ABSTRACT

Background: Porphyromonas gingivalis strain W83, one of the most widely investigated, is considered virulent in the context of periodontitis. The recently isolated P. gingivalis TDC60 has been reported to be highly pathogenic, although it has not yet been investigated in a mouse periodontitis model by oral gavage.

Aim: Our aim was to compare the virulence of both strains by evaluating their impact on alveolar bone loss and the composition of oral microbiota.

Methods: We inoculated by oral gavage C57BL/6 mice with either one of the two P. gingivalis strains and compared to a sham-treated group, without antibiotics pre-treatment. The mandibular alveolar bone of treated mice and controls were assessed, one month after the final inoculation, by microCT measurements. Moreover, at this time, we characterized their oral microbiota by 16S rRNA gene sequencing.

Results: While P. gingivalis W83 successfully initiated periodontitis, TDC60-treated mice only experienced moderate lesions. Furthermore, only W83-treated mice exhibited a specific distinct microbiota, with significantly lower richness and evenness than other samples, and decreased proportions of taxa usually found in healthy individuals.

Conclusion: This association between alveolar bone loss and a major persistent shift of the oral microbiota gives insights into virulence discrepancies among these bacterial strains.

摘要

背景： 牙龈卟啉单胞菌W83菌株是研究最广泛的一种，在牙周炎中被认为具有毒性。据报道，最近分离出的牙龈卟啉单胞菌TDC60具有高致病性，尽管尚未在小鼠牙周炎模型中通过管饲法对其进行研究。

目的：我们的目的是通过评估两种菌株对牙槽骨丢失和口腔微生物群组成的影响来比较两种菌株的毒力。

方法：我们通过口管饲C57BL / 6小鼠接种了两种牙龈卟啉单胞菌菌株之一，并与未经抗生素预处理的假治疗组进行了比较。在最终接种后一个月，通过microCT测量评估了治疗小鼠和对照的下颌牙槽骨。此外，此时，我们通过16S rRNA基因测序对他们的口腔微生物群进行了表征。

结果：虽然牙龈卟啉单胞菌W83成功引发了牙周炎，但TDC60治疗的小鼠仅出现中度病变。此外，只有W83处理的小鼠表现出特定的独特微生物群，其丰富度和均匀度明显低于其他样品，并且降低了健康个体中常见的分类单元的比例。

结论：牙槽骨丢失与口腔微生物群的主要持续性变化之间的这种联系为洞悉这些细菌菌株之间的毒力差异提供了见识。