Department of Endodontics, School of Stomatology, Capital Medical University.
Affiliated Stomatology Hospital of Guangzhou Medical University.
J Appl Oral Sci. 2021 Mar 1;29:e20200733. doi: 10.1590/1678-7757-2020-0733. eCollection 2021.
Enterococcus faecalis (E. faecalis), one of the main pathogens responsible for refractory periapical periodontitis and nosocomial infections, exhibits markedly higher pathogenicity in biofilms. Studies have shown that caseinolytic protease P (ClpP) is involved in biofilm formation. However, to date, few studies have investigated the role of ClpP in the survival of E. faecalis, and in enhancing biofilm formation. Therefore, we investigated the role of ClpP in the formation of E. faecalis biofilms.
In our study, we used homologous recombination to construct clpP deleted and clpP complement strains of E. faecalis ATCC 29212. A viable colony counting method was used to analyze the growth patterns of E. faecalis. Crystal violet staining (CV) and confocal scanning laser microscopy (CLSM) were used to characterize biofilm mass formation and scanning electron microscopy (SEM) was used to observe the biofilm microstructure. Data was statistically analyzed via Student's t-test or one-way analysis of variance (ANOVA).
The results exhibited altered growth patterns for the clpP deletion strains and depleted polysaccharide matrix, resulting in reduced biofilm formation capacity compared to the standard strains. Moreover, ClpP was observed to increase biofilm formation in E. faecalis.
Our study shows that ClpP can increase biofilm formation in E. faecalis and emphasizes the importance of ClpP as a potential target against E. faecalis.
粪肠球菌（E. faecalis）是导致难治性根尖周炎和医院感染的主要病原体之一，在生物膜中表现出更高的致病性。研究表明，组织蛋白酶 P（ClpP）参与生物膜的形成。然而，迄今为止，很少有研究调查 ClpP 在粪肠球菌存活和增强生物膜形成中的作用。因此，我们研究了 ClpP 在粪肠球菌生物膜形成中的作用。
在我们的研究中，我们使用同源重组构建了粪肠球菌 ATCC 29212 的 clpP 缺失和 clpP 互补菌株。使用活菌计数法分析粪肠球菌的生长模式。结晶紫染色（CV）和共聚焦扫描激光显微镜（CLSM）用于表征生物膜质量形成，扫描电子显微镜（SEM）用于观察生物膜微观结构。通过学生 t 检验或单向方差分析（ANOVA）对数据进行统计学分析。
结果显示 clpP 缺失菌株的生长模式发生改变，多糖基质耗竭，导致与标准菌株相比生物膜形成能力降低。此外，观察到 ClpP 增加了粪肠球菌的生物膜形成。
我们的研究表明 ClpP 可以增加粪肠球菌的生物膜形成，并强调 ClpP 作为针对粪肠球菌的潜在靶标重要性。
