Sulfated vizantin, a recently developed immunostimulant, has also been found to exert antibiofilm properties. It acts not as a bactericide, but as a detachment-promoting agent by reducing the biofilm structural stability. This study aimed to investigate the mechanism underlying this activity and its species specificity using two distinct ex vivo oral biofilm models derived from human saliva. The biofilm, composed mainly of the genus Streptococcus and containing 50 μM of sulfated vizantin, detached significantly from its basal surface with rotation at 500 rpm for only 15 s, even when 0.2% sucrose was supplied. Expression analyses for genes associated with biofilm formation and bacterial adhesion following identification of the Streptococcus species, revealed that a variety of Streptococcus species in a cariogenic biofilm showed downregulation of genes encoding glucosyltransferases involved in the biosynthesis of water-soluble glucan. The expression of some genes encoding surface proteins was also downregulated. Of the two quorum sensing systems involved in the genus Streptococcus, the expression of luxS in three species, Streptococcus oralis, Streptococcus gordonii, and Streptococcus mutans, was significantly downregulated in the presence of 50 μM sulfated vizantin. Biofilm detachment may be facilitated by the reduced structural stability due to these modulations. As a non-specific reaction, 50 μM sulfated vizantin decreased cell surface hydrophobicity by binding to the cell surface, resulting in reduced bacterial adherence. Sulfated vizantin may be a candidate for a new antibiofilm strategy targeting the biofilm matrix while preserving the resident microflora.

中文翻译：

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硫酸化 vizantin 导致主要由链球菌属组成的生物膜脱离，而不影响细菌生长和活力

硫酸化 vizantin 是一种最近开发的免疫刺激剂，也被发现具有抗生物膜特性。它不是杀菌剂，而是通过降低生物膜结构稳定性来促进分离。本研究旨在使用源自人类唾液的两种不同的离体口腔生物膜模型来研究这种活动的潜在机制及其物种特异性。生物膜主要由链球菌属组成并含有 50 μM 的硫酸化 vizantin，即使在提供 0.2% 蔗糖的情况下，在以 500 rpm 的转速旋转仅 15 秒时，它也会从其基底表面显着分离。鉴定链球菌后对与生物膜形成和细菌粘附相关的基因进行表达分析，揭示了致龋生物膜中的多种链球菌物种显示出编码参与水溶性葡聚糖生物合成的葡萄糖基转移酶的基因的下调。一些编码表面蛋白的基因的表达也被下调。在涉及链球菌属的两个群体感应系统中，在 50 μM 硫酸化 vizantin 存在的情况下，luxS 在口腔链球菌、戈登链球菌和变形链球菌这三个物种中的表达显着下调。由于这些调制而降低的结构稳定性可能会促进生物膜分离。作为一种非特异性反应，50 μM 硫酸化 vizantin 通过与细胞表面结合来降低细胞表面疏水性，从而降低细菌粘附。