【作者】 李润美；

【导师】 韩英；

【作者基本信息】 中国人民解放军军医进修学院 ， 内科学， 2006， 硕士

【摘要】 炎症性肠病(Inflammatory Bowel Disease,IBD)是一组病因不明的慢性肠道炎症性疾病。微生物在IBD发病中的作用一直受到重视,但至今尚未找到某一特异病原微生物与IBD有恒定关系。由于目前能够分离培养的肠道细菌种类只占肠道细菌总数的少数,而以PCR技术为基础的DNA指纹图谱就可以用来分析肠道菌丛的组成。ERIC序列(Enterobacterial Repetitive Intergenic Consensus,肠杆菌基因间的重复共有序列)是主要存在于肠道细菌中的一段长为126 bp的反向重复序列,该序列高度保守,而且染色体定位具有种特异性,ERIC-PCR扩增的产物大小在50-3000bp之间,每种菌株均存在数目不等的各自独特的电泳带型,各特异性扩增的主带型能重复稳定出现,可以区别不同种类的细菌和同一种类细菌中不同的菌株。本研究应用ERIC-PCR技术建立10例IBD患者及10例正常对照者的肠道细菌DNA指纹图谱,分析IBD患者及正常对照者的肠道菌丛的整体差异。经分析发现IBD患者及正常对照者的肠道菌丛存在整体差异,正常对照组ERIC-PCR指纹图谱电泳DNA条带多,主带位置无统一趋势;IBD组ERIC-PCR指纹图谱电泳DNA条带较少,且所有样本主带分布非常一致,均出现在约1.1kb处。从而推断正常人肠道细菌种类多,IBD患者少。IBD组1.1kb处主带可能为某一种肠道细菌中特有的序列,或为不同序列或几个序列的混合物。更多还原

【Abstract】 Inflammatory bowel disease (IBD) is a group of chronic enteric inflammatory diseases without definite etiopathogenisis. Microorganism plays an important role in pathogenesis of IBD. But no specific pathogenic microorganism has been found related to IBD so far. The number of enterobacteria species could be cultured in vitro only accounts for small percent of the total number of enterobacteria species. DNA fingerprinting based on PCR technology could be used to analyze the makeup of intestinal flora. Enterobacterial Repetitive Intergenic Consensus (ERIC) sequence is a kind of reverse and repeated sequence mostly located in the enterobacteria genome that is 126bp in size and highly conservative. ERIC-PCR generates multiple distinct amplification products of sizes ranging from approximately 50 to 3000 bp. Each kind of bacteria has special electrophoretic bands with different number and the main band could be appeared stably and repeatedly. The unique location of ERIC elements in bacterial genomes allows discrimination at genus, species and strain levels based on the electrophoretic pattern amplification products. In this study, we set up the DNA fingerprinting of IBD patients and healthy persons based on ERIC-PCR technology. We have identified the DNA fingerprintings of IBD patients and the healthy persons, and a significant difference was noticed between them.There are a lot of bands in the DNA fingerprinting of the healthy group but fewer in the DNA fingerprinting of the IBD patients. Strikingly, a same band of DNA fingerprinting was noticed in IBD patients. So the variaty of intestinal flora of healthy patients is more than it of IBD patients.The unique band might be the sequence of specific bacterium. Or it might be the sequence of different bacterium and the mixed sequence.更多还原