饮水中地塞米松污染对小鼠肠道菌群的影响  

Effect of dexamethasone contamination in drinking water on intestinal flora in mice

作　　者：杨茜[1] 李晓愚[1] 斯丹[1] 杨致邦[1] 贺中原[2] 张楠晨 张钐钐 石中全[3] 

机构地区：[1]重庆医科大学基础医学院病原生物学教研室,重庆400016 [2]重庆医科大学,重庆400016 [3]重庆三峡医药高等专科学校免疫学与病原生物学教研室,重庆404120

出　　处：《南方医科大学学报》2016年第2期238-243,共6页Journal of Southern Medical University

基　　金：重庆市教委科学技术研究项目(KJ1402506);国家级大学生创新创业训练计划项目(201310631002)

摘　　要：目的探讨水环境地塞米松污染对小鼠肠道菌群的影响。方法将20只Balb/c小鼠随机分为对照组和实验组,每组5只。实验低剂量组灌喂含0.035 ng地塞米松磷酸钠的饮用水,中剂量组为0.225 ng、高剂量组为2.25 ng,对照组灌喂不含地塞米松磷酸钠的饮用水。每日观察小鼠行为、皮毛、大便等的变化。灌喂第36 d处死小鼠,取回盲部组织提取细菌基因组DNA,扩增16S r DNA V6可变区,扩增产物变性凝胶梯度电泳(DGGE)后分析。切取DGGE图谱上的优势条带,扩增、纯化后克隆测序,其序列BLAST比对分析。结果各实验组小鼠均出现性情暴躁、斗殴打架、咬断尾部等现象。DGGE图谱聚类分析表明各组小鼠回盲部均具有较稳定的菌群;主成分分析表明各组的优势菌群存在一定差异;菌群多样性分析表明,与对照组相比,低剂量组菌群的种类和数量明显增加(P<0.05);中、高剂量组种类和数量显著增加(P<0.01)。16S r DNA V6区序列分析显示实验组和对照组具有共有菌属15种、差异菌属2种,优势菌种类和比例发生了改变。对照组有乳杆菌属的细菌定植,而中、高剂量实验组乳杆菌属的细菌消失,却出现志贺菌属的细菌。结论饮水地塞米松污染可影响小鼠神经系统,使小鼠肠道内细菌的种类、数量及优势菌所占的比例发生改变,菌群多样性增加;抑制肠道益生菌的定植,利于肠道致病菌的入侵。Objective To evaluate the effect of water pollution with dexamethasone on intestinal flora in mice. Methods Twenty Balb/c mice were randomly divided into control group and low-, moderate- and high-dose dexamethasone groups. The mice in dexamethasone groups were exposed to dexamethasone sodium phosphate in drinking water at doses of 0.035, 0.225, and2.25 ng for 36 days. The changes in behaviors, fur condition, and feces of the mice were observed daily. All the mice were sacrificed at 36 days and the tissues in the ileocecal region was collected for denaturant gradient gel electrophoresis（DGGE） of16 S r DNA V6 variable regions of microbes and sequence analysis with BLAST. Results The mice in the 3 dexamethasone groups all showed aggressive behaviors. Cluster analysis of DGGE graph showed relatively stable floras in the ileocecal region in all the mice, but principal component analysis identified differences in the dominating flora among the groups. Diversity analysis of the flora revealed significantly increased amount and types of bacteria in the intestinal flora in all the 3dexamethasone groups（P〈0.05 or 0.01） compared with the control group. Sequence analysis of 16 S r DNA V6 regions showed15 common bacterial species and 2 differential species between the dexamethasone groups and the control group with changes in the type and proportion of the dominating bacterium in the dexamethasone groups. Lactobacillus colonization was detected in the control group but not in moderate- and high-dose dexamethasone groups, and Shigella species were found in the latter two groups. Conclusion Water contamination with dexamethasone can affect the nervous system of mice, cause changes in the types and amounts of intestinal bacteria and the dominating bacteria, and inhibit the colonization of probiotics in the intestinal floras to increase the risk of invasion by intestinal pathogenic bacteria.

关 键 词：地塞米松磷酸钠 污染 饮水 肠道菌群 变性凝胶梯度电泳 16S RDNA V6区 

分 类 号：R123[医药卫生—环境卫生学]