Competition and coexistence between Streptococcus mutans and Streptococcus sanguinis in the dental biofilm
Competition and coexistence between Streptococcus mutans and Streptococcus sanguinis in the dental biofilm
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DOI：
10.1128/jb.187.21.7193-7203.2005
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发表时间：
2005-11-01
影响因子：
3.2
通讯作者：
Qi, FX
中科院分区：
文献类型：
--
作者：
Kreth, J;Merritt, J;Qi, FX
人体粘膜表面由土著微生物群落定殖，其通常维持不同物种之间的生态平衡。然而，某些环境或生物因素可能会破坏这种平衡，导致微生物疾病。在这项研究中，我们使用了两种口腔细菌，变形链球菌和血链球菌（以前的S。sanguis），作为探讨同一生态位不同物种间竞争/共存的可能机制的模型。我们发现，这两个物种在时间和空间上进行了大量的拮抗性相互作用;一个物种的生态位的占领排除了其他殖民，而同时殖民两个物种的结果共存。环境条件，如细胞密度、营养可用性和pH值，在决定这些相互作用的结果方面起着重要作用。遗传和生物化学分析表明，这些种间的相互作用可能是通过一个良好的调节产生的化学物质，如细菌素（由S。变形杆菌）和过氧化氢（由S. sanguinis）。与表型特征一致，细菌素和H2 O2的产生受到环境条件以及两个物种并置的调节。这些复杂的种间相互作用可以在平衡多物种微生物群落内的竞争/共存方面发挥重要作用。
The human mucosal surface is colonized by the indigenous microflora, which normally maintains an ecological balance among different species. Certain environmental or biological factors, however, may trigger disruption of this balance, leading to microbial diseases. In this study, we used two oral bacterial species, Streptococcus mutans and Streptococcus sanguinis (formerly S. sanguis), as a model to probe the possible mechanisms of competition/coexistence between different species which occupy the same ecological niche. We show that the two species engage in a multitude of antagonistic interactions temporally and spatially; occupation of a niche by one species precludes colonization by the other, while simultaneous colonization by both species results in coexistence. Environmental conditions, such as cell density, nutritional availability, and pH, play important roles in determining the outcome of these interactions. Genetic and biochemical analyses reveal that these interspecies interactions are possibly mediated through a well-regulated production of chemicals, such as bacteriocins (produced by S. mutans) and hydrogen peroxide (produced by S. sanguinis). Consistent with the phenotypic characteristics, production of bacteriocins and H2O2 are regulated by environmental conditions, as well as by juxtaposition of the two species. These sophisticated interspecies interactions could play an essential part in balancing competition/coexistence within multispecies microbial communities.