Chen Juxiu, Chen Zhanyi, Yuan Keyong, Huang Zhengwei, Mao Mengying
Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China.
National Clinical Research Center for Oral Diseases, Shanghai, China.
J Oral Microbiol. 2020 Dec 24;13(1):1860398. doi: 10.1080/20002297.2020.1860398.
Bacteriophage T4 RNA ligase 1 (T4 Rnl1) can be stably expressed in many bacteria and has been reported to affect the bioactivity of the host bacteria. Recently, we constructed bacteriophage T4 Rnl1 expressing system in Streptococcus mutans, a crucial biofilm-forming and dental caries-causing oral pathogen. Here, we characterized the function of recombinant bacteriophage T4 Rnl1 in biofilm formation of S. mutans. The T4 Rnl1 mutant exhibited similar growth phenotype but resulted in a significant reduction of biofilm biomass compared to wild type strain and empty plasmid carrying strain. The abnormal biofilm of the T4 Rnl1 mutant harbored loose bacterial clusters with defective production and distribution of exopolysaccharides. Moreover, the expression of several biofilm formation-associated genes was dysregulated at mRNA level in the T4 Rnl1 mutant. These results reveal that the bacteriophage T4 Rnl1 exert antibiofilm activities against the cariogenic bacterium S. mutans, which impacts the spatial organization of the exopolysaccharides and further impairs the three-dimensional biofilm architecture. These findings implicate that manipulation of bacteriophage T4 Rnl1, a biological tool used for RNA ligation, will provide a promising approach to cariogenic biofilm control.
噬菌体T4 RNA连接酶1（T4 Rnl1）可在多种细菌中稳定表达，据报道它会影响宿主细菌的生物活性。最近，我们在变形链球菌（一种关键的生物膜形成菌和致龋口腔病原体）中构建了噬菌体T4 Rnl1表达系统。在此，我们对重组噬菌体T4 Rnl1在变形链球菌生物膜形成中的功能进行了表征。与野生型菌株和携带空质粒的菌株相比，T4 Rnl1突变体表现出相似的生长表型，但生物膜生物量显著减少。T4 Rnl1突变体的异常生物膜含有松散的细菌簇，胞外多糖的产生和分布存在缺陷。此外，在T4 Rnl1突变体中，几个与生物膜形成相关的基因在mRNA水平上表达失调。这些结果表明，噬菌体T4 Rnl1对致龋菌变形链球菌具有抗生物膜活性，这会影响胞外多糖的空间组织，并进一步损害三维生物膜结构。这些发现表明，操纵用于RNA连接反应的生物工具噬菌体T4 Rnl1，将为控制致龋生物膜提供一种有前景的方法。
