A dysbiotic microbial community whose members have specific/synergistic functions that are modulated by environmental conditions, can disturb homeostasis in the subgingival space leading to destructive inflammation, plays a role in the progression of periodontitis. Filifactor alocis, a gram-positive, anaerobic bacterium, is a newly recognized microbe that shows a strong correlation with periodontal disease. Our previous observations suggested F. alocis to be more resistant to oxidative stress compared to Porphyromonas gingivalis. The objective of this study is to further determine if F. alocis, because of its increased resistance to oxidative stress, can affect the survival of other ‘established’ periodontal pathogens under environmental stress conditions typical of the periodontal pocket. Here, we have shown that via their interaction, F. alocis protects P. gingivalis W83 under H₂O₂-induced oxidative stress conditions. Transcriptional profiling of the interaction of F. alocis and P. gingivalis in the presence of H₂O₂-induced stress revealed the modulation of several genes, including those with ABC transporter and other cellular functions. The ABC transporter operon (PG0682–PG0685) of P. gingivalis was not significant to its enhanced survival when cocultured with F. alocis under H₂O₂-induced oxidative stress. In F. alocis, one of the most highly up-regulated operons (FA0894–FA0897) is predicted to encode a putative manganese ABC transporter, which in other bacteria can play an essential role in oxidative stress protection. Collectively, the results may indicate that F. alocis could likely stabilize the microbial community in the inflammatory microenvironment of the periodontal pocket by reducing the oxidative environment. This strategy could be vital to the survival of other pathogens, such as P. gingivalis, and its ability to adapt and persist in the periodontal pocket.

中文翻译：

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Filifactor alocis 增强牙龈卟啉单胞菌 W83 对 H2O2 诱导应激的存活率

一个失调的微生物群落，其成员具有受环境条件调节的特定/协同功能，可以扰乱龈下空间的稳态，导致破坏性炎症，在牙周炎的进展中发挥作用。Filifactor alocis是一种革兰氏阳性厌氧细菌，是一种新发现的微生物，与牙周病有很强的相关性。我们之前的观察表明，与牙龈卟啉单胞菌相比， F. alocis对氧化应激具有更强的抵抗力。本研究的目的是进一步确定F. alocis由于其对氧化应激的抵抗力增强，是否可以影响其他“既定”牙周病原体在牙周袋典型环境应激条件下的生存。在这里，我们通过它们的相互作用证明了F。alocis在 H ₂ O ₂诱导的氧化应激条件下保护牙龈卟啉单胞菌W83 。_{在 H 2} O ₂诱导的应激存在下，F. alocis和P. gingivalis相互作用的转录谱揭示了几个基因的调节，包括具有 ABC 转运蛋白和其他细胞功能的基因。当在H ₂ O ₂诱导的氧化应激下与F. alocis共培养时，牙龈卟啉单胞菌的ABC转运蛋白操纵子( PG0682–PG0685 )对其存活率的提高并不显着。在F. alocis中，上调程度最高的操纵子之一 ( FA0894–FA0897 ) 预计会编码一种假定的锰 ABC 转运蛋白，该转运蛋白在其他细菌中可以在氧化应激保护中发挥重要作用。总的来说，这些结果可能表明F. alocis可能通过减少氧化环境来稳定牙周袋炎症微环境中的微生物群落。这种策略对于其他病原体（例如牙龈卟啉单胞菌）的生存及其在牙周袋中的适应和持续存在的能力至关重要。