Effect of the Biofilm Age and Starvation on Acid Tolerance of Biofilm Formed by Streptococcus mutans Isolated from Caries-Active and Caries-Free Adults.
Effect of the Biofilm Age and Starvation on Acid Tolerance of Biofilm Formed by Streptococcus mutans Isolated from Caries-Active and Caries-Free Adults.
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生物膜年龄和饥饿对从龋齿活跃和无龋成人中分离的变形链球菌形成的生物膜耐酸性的影响
DOI：
10.3390/ijms18040713
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发表时间：
2017-03-30
影响因子：
5.6
通讯作者：
Cai Z
中科院分区：
文献类型：
--
作者：
Jiang S;Chen S;Zhang C;Zhao X;Huang X;Cai Z
变形链球菌（S.变形菌）被认为是龋齿的主要原因。S的能力。变形杆菌耐受低pH是其致龋性所必需的。S.变形杆菌与其对口腔环境压力的适应有关。本研究旨在探讨生物膜年龄和饥饿条件对S.变异株临床分离株。S.将分离自龋齿活跃（SM 593）和无龋齿（SM 18）成人的变异株临床菌株和参考菌株（ATCC 25175）用于生物膜形成。(1)形成年轻和成熟的生物膜，然后暴露于pH 3.0的30分钟（酸适应组）或不（非适应组）预暴露于pH 5.5的三个小时。(2)将成熟的生物膜用磷酸盐缓冲液（PBS）（饥饿组）或TPY（聚蛋白胨-酵母提取物）培养基（非饥饿组）在pH 7.0下培养24 h，然后浸泡在pH 3.0的培养基中30 min。在所有三种菌株中，成熟的、酸适应的和饥饿的生物膜在酸休克后分别比年轻的、非适应的和非饥饿的生物膜显示出显著更少的破坏性结构和更多的活菌（均p < 0.05）。此外，在每种条件下，SM 593生物膜更致密，具有比SM 18和ATCC 25175显著更大数量的活细菌（所有p < 0.05）。结果表明，成熟、酸适应和饥饿可能对三种S.变异株抵抗酸休克。此外，与SM 18和ATCC 25175相比，SM 593表现出更大的耐酸性，这表明临床菌株的高致龋性的定殖可能导致个体的高龋齿风险。
Streptococcus mutans (S. mutans) is considered a leading cause of dental caries. The capability of S. mutans to tolerate low pH is essential for its cariogenicity. Aciduricity of S. mutans is linked to its adaptation to environmental stress in oral cavity. This study aimed to investigate the effect of biofilm age and starvation condition on acid tolerance of biofilm formed by S. mutans clinical isolates. S. mutans clinical strains isolated from caries-active (SM593) and caries-free (SM18) adults and a reference strain (ATCC25175) were used for biofilm formation. (1) Both young and mature biofilms were formed and then exposed to pH 3.0 for 30 min with (acid-adapted group) or without (non-adapted group) pre-exposure to pH 5.5 for three hours. (2) The mature biofilms were cultured with phosphate-buffered saline (PBS) (starved group) or TPY (polypeptone-yeast extract) medium (non-starved group) at pH 7.0 for 24 h and then immersed in medium of pH 3.0 for 30 min. Biofilms were analyzed through viability staining and confocal laser scanning microscopy. In all three strains, mature, acid-adapted and starved biofilms showed significantly less destructive structure and more viable bacteria after acid shock than young, non-adapted and non-starved biofilms, respectively (all p < 0.05). Furthermore, in each condition, SM593 biofilm was denser, with a significantly larger number of viable bacteria than that of SM18 and ATCC25175 (all p < 0.05). Findings demonstrated that mature, acid-adapted and starvation might protect biofilms of all three S. mutans strains against acid shock. Additionally, SM593 exhibited greater aciduricity compared to SM18 and ATCC25175, which indicated that the colonization of high cariogenicity of clinical strains may lead to high caries risk in individuals.