Dental caries is a common disease affecting quality of life globally. In the present study, we found that a bacteriophage lysin LysP53 against Acinetobacter baumannii possesses selective activity on Streptococcus mutans, the main etiological agent of dental caries, even in low pH caries microenvironments, whereas only minor LysP53 activity was detected against Streptococcus sanguinis, Streptococcus oralis, and Streptococcus mitis. Testing activity against S. mutans planktonic cells showed that 4 μM LysP53 could kill more than 84% of S. mutans within 1 min in buffer with optimal pHs ranging from 4.0 to 6.5. Daily application of LysP53 on biofilms formed in BHI medium supplemented or not with sucrose could reduce exopolysaccharides, expression of genes related to acid resistance and adhesion, and the number of live bacteria in the biofilms. LysP53 treatment also showed similar effects as 0.12% chlorhexidine in preventing enamel demineralization due to S. mutans biofilms, as well as effective removal of S. mutans colonization of tooth surfaces in mice without observed toxic effects. Because of its selective activity against main cariogenic bacteria and good activity in low pH caries microenvironments, it is advantageous to use LysP53 as an active agent for preventing caries.

中文翻译：

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赖氨酸 LysP53 对变形链球菌的抗菌活性。

龋齿是影响全球生活质量的常见疾病。在本研究中，我们发现，即使在低pH值的龋齿微环境中，针对鲍曼不动杆菌的噬菌体溶素LysP53对龋齿的主要病原菌变形链球菌也具有选择性活性，而针对血链球菌、口腔链球菌仅检测到较小的LysP53活性。和轻症链球菌。针对变形链球菌浮游细胞的测试活性表明，在最佳 pH 范围为 4.0 至 6.5 的缓冲液中，4 μM LysP53 可以在 1 分钟内杀死超过 84% 的变形链球菌。每天在添加或不添加蔗糖的 BHI 培养基中形成的生物膜上施用 LysP53 可以减少胞外多糖、与耐酸性和粘附相关的基因的表达以及生物膜中活细菌的数量。LysP53 处理在防止变形链球菌生物膜引起的牙釉质脱矿方面也表现出与 0.12% 洗必泰类似的效果，并有效去除小鼠牙齿表面的变形链球菌定植，而没有观察到毒性作用。由于其对主要致龋菌的选择性活性以及在低pH龋齿微环境中良好的活性，使用LysP53作为防龋活性剂是有利的。