Abstract Following antimicrobial administrations in oral environments, bacteria become exposed to a sub-minimum inhibitory concentration (sub-MIC), which can induce in vitro single-species biofilms. This study explored the effects of chlorhexidine gluconate (CHG) at a sub-MIC on in vitro multi-species biofilms comprising Streptococcus mutans, Streptococcus oralis and Actinomyces naeslundii. CHG at a sub-MIC was found to induce in vitro biofilm growth, although the bacterial growth was not significantly different from that in the control. The gene transcription related to S. mutans multi-species biofilm formation with CHG at a sub-MIC was significantly higher than that of the control, but this was not found in S. mutans single-species biofilms. The bio-volume of extracellular polysaccharides with CHG at a sub-MIC was significantly higher than that of the control. This suggests that CHG at a sub-MIC may promote the development of multi-species biofilms by affecting the gene transcription related to S. mutans biofilm formation.

中文翻译：

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葡萄糖酸氯己定亚最低抑菌浓度对体外多物种生物膜形成的影响

摘要 在口腔环境中使用抗菌药物后，细菌会暴露于亚最低抑菌浓度 (sub-MIC)，这会在体外诱导单物种生物膜。本研究探讨了葡萄糖酸氯己定 (CHG) 在亚 MIC 下对体外多物种生物膜的影响，包括变形链球菌、口腔链球菌和内氏放线菌。发现亚 MIC 的 CHG 诱导体外生物膜生长，尽管细菌生长与对照中的细菌生长没有显着差异。与变异链球菌多物种生物膜形成相关的基因转录与亚 MIC 的 CHG 显着高于对照，但这在变异链球菌单物种生物膜中未发现。在亚 MIC 下，含有 CHG 的细胞外多糖的生物体积显着高于对照。这表明亚 MIC 的 CHG 可能通过影响与变形链球菌生物膜形成相关的基因转录来促进多物种生物膜的发展。