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大肠杆菌噬菌体对小鼠机体健康和肠道菌群的影响【字数:13086】

2024-11-24 15:26编辑: www.jxszl.com景先生毕设

目录
摘 要 Ⅰ
ABSTRACT Ⅱ
第一章 文献综述 1
引言 1
1 噬菌体的结构与分类 1
2 噬菌体的溶菌机制 1
3 噬菌体对鸡肠道菌群影响的研究 2
4 讨论 3
第二章 大肠杆菌噬菌体对小鼠机体健康和肠道菌群的影响 4
引言 4
1 材料与方法 4
1.1 供试材料 4
1.1.1 试验动物 4
1.1.2 试验所用菌株 4
1.1.3 试验设备 4
1.1.4 试验试剂 4
1.1.5 试验所用试剂盒 5
1.2 试验设计及样品采集 5
1.2.1 试验设计 5
1.2.2 样品采集 5
1.3 噬菌体的制备与计数方法 5
1.3.1 噬菌体扩增 5
1.3.2 提取噬菌体 5
1.3.3 噬菌体提取液纯化 5
1.3.4 噬菌体稀释 5
1.3.5 噬菌体计数 5
1.4 粪样中噬菌体计数 6
1.5 内毒素检测 6
1.6 粪便样品DNA提取 6
1.7 高通量测序 7
1.8 实验数据整理与分析 7
2 结果与分析 7
2.1 灌胃噬菌体对体重变化的影响 7
2.2 灌胃噬菌体对白细胞数量的影响 8
2.3 灌胃噬菌体对肠道噬菌体数量的影响 8
2.4 灌胃噬菌体对肠道内毒素浓度的影响 9
2.5 灌胃噬菌体对小鼠粪便菌群的影响 9
2.5.1 灌胃噬菌体菌群α和β多样性的影响 9
2.5.2 灌胃噬菌体对菌群不同分类学水平下菌群组成的影响 11
3 讨论 16
第三章 结论与展望 18
参考文献 19
致 谢 21
大肠杆菌噬菌体对小鼠机体健康和肠道菌群的影响
摘 要
引言
 *51今日免费论文网|www.51jrft.com +Q: ^351916072
本试验的目的是研究大肠杆菌噬菌体对健康小鼠机体和肠道菌群的影响,了解外源噬菌体进入小鼠肠道后对小鼠机体产生的具体影响,试验研究分析对象包括灌胃噬菌体后小鼠体重、白细胞指数、粪样噬菌体数、肠道内毒素浓度和粪样菌群组成情况,从而得到多方数据支持的小鼠机体变化情况。具体方法是对小鼠随机分组后,每天定时定量进行SM缓冲液或噬菌体灌胃,在各个时间点对小鼠称重、取血样检查血常规、取粪样测噬菌体数、取小鼠小肠和大肠肠段测内毒素浓度、提取粪样DNA进行高通量测序。
试验结果显示灌胃外源噬菌体对小鼠体重增长和血白细胞数量无显著影响(P > 0.05);小鼠肠道内毒素浓度未受到显著性影响(P > 0.05);外源噬菌体灌胃后随粪便排出,未在小鼠肠道定植。
灌胃噬菌体使小鼠肠道少部分细菌丰度发生变化。“科”水平:Bacteroidaceae第14天出现显著性差异(P < 0.05);Prevotellaceae第0天有显著性差异(P < 0.05),之后差异消失;Rikenellaceae第21天出现显著性差异(P < 0.05);“属”水平:Alistipes第21天出现显著性差异(P < 0.05);Alloprevotella第0天有显著性差异(P < 0.05),之后差异消失;Bacteroides第14天出现显著性差异(P < 0.05);Blautia第21天出现显著性差异(P < 0.05);Rikenellaceae_RC9_gut_group第7天、第14天均有显著性差异(P < 0.05)。
两组小鼠肠道菌群的α多样性中Observed 指数在第14 天时出现显著性差异(P < 0.05);Chao1指数、ACE指数、香农指数和辛普森指数在21天里都没有出现显著性差异(P > 0.05);两组小鼠肠道菌群的β多样性第0、7、14、21天均没有显著性差异(P > 0.05)。
EFFECTS OF ESCHERICHIA COLI PHAGES ON THE HEALTH AND INTESTINAL FLORA OF MICE
ABSTRACT
The use of antibiotics in animal husbandry has been increasing in recent decades, and antibiotic residues have caused a number of problems. Many superbugs and novel pathogens that are not sensitive to most antibiotics have been discovered one after another, and had brought great losses to the livestock industry. Phage preparations are expected to replace antibiotics in animal husbandry because of their specificity, nondamage to human and animal normal cells, and nondevelopment of drug resistance.
The purpose of this experiment is to study the effects of Escherichia coli phages on the health and intestinal flora of healthy mice. To understand the specific effects of exogenous phages on the body of mice after entering the intestinal tract, the body weight, the number of white blood cell,chyme endotoxin concentration and fecal flora composition of mice were analyzed after phage gavage. In this way, the body changes of mice supported by multiple data were obtained. To do this, mice were given phage gavage, blood samples were taken at each time point to check blood routine, fecal samples were taken to measure endotoxin concentration, and fecal DNA was extracted for highthroughput sequencing and weighing.

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