儿童肠道菌群的组成及β-内酰胺类抗生素对儿童肠道菌群影响的实验研究

发布时间：2018-11-13 17:51

【摘要】：目的：了解儿童肠道菌群的组成和使用β-内酰胺类抗生素后肠道细菌组成的影响。 方法：1.标本采集：分别采集3-5岁健康且一月内无抗生素使用史儿童粪便样本10例(对照组)及同年龄组一周内有β-内酰胺类抗生素使用史的儿童粪便样本4例(抗生素组)。2.提取粪便DNA并进行16S rRNA基因扩增；将扩增产物与扩增质粒连接后转导到大肠杆菌,建立DNA克隆文库,每个样本分别随机选择160个克隆进行DNA序列测定。3.序列分类和种系分析：保守序列直接在GenBank上进行BLAST比较,然后用RDPII9.49进行细菌门类及属类分类。≥97%一致序列确定为同一属,用MEGA5.0进行相邻合并分析绘制种系结构图。 结果：1.对照组10个样本测序共获得1317个16SrRNA基因序列,抗生素组4个样本共获得536个16S rRNA基因序列。2.细菌门水平的分类显示儿童粪便中优势菌群为厚壁菌门和拟杆菌门,在对照组中分别占菌群总数的55.2%和40.9%,在抗生素组中分别占菌群总数的50.8%和42.7%,此外,两组中均含少量变形菌门、放线菌门、栖热菌门和未分类菌门。3.对照组和抗生素组两组各主要门类下各属水平的分布无明显差异并且两组样本分布结构相似。4.各样本的菌群结构各不相同,厚壁菌门比例从12%到85.4%不等,拟杆菌门从12.7%到83%不等。 结论：1.儿童粪便优势菌群由厚壁菌门(55.2%)、拟杆菌门(40.9%)组成,变形杆菌门、放线菌门和梭杆菌门共计少于5%；厚壁菌门中Faecalibacterium (53%)、 Roseburia (8.5%)和Lachnospiraceae incertae sedis (6.2%)为优势菌属；拟杆菌门中Prevotella (47.2%)和Bacteroides(42.8%)为优势菌属;2.不管在门或属的水平上,儿童粪便菌群在各个体有其独特的菌群结构分布；3.4例一周内使用β-内酰胺类抗生素儿童粪便样本菌群组成与对照组比较统计分析无明显差异,这可能与分析例数少或对照组在既往中使用抗生素有关。
[Abstract]:Objective: to investigate the composition of intestinal flora and the effect of 尾-lactam antibiotics on intestinal bacterial composition in children. Method 1: 1. Specimen collection: the fecal samples of 10 healthy children aged 3-5 years with no history of antibiotic use within one month (control group) and 4 children of the same age group who had a history of using 尾 -lactam antibiotics within one week were collected. Antibiotic group) Fecal DNA was extracted and 16s rRNA gene was amplified, the amplified product was transferred to Escherichia coli by ligation with amplified plasmid, and DNA clone library was established. 160 clones were randomly selected for DNA sequencing in each sample. Sequence classification and phylogenetic analysis: conserved sequences were compared directly with BLAST on GenBank, and then bacteria and genera were classified by RDPII9.49. 鈮，

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