幽门螺杆菌感染对小鼠食道下端菌群的影响

目的通过小鼠动物模型，检测幽门螺杆菌感染后食道下端菌群的变化，探讨其与食道下端疾病发生的关系。方法将30
只BALB/C小鼠随机均分为阴性对照组和感染组。感染组通过灌喂幽门螺杆菌菌液建立动物感染模型，两组小鼠均在末次灌
喂菌液4周后同时处死，取食道下端组织提取细菌的DNA，以原核生物16S rDNA V6区通用引物采用聚合酶链反应-变性梯度
凝胶技术（PCR-DGGE）对V6区进行扩增，用Quantity-One 1-D Analysis software.对DGGE图谱进行菌群分析，并将DGGE图
谱上的组间差异条带用16S rDNA V6区引物分别扩增后，DNA测序，BLAST比对分析。结果DGGE指纹图谱分析显示，实验
组DNA条带数量极显著高于对照组（P<0.01），多样性指数、丰富度指数均显著高于对照组（0.01好地在相似性系统树中分开，主成分分析不同组的菌群分别聚集在不同的位置，BLAST比对分析感染组出现特有细菌。结论
食道下端定植着以乳杆菌、拟杆菌为优势菌的稳定菌群，幽门螺杆菌感染后菌群结构变化为以葡萄球菌、不动杆菌、无芽胞杆菌
为优势菌的菌群。

Effect of Helicobacter pylori infection on bacterial flora in the lower esophagus of mice

Objective To explore the relationship between Helicobacter pylori (H. pylori) infection and lower esophageal diseases
in light of the changes of the bacterial flora in the lower esophagus. Methods Thirty BALB/C mice were randomized into
negative control group and H. pylori infection group, and in the latter group, the mice were subjected to intragastric
administration of solution containing H. pylori. After 4 weeks of administration, all the mice were sacrificed, and the V6 areas
in 16S rDNA were amplified from the bacterial DNA extracted from the lower esophagus using polymerase chain
reaction-denaturing gradient gel electrophoresis. The bacterial floras were analyzed on DGGE atlas with Quantity-One 1-D
analysis software, and the differential bands between the two groups were amplified using a 16S rDNA v6 area primer
followed by DNA sequencing and BLAST analysis. Results DGGE finger-prints showed a significantly greater number of DNA
bands in the infection group than in the negative control group (P<0.01). The diversity index and richness index were also
significantly higher in the infection group (0.01infection group. Principal component analysis showed that different groups of bacteria gathered in different locations, and
BLAST analysis revealed the presence of special bacteria in the infection group. Conclusions In normal mice, Lactobacillus and
the Bacteroides are the predominant bacterial flora colonizing in the lower esophagus, and Staphylococcus, Acinetobacter and
Bacteridium become the predominant bacteria after H. pylori infection.