Streptococcus mutans (S. mutans) is one of the main cariogenic bacteria for caries. It was found that the clinical strains of S. mutans isolated from caries active population have stronger cariogenic ability than the isolates from caries-free (CF) people. Previous studies have found that curcumin can inhibit biofilm formation of S. mutans UA159. The objective of this study is to explore the antibiofilm effect of curcumin on the clinical isolates of S. mutans from severe early childhood caries(SECC). The isolates from SECC group had more biomass than CF group (t = 4.296, P < 0.001). The acidogenicity and aciduricity of the strains from two groups showed no significant difference. After treatment with curcumin, the viability of biofilm was reduced to 61.865% ± 7.108% in SECC and to 84.059% ± 10.227% in CF group at 24 h (P < 0.05). The net reduction of live bacteria and total bacteria in the SECC group was significantly higher than that of the CF group (live bacteria t = 3.305, P = 0.016; total bacteria t = 2.378, P = 0.045) at 5 min. For 24 h, the net reduction of live bacteria and total bacteria in the SECC group was significantly higher than that of the CF group (live bacteria t = 3.305, P = 0.016; total bacteria t = 2.378, P = 0.045). The reduction of biofilm thickness reduced significantly in 5 min (t = 4.110, P = 0.015) and in 24 h (t = 3.453, P = 0.014). Long-term (24 h) curcumin treatment inhibited the amount of EPS in SECC group from (25.980 ± 1.156) μm3/μm2 to (20.136 ± 1.042) μm3/μm2, the difference was statistically significant (t = 7.510, P < 0.001). The gene of gtfC, gtfD, ftf, gbpB, fruA and srtA in the CF group and the gtfB, gtfC, gtfD, ftf, gbpB, srtA in SECC group were respectively reduced after 5 min curcumin treatment. After 24 h treatment, the gtfB, gtfC, gtfD, ftf, gbpB, fruA and srtA in both two groups were downregulation, all the differences were statistically significant. Curcumin has antibiofilm activity on clinical strains of S. mutans, especially for those isolated from SECC.

中文翻译：

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姜黄素对来自严重幼儿龋齿的变形链球菌菌株的增强抗生物膜活性。

变形链球菌（S. mutans）是龋病的主要致龋菌之一。结果发现，从龋病活跃人群中分离的变形链球菌临床菌株比从无龋（CF）人群中分离的菌株具有更强的致龋能力。以前的研究发现姜黄素可以抑制变形链球菌 UA159 的生物膜形成。本研究的目的是探讨姜黄素对严重早期儿童龋齿 (SECC) 变形链球菌临床分离株的抗生物膜作用。来自 SECC 组的分离株比 CF 组具有更多的生物量（t = 4.296，P < 0.001）。两组菌株的酸度和酸度均无显着差异。姜黄素治疗后，24 h 时，SECC 生物膜存活率降至 61.865% ± 7.108%，CF 组降至 84.059% ± 10.227%（P < 0.05）。在5分钟时，SECC组活菌和总菌数的净减少显着高于CF组（活菌t=3.305，P=0.016；总菌数t=2.378，P=0.045）。24 h 内，SECC 组活菌和总菌数的净减少显着高于 CF 组（活菌 t = 3.305，P = 0.016；总菌 t = 2.378，P = 0.045）。生物膜厚度的减少在 5 分钟（t = 4.110，P = 0.015）和 24 小时（t = 3.453，P = 0.014）内显着减少。长期（24 h）姜黄素治疗使SECC组EPS的抑制量从（25.980±1.156）μm3/μm2降至（20.136±1.042）μm3/μm2，差异有统计学意义（t=7.510，P<0.001） . CF组gtfC、gtfD、ftf、gbpB、fruA、srtA基因及gtfB、gtfC、gtfD、ftf、gbpB、SECC组srtA在姜黄素处理5分钟后分别降低。治疗24 h后，两组的gtfB、gtfC、gtfD、ftf、gbpB、fruA和srtA均下调，差异均有统计学意义。姜黄素对 S. mutans 的临床菌株具有抗生物膜活性，尤其是对从 SECC 中分离的菌株。