粪肠球菌B-8和棒状乳杆菌W-17对鲫鱼非特异性免疫基因表达的影响

Effects of Enterococcus faecalis B-8 and Lactobacillus coryniformis W-17 on Non-specific Immune Gene Expression of Carassius auratus

为了探究乳酸菌在鲫鱼微生态制剂中的应用,选取鱼源棒状乳杆菌W-17和粪肠球菌B-8饲喂鲫鱼,对比研究2株乳酸菌对鲫鱼免疫指标的不同影响以及各脏器中非特异性免疫基因表达的影响。试验在每克鲫鱼饲料中分别添加1.0×10^(8)CFU/mL的粪肠球菌B-8和1.0×10^(8)CFU/mL的棒状乳杆菌W-17,饲喂初始体质量为(30.0±1.0)g的鲫鱼,持续4周。应用ELISA方法检测IL-1β、TNF-α、IL-10、IFN-γ及IgM的含量。并提取鲫鱼心脏、肝脏、脾脏、肾脏和肠道的RNA进行RT-PCR,测定IL-1β、TNF-α、IL-10和IFN-γ的基因表达量。结果表明:在免疫28 d时,乳酸菌组血清中各非特异性抗体含量均高于对照组,且粪肠球菌B-8组高于棒状乳杆菌W-17组。乳酸菌组各脏器中非特异性免疫基因表达量均显著高于对照组,且粪肠球菌B-8组各脏器中非特异性免疫基因表达量高于棒状乳杆菌W-17组。说明粪肠球菌B-8可以在一定程度上增强鲫鱼的非特异性免疫,为该株乳酸菌在鲫鱼养殖业中的应用奠定理论基础。

In order to investigate the application of lactic acid bacteria(LAB)in the microecological preparation of Carassius auratus,Lactobacillus coryneform W-17 and Enterococcus faecalis B-8 isolated from the intestinal tract of Megalobrama and Hypophthalmichthys molitrix were selected to feed Carassius auratus.The effects of two strains of lactic acid bacteria on the immune indexes of Carassius auratus and the expression of non-specific immune genes in various organs were studied.Enterococcus faecium B-8 at a concentration of 1.0×10^(8)CFU/mL and Lactobacillus coryneformus W-17 at a concentration of 1.0×10^(8)CFU/mL were added to each gram of the feed of Carassius auratus with an initial body mass of(30.0±1.0)g for 4 weeks.ELISA method was used to detect the contents of IL-1β,TNF-α,IL-10,IFN-γand IgM.RNA from heart,liver,spleen,kidney,and intestine of Carassius auratus was extracted for RT-PCR to measure the expression levels of IL-1β,TNF-α,IL-10 and IFN-γ.The results showed that at 28 days of immunization,the levels of non-specific antibodies in the serum of the lactic acid bacteria group were higher than the control group,and those of Enterococcus faecalis B-8 group were higher than those of Lactobacillus coryneform W-17 group.The expression levels of non-specific immune genes in each organ of the lactic acid bacteria group were significantly higher than the control group,and the expression levels of non-specific immune genes in each organ of Enterococcus faecalis B-8 group were higher than those of Lactobacillus coryneform W-17 group.This indicates that the Enterococcus faecium B-8 can enhance the non-specific immunity of Carassius auratus to a certain extent,laying a theoretical foundation for the application of lactic acid bacteria in the Carassius auratus breeding industry.