Biology of Oral Streptococci.
Biology of Oral Streptococci.
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DOI：
10.1128/microbiolspec.gpp3-0042-2018
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发表时间：
2018-10
影响因子：
3.7
通讯作者：
Lemos JA
中科院分区：
文献类型：
--
作者：
Abranches J;Zeng L;Kajfasz JK;Palmer SR;Chakraborty B;Wen ZT;Richards VP;Brady LJ;Lemos JA
属于链球菌属的细菌是口腔的第一批居民，其可以在出生后立即获得，因此在口腔微生物群的组装中发挥重要作用。在这一章中，我们将讨论链球菌居住的不同口腔环境以及占据每个生态位的物种。特别注意链球菌的分类，因为该属现在被分为8个不同的组，其中6个组中发现了口腔种。口腔链球菌产生大量的粘附分子，使它们能够有效地在口腔中的不同组织中定植。此外，它们具有通过发酵代谢碳水化合物的显著能力，从而产生酸作为副产物。口腔环境的过度酸化由耐酸的物种如变形链球菌直接与龋齿的发展有关。然而，耐酸性较差的菌种如唾液链球菌和戈登链球菌产生大量的碱，在口腔的酸碱生理中发挥重要作用。某些口腔链球菌的另一个重要特征是它们能够产生过氧化氢，过氧化氢可以抑制链球菌的生长。变异体因此，口腔链球菌也可以通过产生抑制致病物种的分子而对宿主有益。最后，口腔内的链球菌和致病性链球菌最终会进入血液，引起全身感染，如感染性心内膜炎。
Bacteria belonging to the genus Streptococcus are the first inhabitants of the oral cavity which can be acquired right after birth and thus play an important role in the assembly of the oral microbiota. In this chapter, we will discuss the different oral environments inhabited by streptococci and the species that occupy each niche. Special attention is given to the taxonomy of Streptococcus as this genus is now divided into 8 distinct groups where oral species are found in 6 of them. Oral streptococci produce an arsenal of adhesive molecules that allow them to efficiently colonize different tissues in the mouth. Also, they have a remarkable ability to metabolize carbohydrates via fermentation thereby generating acids as byproducts. Excessive acidification of the oral environment by aciduric species such as Streptococcus mutans is directly associated with the development of dental caries. However, less acid-tolerant species such as Streptococcus salivarius and Streptococcus gordonii produce large amounts of alkali displaying and important role in the acid-base physiology of the oral cavity. Another important characteristic of certain oral streptococci is their ability to generate hydrogen peroxide that can inhibit the growth of S. mutans. Thus, oral streptococci can also be beneficial to the host by producing molecules that are inhibitory to pathogenic species. Lastly, commensal and pathogenic streptococci residing in the oral cavity can eventually gain access to the bloodstream and cause systemic infections such as infective endocarditis.