Huang Z, Meric G, Liu Z, Ma R, Tang Z, Lejeune P
Endodontics Department of Shanghai Ninth People's Hospital affiliated to Medical School, Shanghai Jiao Tong University, Shanghai, China.
J Mol Microbiol Biotechnol. 2009;17(1):12-9. doi: 10.1159/000159193. Epub 2008 Sep 26.
Quorum sensing (QS) is a process by which bacteria communicate with diffusible chemical signaling molecules called autoinducers (AIs). The autoinducer-2 signal (AI-2) produced by the LuxS protein mediates interspecies communication among Gram-positive and Gram-negative bacteria. In this study, we report that luxS-dependent QS is involved in the formation of Streptococcus mutans biofilms.
An S. mutans luxS mutant was constructed, and the differences in growth and biofilm formation were compared between the wild-type strain and the mutant strain. To quantificationally analyze the kinetic biofilm formation of the mutant strain, an assay of BioFilm Ring Test(R) was applied.
There is a small increase in the growth of the luxS mutant strain after the stationary phase, compared with the parent strain. However during the exponential period, there were no significant differences. Using the BioFilm Ring Test(R), it was demonstrated that this luxS mutation was able to accelerate biofilm formation on a polystyrene surface during the mid-exponential growth phase. With 1% glucose treatment, even greater differences were observed between the mutant strain and its parental strain.
These data suggest that a luxS-dependent signal may play an important role in the biofilm formation of S. mutans.
群体感应（QS）是细菌通过可扩散的化学信号分子（称为自诱导物，AIs）进行通讯的过程。由LuxS蛋白产生的自诱导物-2信号（AI-2）介导革兰氏阳性菌和革兰氏阴性菌之间的种间通讯。在本研究中，我们报道了依赖LuxS的群体感应参与变形链球菌生物膜的形成。
构建了变形链球菌luxS突变体，并比较了野生型菌株和突变体菌株在生长和生物膜形成方面的差异。为了定量分析突变体菌株生物膜形成的动力学，应用了生物膜环试验（BioFilm Ring Test®）。
与亲本菌株相比，luxS突变体菌株在稳定期后生长略有增加。然而在指数生长期，没有显著差异。使用生物膜环试验（BioFilm Ring Test®）表明，这种luxS突变能够在指数生长中期加速聚苯乙烯表面生物膜的形成。用1%葡萄糖处理后，突变体菌株与其亲本菌株之间观察到更大的差异。
这些数据表明，依赖LuxS的信号可能在变形链球菌生物膜形成中起重要作用。
