急性下颌智牙冠周炎菌群结构变性梯度凝胶电泳分析

DGGE analysis of bacterial community structure in mandibular third molar pericoronitis

目的应用变性梯度凝胶电泳技术,分析急性下颌智牙冠周炎菌群结构。方法采集29例急性下颌智牙冠周炎盲袋内细菌标本,提取细菌总DNA,巢式聚合酶链反应扩增全部细菌16S rDNA基因V2-V3可变区。变性梯度凝胶电泳对PCR扩增产物进行分离。应用BioNumerics软件对DGGE图像资料进行聚类分析,对比不同类别样本中的临床资料、条带数量和条带模式。结果 29例急性下颌智牙冠周炎细菌16S rDNA基因条带数量和条带模式存在不同。通过聚类分析可将临床样本聚为2组,2组间临床资料的差异没有统计学意义;但条带数量和相似系数均不同,差异具有统计学意义。结论急性下颌智牙冠周炎临床状态基本相同,而菌群结构不同。DGGE技术和聚类分析可用于急性下颌智牙冠周炎细菌菌群结构的研究。

Objective To investigate the bacterial community structure in pericoronitis of the mandibular third molar. Methods Twenty-nine samples were taken from the pockets of pericoronitis of mandibular third molar in 29 patients. All DNA was extracted for a nested amplification of the V2-V3 hypervariable region of 16S ribosomal RNA gene （16S rDNA） with GC rich clamp at the 5＇-end. PCR-generated DNA fragments of the same length but with different basepair sequences were separated by denaturing gradient gel electrophoresis （DGGE）. DGGE band patterns of 16S rDNA profiles were objectively digitized using BioNumerics software. Results Distinct band number and patterns were observed in all twenty-nine cases. Cluster analysis of DGGE band polymorphism clearly divided pericoronitis cases into two groups according to band patterns. The overall differences in the band number and patterns between cluster A and cluster B were statistically significant. Conclusion Pericornnitis of the mandibular third molar presents the same symptoms whereas the structure of the bacterial community in pericoronitis cases are significantly different. The structure of the bacterial community is different between the two clusters.