Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO, United States of America.
Department of Internal Medicine, University of Missouri, Columbia, MO, United States of America.
PLoS One. 2022 Sep 14;17(9):e0274523. doi: 10.1371/journal.pone.0274523. eCollection 2022.
The objective of this study was to investigate the treatment effects of non-thermal atmospheric gas plasmas (NTAP) on destruction and the recovery (or re-colonization) of Porphyromonas gingivalis (P. gingivalis) in biofilms. P. gingivalis is a well-known keystone periodontal pathogen strongly associated with periodontal diseases, especially periodontitis. P. gingivalis biofilms were formed on stainless steel coupons and treated for 1, 2, and 5 minutes by NTAP of pure argon gas and argon+oxygen gas mixture. MTT assay, colony forming unit (CFU) counting assay and confocal laser scanning microscopy (CLSM) were used to assess the destruction efficiency. In addition, the plasma treated biofilms were re-cultured in the medium supplemented with antibiotics and oxidative stress sources to determine the synergy of the NTAP with other antimicrobial agents. The results showed the plasma treatment could result in 2.7 log unit reduction in bacterial load. The recovered biofilm CFU with NTAP treatment combined with sub minimal inhibition concentration of amoxicillin was 0.33 log units less than the biofilm treated with amoxicillin alone. The recovered biofilm CFU in NTAP groups was about 2.0 log units less than that in the untreated controls under H2O2 treatment. There was approximately 1.0 log unit reduction of biofilm CFU in plasma treated biofilm compared with untreated control under paraquat treatment. The plasma treated biofilms exhibited less resistance to amoxicillin and greater susceptibility to hydrogen peroxide (H2O2) and paraquat, suggesting that NTAP may enhance biofilm susceptibility to host defense. These in vitro findings suggested that NTAP could be a novel and effective treatment method of oral biofilms that cause periodontal diseases.
本研究旨在探讨非热大气压气体等离子体（NTAP）对龈卟啉单胞菌（P. gingivalis）生物膜破坏及恢复（或再定植）的治疗效果。P. gingivalis 是一种众所周知的牙周关键病原体，与牙周病，尤其是牙周炎密切相关。将 P. gingivalis 生物膜形成在不锈钢试片上，并通过纯氩气和氩+氧气混合气体的 NTAP 处理 1、2 和 5 分钟。使用 MTT 测定法、集落形成单位（CFU）计数测定法和共聚焦激光扫描显微镜（CLSM）来评估破坏效率。此外，将经等离子体处理的生物膜再培养在补充有抗生素和氧化应激源的培养基中，以确定 NTAP 与其他抗菌剂的协同作用。结果表明，等离子体处理可使细菌负荷减少 2.7 个对数单位。与单独使用阿莫西林相比，经 NTAP 处理联合亚最小抑制浓度阿莫西林的回收生物膜 CFU 减少了 0.33 个对数单位。在 H2O2 处理下，NTAP 组的回收生物膜 CFU 比未处理对照组低约 2.0 个对数单位。与未经处理的对照相比，在百草枯处理下，等离子体处理的生物膜 CFU 减少了约 1.0 个对数单位。与未经处理的对照相比，等离子体处理的生物膜对阿莫西林的抵抗力降低，对过氧化氢（H2O2）和百草枯的敏感性增加，表明 NTAP 可能增强生物膜对宿主防御的敏感性。这些体外发现表明，NTAP 可能是一种治疗牙周病相关口腔生物膜的新型有效治疗方法。
