Contribution of Severe Dental Caries Induced by Streptococcus mutans to the Pathogenicity of Infective Endocarditis
Contribution of Severe Dental Caries Induced by Streptococcus mutans to the Pathogenicity of Infective Endocarditis
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DOI：
10.1128/iai.00897-19
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发表时间：
2020-07-01
影响因子：
3.1
通讯作者：
Nakano, Kazuhiko
中科院分区：
文献类型：
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作者：
Nomura, Ryota;Matayoshi, Saaya;Nakano, Kazuhiko
变形链球菌是龋齿的主要病原体，被认为是感染性心内膜炎（IE）的病原体，主要发生在患有基础心脏病的患者中。然而，它仍然是未知的，是否严重的龋齿延伸到牙髓空间代表一个可能的感染途径。在本研究中，我们评估了S.使用并发严重龋齿和心脏瓣膜损伤的大鼠进行IE发展的研究。通过致龋饮食和S.口腔内的变异菌然后，在全身麻醉下使用无菌导管和金属丝损伤一组大鼠的心脏瓣膜。在龋齿的不同阶段，在不同时间对大鼠实施安乐死。暴露牙髓的大鼠患龋牙数呈时间依赖性增加。S.从损伤的心脏组织中回收了变形链球菌，这主要在具有较高数量的变形链球菌的大鼠中观察到。在下颌骨和大量龋齿扩展到牙髓的牙齿中存在变形菌。有心脏损伤的大鼠龋齿较无心脏损伤的大鼠严重。以16S rRNA为靶点的序列分析显示，特定的口腔细菌仅出现在心脏损伤的大鼠中，这可能与龋齿的发生有关。我们的研究结果表明，由S。变形链球菌感染和蔗糖摄入可能有助于S.变形菌在受损心脏组织中的定植。
Streptococcus mutans, a major pathogen of dental caries, is regarded as a causative agent of infective endocarditis (IE), which mainly occurs in patients with underlying heart disease. However, it remains unknown whether severe dental caries that extend to pulp space represent a possible route of infection. In the present study, we evaluated the virulence of S. mutans for IE development using rats with concurrent severe dental caries and heart valve injury. Dental caries was induced in rats through the combination of a caries-inducing diet and the administration of S. mutans into the oral cavity. Then, the heart valves of a subset of rats were injured using a sterile catheter and wire under general anesthesia. The rats were euthanized at various times with various stages of dental caries. The number of teeth affected by dental caries with pulp exposure was increased in the rats in a time-dependent manner. S. mutans was recovered from injured heart tissue, which was mainly observed in rats with higher number of S. mutans bacteria in mandibular bone and a larger number of teeth in which caries extended to pulp. Dental caries was more severe in rats with heart injury than in rats without heart injury. Sequencing analysis targeting 16S rRNA revealed that specific oral bacteria appeared only in rats with heart injury, which may be related to the development of dental caries. Our findings suggest that dental caries caused by the combination of S. mutans infection and sucrose intake may contribute to S. mutans colonization in injured heart tissue.