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

牙菌斑生物膜的形成通过先驱生物(如戈登葡萄球菌)附着到牙齿表面而启动的发育途径进行。通过各种协同作用，先锋生物促进了后来到达的人的定居，包括牙周病的潜在病原体牙龈假单胞菌。我们已经研究了戈登葡萄球菌支持与牙龈假单胞菌异型生物被膜群落所需的基因。通过对S Gordonii菌质粒整合文库的筛选，鉴定出了影响R ggivalis细胞形成多物种生物膜的关键基因。通过特异性突变和互补分析对这些基因进行了进一步研究。根据可能的功能，与生物膜相关的基因可分为以下几大类：i)细胞间或细胞内信号转导(CBE和spxB)，ii)细胞壁完整性和黏附蛋白的维持(Mure，MSRA和ATF)，iii)胞外被膜生物合成(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。生物膜可视化和共聚焦显微镜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展。这些结果表明，戈登葡萄球菌通过多种遗传途径调控异型口腔生物膜的发育。

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.