SYBR GREEN实时荧光定量分析牙龈卟啉单胞菌在初次感染和再感染根管内的定植

Molecular identification and quantification of Porphyromonas gingivalis from endodontic infections using SYBR GREEN real-time polymerase chain reaction

目的采用SYBR GREEN实时荧光定量PCR分析和比较牙龈卟啉单胞菌(Porphyromonas gingivalis,P.gingivalis)在初次治疗和再治疗感染根管中的定植情况。方法选择2013年9月至2014年10月于首都医科大学附属北京口腔医院牙体牙髓科就诊的慢性根尖周炎患者的120颗单根管患牙为研究对象,按初次治疗和再治疗分为2组,每组60人。采用SYBR GREEN实时荧光定量PCR(real-time fluorescence quantitative polymerase chain reaction,RTFQ-PCR)比较P.gingivalis在两种感染根管内的检出率和DNA表达水平。结果 RTFQ-PCR结果发现P.gingivalis在初次治疗的感染根管内检出率为45.0%,再治疗感染根管的检出率为41.7%,两者间差异无统计学意义(P=0.713);P.gingivalis在初次治疗的感染根管内的DNA相对表达量(0.197±0.380)和再感染根管内相对表达量(0.449±0.150)比较差异无统计学意义(P=0.301)。结论 P.gingivalis与两种感染根管关系均密切,提示其在初次感染和再感染根尖周炎的发病过程中都发挥致病作用。

Objective To assess and compare the colonization of Porphyromonas gingivalis （P. gingivalis） in root canals associated with primary and secondary endodontic infections by using quantitative real-time polymerase chain reaction （RTFQ-PCR）. Methods One hundred and twenty adult patients with one radiographically documented periapical lesion were included, including sixty teeth with primary infections and 60 with secondary infections. Samples were obtained by using sterilized paper points, and DNAs extracted from the samples were amplified by PCR with universal bacterial primers based on 16S rRNA gene sequences. The detection rate and DNA expression of P. gingivalis were compared by SYBRGREEN real-time fluorescence quantitative PCR. Results The detection rate of P. gingivalis in the root canals with primary infections （45.0%） was not significantly different from those with secondary infections （41.7%）. In addition, RTFQ-PCR results showed there was no significant difference in the quantity of DNA expression between the two groups （0.197±0.38 vs 0.449±0.15, P〉0.05）. Conclusion P. gingivalis was associated closely with both primary and secondary endodontic infections.