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目的应用PCR-变性梯度凝胶电泳(PCR-DGGE)技术动态分析分娩方式对新生儿早期肠道菌群结构的影响。方法选择32例同期出生的健康足月儿为研究对象,按分娩方式分为自然分娩组和剖宫产组(每组各16例),分别于出生后第1天(>12 h)、第3天及第5天采集粪便样本,抽提样本中细菌基因组总DNA,并对其16S rDNA V3可变区进行PCR扩增和DGGE测定,获得肠道菌群指纹图谱,进行多样性和相似性等特征分析。结果 1.新生儿出生第1天肠道菌群定植较少,生命早期肠道菌群定植具有个体特异性,并呈动态变化。2.多样性分析显示:出生第3天2组间多样性比较差异无统计学意义;第5天剖宫产组多样性指数H’和优势度指数D均显著低于自然分娩组(Pa<0.05)。3.成对相似性分析:出生第3天,剖宫产组内成对相似性系数Cs高于自然分娩组;剖宫产组内Cs值<0.30的占该组总Cs值个数的百分比(21.4%)显著低于自然分娩组(76.0%)(Pa<0.01)。第5天,2组Cs值及分布情况比较无明显差异。结论出生第3天,剖宫产个体间较自然分娩儿表现出更高的菌群结构相似性,第5天剖宫产儿肠道菌群种类及数量均落后于自然分娩儿,分娩方式影响了生命早期肠道菌群结构的建立。PCR-DGGE法在新生儿肠道菌群结构多态性及演进变化方面提供了更详尽的资料。
Objective To analyze the effect of delivery mode on early intestinal microflora in neonates by PCR-denaturing gradient gel electrophoresis (PCR-DGGE). Methods 32 full-term healthy full-term infants born at the same period were enrolled in this study. They were divided into spontaneous labor group and cesarean delivery group (16 cases in each group) according to mode of delivery. 3 days and 5 days to collect stool samples, the total bacterial DNA extracted samples, and its 16S rDNA V3 variable region PCR amplification and DGGE determination of gut microflora fingerprint, diversity and similarity And other characteristics of analysis. On the first day after birth, intestinal flora colonized less, early colonization of intestinal flora with individual specificity, and showed dynamic changes. The results of diversity analysis showed that there was no significant difference in the diversity between the two groups on the third day of birth. On the fifth day, the diversity indexes H ’and dominance index D of the cesarean section group were significantly lower than those of the spontaneous delivery group (Pa < 0.05). Paired similarity analysis: the third day of birth, the cesarean section group paired similarity coefficient Cs higher than the natural delivery group; cesarean section group Cs <0.30 percentage of the total number of Cs in the group (21.4%) was significantly lower than the spontaneous delivery group (76.0%) (Pa <0.01). On the fifth day, there was no significant difference between the two groups in the values of Cs and their distribution. Conclusion On the 3rd day of life, the individuals of cesarean section showed higher flora similarity than the natural childbirth. On the 5th day, the types and numbers of intestinal flora in cesarean section lagged behind that of natural childbirth, and the mode of delivery The establishment of intestinal flora structure early in life. PCR-DGGE method in neonatal intestinal flora structure and evolution of polymorphisms provide more detailed information.