脱氧核糖核酸酶deoC对变形链球菌生物膜形成的影响

Effect of Deoxyribonuclease(deoC) on the Biofilm Formation of Streptococcus Mutans

目的研究分析deo C蛋白对变形链球菌(Streptococcus mutans,S.mutans)生物膜形成的影响。方法建立变形链球菌成熟生物膜模型,将变形链球菌UA159分别接种于两种不同的BHI培养液中厌氧培养,实验组加入含有deo C蛋白的BHI+1%蔗糖培养基,对照组加入等体积的BHI+1%蔗糖培养基。运用激光共聚焦扫描显微镜(CLSM)观察各组生物膜中活菌数及其厚度。结果实验组生物膜菌量明显减少,呈条状散在分布;对照组可见生物膜细菌致密,且大部分为活菌。实验组的变形链球菌生物膜厚度及内层、中间层与外层的活菌百分比均明显低于对照组,差异有统计学意义(P<0.01)。结论 deo C蛋白可能通过分解变形链球菌生物膜形成的胞外基质e DNA而抑制变形链球菌的生物膜形成;通过过表达deo C蛋白,减少变形链球菌在口腔软硬组织或修复体表面的附着,降低其对抗菌药物的耐受性可能成为龋病治疗的新方法。

Objective To study and analyze the effect ofdeoxyribonuclease （deoC） protein on the biofilm formation of streptococcus mutans （S.mutans）. Methods The mature biofilm model of S.mutans was established. The S.rnutans UA159 was anaerobically cultured in two different BHI culture medium, the experimental group was cultured in BHI ＋ 1% sucrose medium that containing deoC protein, the control group was cultured in isometric BHI ＋ 1% sucrose medium. The viable counts and thickness ofbiofilms in two groups were observed by confocal laser scanning microscope （CLSM）. Results The biofilms viable counts of experimental group decreased significantly, and showed strip diffused distribution; the biofilms viable counts of control group were compact, and most of bacteria were live. The biofilm thickness and percentage of live bacteria in inner layer, inter layer, outer layer of experimental group were significantly lower than those of control group, with statistical difference （P 〈0.05）. Conclusions deoC protein may inhibit biofilm formation of S.mutans by resolving the extracellular matrix （eDNA） secreted by S.mutans biofilm. The adhesion of S.rnutans in oral soft and hard tissues or the surface of restoration, and the tolerance of antimicrobial drugs can be reduced by over-expressing deoC protein, which may be an effective therapeutic approach to prevent caries disease caused by S.mutans.