Oral Health Cooperative Research Centre, Melbourne Dental School, Bio21 Institute, The University of Melbourne, Melbourne, VIC, Australia.
Front Cell Infect Microbiol. 2019 Dec 18;9:432. doi: 10.3389/fcimb.2019.00432. eCollection 2019.
Chronic periodontitis has a polymicrobial biofilm etiology and interactions between key oral bacterial species, such as and contribute to disease progression. and are co-localized in subgingival plaque and have been previously shown to exhibit strong synergy in growth, biofilm formation and virulence in an animal model of disease. The motility of , although not considered as a classic virulence factor, may be involved in synergistic biofilm development between and . We determined the role of motility in polymicrobial biofilm development using an optimized transformation protocol to produce two mutants targeting the motility machinery. These deletion mutants were non-motile and lacked the gene encoding the flagellar hook protein of the periplasmic flagella (Δ) or a component of the stator motor that drives the flagella (Δ). The specificity of these gene deletions was determined by whole genome sequencing. Quantitative proteomic analyses of mutant strains revealed that the specific inactivation of the motility-associated gene, , had effects beyond motility. There were 64 and 326 proteins that changed in abundance in the Δ and Δ mutants, respectively. In the Δ mutant, motility-associated proteins showed the most significant change in abundance confirming the phenotype change for the mutant was related to motility. However, the inactivation of as well as stopping motility also upregulated cellular stress responses in the mutant indicating pleiotropic effects of the mutation. wild-type and displayed synergistic biofilm development with a 2-fold higher biomass of the dual-species biofilms than the sum of the monospecies biofilms. Inactivation of and reduced this synergy. A 5-fold reduction in dual-species biofilm biomass was found with the motility-specific Δ mutant suggesting that periplasmic flagella are essential in synergistic biofilm formation with .
慢性牙周炎的病因是多微生物生物膜，关键口腔细菌物种之间的相互作用，如 和 ，有助于疾病的进展。 和 在龈下菌斑中共同定殖，并且以前在疾病的动物模型中表现出在生长、生物膜形成和毒力方面的强烈协同作用。 的运动性，虽然不被认为是经典的毒力因素，但可能参与 和 之间协同生物膜的发展。我们使用优化的转化方案来产生针对运动机制的两个 突变体，以确定 运动性在多微生物生物膜发展中的作用。这些缺失突变体是非运动性的，并且缺乏编码周质鞭毛的鞭毛钩蛋白的基因（Δ）或驱动鞭毛的定子马达的一个组成部分（Δ）。这些基因缺失的特异性通过全基因组测序来确定。突变株的定量蛋白质组学分析表明，运动相关基因 的特异性失活除了运动性之外还有其他影响。在 Δ 和 Δ 突变体中，分别有 64 和 326 种蛋白质的丰度发生变化。在 Δ 突变体中，与运动相关的蛋白质的丰度变化最显著，证实突变体的表型变化与运动有关。然而， 的失活以及停止运动也在上调突变体中的细胞应激反应，表明突变的多效性影响。 野生型和 与 协同生物膜发育，双物种生物膜的生物量比单物种生物膜的总和高 2 倍。 的失活和 的失活降低了这种协同作用。在运动特异性 Δ 突变体中发现双物种生物膜生物量减少了 5 倍，表明 周质鞭毛在与 协同生物膜形成中是必不可少的。
