中华口腔医学研究杂志(电子版) ›› 2012, Vol. 6 ›› Issue (04) : 314 -319. doi: 10.3877/cma.j.issn.1674-1366.2012.04.002 × 扫一扫
基础研究
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Kai ZHANG1, Jun-qi LING1,†(), Jia LIU1, Li-jun HUO1, Jun-ni MAI1
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张恺, 凌均棨, 刘佳, 霍丽珺, 麦俊妮. 变形链球菌ComCDE 密度感应参与不同菌种的竞争[J/OL]. 中华口腔医学研究杂志(电子版), 2012, 6(04): 314-319.
Kai ZHANG, Jun-qi LING, Jia LIU, Li-jun HUO, Jun-ni MAI. Quorum sensing system is involved in bacteriocin production and bacterial competition of Streptococcus mutans[J/OL]. Chinese Journal of Stomatological Research(Electronic Edition), 2012, 6(04): 314-319.
目的
研究口腔变形链球菌(S.mutans)ComCDE 密度感应系统参与血链球菌(S.sanguinis)的相互竞争作用。
方法
采用LIVE\DEAD BacLightTM 荧光染色结合激光共聚焦显微镜,观察变形链球菌(简称变链菌)在CSP 信号肽诱导下群体细菌自身死亡变化;通过荧光定量反转录聚合酶链反应(RT-PCR)测定细菌素以及细菌素免疫蛋白相关基因表达变化,分析变链菌ComCDE 系统参与菌群生存竞争的调控机制。
结果
在细菌竞争中,变形链球菌ΔcomC、ΔcomD、ΔcomE 突变株失去不同菌种间的竞争力,无法抑制相邻S.sanguinis 的正常生长;只有野生株保持竞争力,抑制相邻S.sanguinis 生长,形成缺陷菌环。 CSP 信号肽诱导下,变链菌群体死菌/活菌率增高58.1%(P<0.05);细菌素及免疫蛋白相关SMU.151、SMU.423、SMU.1913c 基因分别升高23.3 倍(P=0.00)、15.9 倍(P<0.05)、19.3 倍(P<0.05)。
结论
变形链球菌ComCDE 密度感应系统调控变链菌的变链素及免疫蛋白产生、参与不同菌种间竞争生存。
Objective
To study the role of ComCDE quorum sensing system of Streptococcus mutans (S.mutans) in bacteriocin production and bacterial competition.
Methods
Growth competition between S.mutans and Streptococcus sanguis (S.sanguis) was analyzed through the bacterial competition assay. Cellular growth and death of S. mutans with and without CSP peptide was monitored by using the laser confocal microscopy and LIVE/DEAD BacLightTM staining. Bacteriocin and bacteriocin immunity protein related gene expression was determined by real-time RT-PCR.
Results
Competition assay showed that S.mutans ΔcomC, ΔcomD, and ΔcomE mutant lost the ability of competition, and they could not suppress the normal growth of S.sanguinis, while S.mutans UA159 wild type strain inhibited the normal growth of the adjacent S.sanguinis. In the presence of CSP peptide, the ratio of Dead/live cells of S.mutans UA159 was increased 58.1% (P<0.05), and bacteriocin and immunity protein related genes SMU.151, SMU.423, and SMU.1913c, were increased 23.3-fold (P=0.00), 15.9-fold (P<0.05),and 19.3-fold (P<0.05) respectively.
Conclusion
Quorum sensing system of S.mutans is involved in bacteriocin production and bacterial competition.