Effect of the quorum-sensing luxS gene on biofilm formation by Enterococcus faecalis
Effect of the quorum-sensing luxS gene on biofilm formation by Enterococcus faecalis
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群体感应luxS基因对粪肠球菌生物膜形成的影响
DOI：
10.1111/eos.12269
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发表时间：
2016-06-01
影响因子：
1.9
通讯作者：
Huang, Zhengwei
中科院分区：
文献类型：
--
作者：
He, Zhiyan;Liang, Jingping;Huang, Zhengwei
粪肠球菌是最常从表现出根管治疗难治性慢性根尖牙周炎的牙齿的根管中分离出的细菌。在本研究中，我们评估了S-核糖基同型半胱氨酸裂解酶（luxS）群体感应基因对E。通过构建基因敲除突变体来形成粪菌生物膜。E. faecalis及其luxS突变株用MTT法进行评价。还研究了影响生物膜形成的重要参数，包括细胞表面疏水性和生长培养基的营养含量。采用激光共聚焦显微镜观察生物膜的结构，采用RT-PCR检测生物膜相关基因的表达。结果表明，luxS基因可以影响生物膜的形成，但不影响细菌的生长速率。luxS基因的缺失也增加了细胞表面的疏水性。生物膜的形成加速了增加浓度的葡萄糖的加入。CLSM图像显示，luxS突变株倾向于聚集成不同的簇和相对致密的结构，而野生型菌株出现融合和更均匀地分布。所有检测的基因在由luxS突变株形成的生物膜中均上调。群体感应luxS基因可以影响E.粪便生物膜形成。
Enterococcus faecalis is the species of bacterium most frequently isolated from the root canals of teeth that exhibit chronic apical periodontitis refractory to endodontic treatment. In this study, we evaluated the effect of the S-ribosylhomocysteine lyase (luxS) quorum-sensing gene on E. faecalis biofilm formation by constructing a knockout mutant. The biofilms formed by both E. faecalis and its luxS mutant strain were evaluated using the MTT method. Important parameters that influence biofilm formation, including cell-surface hydrophobicity and the nutrient content of the growth medium, were also studied. Biofilm structures were observed using confocal laser scanning microscopy (CLSM), and expression of biofilm-related genes was investigated using RT-PCR. The results showed that the luxS gene can affect biofilm formation, whereas it does not affect the bacterial growth rate. Deletion of the luxS gene also increased cell-surface hydrophobicity. Biofilm formation was accelerated by the addition of increasing concentrations of glucose. The CLSM images revealed that the luxS mutant strain tends to aggregate into distinct clusters and relatively dense structures, whereas the wild-type strain appears confluent and more evenly distributed. All genes examined were up-regulated in the biofilms formed by the luxS mutant strain. The quorum-sensing luxS gene can affect E. faecalis biofilm formation.