齿垢密螺旋体在慢性牙周炎龈下菌斑中的分布

Distribution of Treponema denticola in chronic periodontitis

目的:采用聚合酶链反应(PCR)技术,检测慢性牙周炎患者患病部位和相对健康部位龈下菌斑中齿垢密螺旋体(Treponema denticola,Td),了解齿垢密螺旋体在不同部位龈下菌斑中的分布情况,并探讨其检出率与慢性牙周炎的关系。方法:选择58例慢性牙周炎患者患病部位和相对健康部位龈下菌斑,对齿垢密螺旋体tdpA基因片段进行扩增和克隆测序。结果:34例(58.6%)患病部位PCR为阳性,相对健康部位中5例(8.62%)PCR为阳性,患病部位齿垢密螺旋体检出率高于相对健康部位(P<0.001)。对tdpA基因克隆后测序,结果与B last比对与Gen Bank中已登陆的tdpA基因同源性为94%。结论:在慢性牙周炎患者患病部位龈下菌斑中,齿垢密螺旋体检出率高于相对健康部位,与慢性牙周炎关系密切,利用PCR方法检测Td,简便、特异性高。

AIM：To detect the Treponema denticola（Td） subgingivally in diseased and healthy sites of chronic periodontitis with PCR assay,in order to observe the distribution of Td in subgingival plaque and clarify the relationship between the presence of Td and chronic periodontitis. METHODS： Subgingival plaque samples were taken from diseased sites and healthy sites of 58 patients with chronic periodontitis and treated with 10 mL/L Triton X - 100 and 100℃ for 10 minutes to prepare DNA templates. The fragments of tdpA gene which encode 53 × 10^3 outer membrane protein were detected by PCR and subsequent cloning. RESULTS：34 of 58 （58.6%） subgingival samples from diseased sites and 5 of 58 （ 8.62% ） healthy sites showed positive PCR results （ P 〈 0. 001 ）. The sequencing results of tdpA gene fragments demonstrated that it had 94% similarity with the report in Genebank. CONCLUSION：The detection rate of Td in diseased sites was much higher than the healthy sites. It must be the putative etiologic agent in chronic periodontitis. PCR is the sensitive and reliable method to detect Td.