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目的利用16S r DNA PCR及变性梯度凝胶电泳(DGGE)技术,探讨生后经验性应用抗生素对早产儿早期肠道菌群的影响。方法以2014年1月至2015年1月在重庆医科大学附属儿童医院住院治疗的早产儿为研究对象,使用哌拉西林-他唑巴坦>7 d为哌拉西林组,7 d内未使用抗生素为对照组。收集胎粪(<12 h)和3、5、7日龄(d3、d5、d7)的粪便标本,采用PCR-DGGE方法对肠道菌群的变化行动态观察,同时行克隆测序分析菌群组成的变化。结果 24例早产儿的96份粪便标本进入分析,哌拉西林组和对照组各12例,两组基线具可比性。24份胎粪提取细菌DNA后行PCR扩增失败,未行DGGE分析。1哌拉西林组d3、d5、d7时点的Shannon指数中位数(P25~P75)分别为1.64(1.16~1.92)、1.97(1.69~2.20)和1.22(0.69~2.10);对照组分别为1.39(0.94~1.94)、2.24(2.07~2.49)和2.38(2.07~2.61),哌拉西林组d7时点的Shannon指数显著低于对照组(P<0.05)。2随日龄增加,对照组Shannon指数逐渐升高;哌拉西林组Shannon指数呈降低趋势。3d7时点哌拉西林组和对照组均以克雷伯菌属占绝对优势(35.5%和42.4%),且乳酸杆菌属检出率均较低(1.6%和0.8%)。哌拉西林组较对照组肠球菌属(21.0%vs 7.2%)及链球菌属(25.8%vs 4.0%)比例明显增加,肠杆菌比例明显降低(3.2%vs 12.8%)。结论早产儿菌群结构简单,生后抗生素应用会降低肠道菌群多样性。
Objective To investigate the effects of postnatal antibiotics on early intestinal flora in preterm infants by 16S r DNA PCR and denaturing gradient gel electrophoresis (DGGE). Methods From January 2014 to January 2015, preterm infants hospitalized in Children’s Hospital of Chongqing Medical University were enrolled. Piperacillin-tazobactam was used for 7 days in piperacillin group and was not used within 7 days Antibiotics as control group. Stool samples of meconium (<12 h) and 3, 5 and 7 days of age (d3, d5 and d7) were collected and the dynamic changes of intestinal flora were detected by PCR-DGGE. Meanwhile, Composition changes. Results A total of 96 stool samples from 24 preterm infants were included in the analysis. Piperacillin group and control group were all 12 cases. The baseline of the two groups were comparable. Twenty-four fetal bovine samples were used to extract bacterial DNA after PCR amplification failed, and no DGGE analysis was performed. 1 The median Pillency index (P25 ~ P75) of piperacillin group at d3, d5 and d7 were 1.64 (1.16-1.92), 1.97 (1.69-2.20) and 1.22 (0.69-2.10) respectively. The control group were 1.39 (0.94-1.94), 2.24 (2.07-2.49) and 2.38 (2.07-2.61). The Shannon index of piperacillin group at d7 was significantly lower than that of control group (P <0.05). 2 With the increase of age, the Shannon index of control group gradually increased; Shannon index of piperacillin group showed a decreasing trend. Piperacillin and control groups at 3d7 were predominantly Klebsiella (35.5% and 42.4%), and lactobacilli were detected at low rates (1.6% and 0.8%). The ratio of Enterobacter (21.0% vs 7.2%) and Streptococcus (25.8% vs 4.0%) in piperacillin group was significantly increased, and the percentage of Enterobacteriaceae was significantly decreased (3.2% vs 12.8%). Conclusion The structure of preterm infants is simple, antibiotic application after birth will reduce the diversity of intestinal flora.