Yoneda Saori, Loeser Brandon, Feng Joseph, Dmytryk John, Qi Fengxia, Merritt Justin
Department of Oral Medical Science, Ohu University, Fukushima, Japan.
Department of Periodontology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America.
PLoS One. 2014 Jun 4;9(6):e99263. doi: 10.1371/journal.pone.0099263. eCollection 2014.
Fusobacterium nucleatum is a ubiquitous member of the human oral flora and is associated with the development of periodontitis and a variety of other types of polymicrobial infections of the mucosa. In the oral cavity, this species is one of the few that is prevalent in both healthy and diseased subgingival plaque. Using microarray analysis, we examined the transcriptional response of F. nucleatum subspecies nucleatum to whole blood in order to identify some of the genetic responses that might occur during the transition from health to disease. From these studies, we identified a sialic acid catabolism operon that was induced by the presence of blood. We subsequently confirmed that this operon was inducible by the presence of synthetic sialic acid, but we found no evidence suggesting sialic acid was used as a major carbon source. However, this organism was found to possess a de novo synthesized surface sialylation ability that is widely conserved among the various F. nucleatum subspecies as well as in F. periodonticum. We provide evidence that fusobacterial sialylation does occur in the oral cavity irrespective of health status. Interestingly, only a minority of fusobacterial cells exhibit surface sialylation within dental plaque, whereas most cells are uniformly sialylated when grown in pure culture. The implications of these results are discussed.
具核梭杆菌是人类口腔菌群中普遍存在的一种细菌，与牙周炎以及多种其他类型的黏膜混合感染的发生有关。在口腔中，该菌种是在健康和患病龈下菌斑中均普遍存在的少数菌种之一。我们利用微阵列分析检测了具核梭杆菌具核亚种对全血的转录反应，以确定在从健康状态转变为疾病状态过程中可能发生的一些基因反应。通过这些研究，我们鉴定出一个由血液诱导的唾液酸分解代谢操纵子。随后我们证实该操纵子可由合成唾液酸诱导，但未发现证据表明唾液酸被用作主要碳源。然而，我们发现这种微生物具有从头合成的表面唾液酸化能力，这在各种具核梭杆菌亚种以及牙周梭杆菌中广泛保守。我们提供的证据表明，无论健康状况如何，口腔中确实会发生梭杆菌的唾液酸化。有趣的是，在牙菌斑中只有少数梭杆菌细胞表现出表面唾液酸化，而在纯培养中生长时大多数细胞会被均匀地唾液酸化。我们讨论了这些结果的意义。
