早产儿喂养不耐受肠道菌群组成多样性研究

发布时间：2018-03-23 03:16

本文选题：早产儿　切入点：喂养不耐受　出处：《重庆医科大学》2012年硕士论文　论文类型：学位论文

【摘要】：第一部分：PCR-DGGE分析早产儿喂养不耐受肠道菌群【目的】利用PCR-DGGE技术分析喂养不耐受早产儿和喂养耐受早产儿（对照组）的大便菌群的结构差异。【方法】采集15例喂养不耐受早产儿和15例喂养耐受早产儿（对照组）生后第1d，出现喂养不耐受，喂养不耐受恢复后大便标本。提取大便中的细菌混合DNA，再对其16S rDNA的V3可变区进行PCR扩增，扩增产物经DGGE电泳后比较谱带的异同，找出特征性条带，，回收测序后确定菌属。【结果】组别相匹配的喂养不耐受组和对照组的DGGE条带有明显的差异，多出或缺失几条明显的优势条带，特征性条带经回收测序确定属于大肠埃希菌、肺炎克雷伯菌、粪肠球菌和乳酸杆菌。【结论】喂养不耐受组较对照组而言，肠道的优势菌群发生了变化。第二部分Real-Time PCR定量分析早产儿喂养不耐受肠道菌群变化【目的】观察早产儿喂养不耐受肠道中大肠埃希菌、粪肠球菌、肺炎克雷伯菌、乳酸杆菌和双歧杆菌的变化。【方法】采用实时荧光定量PCR技术，分别对15例喂养不耐受早产儿和15例喂养耐受早产儿（对照组）生后第1d，出现喂养不耐受，喂养不耐受恢复后大便标本中的大肠埃希菌、肺炎克雷伯菌、粪肠球菌、乳酸杆菌和双歧杆菌进行定量分析。【结果】喂养不耐受组中大肠埃希菌的拷贝数对数值（lg copies/g）分别为2.62±0.22、5.47±1.28、3.04±0.70，对照组分别为2.56±0.19、2.82±0.4、2.80±0.39；肺炎克雷伯菌的拷贝数对数值（lg copies/g）分别为4.37±0.22、6.56±0.27、4.17±0.27，对照组分别为4.35±0.22、4.19±0.14、4.15±0.25；粪肠球菌的拷贝数（copies/g）分别为79.17±93.46、42.84±47.57、101.68±43.78，对照组分别为70.16±78.41、740.05±657.71、104.57±38.39；乳酸杆菌的拷贝数（copies/g）分别为204.03±25.57、326.04±82.42、677.73±559.49，对照组中205.48±16.65、678.79±124.93、663.33±491.57；双歧杆菌的拷贝数对数值（lg copies/g）分别为4.79±0.07、5.27±0.17、5.65±0.25，对照组4.76±0.07、5.57±0.09、5.64±0.15。出现喂养不耐受时，两组的5种细菌拷贝数比较差异具有显著性（P＜0.05），而出现之前和恢复后两组细菌拷贝数差异无显著性（P0.05）。【结论】喂养不耐受时大肠埃希菌、肺炎克雷伯菌数量显著增高，可能参与喂养不耐受的发生，而粪肠球菌、乳酸杆菌、双歧杆菌呈现显著降低，可能起保护作用。
[Abstract]:Part one: PCR-DGGE analysis of intestinal flora in premature infants with feeding intolerance. [objective] to analyze the differences of fecal flora between preterm infants fed intolerant and those fed with preterm infants (control group) by PCR-DGGE technique. [methods] Fifteen cases of preterm infants with feeding intolerance and 15 cases with feeding tolerance of premature infants (control group) were collected at the first day after birth. Fecal specimens after feeding intolerance recovered, the mixed DNA of bacteria was extracted from feces, and the V3 variable region of 16s rDNA was amplified by PCR. The amplified products were compared with the similarities and differences of the bands by DGGE electrophoresis, and the characteristic bands were found and sequenced to determine the genus of bacteria. [results] there were significant differences in the DGGE bands between the feeding intolerance group and the control group. The DGGE bands were found to be Escherichia coli and Klebsiella pneumoniae, and the characteristic bands were found to belong to Escherichia coli and Klebsiella pneumoniae. Enterococcus faecalis and Lactobacillus. [conclusion] compared with the control group, the dominant flora of the intestinal tract in the feeding intolerance group changed. The second part of Real-Time PCR quantitative analysis of intestinal flora changes of preterm infants with feeding intolerance. [objective] to observe the changes of Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, Lactobacillus and Bifidobacterium in feeding intolerance of premature infants. [methods] Fifteen cases of preterm infants fed intolerant and 15 cases fed with preterm infants (control group) were treated with real-time fluorescence quantitative PCR. The first day of feeding intolerance and feeding intolerance of Escherichia coli in fecal specimens after recovery were observed in 15 cases of preterm infants and 15 cases of feeding tolerant preterm infants (control group) at the first day after birth. Klebsiella pneumoniae, Enterococcus faecalis, Lactobacillus and Bifidobacterium were quantitatively analyzed. [results] the logarithmic copy numbers of Escherichia coli in the feeding intolerance group were 2.62 卤0.225.47 卤1.283.04 卤0.70, 2.56 卤0.192.82 卤0.4 卤2.80 卤0.39, 4.37 卤0.226.56 卤0.274.17 卤0.27, 4.35 卤0.224.19 卤0.144.15 卤0.25, respectively, for Klebsiella pneumoniae, the logarithmic values were 4.37 卤0.226.56 卤0.274.17 卤0.274.17, 4.35 卤0.224.19 卤0.144.15 卤0.25 for Klebsiella pneumoniae, respectively. The copy numbers of Lactobacillus sp. were 79.17 卤93.46.46 卤42.84 卤47.57101.68 卤43.78, 70.16 卤78.41740.05 卤657.71104.57 卤38.39, and 204.03 卤25.57326.04 卤82.42677.73 卤559.49, 205.48 卤16.65678.79 卤124.93663.33 卤491.57 in the control group, 4.79 卤0.075.27 卤0.175.65 卤0.2565 卤0.2575 in the control group respectively, and 4.76 卤0.075.57 卤0.095.64 卤0.15. There was a significant difference in the number of copies of the five bacteria between the two groups (P < 0.05), but there was no significant difference in the number of copies between the two groups before and after recovery (P < 0.05). [conclusion] the number of Escherichia coli and Klebsiella pneumoniae increased significantly during feeding intolerance, which may be involved in the development of feeding intolerance, while Enterococcus faecalis, Lactobacillus and Bifidobacterium decreased significantly, which may play a protective role.
【学位授予单位】：重庆医科大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R722.6

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