Preethee Thomas, Kandaswamy Deivanayagam, Hannah Rosaline
Department of Conservative Dentistry and Endodontics, Amrita School of Dentistry, Kochi, Kerala, India.
J Conserv Dent. 2012 Oct;15(4):319-22. doi: 10.4103/0972-0707.101886.
Enterococcus faecalis has long been implicated in persistent root canal infections and therapy-resistant endodontic infections. It has also been associated with bacteremia, that is, infective endocarditis arising from certain invasive dental procedures. E. faecalis endocarditis antigen (efaA) has been identified as one of the principal virulence factors associated with infective endocarditis.
To detect the presence of putative E. faecalis virulence factor, efaA in root canals of therapy-resistant endodontic infections using polymerase chain reaction (PCR) amplification.
Samples were obtained from 32 patients (20-70 years) undergoing endodontic retreatment, which were incubated in prereduced thioglycollate broth and subcultured onto ethyl violet azide broth (EVA; selective medium for E. faecalis). Deoxyribonucleic acid (DNA) was extracted from the samples and analyzed for the endocarditis virulence factor efaA using PCR.
Among the positive E. faecalis samples, efaA gene was identified in 11 out of 15 samples.
Our findings indicate that efaA, a potent E. faecalis virulence gene can be found in E. faecalis strains detected in root canals of therapy-resistant endodontic infections similar to reports for 'medical' strains.
粪肠球菌长期以来一直与持续性根管感染和治疗抵抗性牙髓感染有关。它还与菌血症有关，即某些侵入性牙科手术引起的感染性心内膜炎。粪肠球菌心内膜炎抗原（efaA）已被确定为与感染性心内膜炎相关的主要毒力因子之一。
使用聚合酶链反应（PCR）扩增检测治疗抵抗性牙髓感染根管中假定的粪肠球菌毒力因子efaA的存在。
从32名（20至70岁）接受根管再治疗的患者中获取样本，将其在预先还原的硫乙醇酸盐肉汤中孵育，并转接至乙基紫叠氮肉汤（EVA；粪肠球菌的选择性培养基）上。从样本中提取脱氧核糖核酸（DNA），并使用PCR分析心内膜炎毒力因子efaA。
在粪肠球菌阳性样本中，15个样本中有11个检测到efaA基因。
我们的研究结果表明，efaA是一种有效的粪肠球菌毒力基因，在治疗抵抗性牙髓感染根管中检测到的粪肠球菌菌株中可以发现，这与“医学”菌株的报道相似。
