de Oliveira Rosa Virginia Dutra, Bonafé Fernanda Salloume Sampaio, Spolidorio Denise Madalena Palomari, Koga-Ito Cristiane Yumi, Farias Aline Leite de, Kirker Kelly R, James Garth A, Brighenti Fernanda Lourenção
School of Dentistry, São Paulo State University (UNESP), Araraquara, SP 14801-385, Brazil.
São José dos Campos Institute of Science and Technology, São Paulo State University (UNESP), São José dos Campos, SP 12245-000, Brazil.
Microorganisms. 2020 Jan 31;8(2):194. doi: 10.3390/microorganisms8020194.
The study of bacterial interaction between Streptococcus mutans and Actinomyces naeslundii may disclose important features of biofilm interspecies relationships. The aim of this study was to characterize-with an emphasis on biofilm formation and composition and metabolic activity-single- and dual-species biofilms of S. mutans or A. naeslundii, and to use a drip flow reactor (DFR) to evaluate biofilm stress responses to 0.2% chlorhexidine diacetate (CHX). Single- and dual-species biofilms were grown for 24 h. The following factors were evaluated: cell viability, biomass and total proteins in the extracellular matrix, 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide-"XTT"-reduction and lactic acid production. To evaluate stress response, biofilms were grown in DFR. Biofilms were treated with CHX or 0.9% sodium chloride (NaCl; control). Biofilms were plated for viability assessment. Confocal laser-scanning microscopy (CLSM) was also performed. Data analysis was carried out at 5% significance level. viability and lactic acid production in dual-species biofilms were significantly reduced. showed a higher resistance to CHX in dual-species biofilms. Total protein content, biomass and XTT reduction showed no significant differences between single- and dual-species biofilms. CLSM images showed the formation of large clusters in dual-species biofilms. In conclusion, dual-species biofilms reduced viability and lactic acid production and increased resistance to chlorhexidine.
变形链球菌与内氏放线菌之间细菌相互作用的研究可能会揭示生物膜种间关系的重要特征。本研究的目的是着重从生物膜形成、组成和代谢活性方面，对变形链球菌或内氏放线菌的单菌种和双菌种生物膜进行表征，并使用滴流反应器（DFR）评估生物膜对0.2%双醋酸氯己定（CHX）的应激反应。单菌种和双菌种生物膜培养24小时。评估了以下因素：细胞活力、细胞外基质中的生物量和总蛋白、2,3-双（2-甲氧基-4-硝基-5-磺基苯基）-2H-四唑-5-羧苯胺（“XTT”）还原和乳酸产生。为了评估应激反应，生物膜在DFR中培养。生物膜用CHX或0.9%氯化钠（NaCl；对照）处理。生物膜进行平板接种以评估活力。还进行了共聚焦激光扫描显微镜（CLSM）检查。数据分析在5%显著性水平进行。双菌种生物膜中的活力和乳酸产生显著降低。双菌种生物膜对CHX表现出更高的抗性。单菌种和双菌种生物膜之间的总蛋白含量、生物量和XTT还原没有显著差异。CLSM图像显示双菌种生物膜中形成了大的聚集体。总之，双菌种生物膜降低了活力和乳酸产生，并增加了对氯己定的抗性。
