pH landscapes in a novel five-species model of early dental biofilm.
pH landscapes in a novel five-species model of early dental biofilm.
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DOI：
10.1371/journal.pone.0025299
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发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
Nyvad B
中科院分区：
文献类型：
--
作者：
Schlafer S;Raarup MK;Meyer RL;Sutherland DS;Dige I;Nyengaard JR;Nyvad B
尽管不断采取预防措施，龋齿仍然是人类最常见的疾病。牙菌斑中微生物产生的有机酸对于龋损的发展起着至关重要的作用。在发病过程的早期阶段，反复的 pH 值下降会引起微生物组成的变化，并有利于建立越来越多的产酸和尿酸微生物群。牙齿生物膜的复杂结构允许多种不同的生态环境紧密相连，但在很大程度上仍未得到探索。在这项研究中，我们设计了一个实验室生物膜模型，模拟龋齿过程早期产酸阶段存在的细菌群落。然后，我们对细菌生物膜和底层基质之间界面的细胞外 pH 值进行了时间分辨显微镜分析。该模型中使用了口腔链球菌、血链球菌、轻症链球菌、唐氏链球菌和内斯伦迪放线菌的菌株。生物膜在流道中生长，允许对生物膜进行原位直接显微镜分析。使用荧光原位杂交和共焦激光扫描显微镜分析生物膜的结构和组成。生物膜结构和组成都具有高度可重复性，并且与体内生长的牙菌斑相似。我们采用 pH 敏感比例探针 C-SNARF-4 对含葡萄糖唾液溶液的生物膜 pH 值进行实时显微分析。模型生物膜中的无氧糖酵解创造了弱酸性环境。生物膜不同区域的 pH 值下降情况各不相同，并且不同的细胞外 pH 微环境在几个小时内得以保留。设计的生物膜模型是确定潜在治疗剂对生物膜生长、组成和细胞外 pH 值影响的有前途的工具。使用 C-SNARF-4 进行比率 pH 分析可以详细了解活生物膜的 pH 情况，并有助于我们对体内生长的细菌生物膜的代谢过程的总体了解。
Despite continued preventive efforts, dental caries remains the most common disease of man. Organic acids produced by microorganisms in dental plaque play a crucial role for the development of carious lesions. During early stages of the pathogenetic process, repeated pH drops induce changes in microbial composition and favour the establishment of an increasingly acidogenic and aciduric microflora. The complex structure of dental biofilms, allowing for a multitude of different ecological environments in close proximity, remains largely unexplored. In this study, we designed a laboratory biofilm model that mimics the bacterial community present during early acidogenic stages of the caries process. We then performed a time-resolved microscopic analysis of the extracellular pH landscape at the interface between bacterial biofilm and underlying substrate. Strains of Streptococcus oralis, Streptococcus sanguinis, Streptococcus mitis, Streptococcus downei and Actinomyces naeslundii were employed in the model. Biofilms were grown in flow channels that allowed for direct microscopic analysis of the biofilms in situ. The architecture and composition of the biofilms were analysed using fluorescence in situ hybridization and confocal laser scanning microscopy. Both biofilm structure and composition were highly reproducible and showed similarity to in-vivo-grown dental plaque. We employed the pH-sensitive ratiometric probe C-SNARF-4 to perform real-time microscopic analyses of the biofilm pH in response to salivary solutions containing glucose. Anaerobic glycolysis in the model biofilms created a mildly acidic environment. Decrease in pH in different areas of the biofilms varied, and distinct extracellular pH-microenvironments were conserved over several hours. The designed biofilm model represents a promising tool to determine the effect of potential therapeutic agents on biofilm growth, composition and extracellular pH. Ratiometric pH analysis using C-SNARF-4 gives detailed insight into the pH landscape of living biofilms and contributes to our general understanding of metabolic processes in in-vivo-grown bacterial biofilms.
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影响因子：
1.9
作者：
Lima, Juliana P. M.;Sampaio de Melo, Mary A.;Zanin, Iriana C. J.
通讯作者：
Zanin, Iriana C. J.
影响因子：
7.6
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BOUE, D;ARMAU, E;TIRABY, G
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3.1
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CISAR, JO;KOLENBRANDER, PE;MCINTIRE, FC
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ten Cate, JM
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4.4
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DEJONG, MH;VANDERHOEVEN, JS;OLIJVE, JH
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OLIJVE, JH