金霉素对獭兔盲肠菌群和免疫功能的影响
Effect of chlortetracycline on cecum microflora and immune function of rex rabbits

为研究饲用金霉素对獭兔盲肠菌群和免疫功能的影响，采用聚合酶链式反应-变性梯度凝胶电泳（PCR-DGGE）和实时荧光定量PCR（qPCR）技术分析獭兔盲肠菌群；酶联免疫吸附试验（ELISA）测定细胞因子；qPCR技术对TLR2、TLR4 mRNA进行定量检测。试验分为2组：对照组饲喂基础日粮；金霉素组在基础日粮中添加金霉素50 mg/kg。结果表明：1）PCR-DGGE图谱显示，与对照组比较，金霉素组盲肠菌群结构和多样性等没有显著变化（P>0.05）；2）qPCR检测金霉素组普雷沃氏菌属数量是10.48（logcopy/g），对照组是10.10（logcopy/g），差异显著（P<0.05）；3）金霉素组獭兔外周血细胞因子IL-2、IL-4、TNF-α的浓度显著升高（P<0.05），脾脏和肝脏指数均降低；4）回肠的TLR2、TLR4 mRNA相对表达量和肝脏的TLR2 mRNA相对表达量均高于对照组，但差异不显著（P>0.05）。在饲料中添加50 mg/kg金霉素，对獭兔盲肠菌群结构和免疫功能均没有显著影响。
Experimental animals were randomly divided into two groups:Control group was fed basal diet without any antibiotics,Chlortetracycline group were fed basal diet added with 50 mg/kg chlortetracycline.Microflora changes in rex rabbit cecum were studied by PCR-DGGE and qPCR technologies.ELISA detection method was applied on cytokine determination.qPCR technology was used to analysis rex rabbits organizations for TLR2 and TLR4 mRNA.PCR-DGGE profile results showed chlortetracycline,the structure and diversity of cecum microflora were not significantly changed (P>0.05) compared with the control group.qPCR detection results showed that Bacteroides-Prevotella-Porphyromonas of the chlortetracycline and control group was 10.48 and 10.10 (logcopy/g),respectively.The chlortetracycline group's Bacteroides-Prevotella-Porphyromonas was greatly increased (P<0.05).Effect of chlortetracycline on immune function,peripheral blood cytokines concentrations IL-1,IL-2,IL-4,TNF-α were increased significantly (P<0.05).Spleen and liver indexes were decreased.TLR2 and TLR4 mRNA in ileum and TLR2 mRNA in liver relative expression level were higher than control group,but not significant (P>0.05).The results suggested that adding of 50 mg/kg chlortetracycline in basal diet had no significant effect on the microflora in rex rabbits cecum and its immune function.