胞吞噬活性、血清溶菌酶活力、血清SOD酶活性和补体C3的含量显著高于A0组（P〈0．05）,分别于第28、第21、第14、第14天达到最大值;A,组的白细胞吞噬活性、血清溶菌酶活力、血清SOD酶活性和补体C3的含量显著高于A0组（p〈0．05）,分别于第14、第14、第7、第14天达到最大值。A3组的补体C3的含量显著高于A2组（P〈0．05）,白细胞吞噬活性、血清溶菌酶活力、血清SOD酶活性与A2组相比差异不显著,但其活性高于A2组。A1组、A4组与A0组之间的白细胞吞噬活性、血清溶菌酶活力、血清SOD酶活性和补体C3的含量在各时间点均无显著差异。     

酵母多糖对中华条颈龟非特异性免疫机能的影响

本研究旨在探讨饲料中添加不同水平的酵母多糖对中华条颈龟(Mauremys sinensis)非特异性免疫机能的影响。选取体重为134.7±19.1 g的中华条颈龟,随机分成Ⅰ、Ⅱ、Ⅲ、Ⅳ四个组,各组饲料中酵母多糖的添加量分别为每千克龟重0 mg、800 mg、1200 mg和1600mg,并在第15d、30d检测各组免疫器官指数、白细胞数目、血清中溶菌酶及补体C3、C4活性等免疫指标。结果表明,各实验组脾脏指数和肝脏指数与对照组之间差异均不显著(p>0.05);各实验组白细胞数目相比对照组显著增多(p<0.05);在第15d血清中溶菌酶和C3、C4活性均显著高于对照组(p <0.05),在添加量为1200 mg/kg时活性最高,在第30d 各实验组溶菌酶和补体C4活性与同剂量组相比显著下降,补体C4活性与对照组差异不显著(p>0.05)。由此得出,饲料中添加酵母多糖可提升中华条颈龟的非特异性免疫机能,以1200 mg/kg添加水平的效果最佳,且投喂时间不宜过长。     

酵母多糖对中华条颈龟幼体非特异性免疫机能的影响

本研究旨在探讨饲料中添加不同水平的酵母多糖对中华条颈龟(Mauremys sinensis)幼体非特异性免疫机能的影响。选取体重为(134.7±19.1)g的中华条颈龟幼体,随机分成Ⅰ、Ⅱ、Ⅲ、Ⅳ4个组,按照龟体重各组饲料中酵母多糖的添加量分别为0 mg/kg(对照组)、800 mg/kg、1 200 mg/kg和1 600 mg/kg,并在第15天、30天检测各组的免疫器官指数、白细胞数目及血清中溶菌酶和补体C3、C4含量等免疫指标。结果表明,各实验组脾指数和肝指数与对照组之间差异均不显著(P0.05);各实验组白细胞数目比对照组显著增多(P0.05);在第15天血清中溶菌酶和C3、C4含量均显著高于对照组(P0.05),在添加量为1 200 mg/kg时活性最高;在第30天各实验组溶菌酶和补体C4含量与第15天同剂量组相比显著下降,补体C4含量与对照组差异不显著(P0.05)。由此得出,饲料中添加酵母多糖可提升中华条颈龟幼体的非特异性免疫机能,以1 200 mg/kg添加水平的效果最佳,且投喂时间不宜过长。     

嗜麦芽寡养单胞菌脂多糖对斑点叉尾免疫保护作用

嗜麦芽寡养单胞菌(Stenotrophomonas maltophilia)是近年来引起斑点叉尾高致死性、传染性疾病的主要病原之一。为了研究嗜麦芽寡养单胞菌脂多糖对斑点叉尾的免疫保护作用,实验选用了400尾健康斑点叉尾,随机分成Ⅰ、Ⅱ、Ⅲ、Ⅳ四个组,每组用鱼100尾,每组下设两个重复,每个重复用鱼50尾,以腹腔注射的方式分别向Ⅰ、Ⅱ、Ⅲ、Ⅳ四个组的斑点叉尾注射嗜麦芽寡养单胞菌脂多糖、无花果多糖加脂多糖、全菌灭活苗和生理盐水,在试验第0、第28天时分别进行首次免疫和加强免疫,试验期间每隔7d,对试验鱼的血液白细胞杀菌活性、补体C3含量、IgM含量和血清凝集效价滴度进行测定;试验第49天时进行活菌攻毒。结果表明,首免后,接种脂多糖、无花果多糖加脂多糖的试验鱼血清凝集效价滴度明显升高,白细胞杀菌活性、补体C3含量、IgM含量也明显增加;加强免疫后,脂多糖、无花果多糖加脂多糖的试验鱼血清凝集效价滴度峰值分别为1∶256和1∶512,白细胞杀菌活性峰值分别为0.565和0.511,补体C3含量峰值分别0.194和0.180mg/mL,IgM含量峰值分别1.415和1.464mg/mL,免疫保护率分别为70.0%和65%。嗜麦芽寡养单胞菌脂多糖和脂多糖+无花果多糖受免鱼的上述指标均显著(P<0.05)或极显著(P<0.01)地高于生理盐水注射组,这两者的免疫保护效果优越于全细胞灭菌苗。     

饲料中酵母免疫多糖对七彩神仙鱼仔幼鱼非特异性免疫的影响

该研究采用在饲料中添加0～2500 mg·kg^-1的酵母免疫多糖的方法,对900尾七彩神仙鱼仔幼鱼血清的替代补体活力、溶菌酶活力和白细胞吞噬活性影响进行了研究.结果表明,当饲料中酵母免疫多糖添加剂量达到500 mg·kg^-1(Ⅴ组)以上时,七彩神仙鱼仔幼鱼血清替代补体活力、溶菌酶活力和白细胞吞噬活性均开始显著高于对照组(P<0.05),且同一水平随时间的增加而升高.添加量达2000mg·kg^-1(Ⅷ组)及以上时,随着饲料中的酵母免疫多糖添加量的进一步增加,各组数据反而呈下降变化趋势.可见饲料中适量添加酵母免疫多糖能够提高七彩神仙仔幼鱼的非特异性免疫力,缺乏和过量都会对七彩神仙仔幼鱼带来不利影响.     

维生素C和E混合饲喂对中华鳖幼鳖抗酸应激能力的影响

来自甲鱼养殖场的60只中华鳖(Pelodiscus sinensis)幼鳖驯养3周后,实验设5组：对照组、处理Ⅰ、Ⅱ、Ⅲ和Ⅳ组。各组设2个平行,依次在饵料中混合添加维生素C(Vc)和E(VE)为0和0、250和50、2500和50、250和250、2500和250mg／kg,喂食4周后,每组取半数幼鳖经酸应激处理24h。取幼鳖血液,用镜检法测定血细胞的吞噬率,透射比浊法测定血清溶菌活力、杀菌活力以及补体C3和C4含量。①经酸应激与未经酸应激处理相比：对照组血细胞吞噬率显著降低,而处理Ⅰ-Ⅳ组无显著变化;对照组和处理Ⅰ组血清溶菌活力和补体C3含量显著下降,而处理Ⅱ-Ⅳ组无显著变化;血清杀菌活力均有显著下降(对照组、处理Ⅰ和Ⅲ组极显著,处理Ⅱ组和Ⅳ组显著);对照组、处理Ⅰ和Ⅲ组血清补体C4显著下降,而处理Ⅱ和Ⅴ组无显著变化。②经酸应激处理,血细胞吞噬率、血清溶菌活力、杀菌活力和补体C3含量,处理Ⅰ～Ⅳ组的均显著高于对照组,处理Ⅳ组显著高于其他4组;血清杀菌活力,处理Ⅱ组又高于处理Ⅰ和Ⅲ组;血清补体C4,对照组显著低于处理Ⅰ-Ⅳ组,而处理Ⅰ-Ⅳ组间无显著相异。Vc和VE混合饲喂对酸应激后中华鳖血细胞吞噬率、血清溶菌活力、杀菌活力和补体C3含量有显著协同促进作用,对血清补体C4的合成无协同作用。说明Vc和VE混合饲喂能显著增强中华鳖抗酸应激能力,缓解或部分缓解酸应激造成的不利影响。     

维生素C和E合用对中华鳖幼鳖非特异性免疫功能的影响

本研究旨在探讨维生素C和E合用对中华鳖幼鳖非特异性免疫功能的影响。实验设 5组 ,5组饵料中维生素C和E的添加量依次为 0和 0mg/kg(对照组 ) ;2 5 0和 5 0mg/kg(实验Ⅰ组 ) ;2 5 0 0和 2 5 0mg/kg(实验Ⅱ组 ) ;2 5 0和2 5 0mg/kg(实验Ⅲ组 ) ;2 5 0 0和 2 5 0mg/kg(实验Ⅳ组 )。喂食 4周 ,取其血液 ,测定中华鳖血细胞的吞噬率、血清溶菌活力、杀菌活力、补体C3和C4。结果表明 ,实验Ⅱ—Ⅳ组 ,血细胞吞噬率和血清杀菌活力明显高于对照组 ,实验Ⅳ组明显高于其他 4组 ,并且维生素C和E之间有明显的协同作用。血清溶菌活力和补体C3的含量 ,在实验Ⅰ—Ⅳ组明显高于对照组 ,实验Ⅳ组明显高于其他 4组。补体C4在实验Ⅰ—Ⅳ组明显高于对照组 ,但实验Ⅰ—Ⅳ组间没有明显差别 ,维生素C和E间也没有协同作用。     

香菇多糖对幼建鲤免疫指标的影响

在基础饲料中添加0 g/kg、0.8 g/kg、1.2 g/kg、1.6 g/kg、2.0 g/kg、2.4 g/kg饲料的香菇多糖,连续饲喂幼建鲤Cyprinus carpio var.Jian 49 d后,检测香菇多糖对幼建鲤红细胞、白细胞数量及白细胞杀菌指数、血清溶菌酶活性、血清SOD活性及IgM含量的影响。结果表明,试验第49 d时,不同添加剂量的香菇多糖对各组实验鱼白细胞、红细胞数量影响不大,与对照组无显著差异(P>0.05)。在饲料中添加不同剂量香菇多糖后对幼建鲤白细胞杀菌指数、血清溶菌酶活性、血清SOD活性及IgM含量有不同程度影响。试验期间,0.8 g/kg、1.2 g/kg、1.6 g/kg、2.0 g/kg和2.4 g/kg组试验幼建鲤白细胞杀菌活性比对照组明显增强,差异极显著(P<0.01);血清溶菌酶活性逐渐升高,1.6 g/kg、2.0 g/kg和2.4 g/kg组极显著高于对照组和0.8 g/kg组(P<0.01),当香菇多糖添加量增加到1.6 g/kg时,对血清溶菌酶活力增加不显著(P>0.05)。在饲料中添加不同剂量香菇多糖后对幼建鲤血清SOD活性有不同程度影响。2.0 g/kg添加组对SOD增加明显,与对照组、0.8 g/kg、1.2 g/kg组差异极显著(P<0.01),与2.4 g/kg组差异显著(P<0.05)。试验期间,0.8 g/kg、1.2 g/kg、1.6 g/kg、2.0 g/kg和2.4 g/kg组试验幼建鲤血清IgM含量变化与对照组相比变化不明显,各组间差异不显著(P>0.05)。     

邻苯二甲酸二乙基己酯对鲤非特异性免疫的影响及遗传毒性

以水和吐温-80为对照,用5、20、80、160 mg/L的邻苯二甲酸二乙基己酯（DEHP）对鲤染毒20d,研究了DEHP对鲤非特异性免疫功能的影响及遗传毒性。结果表明: 吐温-80组与水对照组相比除红细胞总核异常率显著升高外,所测定的各项指标差异均不显著。80、160 mg/L组白细胞吞噬活力、吞噬指数,血清抗菌活力,溶菌酶活性均显著低于水对照组和吐温-80组（P0.05或P0.01）,且20 mg/L组白细胞吞噬活力、吞噬指数显著低于水对照组。与吐温-80组相比,160 mg/L组血清C3含量显著降低,5、20、80 mg/L组C3含量,5、20、80、160 mg/L组C4含量则无显著性差异。20、80、160 mg/L组C3含量,160 mg/L组C4含量显著低于水对照组（P0.05或P0.01）。160 mg/L组红细胞微核率显著高于吐温-80组,80、160 mg/L组红细胞微核率显著高于水对照组。在DEHP实验浓度范围内,红细胞核异常率、总核异常率,肝细胞DPC系数均显著高于水对照组和吐温-80组。一定浓度的DEHP对鲤具有免疫毒性和遗传毒性。       

水体pH胁迫对异育银鲫皮质醇激素和非特异性免疫的影响

实验比较了不同pH胁迫对异育银鲫(Carassius auratus gibelio)皮质醇激素和非特异性免疫的影响。3个实验组水质的pH分别为6.0、8.5、9.5,对照组是pH为7.4的曝气自来水。分别在实验的第0、14和30天采血,血浆用于测定皮质醇含量和溶菌酶活性;分离的白细胞,采用流式细胞术测定吞噬活性和呼吸暴发。在实验的第4天多取1次血样,用于皮质醇含量测定。在实验的第31天,测量鱼的体重,并用柱状黄杆菌(Flavobacterium columnare)浸泡攻毒,7d后统计死亡情况。结果显示:在pH 6.0的胁迫下,白细胞的吞噬活性在第14、30天显著降低,而呼吸暴发和皮质醇含量没有显著变化,溶菌酶活性和生长与对照组没有显著差异,用黄杆菌攻毒也没有出现死亡。而在pH 8.5和9.5的胁迫下,皮质醇含量在第14、30天显著升高,白细胞的吞噬活性、呼吸暴发显著降低;在pH 9.5胁迫下的溶菌酶活性显著降低,用柱状黄杆菌攻毒两组都出现死亡。实验表明pH为8.5和9.5的胁迫严重影响了异育银鲫的非特异性免疫功能,流式细胞术能较客观测定白细胞的吞噬活性和呼吸暴发,可用于评价胁迫对鱼类健康的影响。     

黄连须和小檗碱对草鱼非特异性免疫系统的影响及对嗜水气单胞菌感染的抵抗作用

为了评估黄连须(FRC)和小檗碱(BBR)对草鱼(Ctenopharyngodon idella)的非特异性免疫及对抵抗嗜水气单胞菌感染的影响, 鱼喂食含1.00%、0.50%、0.25%, 0.10%, 0.00%的FRC和0.05%BBR的饲料28d。喂养28d后, 鱼注射嗜水气单胞菌, 记录感染14d后的存活率。检测NBT活性、血清溶菌酶活性、吞噬活性和补体C3水平来评价药物对草鱼的免疫反应。结果表明, 与模型组相比, 喂养饲料含有FRC和BBR的各组提高NBT活性、血清溶菌酶活性、吞噬活性和草鱼补体C3水平。喂食0.50%FRC组感染细菌后的存活率最高, 与模型组比较增加44%。FRC和BBR的体外抗菌活性采用最小抑菌浓度的方法进行了研究, 并显示出较强的抑制作用。结果表明, FRC和BBR可以用作免疫刺激剂以提高草鱼非特异性免疫和对嗜水气单胞菌引起疾病的抵抗。       

Coriolus versicolor polysaccharides enhance the immune response of crucian carp (Corassius auratus gibelio) and protect against Aeromonas hydrophila

To investigate the effect of Coriolus versicolor polysaccharides (CVPS) on the immune response of crucian carp (Corassius auratus gibelio), fish were fed diets containing CVPS at different concentrations including 0.5, 1.0 and 2.0 g kg^?1 for 5 weeks. Other groups of fish were vaccinated by intraperitoneal injection (i.p.) against Aeromonas hydrophila with a killed bacterin at the beginning of the experiment and fed the same diets as described above. Additionally, control fish and vaccinated‐only fish were fed basal diets without CVPS supplementation. The phagocytosis, lysozyme activity, complement components C3 and C4, E‐C3bRR (Erythrocyte‐C3b rosette rate) and E‐CIRR (Erythrocyte‐immune complex rosette rate) levels and circulating antibody titers in the serum were monitored. Five weeks after feeding the prescribed diet, fish were challenged with A. hydrophila and the mortalities recorded. Results showed that feeding non‐vaccinated and vaccinated crucian carp with CVPS stimulated the phagocytosis of leukocytes, lysozyme, complement components C3 and C4, erythrocyte immune adherence, and circulatory antibody titers in serum in vaccinated crucian carp. Immune parameters increased to their highest levels after 3 weeks of feeding the diet containing 0.5 or 1.0 g kg^?1 CVPS. These doses also resulted in the highest protection in the challenge experiment. Best survival (85%) was in the vaccinated group fed the diet containing 1.0 g kg^?1 CVPS, whereas almost 80% of control fish (negative control) and 50% of vaccinated‐only fish (positive control) died.     

Immunomodulatory effect of sodium alginate enriched diet in kelp grouper Epinephelus brneus against Streptococcus iniae

The effect of diets containing sodium alginate at 0, 0.5, 1.0, and 2.0 g kg^?1 following challenge with Streptococcus iniae in kelp grouper Epinephelus bruneus were assessed with reference to survival rate and innate immune parameters such as alternative complement, lysozyme, natural haemagglutination, respiratory burst, superoxide dismutase, and phagocytic activities on week 1, 2, and 4. Fish fed with sodium alginate containing diet at 1.0 and 2.0 g kg^?1 after being challenged with S. iniae had higher survival rates of 75% and 60%, respectively than those fed with control diet (0 g kg^?1). With any enriched diet the percentage of macrophages significantly decreased from week 1–4, while the percentage of neutrophils and lymphocytes significantly increased. The alternate complement activity, natural haemagglutination, and phagocytic activities of infected fish fed with sodium alginate containing diet at 1.0 g kg^?1 on week 2 and 1.0 and 2.0 g kg^?1 diets on week 4 were significantly higher when compared to the control. The lysozyme, respiratory bursts, and superoxide dismutase activities of fish fed with enriched diets at 1.0 and 2.0 g kg^?1 were significantly increased on week 2 and 4. We therefore recommend that at 1.0 or 2.0 g kg^?1 dietary administration of sodium alginate can enhance innate immunity and disease resistance in kelp grouper against S. iniae.     

Effects of dietary cholesterol on antioxidant capacity,non-specific immune response,and resistance to Aeromonas hydrophila in rainbow trout (Oncorhynchus mykiss) fed soybean meal-based diets

This study evaluated the effects of dietary cholesterol on antioxidant capacity, non-specific immune response and resistance to Aeromonas hydrophila in rainbow trout (Oncorhynchus mykiss) fed soybean meal-based diets. Fish were fed diets supplemented with graded cholesterol levels (0 [control], 0.3, 0.6, 0.9, 1.2, and 1.5%) for nine weeks. The fish were then challenged by A. hydrophila and their survival rate recorded for the next week. Dietary cholesterol supplementation generally increased the serum and hepatic superoxide dismutase (SOD), glutathione-peroxidase (GSH-Px), catalase (CAT), and total antioxidant capacity (TAC) activities, but decreased the serum and hepatic malondialdehyde (MDA) contents. Further, the hepatic CAT and serum SOD, CAT, and TAC activities were significantly higher in fish fed diets supplemented with 0.9 or 1.2% cholesterol compared to those fed the control diet, whereas the serum and hepatic MDA contents were significantly lower. The respiratory burst activity, alternative complement activity, and hepatic lysozyme activity increased steadily when the supplemental cholesterol was increased by up to 1.2% and then declined with further addition. The serum lysozyme activity and phagocytic activity increased steadily with increasing dietary supplemental cholesterol level up to 0.9% and then declined with further addition. Dietary cholesterol supplementation generally enhanced the protection against A. hydrophila infection, and fish fed diets supplemented with 0.9 or 1.2% cholesterol exhibited the highest post-challenge survival rate. The results indicated that cholesterol may be under-supplied in rainbow trout fed soybean meal-based diets, and dietary cholesterol supplementation (0.9–1.2%) contributed to improved immune response and disease resistance of rainbow trout against A. hydrophila.     

Chinese herbs (Astragalus radix and Ganoderma lucidum) enhance immune response of carp, Cyprinus carpio, and protection against Aeromonas hydrophila

The effect of Chinese herbs (Astragalus radix and Ganoderma lucidum) on immune response of carp was investigated. Fish were fed diets containing Astragalus (0.5%), Ganoderma (0.5%) and combination of two herbs (Astragalus 0.5% and Ganoderma 0.5%) for 5 weeks. Other groups of fish were vaccinated (i.p.) against Aeromonas hydrophila/Aeromonas salmonicida (Shering Plough, Essex, U.K.) at the beginning of the experiment and fed the same diets as described above. Control fish (negative control) and fish vaccinated only (positive control) were fed basal diets without supplements of herbs. The respiratory burst activity, phagocytosis, lysozyme activity and circulatory antibody titres in plasma were monitored. Following 5 weeks after feeding, fish were infected with A. hydrophila and mortalities were recorded. The results of this study showed that feeding non-vaccinated and vaccinated carp with combination of Astragalus and Ganoderma stimulated respiratory burst activity, phagocytosis of phagocytic cells in blood and lysozyme and circulatory antibody titres in plasma in vaccinated carp. Fish challenged with A. hydrophila had variable survival. The best survival (60%) was in vaccinated group fed with both herbs, while almost 90% of control fish (negative control) and 60% of fish vaccinated only (positive control) died.     

Propolis and Herba Epimedii extracts enhance the non-specific immune response and disease resistance of Chinese sucker,Myxocyprinus asiaticus

The effect of traditional Chinese medicine (TCM) formulated from propolis and Herba Epimedii extracts at the ratio of 3:1 (w/w) on non-specific immune response of Chinese sucker (Myxocyprinus asiaticus) was investigated. Fish were fed diets containing 0 (control), 0.1%, 0.5% or 1.0% TCM extracts for five weeks. The respiratory burst and phagocytic activities of blood leukocytes, lysozyme and natural haemolytic complement activities in plasma were measured weekly. After five weeks of feeding, fish were infected with Aeromonas hydrophila and mortalities were recorded. Results of this study showed that feeding Chinese sucker with different dosage of TCM extracts stimulated respiratory burst activity, phagocytosis of phagocytic cells in blood and lysozyme activity in plasma. They had no effect on plasma natural haemolytic complement activity. All dosage of treated groups showed reduced mortality following A. hydrophila infection. Feed containing 0.5% TCM extracts was the most effective with the mortality of the fish significantly reduced by 35% compared to the control. The results indicate that propolis and Herba Epimedii extracts in combination enhances the non-specific immune response and disease resistance of Chinese sucker against A. hydrophila.     

Effects of graded levels of dietary methionine hydroxy analogue on immune response and antioxidant status of immune organs in juvenile Jian carp (Cyprinus carpio var. Jian)

Immune response and antioxidant status of immune organs in juvenile Jian carp (Cyprinus carpio var. Jian) fed graded levels of methionine hydroxy analogue (MHA) (0, 5.1, 7.6, 10.2, 12.7, 15.3 g kg(-1) diet) for 60 days were investigated. Results indicated that head kidney index, spleen index, red and white blood cell counts significantly increased with increasing MHA levels up to a point (P < 0.05), whereupon decreased (P < 0.05). Glutathione reductase activity in head kidney and spleen, anti-hydroxy radical and glutathione-S-transferase activities in spleen, catalase activity and GSH content in head kidney significantly increased by MHA supplement, while malondialdehyde content, anti-superoxide anion, superoxide dismutase, glutathione peroxidase activities in head kidney and spleen, protein carbonyl content and catalase activity in spleen, anti-hydroxy radical activity in head kidney significantly decreased by MHA supplement. However, protein carbonyl content and glutathione-S-transferase activity in head kidney, GSH content in spleen remained unaffected. After 60-day feeding trial, a challenge study was conducted by injection of Aeromonas hydrophila for 17 days. Results showed that survival rate, leukocytes phagocytic activity, lysozyme activity, acid phosphatase activity, total iron-binding capacity, haemagglutination titre, complement 3, 4 and immunoglobulin M contents significantly increased by optimal dietary MHA supplement (P < 0.05). These data suggested that MHA affected antioxidant status of immune organs and promoted immune response in juvenile Jian carp.     

Effects of three strains of intestinal autochthonous bacteria and their extracellular products on the immune response and disease resistance of common carp,Cyprinus carpio

The study isolated three strains of intestinal autochthonous bacteria Aeromonas veronii BA-1, Vibrio lentus BA-2, and Flavobacterium sasangense BA-3 from the intestinal tract of the common carp (Cyprinus carpio). To reveal the effects of these three strains of bacteria on the innate immunity of carp, the lysozyme, complement C3, total serum protein, albumin and globulin levels, respiratory burst activity, phagocytic activity by blood leucocytes and the expression of IL-1b, lysozyme-C, and TNF-α were examined after feeding with seven different diets for up to 28 days. Also the survival of carp against Aeromonas hydrophila was challenged for 14 days. The carp were fed seven different diets: one control, three diets supplemented with 1 × 10⁸ cell g⁻¹ of carp intestinal bacteria BA-1 (Group D-I), BA-2 (Group D-II) and BA-3 (Group D-III), and three diets supplemented with extracellular products FA-1 (Group E-I), FA-2 (Group E-II) and FA-3 (Group E-III) which were corresponding to the strains BA-1, BA-2, and BA-3, respectively, up to 28 days. For groups D-I, D-III, E-I and E-III, the innate immune parameters of carp were significantly increased, the expression of three immune-related genes in blood was significantly up-regulated examined during 7, 14, and 21 days of feeding, and the survival rate was improved. The study indicates that the two isolated intestinal autochthonous bacteria A. veronii BA-1 and F. sasangense BA-3 could positively influence immune response and enhance disease resistance of carp against A. hydrophila infection.     

Dietary sodium alginate administration affects fingerling growth and resistance to Streptococcus sp. and iridovirus, and juvenile non-specific immune responses of the orange-spotted grouper, Epinephelus coioides

The percent weight gain (PWG) and feeding efficiency (FE) of fingerling orange-spotted grouper, Epinephelus coioides, fed diets containing sodium alginate at 1.0 and 2.0 g kg(-1) were calculated on the 2nd, 4th, 6th, and 8th weeks after feeding. Survival rates of the fingerling grouper against Streptococcus sp. and an iridovirus, and non-specific immune parameters such as alternative complement activity (ACH50), lysozyme activity, natural haemagglutination activity, respiratory bursts, superoxide dismutase (SOD) activity, and phagocytic activity of juvenile grouper were also determined when the fish were fed diets containing sodium alginate at 0.5, 1.0, or 2.0 g kg(-1). The PWG and FE of fish were better when the fish were fed diets containing sodium alginate at 1.0, and 1.0 and 2.0 g kg(-1), respectively. The PWG and FE of fish fed the 0, 1.0 and 2.0 g kg(-1) sodium alginate-containing diets after 8 weeks were 271.0%, 454.4% and 327.8%, and 0.61, 0.72 and 0.68, respectively. Fish fed a diet containing sodium alginate at the level of 2.0 g kg(-1) had a significantly higher survival rate than those fed the control diet after challenge with Streptococcus sp. and an iridovirus causing an increase of survival rate by 25.0% and 16.7%, respectively, compared to the control group. The ACH(50) level of fish fed the sodium alginate-containing diets at 2.0 g kg(-1) was significantly higher than those fed the 1.0 g kg(-1) sodium alginate diet and control diet after 12 days, and had increased to 1.9-fold, compared to those fed the control diet. The lysozyme activity, phagocytic activity, respiratory bursts, and SOD level of fish fed the sodium alginate-containing diets at 1.0 and 2.0 g kg(-1) were significantly higher than those fed the control diet after 12 days, and had increased to 1.97- and 1.68-fold, 1.35- and 1.50-fold, 1.63- and 1.81-fold, and 1.23- and 1.31-fold, respectively, compared to those fed the control diet. We therefore recommend dietary sodium alginate administration at 1.0 and 2.0 g kg(-1), respectively, to promote growth and enhance immunity and resistance against Streptococcus sp. and an iridovirus.