Identification of Streptoooocus gordoniigenes involved in recruiting Porphyromonas gingivatiscens into a multispecies biofilm

牙菌斑生物膜的形成是通过一个由先驱生物（如s.g ordonii）附着在牙齿表面所启动的发育途径进行的。通过各种协同作用，先锋生物促进了包括牙龈假单胞菌在内的后来者的定植，这是一种潜在的牙周病原体。我们研究了支持牙龈卟啉卟啉菌异型生物膜群落所需的gordonii基因。通过筛选S gordonii的质粒整合文库，确定了浮游R gingivalis细胞聚集成多物种生物膜的关键基因。通过特异性突变和互补分析进一步研究了这些基因。生物膜相关基因可以根据推测的功能分为以下几类：i)细胞间或细胞内信号传导（cbe和spxB）， ii)细胞壁完整性和粘附蛋白的维持（murE， msrA和atf）， iii)细胞外胶囊生物合成（pgsA和atf）， iv)生理（gdhA， ccmA和ntpB）。此外，还鉴定了一种假想蛋白质的基因。通过共聚焦显微镜的生物膜可视化和定量证实了这些基因在多物种群落成熟过程中的作用，包括生物膜结构的发育。结果表明，戈氏球菌通过多种遗传途径调控口腔异型生物膜的形成。

Dental plaque biofilm formation proceeds through a developmental pathway initiated by the attachment of pioneer organisms, such as S. gordonii, to tooth surfaces. Through a variety of synergistic interactions, pioneer organisms facilitate the colonization of later arrivals including P. gingivalis, a potential periodontal pathogen. We have investigated genes of S. gordonii required to support a heterotypic biofilm- community with P gingivalis. By screening a plasmid integration library of S gordonii, genes were identified that are crucial for the accumulation of planktonic R gingivalis cells into a multispecies biofilm. These genes were further investigated by specific mutation and complementation analyses. The biofilm-associated genes can be grouped into broad categories based on putative function as follows: i) intercellular or intracellular signaling (cbe and spxB), ii) cell wall integrity and maintenance of adhesive proteins (murE, msrA and atf), iii) extracellular capsule biosynthesis (pgsA and atf), iv) physiology (gdhA, ccmA and ntpB). In addition, a gene for a hypothetical protein was identified. Biofilm visualization and quantitation by confocal microscopy confirmed the role of these genes in the maturation of the multispecies community, including biofilm architectural development. The results suggest that S. gordonii governs the development of heterotypic oral biofilms through multiple genetic pathways.