硫酸粘杆菌素对獭兔肠道菌群及免疫功能的影响

Effects ofcolistin sulfate on intestinal flora and immunity in rex rabbit

为探讨硫酸粘杆菌素对獭兔盲肠菌群和免疫器官组织TLR2、TLR4mRNA相对表达量及外周血细胞因子含量的影响,试验分为2组,Ⅰ组(对照组)饲喂基础全价饲料;Ⅱ组饲喂含20mg/kg硫酸粘杆菌素的基础全价饲料。试验期为28d。试验应用PCR-DGGE及Real-Time PCR技术比较分析獭兔盲肠菌群结构的差异,采用ELISA检测外周血中细胞因子的含量,Real-Time PCR检测TLR2、TLR4mRNA相对表达量。结果表明:Ⅱ组盲肠菌群多样性与Ⅰ组相似(P>0.05);Ⅱ组盲肠中梭菌类群XIVa、肠球菌属、链球菌属数量明显高于Ⅰ组(P<0.05),梭菌类群Ⅳ明显低于Ⅰ组(P<0.05);Ⅱ组盲肠TLR2/4和回肠TLR4的相对表达量高于Ⅰ组,盲肠TLR4差异显著(P<0.05),其余差异不显著(P>0.05)。与Ⅰ组相比,Ⅱ组獭兔脾脏指数和脾脏TLR2/4表达量增加,肝脏指数和肝脏TLR4表达量减少,均无显著差异(P>0.05),但肝脏TLR2显著增加(P<0.05);Ⅱ组外周血细胞因子IL-4的浓度显著高于Ⅰ组(P<0.05)。饲料中添加20mg/kg的硫酸粘杆菌素可在一定程度上促进断奶幼兔脾脏发育并提高机体免疫力。

To investigate the effects of colistin sulfate on cecal microflora and immune organs of TLR2,TLR4 mRNA relative expression and the content of peripheral blood cell factor in Rex Rabbit.Thirty rex rabbits of 35 days old were randomly divided !into two groups.Group Ⅰ（Control group）was fed the basic diet.Group Ⅱ was fed with the basic diet containing 20 mg/kg colistin sulfate.PCR-DGGE and Real-Time PCR were applied to analyze the differences of cecum microflora,contents of cytokines in peripheral blood were detected by ELISA and real-time PCR was used to detect the expression of TLR2 and TLR4mRNA relative expression.The diversity of cecal microflora in group Ⅱ was similar to groupⅠ（P 〉0.05）.The numbers of Clostridium cluster XIVa,Enterococcus spp.,and Streptococcus spp.in the caecum of groupⅡ were superior to those of groupⅠ（P 〈0.05）,and Clostridium cluster Ⅳ was significantly lower than that in group Ⅰ（P 〈0.05）.The addition of colistin sulfate increased the relative expression of TLR2/4mRNA in appendix and TLR4 in ileum,but only the TLR4 of the caecum was significantly different（P 〈0.05）.Furthermore,Spleen index and relative expression of TLR2/4 mRNA in group Ⅱ were higher than group Ⅰ,while a decreasing trend was observed in liver index and relative expression of TLR4 mRNA.However,there was no significantlydifference（P〉0.05）.Liver TLR2 was increased significantly（P 〈0.05）.In Addition,the concentration of IL-4in peripheral blood was higher than that in group Ⅰ（P 〈0.05）.The basic diet with 20 mg/kg colistin sulfate could promote the development of the spleen and improve the body immunity in Rex Rabbit.