Role of the Streptococcus gordonii SspB protein in the development of Porphyromonas gingivalis biofilms on streptococcal substrates
Role of the Streptococcus gordonii SspB protein in the development of Porphyromonas gingivalis biofilms on streptococcal substrates
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DOI：
10.1099/00221287-148-6-1627
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发表时间：
2002-06-01
期刊：
影响因子：
2.8
通讯作者：
Demuth, DR
中科院分区：
文献类型：
--
作者：
Lamont, RJ;El-Sabaeny, A;Demuth, DR
牙龈卟啉单胞菌是一种侵袭性的牙周病原体，它在牙齿表面的混合菌种菌斑生物膜中持续存在。牙龈卟啉单胞菌细胞附着于菌斑共生菌戈登链球菌上，这种共黏附事件导致牙龈卟啉单胞菌生物膜的形成。这些微生物的结合是多模式的，涉及牙龈卟啉单胞菌主要菌毛FimA蛋白以及次要菌毛Mfa1蛋白与链球菌SspB蛋白的种特异性相互作用。本研究检测了Mfa1 - SspB相互作用对牙龈卟啉单胞菌生物膜形成的贡献。牙龈卟啉单胞菌生物膜容易在戈登链球菌DL1的基质上形成，但不会在缺乏SspB共黏附介导同源物的变形链球菌细胞上形成。牙龈卟啉单胞菌中mfa1基因的插入失活导致一种缺乏与戈登链球菌结合能力且无法形成生物膜的表型。此外，使用重组链球菌和肠球菌进行的分析表明，牙龈卟啉单胞菌生物膜在表达SspB的粪肠球菌菌株上形成，或者在含有SspB的牙龈卟啉单胞菌黏附结构域（SspB黏附区域，BAR）的SspB与SpaP（变形链球菌中不具黏附性的SspB同源物）的翻译融合蛋白上形成。相反，戈登链球菌DL1的同基因Ssp缺失突变体即使以与野生型戈登链球菌DL1相似的水平结合牙龈卟啉单胞菌FimA，也无法支持生物膜生长。最后，BAR中两个功能性氨基酸残基的位点特异性突变导致SspB多肽无法促进牙龈卟啉单胞菌生物膜的形成。这些结果表明，在链球菌底物上诱导牙龈卟啉单胞菌生物膜需要有功能的SspB - 次要菌毛相互作用。
Porphyromonas gingivalis is an aggressive periodontal pathogen that persists in the mixed-species plaque biofilm on tooth surfaces. P. gingivalis cells attach to the plaque commensal Streptococcus gordonii and this coadhesion event leads to the development of A gingivalis biofilms. Binding of these organisms is multimodal, involving both the P. gingivalis major fimbrial FimA protein and the species-specific interaction of the minor fimbrial Mfa1 protein with the streptococcal SspB protein. This study examined the contribution of the Mfa1-SspB interaction to P. gingivalis biofilm formation. A gingivalis biofilms readily formed on substrata of S. gordonii DL1 but not on Streptococcus mutans cells which lack a coadhesion-mediating homologue of SspB. An insertional inactivation of the mfa1 gene in A gingivalis resulted in a phenotype deficient in S. gordonii binding and unable to form biofilms. Furthermore, analysis using recombinant streptococci and enterococci showed that P. gingivalis biofilms formed on Enterococcus faecalis strains expressing SspB or translational fusions of SspB with SpaP (the non-adherent SspB homologue in S. mutans) containing the A gingivalis adherence domain (SspB adherence region, BAR) of SspB. In contrast, an isogenic Ssp null mutant of S. gordonii DL1 was unable to support biofilm growth, even though this strain bound to A gingivalis FimA at levels similar to wild-type S. gordonii DL1. Finally, site-specific mutation of two functional amino acid residues in BAR resulted in SspB polypeptides that did not promote the development of P. gingivalis biofilms. These results suggest that the induction of A gingivalis biofilms on a streptococcal substrate requires functional SspB-minor fimbriae interactions.