Biofilm Research Laboratory, Institute of Dental Sciences, Faculty of Dental Medicine, Hebrew University-Hadassah POB 12272, Jerusalem 91120, Israel.
BMC Microbiol. 2010 Feb 18;10:51. doi: 10.1186/1471-2180-10-51.
Adhesion and successful colonization of bacteria onto solid surfaces play a key role in biofilm formation. The initial adhesion and the colonization of bacteria may differ between the various types of surfaces found in oral cavity. Therefore, it is conceivable that diverse biofilms are developed on those various surfaces. The aim of the study was to investigate the molecular modifications occurring during in vitro biofilm development of Streptococcus mutans UA159 on several different dental surfaces.
Growth analysis of the immobilized bacterial populations generated on the different surfaces shows that the bacteria constructed a more confluent and thick biofilms on a hydroxyapatite surface compared to the other tested surfaces. Using DNA-microarray technology we identified the differentially expressed genes of S. mutans, reflecting the physiological state of biofilms formed on the different biomaterials tested. Eight selected genes were further analyzed by real time RT-PCR. To further determine the impact of the tested material surfaces on the physiology of the bacteria, we tested the secretion of AI-2 signal by S. mutans embedded on those biofilms. Comparative transcriptome analyses indicated on changes in the S. mutans genome in biofilms formed onto different types of surfaces and enabled us to identify genes most differentially expressed on those surfaces. In addition, the levels of autoinducer-2 in biofilms from the various tested surfaces were different.
Our results demonstrate that gene expression of S. mutans differs in biofilms formed on tested surfaces, which manifest the physiological state of bacteria influenced by the type of surface material they accumulate onto. Moreover, the stressful circumstances of adjustment to the surface may persist in the bacteria enhancing intercellular signaling and surface dependent biofilm formation.
细菌在固体表面的黏附和成功定殖对于生物膜的形成起着关键作用。不同类型的口腔表面可能会导致初始黏附和细菌定殖的差异。因此，可以想象不同的生物膜会在这些不同的表面上形成。本研究的目的是研究变形链球菌 UA159 在几种不同的牙面表面体外生物膜形成过程中的分子变化。
对不同表面固定化细菌群体的生长分析表明，与其他测试表面相比，细菌在羟磷灰石表面上形成了更密集和更厚的生物膜。使用 DNA 微阵列技术，我们鉴定了变形链球菌中差异表达的基因，反映了不同测试生物材料上形成的生物膜的生理状态。进一步通过实时 RT-PCR 分析了 8 个选定的基因。为了进一步确定测试材料表面对细菌生理学的影响，我们测试了嵌入这些生物膜中的变形链球菌 AI-2 信号的分泌。比较转录组分析表明，不同类型表面上形成的生物膜中变形链球菌基因组发生了变化，并使我们能够识别出在这些表面上差异表达最明显的基因。此外，来自各种测试表面的生物膜中的自动诱导物-2 水平也不同。
我们的结果表明，在测试表面上形成的生物膜中变形链球菌的基因表达存在差异，这表明了受其积累的表面材料类型影响的细菌生理状态。此外，适应表面的应激情况可能会持续存在于细菌中，增强细胞间信号传递和表面依赖的生物膜形成。
