Apical periodontitis is caused by biofilm-mediated root canal infection. Early phase oral bacterial biofilms are inhibited by Lactobacillus plantarum lipoteichoic acid (Lp.LTA). However, mature biofilms that develop over 3 weeks are more resistant to traditional endodontic medicaments. Therefore, this study examined the effectiveness of Lp.LTA on disrupting mature Enterococcus faecalis biofilms, and on enhancing the effects of endodontic medicaments. LTA was purified from L. plantarum through butanol extraction followed by hydrophobic and ion-exchange chromatography. E. faecalis biofilms were formed over 3 weeks on glass bottom dishes and in dentin blocks obtained from human single-rooted premolars. These mature biofilms were treated with or without Lp.LTA for 1 h, followed by additional treatment with either chlorhexidine digluconate (CHX), calcium hydroxide (CH), or triple antibiotics for 24 h. Biofilms on glass were live/dead stained and quantified by ZEN through confocal laser microscopy. Bio-films in dentin were fixed, sputter coated and analyzed by ImageJ with scanning electron microscopy. Preformed E. faecalis mature biofilms on the culture dishes were dose-dependently disrupted by Lp.LTA. Lp.LTA potentiated the effects of CHX or CH on the disruption of mature biofilm. Interestingly, CHX-induced disruption of preformed E. faecalis mature biofilms was synergistically enhanced only when pre-treated with Lp.LTA. Furthermore, in the dentin block model, Lp.LTA alone reduced E. faecalis mature biofilm and pre-treatment with Lp.LTA promoted the anti-biofilm activity of CHX. Lp.LTA could be an anti-biofilm or supplementary agent that can be effective for E. faecalis-biofilm-induced diseases.

中文翻译：

---

植物乳杆菌脂磷壁酸破坏成熟的粪肠球菌生物膜

根尖性牙周炎是由生物膜介导的根管感染引起的。早期口腔细菌生物膜被植物乳杆菌脂磷壁酸（Lp.LTA）抑制。但是，超过3周的成熟生物膜对传统牙髓药物的抵抗力更高。因此，本研究检查了Lp.LTA在破坏成熟的粪肠球菌生物膜以及增强牙髓药物作用方面的有效性。通过丁醇萃取，然后通过疏水和离子交换色谱法从植物乳杆菌中纯化LTA 。粪肠球菌在玻璃底盘上和从人单根前磨牙获得的牙本质块中，在三周内形成了生物膜。这些成熟的生物膜在有或没有Lp.LTA的情况下处理1小时，然后再用洗必太二葡萄糖酸（CHX），氢氧化钙（CH）或三重抗生素处理24小时。通过共聚焦激光显微镜对ZEN上的生物膜进行活/死染色和定量分析。固定牙本质中的生物膜，进行溅射涂覆，并通过ImageJ用扫描电子显微镜进行分析。预形成的粪肠球菌成熟的培养皿生物膜剂量依赖性通过Lp.LTA破坏。Lp.LTA增强了CHX或CH对成熟生物膜破坏的影响。有趣的是，CHX对预制的粪肠球菌的破坏仅当用Lp.LTA预处理时，成熟的生物膜才会协同增强。此外，在牙本质阻断模型中，单独的Lp.LTA可以减少粪肠球菌的成熟生物膜，而用Lp.LTA进行预处理可以提高CHX的抗生物膜活性。Lp.LTA可能是一种抗生物膜或补充剂，可有效治疗屎肠球菌-生物膜诱导的疾病。