Combined NMR/Optical Microscopy of Oral Biofilm Physiology Studies

描述（由申请人提供）：细菌生物膜在自然界中几乎无处不在，并且被认为是持续感染的原因。微生物代谢和表型在生物膜内变化迅速，这至少是它们对抗菌剂产生耐药性的部分原因。龋齿病是人类最普遍和最昂贵的细菌感染之一。龋齿和相关的蛀牙与口腔生物膜（口腔细菌膜，即牙菌斑）产生有机酸引起的持续pH值下降密切相关。关于这些有机酸分布及其代谢过程的详细知识缺乏。这部分是由于：[i]生物膜的复杂性，其中包含了底物、氧、有机酸等的时空变化的空间浓度梯度，以及[ii]当前微生物代谢方法的不足，这些方法具有破坏性，通常无法产生空间分辨率。这个为期两年的R21项目的目标是适应，改进和应用独特的联合核磁共振和荧光共聚焦（NMR/光学）显微镜仪器和技术，用于时间和生物膜深度分辨的活的，致龋口腔生物膜代谢研究。两步培养和测量程序将提供可重复的生物膜样品，以便在相关（口腔）生长环境中进行可重复的深度分辨代谢测量。单种和双种生物膜将以这种方式进行研究。核磁共振光谱成像和相关方法将被用于绘制生物膜代谢作为深度的函数，分辨率为10微米。具体目标是：1)适应和改进联合核磁共振/光学显微镜来研究口腔生物膜生理；2)利用新的能力实时监测与龋相关的动态过程。由此产生的生物膜技术和代谢数据将显著提高我们对口腔疾病过程的理解。由此产生的技术将普遍适用于各种混合物种，医学相关的生物膜，从而为对抗细菌性疾病提供关键的代谢信息。

DESCRIPTION (provided by applicant): Bacterial biofilms are found nearly everywhere in nature and are becoming recognized as the cause of persistent infections. Microbial metabolism and phenotype vary rapidly within a biofilm - this is at least partly responsible for their resistance to antimicrobial agents. Dental caries disease is one of the most prevalent and costly bacterial infections in humans. Caries and associated tooth decay are strongly correlated with a sustained pH decrease induced by oral biofilm (oral bacterial films, i.e. dental plaque) production of organic acids. Detailed knowledge is lacking about these organic acid distributions and the metabolic processes involved. This is due in part to: [i] the complexity of biofilms, which contain temporally evolving spatial concentration gradients for substrate, oxygen, organic acids, etc., and [ii] the inadequacy of current microbiological-metabolism methods which are destructive and typically yield no spatial resolution. The objectives of this two-year R21 project are to adapt, improve and apply unique combined nuclear magnetic resonance and fluorescent confocal (NMR/optical) microscopy instrumentation and techniques for time- and biofilm-depth-resolved metabolism studies of live, cariogenic oral biofilms. A two-step cultivation and measurement procedure will provide reproducible biofilm samples for repeatable depth-resolved metabolism measurements in a relevant (oral) growth environments. One and two-species biofilms will be studied in this fashion. NMR spectroscopic imaging and related methods will be employed to map biofilm metabolism as a function of depth with 10-micron resolution. Specific Aims are to: 1) adapt and improve combined NMR/optical microscopy to study oral biofilm physiology, and 2) employ the new capability to monitor dynamic processes relevant to caries in real time. The resulting biofilm technology and metabolic data will significantly improve our understanding of oral disease processes. The resulting technology will generally be applicable to a variety of mixed-species, medically- relevant biofilms, thus providing key metabolic information for battling bacterial diseases.