摘要
目的利用变形链球菌luxS基因敲除突变株，研究这一种属间密度感应系统对生物膜早期形成的影响。方法通过在生物膜培养悬液中加入与菌细胞直径相近的磁性小珠，利用这些小珠在磁场中受到生物膜的位移约束力的原理，采用生物膜定量分析仪，定量比较、分析变形链球菌luxS基因knockout突变株与野生株在生物膜形成上的差异。结果变形链球菌luxS基因突变株与野生株在生物膜形成模式上有显著差别，突变株生物膜自第6小时起开始形成，生物膜形成指数（biofilm index，BFI）差值△BFI=2．015，约第10小时突变株形成的生物膜可完全限制磁珠在磁场中的位移（△BFI=7．025）；而野生株生物膜约第10小时开始形成（△BFI=1．875），明显晚于突变株。12h后两菌株生物膜形成未见明显差异（P〉0．05）。结论变形链球菌luxS基因的缺失可影响生物膜的早期形成。
Objective To investigate the effect of Streptococcus mutaus luxS mutantation on the early biofilm formatien. Methods Based on the immobilization of magnetic beads by adherent cells, an assay of biofilm quantitative analysis was developed for the kinetic quantification of biofilm formation in this study. Streptococcus mutans luxS mutant strain was constructed and subject to this hiofilm luxS mutant strain were compared. Results The AluxS mutant started to form a biofilm from the 6 th hour（ △BFI = 2. 015 ）, and the ABFI of luxS mutant increased more quickly than that of the wild type strain, until reaching a complete immobilization of the beads after 10 hours （ △BFI = 7. 025 ）. The wild-type strain start to form a biofilm from the 10 th hour（ △BFI = 1. 875 ） and the beads were completely immobilized between 12 and 14 hours. Conclusions The luxS mutation can accelerate biofilm on a polystyrene surface during the midexponential growth phase. And a luxS-dependent signal may play an important role in the early biofilm formation of Streptococcus mutans.
出处
《中华口腔医学杂志》
CAS
CSCD
北大核心
2009年第2期72-75,共4页
Chinese Journal of Stomatology
基金
国家自然科学基金（30400497、30872886）
