Department of Oral Biology, University of Florida, College of Dentistry, Gainesville, Florida, USA.
Department of Pediatric Dentistry, Beijing Stomatological Hospital, Capital Medical University, Beijing, China.
Appl Environ Microbiol. 2020 Dec 17;87(1). doi: 10.1128/AEM.01459-20.
Amino sugars, particularly glucosamine (GlcN) and -acetylglucosamine (GlcNAc), are abundant carbon and nitrogen sources supplied in host secretions and in the diet to the biofilms colonizing the human oral cavity. Evidence is emerging that these amino sugars provide ecological advantages to beneficial commensals over oral pathogens and pathobionts. Here, we performed transcriptome analysis on and growing in single-species or dual-species cultures with glucose, GlcN, or GlcNAc as the primary carbohydrate source. Compared to glucose, GlcN caused drastic transcriptomic shifts in each species of bacteria when it was cultured alone. Likewise, cocultivation in the presence of GlcN yielded transcriptomic profiles that were dramatically different from the single-species results from GlcN-grown cells. In contrast, GlcNAc elicited only minor changes in the transcriptome of either organism in single- and dual-species cultures. Interestingly, genes involved in pyruvate metabolism were among the most significantly affected by GlcN in both species, and these changes were consistent with measurements of pyruvate in culture supernatants. Differing from what was found in a previous report, growth of alone with GlcN inhibited the expression of multiple operons required for mutacin production. Cocultivation with consistently increased the expression of two manganese transporter operons ( and ) and decreased expression of mutacin genes in Conversely, appeared to be less affected by the presence of but did show increases in genes for biosynthetic processes in the cocultures. In conclusion, amino sugars profoundly alter the interactions between pathogenic and commensal streptococci by reprogramming central metabolism. Carbohydrate metabolism is central to the development of dental caries. A variety of sugars available to dental microorganisms influence the development of caries by affecting the physiology, ecology, and pathogenic potential of tooth biofilms. Using two well-characterized oral bacteria, one pathogen () and one commensal (), in an RNA deep-sequencing analysis, we studied the impact of two abundant amino sugars on bacterial gene expression and interspecies interactions. The results indicated large-scale remodeling of gene expression induced by GlcN in particular, affecting bacterial energy generation, acid production, protein synthesis, and release of antimicrobial molecules. Our study provides novel insights into how amino sugars modify bacterial behavior, information that will be valuable in the design of new technologies to detect and prevent oral infectious diseases.
氨基糖，特别是葡萄糖胺（GlcN）和乙酰氨基葡萄糖（GlcNAc），是宿主分泌物和饮食中提供给定植在人类口腔中的生物膜的丰富碳源和氮源。有证据表明，这些氨基糖为有益共生菌提供了比口腔病原体和条件致病菌更大的生态优势。在这里，我们对 和 在单一或双物种培养物中用葡萄糖、GlcN 或 GlcNAc 作为主要碳水化合物来源进行了转录组分析。与葡萄糖相比，当 GlcN 单独培养时，每种细菌的转录组都会发生剧烈变化。同样，在 GlcN 存在的情况下共培养产生的转录组图谱与 GlcN 培养细胞的单种结果有很大的不同。相比之下，在单种和双种培养物中，GlcNAc 对两种生物的转录组只产生微小的变化。有趣的是，参与丙酮酸代谢的基因是两种物种中受 GlcN 影响最大的基因之一，这些变化与丙酮酸在培养上清液中的测量结果一致。与之前的一项研究不同的是，单独用 GlcN 培养 会抑制产粘菌素所需的多个操纵子的表达。与 共培养一致地增加了两个锰转运体操纵子（ 和 ）的表达，并降低了 中粘菌素基因的表达。相反， 似乎较少受到 的存在的影响，但在共培养物中确实显示出生物合成过程基因的增加。总之，氨基糖通过重新编程中心代谢深刻改变了致病性和共生链球菌之间的相互作用。碳水化合物代谢是龋齿发展的核心。口腔微生物可用的各种糖通过影响牙生物膜的生理学、生态学和致病潜力来影响龋齿的发展。我们使用两种经过充分表征的口腔细菌，一种病原体（）和一种共生菌（），在 RNA 深度测序分析中，研究了两种丰富的氨基糖对细菌基因表达和种间相互作用的影响。结果表明，GlcN 特别是诱导的大规模基因表达重编程，影响细菌的能量产生、产酸、蛋白质合成和抗菌分子的释放。我们的研究提供了关于氨基糖如何改变细菌行为的新见解，这些信息对于设计检测和预防口腔传染病的新技术将是有价值的。
