More Than Mechanical Retention: Characterization of Lactobacillus Clinical Strains Using In Vitro Models

摘要 龋齿仍然是世界上最流行的传染病之一，给美国造成了数百亿美元的损失 每年在相关护理和生产力损失上损失数十亿美元。龋齿是一种不平衡的 牙齿表面的本土微生物群，称为牙菌斑，以及细菌的酸性代谢物 新陈代谢与疾病的发展直接相关。众所周知，像这样的条件 持续摄入可发酵糖，特别是蔗糖和唾液不足，有利于 一个高度产酸和耐酸的菌斑微生物区系紧急情况，包括变形链球菌和 乳酸菌。乳杆菌(Lb)sp.是一个多世纪前第一个与龋齿有关的人，但严重的 关于不同的Lb sp.树立和坚持在斑块上 微生物区系和促进龋损的发展。在这项研究中，收集了数百名 不同的临床lb分离株将使用成熟的体外模型进行检查，以阐明主要的 Lb sp.群在表面上定居和建立；变形链球菌和环境条件如何 调理大梁的能力。建立一个混合物种联盟并在其中竞争；以及如何 变形链球菌与主要乳杆菌的相互作用。影响条件下的群落动态 典型的口腔病变。人们高度期待这项研究的结果将导致对 这些方面的每一个以及口腔Lb在菌斑微生物区系和龋齿中的作用。团结在一起， 这项研究所得的资料亦应作为进一步调查 口腔淋巴结炎的病理生理学、菌斑生物膜生态学及防治新策略的发展 龋齿和其他病症中，微生物群失调是一个主要的潜在因素。

SUMMARY Dental caries remains among the most prevalent infectious disease worldwide, costing USA tens of billions of dollars annually in associated care and productivity losses. Dental caries is a result of imbalance of the indigenous microbiota on the tooth surface known as dental plaque, and the acidic metabolites of bacterial metabolism are directly linked to the disease development. It is well understood that conditions like continuous consumption of fermentable sugars, especially sucrose and saliva deficiency favor the emergency of a highly acidogenic and aciduric plaque microbiota, which include Streptococcus mutans and lactobacilli. Lactobacillus (Lb) sp. were the first implicated in dental caries over a century ago, but major gaps remain in knowledge concerning how the different Lb sp. establish and persist in the plaque microbiota and promote the development of carious lesions. In this study, a collection of hundreds of different clinical Lb isolates will be examined using well established in vitro models to elucidate how major groups of Lb sp. colonize and establish on a surface; how S. mutans and environmental conditions may modulate the ability of major Lb sp. to establish and compete in a mixed-species consortium; and how interactions between S. mutans and major Lb sp. influence the community dynamics under conditions typical of the oral cavity. It is highly anticipated that the results from this study will lead to novel insights on each of these aspects and the roles of oral Lb in plaque microbiota and dental caries. Together, the information derived from this study should also serve as a foundation for further investigation on the pathophysiology of oral Lb, the plaque biofilm ecology, and the development of novel strategies against dental caries and other conditions where dysbiotic microbiota is a major underlying factor.