Nandakumar Renu, Mirchandani Raksha, Fouad Ashraf
Dental School, University of Maryland, Baltimore, MD 21201, USA.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2007 Mar;103(3):429-32. doi: 10.1016/j.tripleo.2006.08.020. Epub 2006 Nov 7.
BACKGROUND/OBJECTIVE: Recent polymerase chain reaction (PCR)-based studies have shown significant variability in the prevalence of Enterococcus faecalis cases with nonhealing endodontic infections. This variability may be, at least in part, due to the differences in sensitivities of the primers used. The purpose of this study was to compare the sensitivity of 3 sets of PCR primers which have been reported in the endodontic literature.
The 3 primers sets used were: group 1) tuf gene-based primers with genus-level specificity; and groups 2 and 3) 16S rDNA-based primers that were E. faecalis specific. Three strains of E. faecalis at concentrations of 10(2)-10(8) cells/mL were included in this study.
The PCR amplification of E. faecalis strains with the 3 primer pairs showed that group 1 primers consistently had the highest sensitivity, followed by group 2 and group 3 (P<.0001).
A tuf-based PCR identification assay followed by direct sequencing would yield accurate and consistent prevalence rates of E. faecalis in endodontic infections.
背景/目的：最近基于聚合酶链反应（PCR）的研究表明，粪肠球菌导致的牙髓感染不愈合病例的患病率存在显著差异。这种差异至少部分可能是由于所用引物敏感性的不同。本研究的目的是比较牙髓病学文献中报道的3组PCR引物的敏感性。
所使用的3组引物为：第1组）基于tuf基因的具有属水平特异性的引物；第2组和第3组）基于16S rDNA的粪肠球菌特异性引物。本研究纳入了3株浓度为10²-10⁸个细胞/毫升的粪肠球菌。
用3对引物对粪肠球菌菌株进行PCR扩增，结果显示第1组引物始终具有最高的敏感性，其次是第2组和第3组（P<0.0001）。
基于tuf基因的PCR鉴定试验结合直接测序，将得出牙髓感染中粪肠球菌准确且一致的患病率。
